APACHE CORP
10-K, 1999-03-25
CRUDE PETROLEUM & NATURAL GAS
Previous: ANCHOR NATIONAL LIFE INSURANCE CO, POS AM, 1999-03-25
Next: APPALACHIAN POWER CO, DEF 14C, 1999-03-25



<PAGE>   1
 
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
 
                             Washington, D.C. 20549
                                   FORM 10-K
(MARK ONE)
 
     [X]         ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
 
                  FOR THE FISCAL YEAR ENDED DECEMBER 31, 1998,
 
                                       OR
 
     [ ]       TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
 
             FOR THE TRANSITION PERIOD FROM           TO
 
                         COMMISSION FILE NUMBER 1-4300
                               APACHE CORPORATION
 
<TABLE>
<S>                                            <C>
            A DELAWARE CORPORATION                      IRS EMPLOYER NO. 41-0747868
</TABLE>
 
                              ONE POST OAK CENTRAL
                       2000 POST OAK BOULEVARD, SUITE 100
                           HOUSTON, TEXAS 77056-4400
                        TELEPHONE NUMBER (713) 296-6000
          Securities registered pursuant to Section 12(b) of the Act:
 
<TABLE>
<CAPTION>
                                                           NAME OF EACH EXCHANGE
             TITLE OF EACH CLASS                            ON WHICH REGISTERED
             -------------------                           ---------------------
<S>                                            <C>
        Common Stock, $1.25 Par Value                     New York Stock Exchange
                                                           Chicago Stock Exchange
       Preferred Stock Purchase Rights                    New York Stock Exchange
                                                           Chicago Stock Exchange
             9.25% Notes due 2002                         New York Stock Exchange
</TABLE>
 
        Securities Registered Pursuant to Section 12(g) of the Act: NONE
 
     Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.  Yes [X]  No [ ]
 
     Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K.  [ ]
 
<TABLE>
<S>                                                           <C>
Aggregate market value of the voting stock held by
  non-affiliates of registrant as of February 26, 1999......  $1,949,775,431
Number of shares of registrant's common stock outstanding as
  of February 26, 1999......................................      97,794,379
</TABLE>
 
                      DOCUMENTS INCORPORATED BY REFERENCE:
 
     Portions of registrant's proxy statement relating to registrant's 1999
annual meeting of stockholders have been incorporated by reference into Part III
hereof.
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>   2
 
                               TABLE OF CONTENTS
 
                                  DESCRIPTION
 
<TABLE>
<CAPTION>
ITEM                                                                  PAGE
- ----                                                                  ----
<S>     <C>                                                           <C>
                                   PART I
 
  1.    BUSINESS....................................................    1
  2.    PROPERTIES..................................................   11
  3.    LEGAL PROCEEDINGS...........................................   15
  4.    SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.........   15
 
                                  PART II
 
  5.    MARKET FOR THE REGISTRANT'S COMMON EQUITY AND RELATED
        STOCKHOLDER MATTERS.........................................   15
  6.    SELECTED FINANCIAL DATA.....................................   17
  7.    MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
        AND RESULTS OF OPERATIONS...................................   18
  8.    FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA.................   28
  9.    CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING
        AND FINANCIAL DISCLOSURE....................................   28
 
                                  PART III
 
 10.    DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT..........   28
 11.    EXECUTIVE COMPENSATION......................................   28
 12.    SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND
        MANAGEMENT..................................................   28
 13.    CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS..............   28
 
                                  PART IV
 
 14.    EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM
        8-K.........................................................   29
</TABLE>
 
     All defined terms under Rule 4-10(a) of Regulation S-X shall have their
statutorily prescribed meanings when used in this report. Quantities of natural
gas are expressed in this report in terms of thousand cubic feet (Mcf), million
cubic feet (MMcf) or billion cubic feet (Bcf). Oil is quantified in terms of
barrels (bbls); thousands of barrels (Mbbls) and millions of barrels (MMbbls).
Natural gas is compared to oil in terms of barrels of oil equivalent (boe) or
million barrels of oil equivalent (MMboe). Oil and natural gas liquids are
compared with natural gas in terms of million cubic feet equivalent (MMcfe) and
billion cubic feet equivalent (Bcfe). One barrel of oil is the energy equivalent
of six Mcf of natural gas. Daily oil and gas production is expressed in terms of
barrels of oil per day (b/d) and thousands of cubic feet of gas per day (Mcf/d)
or millions of British thermal units per day (MMBtu/d), respectively. Gas sales
volumes may be expressed in terms of one million British thermal units (MMBtu),
which is approximately, equal to one Mcf. With respect to information relating
to the Company's working interest in wells or acreage, "net" oil and gas wells
or acreage is determined by multiplying gross wells or acreage by the Company's
working interest therein. Unless otherwise specified, all references to wells
and acres are gross.
<PAGE>   3
 
                                     PART I
 
ITEM 1. BUSINESS
 
GENERAL
 
     Apache Corporation (Apache or the Company), a Delaware corporation formed
in 1954, is an independent energy company that explores for, develops and
produces natural gas, crude oil and natural gas liquids. In North America,
Apache's exploration and production interests are focused on the Gulf of Mexico,
the Anadarko Basin, the Permian Basin, the Gulf Coast and the Western
Sedimentary Basin of Canada. Outside of North America, Apache has exploration
and production interests offshore Western Australia, in Egypt and offshore the
Ivory Coast, and exploration interests in Poland and offshore The People's
Republic of China (China). Apache common stock, par value $1.25 per share, has
been listed on the New York Stock Exchange since 1969, and on the Chicago Stock
Exchange since 1960.
 
     Apache holds interests in many of its U.S., Canadian and international
properties through operating subsidiaries, such as Apache Canada Ltd., DEK
Energy Company (DEKALB, formerly known as DEKALB Energy Company), Apache Energy
Limited (formerly known as Hadson Energy Limited), Apache International, Inc.,
and Apache Overseas, Inc. Properties referred to in this document may be held by
those subsidiaries. Apache treats all operations as one line of business.
 
1998 RESULTS
 
     In 1998, Apache had a loss attributable to common stock of $131.4 million,
or $1.34 per share, on total revenues of $875.7 million. The loss reflected, in
large part, the effects of a $158 million after-tax, non-cash charge resulting
from a $243 million price-related reduction in Apache's proved oil and gas
reserves in the United States. Net cash provided by operating activities during
1998 was $471.5 million.
 
     Apache had its 21st consecutive year of production growth and 11th
consecutive year of oil and gas reserves growth in 1998. Apache's average daily
production was 75.8 Mbbls of oil and natural gas liquids and 590 MMcf of natural
gas for the year. Giving effect to 1998 production, acquisitions, dispositions,
revisions and drilling activity, the Company's estimated proved reserves
increased by 27.3 MMboe in 1998 over the prior year to 613 MMboe, of which
approximately 59 percent was natural gas. Based on 585.7 MMboe reported at
year-end 1997, Apache's reserve growth from drilling activity during the year
reflects replacement of 236 percent of the Company's 1998 production. Apache's
active drilling and production-enhancement program yielded 276 new producing
wells out of 383 attempts and involved 590 major North American workover and
recompletion projects during the year.
 
     At December 31, 1998, Apache held interests in approximately 4,086 net oil
and gas wells and 1,803,932 net developed acres of oil and gas properties
worldwide. In addition, the Company had approximately 593,204 net undeveloped
acres under North American leases and 22,566,883 net undeveloped acres under
international exploration and production rights.
 
APACHE'S GROWTH STRATEGY
 
     Apache's growth strategy is to increase oil and gas reserves, production,
cash flow and earnings through a combination of exploratory drilling,
development of its inventory of existing projects and property acquisitions
meeting defined financial parameters. The Company's drilling program emphasizes
reserve additions through moderate-risk drilling primarily on its North American
interests, and exploratory drilling primarily on its international interests.
The Company also emphasizes reducing operating costs per unit produced and
selling marginal and non-strategic properties in order to enhance its profit
margins.
 
     Apache's international investments and exploration activities are an
emerging component of its long-term growth strategy. In addition to an active,
moderate-risk drilling program in Apache's North American focus areas,
higher-risk international exploration offers potential for greater rewards and
significant reserve additions. Apache directed its international efforts in 1998
toward development of certain discoveries offshore Western Australia, offshore
the Ivory Coast, in Egypt and offshore China, and toward further exploration
 
                                        1
<PAGE>   4
 
efforts in those areas and on its concessions in Poland. Apache believes that
reserve additions in these international areas are likely to continue through
higher-risk exploration and through improved production practices and recovery
techniques.
 
     For Apache, property acquisition is only one phase in a continuing cycle of
business growth. Apache's aim is to follow each acquisition with a cycle of
reserve enhancement, property consolidation and cash flow acceleration,
facilitating asset growth and debt reduction. This approach requires a well
planned and carefully executed property development program and, where
appropriate, a selective program of property dispositions. It motivates Apache
to target acquisitions that have ascertainable additional reserve potential and
to apply an active drilling, workover and recompletion program to realize the
potential of the acquired undeveloped and partially developed properties. Apache
prefers to operate its properties so that it can best influence their
development; as a result, the Company operates properties accounting for over 80
percent of its production.
 
1998 ACQUISITIONS AND DISPOSITIONS
 
     On November 13, 1998, the Company entered into agreements to acquire
certain oil and gas interests and companies holding oil and gas interests in the
Carnarvon Basin, offshore Western Australia, from subsidiaries of Novus
Petroleum Limited (Novus) for approximately $55 million. The interests have
estimated proved reserves of approximately 5.8 MMboe and daily production of
2,400 barrels of oil equivalent. They are within the Apache-operated Harriet
Joint Venture (which includes production, processing and pipeline infrastructure
associated with the Varanus Island hub), the Airlie Joint Venture (in which the
Company held a prior interest and became operator) and three other exploration
permit areas. The transaction closed in two stages, on December 18, 1998
(approximately $49 million), and on January 29, 1999 (approximately $6 million).
Under the terms of an agreement with Novus, the Company may be required to make
additional payments to Novus based on proved and probable recoverable oil and
condensate reserves, as determined by independent engineers, on a defined
geological structure in the Gipsy-Rose-Lee area, offshore Western Australia. If
required, such payments would be calculated using $2.50 for each barrel of
proved and $1.25 for each barrel of probable oil and condensate reserves. A
payment becomes due if and when a decision is made to construct facilities for
the production of oil or condensate from the designated area.
 
     On February 1, 1999, the Company acquired oil and gas properties located in
the Gulf of Mexico from Petsec Energy Inc. (Petsec) for an adjusted purchase
price of approximately $66.7 million. The Petsec transaction included estimated
proved reserves of approximately 10.4 MMboe on the effective date.
 
     In several transactions with various buyers, Apache also sold largely
marginal properties containing 29.6 MMboe of proved reserves for $131.1 million.
Following the Ampolex Group Transaction described in Apache's 1997 Annual Report
on Form 10-K, the Company entered into an agreement with Hardy Petroleum Limited
(Hardy) pursuant to which Hardy agreed to purchase a 10 percent interest in the
company's East Spar field and related production facilities. This transaction
closed in January 1998 with a total sales price of approximately $63 million in
cash. The Ampolex Group Transaction was recorded net of these interests.
 
     In June 1998, Apache formed a strategic alliance with Cinergy Corp.
(Cinergy) to market substantially all the Company's natural gas production from
North America and sold its 57 percent interest in Producers Energy Marketing LLC
(ProEnergy) for 771,258 shares of Cinergy common stock, subsequently sold for
$26.1 million. ProEnergy will continue to market Apache's North American natural
gas production for 10 years, with an option to terminate after six years, under
an amended and restated gas purchase agreement effective July 1, 1998. During
this period, Apache is generally obligated to deliver most of its North American
gas production to Cinergy and, under certain circumstances, reimburse Cinergy if
certain gas throughput thresholds are not met. Accordingly, Apache recorded a
deferred gain of $20 million, subject to adjustment, on the sale of ProEnergy
that is being amortized over six years.
 
EXPLORATION AND PRODUCTION
 
     The Company's North American exploration and production activities are
diversified among four operating regions: Gulf, Midcontinent, Western and
Canada. Approximately 62 percent of the Company's
                                        2
<PAGE>   5
 
proved reserves are located in these North American regions. Egypt and Australia
are the Company's most important international regions. The Company's Egyptian
operations are headquartered in Cairo, and Apache conducts its Australian
exploration and production operations from Perth. Information concerning the
amount of revenue, operating income (loss) and total assets attributable to
U.S., Canadian and international operations is set forth in Note 12 to the
Company's consolidated financial statements under Item 8 below.
 
     Gulf. The Gulf region encompasses the Texas and Louisiana coasts, central
Texas and the Company's interests in the Gulf of Mexico, offshore Louisiana and
Texas. In 1998, the Gulf region was Apache's leading region for production and
production revenues contributing approximately $224 million in revenues from
production of 17.9 MMboe for the year. The Company performed 182 workover and
recompletion operations during 1998 in the Gulf region and participated in
drilling 30 wells, 11 of which were completed as producers. As of December 31,
1998, the region encompassed 482,546 net acres, and accounted for 81.3 MMboe, or
13 percent, of the Company's year-end 1998 total estimated proved reserves.
 
     Midcontinent. Apache's Midcontinent region operates in Oklahoma, eastern
and northern Texas, Arkansas and northern Louisiana. The region has focused
operations on its sizable position in the Anadarko Basin of western Oklahoma.
Apache has drilled and operated in the Anadarko Basin for over four decades,
developing an extensive database of geologic information and a substantial
acreage position. In 1998, the Midcontinent region had approximately 11.8 MMboe
of production generating $144 million in revenue for the Company.
 
     At December 31, 1998, Apache held an interest in 413,690 net acres in the
region, which accounted for approximately 101.8 MMboe, or 17 percent, of
Apache's total estimated proved reserves. Apache participated in drilling 105
wells in the Midcontinent region during the year, 86 of which were completed as
producing wells. The Company performed 45 workover and recompletion operations
in the region during 1998.
 
     Western. The Western region includes assets in the Permian Basin of western
Texas and New Mexico and the San Juan Basin of New Mexico. In 1998, the Western
region produced approximately 9.9 MMboe and generated $114 million in production
revenue. At December 31, 1998, the Company held 422,914 net acres in the region,
which accounted for 127.8 MMboe or 21 percent, of the Company's total estimated
proved reserves. Apache participated in drilling 98 wells in the Western region,
86 of which were productive wells. Apache performed 294 workovers and
recompletions in the Western region during the year.
 
     Canada. Exploration and development activity in the Canadian region is
concentrated in the Provinces of Alberta and British Columbia. The region
produced approximately 7.4 MMboe and generated $64 million in production revenue
in 1998. Apache participated in drilling 66 wells in this region during the
year, 47 of which were completed as producers. The Company performed 69
workovers and recompletions on operated wells during 1998. At December 31, 1998,
the region encompassed approximately 372,720 net acres, and accounted for 67.3
MMboe, or 11 percent, of the Company's year-end 1998 total estimated proved
reserves.
 
     Egypt. At year end, Apache held 13,279,201 net acres in Egypt with 87.6
MMboe of estimated proved reserves or 14 percent of Apache's total estimated
proved reserves. In 1998, Apache had 10.3 MMboe of production in Egypt, which
generated $129 million in production revenues. Apache owns a 75 percent interest
in the Qarun Block and a 40 percent interest in the Khalda Block, both in the
Western Desert of Egypt. Future production of gas from Khalda is expected to be
delivered for sale to the Egyptian General Petroleum Corporation (EGPC) at a
point west of Alexandria, Egypt, via a 34-inch gas pipeline, construction of
which commenced in 1997 with completion of the pipeline projected to occur in
1999. The costs of building the pipeline will be borne by Apache, the other
Khalda participants, and the owners of a neighboring block. Construction costs
paid by Apache and the other Khalda participants are recoverable from oil and
gas production from the Khalda Block.
 
     Both the Khalda and Qarun Concession Agreements provide that Apache and its
partners in the concessions will pay all of the operating and capital costs for
developing the concessions, while the production will be split between EGPC and
the partners. Up to 40 percent of the oil and gas produced from each of the
concessions is available to the Company and its partners to recover operating
and capital costs for the applicable concession. To the extent eligible costs
exceed 40 percent of the oil and gas produced and sold from
 
                                        3
<PAGE>   6
 
a concession in any given quarter, such excess costs may be carried into future
quarters without limit. The remaining 60 percent of all oil and gas produced
from the concessions is divided between EGPC and Apache and its partners, with
the percentage received by Apache and its partners reducing as the gross daily
average of oil and gas produced on a quarterly basis increases. Under the Khalda
Agreement, capital costs are amortized over four years, while the Qarun
agreement provides for a five-year amortization.
 
     In addition to the Qarun and Khalda Blocks, Apache holds interests in the
East Beni Suef and Asyout Blocks to the south of the Qarun Block, and three
other blocks in the Western Desert of Egypt, the North East Abu Gharadig Block,
the East Bahariya Block, and the West Mediterranean Block No. 1 (partly onshore
and partly offshore). Apache also acquired interests in the Ras El Hekma and Ras
Kanayes concessions from Repsol Exploracion Egipto S.A. in December 1997, and
during 1998, Apache became the operator of the W. Mediterranean and East Beni
Suef Blocks. Exploratory drilling on the East Beni Suef Block commenced in 1997
with a significant discovery made on the #1 well. Delineation drilling continued
in 1998. Due to conflicting governmental requirements regarding the placement of
drilling rigs on the Darag Block, the Company relinquished the Darag concession
in the Gulf of Suez and received a refund of a portion of its expenses related
to the concession.
 
     Australia. Western Australia became an important region for Apache after
the 1993 acquisition of Hadson Energy Resources Corporation (subsequently known
as Apache Energy Resources Corporation). In 1998, natural gas production in the
region increased by 95 percent from the prior year to approximately 51 MMcf/d.
Apache acts as operator for most of its Western Australia properties through its
wholly-owned subsidiary, Apache Energy Limited (AEL). During 1998, Apache had
6.3 MMboe of production generating $70 million of production revenue. Estimated
proved reserves in Australia increased by 66 percent to 132.7 MMboe, or 22
percent of the Company's year-end total estimated proved reserves. The increase
reflects, among other matters, the acquisition from Novus of three companies
with holdings in the East Spar and Harriet fields. As of December 31, 1998,
Apache held 226,720 net developed acres and 1,421,290 net undeveloped acres
offshore Western Australia. Through AEL and its subsidiaries, Apache also
operates the Harriet Gas Gathering Project, a gas processing and compression
facility with a throughput capacity of 175 MMcf/d, and a 60-mile, 12-inch
offshore pipeline with a throughput capacity of 175 MMcf/d that connects to a
pipeline grid onshore. The Company and the other participants in the East Spar
and Harriet joint ventures are currently building a second 60 mile, 16-inch,
natural gas pipeline from Varanus Island to a connection with the existing
Dampier to Banbury gas pipelines, which is expected to be completed in March
1999. See "1998 Acquisitions and Dispositions" and "Oil and Natural Gas
Marketing."
 
     Other International Operations. Outside of Canada, Egypt and Australia,
Apache currently has exploration and production interests offshore the Ivory
Coast, and exploration interests in Poland and offshore China.
 
     Apache obtained its first properties in Poland on April 16, 1997 when the
Company assumed operatorship and a 50 percent interest in over 5.5 million acres
in Poland located near Lublin, southeast of Warsaw, from FX Energy, Inc. (FX
Energy). The Company has since acquired additional acreage in Poland, including
approximately 1.8 million acres in the Carpathian area near the southern border
of Poland and participation in a further 2.275 million acres in the Pomeranian
area of northwest Poland, giving Apache interests in 12,038,676 total gross
undeveloped acres and 7,494,122 net undeveloped acres as of December 31, 1998.
The concessions in Poland include requirements for Apache to drill at least
eleven wells and to shoot at least 1,290 miles of seismic data. At year end, two
wells were being drilled in Poland, but were abandoned in the first quarter of
1999. Subsequent to year end, Apache and FX Energy entered into an Area of
Mutual Interest Agreement, which covers virtually all of Poland, and plan to
enter into further exploration and production agreements with the Polish Oil and
Gas Company (POGC), the national oil company of Poland. Apache's operations in
Poland are headquartered in Warsaw.
 
     Apache is also the operator, with a 50 percent interest, of the Zhao Dong
Block in Bohai Bay, offshore China. In 1994 and 1995, discovery wells tested at
rates between 1,300 and 4,000 b/d of oil. The Company elected to proceed with
the second exploration phase, commencing in May 1996, which involved a
commitment to drill two additional exploratory wells. In early 1997, one well
tested at rates up to 11,571 b/d
 
                                        4
<PAGE>   7
 
of oil and another tested at rates up to 15,359 b/d. An overall development plan
for the C and D Fields in the Zhao Dong Block was submitted to Chinese
authorities in late 1997 and is awaiting approval.
 
     In the Ivory Coast, Apache, as operator of the block and holding a 24
percent interest, completed in January 1999 the development of the "Foxtrot"
offshore gas field and installed a platform and pipeline to shore. In March
1997, Apache and its partners signed a 10 year take or pay contract to supply
approximately 168 Bcf of gas to a power plant in Abidjan at 30 MMcf/d initially,
rising to 50 MMcf/d in the third year. Gas deliveries are expected to commence
in the second quarter of 1999.
 
OIL AND NATURAL GAS MARKETING
 
     On October 27, 1995, wholly owned affiliates of each of Apache, Oryx Energy
Company and Parker & Parsley Petroleum Company (Parker & Parsley) formed
ProEnergy, a Delaware limited liability company. ProEnergy became fully
operational on April 1, 1996, and marketed substantially all of its members'
domestic natural gas pursuant to member gas purchase agreements having an
initial term of 10 years, subject to early termination following specified
events. The price of gas purchased by ProEnergy from its members was based upon
agreed to published indexes. Effective January 1, 1998, Parker & Parsley
withdrew from ProEnergy. As more fully described in "1998 Acquisitions and
Dispositions" above, in June 1998, Apache sold its interest in ProEnergy to
Cinergy and formed a strategic alliance with Cinergy to market substantially all
the Company's natural gas production from North America. ProEnergy will continue
to market Apache's North American natural gas production for 10 years, with an
option to terminate after six years, under an amended and restated gas purchase
agreement effective July 1, 1998. During this period, Apache is generally
obligated to deliver most of its North American gas production to Cinergy and,
under certain circumstances, may have to make payments to Cinergy if certain gas
throughput thresholds are not met.
 
     Separate from its arrangements with Cinergy, Apache is also delivering
natural gas under several long-term supply agreements with terms greater than
one year. In 1998, Apache delivered an average of 35 MMcf/d under such contracts
at an average price of $2.63 per Mcf.
 
     Apache assumed its own U.S. crude oil marketing operations in 1992. Most of
Apache's U.S. crude oil production is sold through lease-level marketing to
refiners, traders and transporters, generally under 30 day contracts that renew
automatically until canceled. Oil produced from Canadian properties is sold to
crude oil purchasers or refiners at market prices, which depend on worldwide
crude prices adjusted for transportation and crude quality. Natural gas produced
from Canadian properties is sold to major aggregators of natural gas, gas
marketers and direct users under long-term and short-term contracts. The oil and
gas contracts provide for sales at specified prices, or at prices that are
subject to change due to market conditions.
 
     The Company diversifies the markets for its Canadian gas production not
presently committed to Cinergy by selling directly or indirectly to customers
through aggregators and brokers in the United States and Canada. Apache
transports natural gas via the Company's firm transportation contracts to
California (12 MMcf/d) and to the Province of Ontario, Canada (four MMcf/d)
through end-users' firm transportation contracts. Pursuant to an agreement
entered into in 1994, the Company is also selling five MMcf/d of natural gas to
the Hermiston Cogeneration Project, located in the Pacific Northwest of the
United States. In 1996, the Company entered into an agreement with Westcoast Gas
Services, Inc. for the sale of 5,000 MMBtu/d for delivery in the United States
for a 10 year term.
 
     In Australia, the Company entered into several gas sales contracts during
1998, bringing its total to 16 contracts, with terms of four to 12 years, to
deliver 311 Bcf of AEL's gas from its Harriet and East Spar fields for mining,
power generation, nickel refining, ammonia production and other industrial and
domestic uses. Under these contacts AEL is required to deliver its gas at
contract rates of approximately 60 MMcf/day increasing to 92 MMcf/day by the
year 2000, with take or pay provisions, net to AEL, of approximately 20 Bcf/year
increasing to 23 Bcf/year by the year 2000. Apache operates both the Harriet and
the East Spar Joint Ventures, holding a 60 percent interest in Harriet and a 45
percent interest in East Spar.
 
     AEL marketed all oil and natural gas liquids produced from its interests in
the Harriet and East Spar fields during 1998 through a contract with Mitsui Oil
(Asia) Pty. Ltd. Pricing under the contract in 1998
 
                                        5
<PAGE>   8
 
represented a fixed premium to the quoted market prices of Tapis crude oil, with
payment made in U.S. dollars. In 1998, the weighted average realized price based
on regional production was $13.07 per barrel. In January 1999, the Mitsui
contract terminated and was replaced by a similar contract with Marubeni
International Petroleum Company.
 
     In Egypt, oil from the Qarun Block is delivered by pipeline to tanks owned
by the Company and its partners in the Qarun Concession at the Dashour pumping
station northeast of the Qarun Block or by truck to the Tebbin refinery south of
Alexandria, Egypt. At the discretion of the operator of the pipelines, oil from
the Qarun Block is put into the two 42-inch diameter SUMED pipelines, which
transport significant quantities of Egyptian and other crude oil from the Gulf
of Suez to Sidi Kherir, west of Alexandria, Egypt, on the Mediterranean Coast.
All Qarun and Khalda crude oil is currently sold to EGPC. In 1996, the Company
and its partners in the Khalda Block entered into a take or pay contract with
EGPC, which obligates EGPC to pay for 75 percent of 200 MMcf/d of future
production of gas from the Khalda Block. Sales of gas under the contract are
expected to begin in May 1999 upon completion of a gas pipeline from the Khalda
Block. In late 1997, the same sellers entered into a supplement to the contract
with EGPC to sell an additional 50 MMcf/d through a southern gas line being
constructed by the Company and its partners from the Khalda Block to a point
near the Qarun Block to tie into an existing gas pipeline.
 
OIL AND NATURAL GAS PRICES
 
     Natural gas prices remained volatile during 1998, with Apache's realized
prices ranging from $2.08 per Mcf in July to $1.73 per Mcf in September.
Fluctuations are largely due to market perceptions about natural gas supply and
demand. Apache's average realized gas price of $1.92 per Mcf for 1998 was down
16 percent from the prior-year average of $2.28 per Mcf, and its 1997 average
realized natural gas price was 13 percent higher than the 1996 average price of
$2.02 per Mcf.
 
     As a result of minimum price contracts which escalate at an average of 80
percent of the Australian consumer price index, AEL's natural gas production in
Western Australia is not subject to the same degree of price volatility as
Apache's U.S. and Canadian gas production; however, natural gas sales under such
Australian minimum price contracts represent less than two percent of the
Company's total natural gas sales at the end of 1998. Total Australian gas sales
in 1998, including long-term contracts and spot sales averaged $1.51 per Mcf,
down 15 percent from the 1997 average of $1.78 per Mcf due to devaluation of the
Australian dollar.
 
     In Egypt, all oil production from the Khalda and Qarun Blocks is currently
sold to EGPC on a spot basis at a "Western Desert" price, which is applied to
virtually all production from the area and is announced periodically by EGPC. In
1998, the average price was $12.57 per barrel. Discussions with EGPC regarding
the possibility of exporting Qarun oil production are continuing. Once gas sales
from the Khalda Block commence, the gas is expected to be sold for a price
which, on a Btu basis, is equivalent to 85 percent of the price of Suez Blend
crude oil, FOB Mediterranean.
 
     Oil prices remained subject to unpredictable political and economic forces
during 1998 and experienced fluctuations similar to those seen in natural gas
prices for the year, but showing a general downward trend. Apache believes that
oil prices will continue to fluctuate in response to changes in the policies of
the Organization of Petroleum Exporting Countries (OPEC), demand from Asian
countries, events in the Middle East and other factors associated with the world
political and economic environment. As a result of the many uncertainties
associated with levels of production maintained by OPEC and other oil producing
countries, the availabilities of worldwide energy supplies and the competitive
relationships and consumer perceptions of various energy sources, the Company is
unable to predict what changes will occur in crude oil and natural gas prices.
 
     In 1998, Apache's realized worldwide crude oil price ranged from $15.11 per
barrel in January to $9.42 per barrel in December. The average crude oil price
of $12.66 per barrel in 1998 was down 34 percent from the average price of
$19.20 per barrel in 1997, and 39 percent lower than the average price of $20.84
per barrel in 1996. The Company's average crude oil price for its Australian
production was $13.07 per barrel in 1998, 36 percent less than the average price
in 1997.
                                        6
<PAGE>   9
 
     From time to time, Apache buys or sells contracts to hedge a limited
portion of its future oil and gas production against exposure to spot market
price changes. See Note 9 to the Company's consolidated financial statements
under Item 8 below.
 
     The Company's business has been and will continue to be affected by future
worldwide changes in oil and gas prices and the relationship between the prices
of oil and gas. No assurance can be given as to the trend in, or level of,
future oil and gas prices.
 
FULL COST CEILING TEST
 
     Under the full cost accounting rules of the Securities and Exchange
Commission (SEC), the Company reviews the carrying value of its proved oil and
gas properties each quarter on a country-by-country basis. Under these rules,
capitalized costs of proved oil and gas properties, net of accumulated
depreciation, depletion and amortization and deferred income taxes, may not
exceed the present value of estimated future net cash flows from proved oil and
gas reserves, discounted at 10 percent, plus the lower of cost or fair value of
unproved properties included in the costs being amortized, net of related tax
effects. These rules generally require pricing future oil and gas production at
the unescalated oil and gas prices in effect at the end of each fiscal quarter
and require a write-down if the "ceiling" is exceeded, even if prices declined
for only a short period of time. The Company recorded a $243.2 million pre-tax
($158.1 million net of tax) non-cash write-down of the carrying value of the
Company's U.S. proved oil and gas properties as of December 31, 1998, due to
these ceiling test limitations. If oil and gas prices deteriorate from the
Company's year-end realized prices, it is likely that additional write-downs
will occur in 1999. Write-downs required by these rules do not impact cash flow
from operating activities.
 
EFFECT OF VOLATILE PRICES
 
     The Company continually analyzes forecasts and updates its estimates of
energy prices for its internal use in planning, budgeting, and estimating and
valuing reserves. The Company's future financial condition and results of
operations will depend upon the prices received for the Company's oil and
natural gas production and the costs of acquiring, finding, developing and
producing reserves. Prices for oil and natural gas are subject to fluctuations
in response to relatively minor changes in supply, market uncertainty and a
variety of additional factors that are beyond the control of the Company. These
factors include worldwide political instability (especially in the Middle East
and other oil-producing regions), the foreign supply of oil and gas, the price
of foreign imports, the level of drilling activity, the level of consumer
product demand, government regulations and taxes, the price and availability of
alternative fuels and the overall economic environment. A substantial or
extended decline in oil and gas prices would have a material adverse effect on
the Company's financial position, results of operations, quantities of oil and
gas that may be economically produced and access to capital. In addition, the
sale of the Company's oil and gas production depends on a number of factors
beyond the Company's control, including the availability and capacity of
transportation and processing facilities. Oil and natural gas prices have
historically been and are likely to continue to be volatile. Such volatility
makes it difficult to estimate with precision the value of producing properties
in acquisitions and to budget and project the return on exploration and
development projects involving the Company's oil and gas properties. In
addition, unusually volatile prices often disrupt the market for oil and gas
properties, as buyers and sellers have more difficulty agreeing on the purchase
price of properties.
 
RESERVES; RATES OF PRODUCTION; DEVELOPMENT EXPENDITURES; CASH FLOW
 
     There are numerous uncertainties inherent in estimating quantities of oil
and natural gas reserves of any category and in projecting future rates of
production and timing of development expenditures, which underlie such reserve
estimates, including many factors beyond the control of the Company. Reserve
data represents only estimates. In addition, the estimates of future net cash
flows from proved reserves of the Company and the present value thereof are
based upon various assumptions about future production levels, prices and costs
that may prove to be incorrect over time (see below). Any significant variance
from the assumptions could result in the actual quantity of the Company's
reserves and future net cash flows therefrom being materially different from the
estimates. In addition, the Company's estimated reserves may be subject to
downward or
                                        7
<PAGE>   10
 
upward revision based upon production history, results of future exploration and
development, prevailing oil and gas prices, operating and development costs, and
other factors. The rate of production from oil and gas properties declines as
reserves are depleted. Except to the extent that the Company acquires additional
properties containing proved reserves, conducts successful exploration and
development activities or, through engineering studies, identifies additional
behind-pipe zones or secondary recovery reserves, the proved reserves of the
Company will decline materially as reserves are produced. Future oil and gas
production is, therefore, highly dependent upon the Company's level of success
in acquiring or finding additional reserves.
 
GOVERNMENT REGULATION OF THE OIL AND GAS INDUSTRY
 
     The Company's exploration, production and marketing operations are
regulated extensively at the federal, state and local levels, as well as by
other countries in which the Company does business. Oil and gas exploration,
development and production activities are subject to various laws and
regulations governing a wide variety of matters. For example,
hydrocarbon-producing states have statutes or regulations addressing
conservation practices and the protection of correlative rights, and such
regulations may affect Apache's operations and limit the quantity of
hydrocarbons Apache may produce and sell. Other regulated matters include
marketing, pricing, transportation, and valuation of royalty payments.
 
     At the U.S. federal level, the Federal Energy Regulatory Commission (FERC)
regulates interstate transportation of natural gas under the Natural Gas Act.
Effective January 1, 1993, the Natural Gas Wellhead Decontrol Act deregulated
natural gas prices for all "first sales" of natural gas, which includes all
sales by Apache of its own production. As a result, all sales of the Company's
natural gas produced in the U.S. may be sold at market prices, unless otherwise
committed by contract.
 
     Apache's gas sales are affected by regulation of intrastate and interstate
gas transportation. In an attempt to promote competition, the FERC has issued a
series of orders, which have altered significantly the marketing and
transportation of natural gas. The effect of these orders has been to enable the
Company to market its natural gas production to purchasers other than the
interstate pipelines located in the vicinity of its producing properties. The
Company believes that these changes have generally improved the Company's access
to transportation. To date, Apache has not experienced any material adverse
effect on its gas marketing activities as a result of these FERC orders;
however, the Company cannot predict what new regulations may be adopted by the
FERC and other regulatory authorities, or what effect subsequent regulations may
have on its future gas marketing activities.
 
ENVIRONMENTAL MATTERS
 
     Apache, as an owner or lessee and operator of oil and gas properties, is
subject to various federal, provincial, state, local and foreign country laws
and regulations relating to discharge of materials into, and protection of, the
environment. These laws and regulations may, among other things, impose
liability on the lessee under an oil and gas lease for the cost of pollution
clean-up resulting from operations, subject the lessee to liability for
pollution damages, and require suspension or cessation of operations in affected
areas.
 
     Apache maintains insurance coverage, which it believes is customary in the
industry, although it is not fully insured against all environmental risks. The
Company is not aware of any environmental claims existing as of December 31,
1998, which would have a material impact upon the Company's financial position
or results of operations.
 
     Apache has made and will continue to make expenditures in its efforts to
comply with these requirements, which it believes are necessary business costs
in the oil and gas industry. The Company has established policies for continuing
compliance with environmental laws and regulations, including regulations
applicable to its operations in Canada, Australia and other countries. Apache
also has established operational procedures and training programs designed to
minimize the environmental impact of its field facilities. The costs incurred by
these policies and procedures are inextricably connected to normal operating
expenses such that the Company is unable to separate the expenses related to
environmental matters; however, the Company does not believe any such additional
expenses are material to its financial position or results of operations.
 
                                        8
<PAGE>   11
 
     Although environmental requirements have a substantial impact upon the
energy industry, generally these requirements do not appear to affect Apache any
differently, or to any greater or lesser extent, than other companies in the
industry. Apache does not believe that compliance with federal, state, local or
foreign country provisions regulating the discharge of materials into the
environment, or otherwise relating to the protection of the environment, will
have a material adverse effect upon the capital expenditures, earnings or
competitive position of the Company or its subsidiaries; however, there is no
assurance that changes in or additions to laws or regulations regarding the
protection of the environment will not have such an impact.
 
COMPETITION
 
     The oil and gas industry is highly competitive. Because oil and gas are
fungible commodities, the principal form of competition with respect to product
sales is price competition. Apache strives to maintain the lowest finding and
production costs possible to maximize profits.
 
     As an independent oil and gas company, Apache frequently competes for
reserve acquisitions, exploration leases, licenses, concessions and marketing
agreements against companies with financial and other resources substantially
larger than Apache possesses. Moreover, many competitors have established
strategic long-term positions and maintain strong governmental relationships in
countries in which the Company may seek new entry. Apache expects this high
degree of competition to continue.
 
INSURANCE
 
     Exploration for and production of oil and natural gas can be hazardous,
involving unforeseen occurrences such as blowouts, cratering, fires and loss of
well control, which can result in damage to or destruction of wells or
production facilities, injury to persons, loss of life, or damage to property or
the environment. The Company maintains insurance against certain losses or
liabilities arising from its operations in accordance with customary industry
practices and in amounts that management believes to be prudent; however,
insurance is not available to the Company against all operational risks.
 
HEDGING
 
     To the extent that the Company engages in hedging activities, it may be
prevented from realizing the benefits of price increases above the levels of the
hedges. In addition, the Company is subject to basis risk when it engages in
hedging transactions, particularly where transportation constraints restrict the
Company's ability to deliver oil and gas volumes to the delivery point to which
the hedging transaction is indexed.
 
ACQUISITION RISKS
 
     The Company from time to time acquires oil and gas properties. Although the
Company performs a review of the acquired properties that it believes is
consistent with industry practices, such reviews are inherently incomplete. It
generally is not feasible to review in depth every individual property involved
in each acquisition. Ordinarily the Company will focus its review efforts on the
higher-value properties and will sample the remainder. However, even a detailed
review of records and properties may not necessarily reveal existing or
potential problems, nor will it permit a buyer to become sufficiently familiar
with the properties to assess fully their deficiencies and potential.
Inspections may not always be performed on every well, and environmental
problems, such as ground water contamination, are not necessarily observable
even when an inspection is undertaken. Even when problems are identified, the
Company often assumes certain environmental and other risks and liabilities in
connection with acquired properties. There are numerous uncertainties inherent
in estimating quantities of proved oil and gas reserves and actual future
production rates and associated costs with respect to acquired properties, and
actual results may vary substantially from those assumed in the estimates (see
above). In addition, there can be no assurance that acquisitions will not have
an adverse effect upon the Company's operating results, particularly during the
periods in which the operations of acquired businesses are being integrated into
the Company's ongoing operations.
 
                                        9
<PAGE>   12
 
GENERAL ECONOMIC CONDITIONS
 
     Virtually all of the Company's operations are subject to the risks and
uncertainties of adverse changes in general economic conditions (domestically,
in specific regions of the United States and Canada, and internationally), the
outcome of pending and/or potential legal or regulatory proceedings, changes in
environmental, tax, labor and other laws and regulations to which the Company is
subject, and the condition of the capital markets utilized by the Company to
finance its operations.
 
RISKS OF NON-U.S. OPERATIONS
 
     The Company's non-U.S. oil and natural gas exploration, development and
production activities are subject to political and economic uncertainties
(including but not limited to changes, sometimes frequent or marked, in
governmental energy policies or the personnel administering them), expropriation
of property, cancellation or modification of contract rights, foreign exchange
restrictions, currency fluctuations, royalty and tax increases and other risks
arising out of foreign governmental sovereignty over the areas in which the
Company's operations are conducted, as well as risks of loss due to civil
strife, acts of war, guerrilla activities and insurrection. These risks may be
higher in the developing countries in which the Company conducts such
activities. Consequently, the company's non-U.S. exploration, development and
production activities may be substantially affected by factors beyond the
Company's control, any of which could materially adversely affect the Company's
financial position or results of operations. Furthermore, in the event of a
dispute arising from non-U.S. operations, the Company may be subject to the
exclusive jurisdiction of courts outside the U.S. or may not be successful in
subjecting non-U.S. persons to the jurisdiction of the courts in the U.S., which
could adversely affect the outcome of such dispute.
 
EMPLOYEES
 
     On December 31, 1998, Apache had 1,281 employees.
 
OFFICES
 
     Apache's principal executive offices are located at One Post Oak Central,
2000 Post Oak Boulevard, Suite 100, Houston, Texas 77056-4400. At year-end 1998,
the Company maintained regional exploration and production offices in Tulsa,
Oklahoma; Houston, Texas; Calgary, Alberta; Cairo, Egypt; Perth, Western
Australia; Beijing, China; Abidjan, Cote d' Ivoire; and Warsaw, Poland.
 
                                       10
<PAGE>   13
 
ITEM 2. PROPERTIES
 
OIL AND GAS EXPLORATION AND PRODUCTION PROPERTIES AND RESERVES
 
  Acreage
 
     The undeveloped and developed acreage including both domestic leases and
international production and exploration rights that Apache held as of December
31, 1998, are as follows:
 
<TABLE>
<CAPTION>
                                           UNDEVELOPED ACREAGE       DEVELOPED ACREAGE
                                         -----------------------   ---------------------
                                           GROSS         NET         GROSS        NET
                                           ACRES        ACRES        ACRES       ACRES
                                         ----------   ----------   ---------   ---------
<S>                                      <C>          <C>          <C>         <C>
GULF
Louisiana..............................     180,047      102,800     267,808     142,541
Texas..................................     145,529       64,313     322,799     172,892
                                         ----------   ----------   ---------   ---------
          Total........................     325,576      167,113     590,607     315,433
                                         ----------   ----------   ---------   ---------
MIDCONTINENT
Arkansas...............................       3,983        3,046       4,625       3,354
Kansas.................................         200           93          --          --
Louisiana..............................      11,809        9,535      48,820      33,823
Michigan...............................       5,052        4,022          --          --
Oklahoma...............................     138,613       51,650     492,790     192,515
Pennsylvania...........................          --           --         796          38
Texas..................................      70,821       44,906     136,998      70,708
                                         ----------   ----------   ---------   ---------
          Total........................     230,478      113,252     684,029     300,438
                                         ----------   ----------   ---------   ---------
WESTERN
Alaska.................................      14,262           --          --          --
Colorado...............................      13,974       12,228      10,979      10,715
Illinois...............................         140           56          --          --
New Mexico.............................      89,746       47,905     101,780      53,475
Ohio...................................          21           11          --          --
Texas..................................     131,081       62,099     253,626     183,116
Utah...................................         140           35          60          15
Wyoming................................      60,040       52,968       1,160         291
                                         ----------   ----------   ---------   ---------
          Total........................     309,404      175,302     367,605     247,612
                                         ----------   ----------   ---------   ---------
          Total United States..........     865,458      455,667   1,642,241     863,483
                                         ----------   ----------   ---------   ---------
INTERNATIONAL
Australia..............................   3,269,200    1,421,290     425,280     226,720
Canada.................................     190,632      137,537     303,016     235,183
China..................................   1,554,930      777,510       5,911       1,448
Egypt..................................  26,197,294   12,811,058     842,863     468,143
Ivory Coast............................     157,258       62,903      37,312       8,955
Poland.................................  12,038,676    7,494,122          --          --
                                         ----------   ----------   ---------   ---------
          Total International..........  43,407,990   22,704,420   1,614,382     940,449
                                         ----------   ----------   ---------   ---------
          Total Company................  44,273,448   23,160,087   3,256,623   1,803,932
                                         ==========   ==========   =========   =========
</TABLE>
 
                                       11
<PAGE>   14
 
  Productive Oil and Gas Wells
 
     The number of productive oil and gas wells, operated and non-operated, in
which Apache had an interest as of December 31, 1998, is set forth below.
 
<TABLE>
<CAPTION>
                                                                   GAS             OIL
                                                              -------------   -------------
                                                              GROSS    NET    GROSS    NET
                                                              -----   -----   -----   -----
<S>                                                           <C>     <C>     <C>     <C>
Midcontinent................................................  1,745     644     515     141
Western.....................................................    260     143   3,635   1,855
Gulf........................................................    405     260     560     394
Canada......................................................    680     425     367     130
Egypt.......................................................     21       8     137      71
Australia...................................................      7       4      20      11
                                                              -----   -----   -----   -----
          Total.............................................  3,118   1,484   5,234   2,602
                                                              =====   =====   =====   =====
</TABLE>
 
  Gross Wells Drilled
 
     The following table sets forth the number of gross exploratory and gross
development wells drilled in the last three fiscal years in which the Company
participated. The number of wells drilled refers to the number of wells
commenced at any time during the respective fiscal year. "Productive" wells are
either producing wells or wells capable of commercial production. At December
31, 1998, the Company was participating in 14 wells in the U.S., 14 Canadian
wells, 14 Egyptian wells, three Australian wells and two Polish wells in the
process of drilling.
 
<TABLE>
<CAPTION>
                                                       EXPLORATORY               DEVELOPMENTAL
                                                 ------------------------   ------------------------
                                                 PRODUCTIVE   DRY   TOTAL   PRODUCTIVE   DRY   TOTAL
                                                 ----------   ---   -----   ----------   ---   -----
<S>                                              <C>          <C>   <C>     <C>          <C>   <C>
1998
United States..................................      20        16     36       163       34     197
Canada.........................................      17        12     29        30        7      37
Egypt..........................................      11        24     35        27        5      32
Australia......................................       7         8     15        --       --      --
Other International............................      --         1      1         1       --       1
                                                     --       ---    ---       ---       --     ---
          Total................................      55        61    116       221       46     267
                                                     ==       ===    ===       ===       ==     ===
1997
United States..................................      27        25     52       234       32     266
Canada.........................................      19        14     33        41        7      48
Egypt..........................................       7        19     26        23        4      27
Australia......................................       3         6      9         6        1       7
Other International............................       1         2      3         1       --       1
                                                     --       ---    ---       ---       --     ---
          Total................................      57        66    123       305       44     349
                                                     ==       ===    ===       ===       ==     ===
1996
United States..................................      28        33     61       201       31     232
Canada.........................................      23        25     48        27        2      29
Egypt..........................................       7         4     11        12       --      12
Australia......................................       4         6     10         1        1       2
Other International............................      --         1      1        --       --      --
                                                     --       ---    ---       ---       --     ---
          Total................................      62        69    131       241       34     275
                                                     ==       ===    ===       ===       ==     ===
</TABLE>
 
                                       12
<PAGE>   15
 
  Net Wells Drilled
 
     The following table sets forth, for each of the last three fiscal years,
the number of net exploratory and net developmental wells drilled by Apache.
 
<TABLE>
<CAPTION>
                                                      EXPLORATORY                DEVELOPMENTAL
                                               -------------------------   -------------------------
                                               PRODUCTIVE   DRY    TOTAL   PRODUCTIVE   DRY    TOTAL
                                               ----------   ----   -----   ----------   ----   -----
<S>                                            <C>          <C>    <C>     <C>          <C>    <C>
1998
United States................................      9.9      11.1   21.0       64.0      18.8    82.8
Canada.......................................     16.2      11.0   27.2       28.3       6.1    34.4
Egypt........................................      5.6      13.5   19.1       11.9       2.8    14.7
Australia....................................      3.5       3.4    6.9         --        --      --
Other International..........................       --        .2     .2         .2        --      .2
                                                  ----      ----   ----      -----      ----   -----
          Total..............................     35.2      39.2   74.4      104.4      27.7   132.1
                                                  ====      ====   ====      =====      ====   =====
1997
United States................................     11.5      11.9   23.4      107.5      19.0   126.5
Canada.......................................     14.5      10.1   24.6       29.0       6.0    35.0
Egypt........................................      3.7      12.3   16.0       14.4       2.0    16.4
Australia....................................      1.0       1.0    2.0        1.8        .2     2.0
Other International..........................       .5       1.4    1.9         .5        --      .5
                                                  ----      ----   ----      -----      ----   -----
          Total..............................     31.2      36.7   67.9      153.2      27.2   180.4
                                                  ====      ====   ====      =====      ====   =====
1996
United States................................     17.2      22.8   40.0       77.9      19.1    97.0
Canada.......................................     18.8      21.5   40.3       24.1       1.4    25.5
Egypt........................................      3.2       3.0    6.2        9.0        --     9.0
Australia....................................      1.1       1.5    2.6         .2        .1      .3
Other International..........................       --        .4     .4         --        --      --
                                                  ----      ----   ----      -----      ----   -----
          Total..............................     40.3      49.2   89.5      111.2      20.6   131.8
                                                  ====      ====   ====      =====      ====   =====
</TABLE>
 
  Production and Pricing Data
 
     The following table describes, for each of the last three fiscal years,
oil, natural gas liquids (NGL) and gas production for the Company, average
production costs (excluding severance taxes) and average sales prices.
 
<TABLE>
<CAPTION>
                                      PRODUCTION                                  AVERAGE SALES PRICE
                              ---------------------------     AVERAGE      ---------------------------------
                                OIL       NGL       GAS      PRODUCTION       OIL         NGL         GAS
YEAR ENDED DECEMBER 31,       (MBBLS)   (MBBLS)   (MMCF)    COST PER BOE   (PER BBL)   (PER BBL)   (PER MCF)
- -----------------------       -------   -------   -------   ------------   ---------   ---------   ---------
<S>                           <C>       <C>       <C>       <C>            <C>         <C>         <C>
1998........................  26,611     1,052    215,389      $2.88        $12.66      $ 7.94       $1.92
1997........................  24,291       843    222,237       3.07         19.20       14.08        2.28
1996........................  19,465       713    205,305       3.43         20.84       16.41        2.02
</TABLE>
 
  Estimated Reserves and Reserve Value Information
 
     The following information relating to estimated reserve quantities, reserve
values and discounted future net revenues is derived from, and qualified in its
entirety by reference to, the more complete reserve and revenue information and
assumptions included in the Company's Supplemental Oil and Gas Disclosures under
Item 8 below. The Company's estimates of proved reserve quantities of its U.S.,
Canadian and international properties have been subject to review by Ryder Scott
Company Petroleum Engineers. In 1996, the proved reserve quantities of certain
of the Company's Egyptian properties were reviewed by Netherland, Sewell &
Associates, Inc. There are numerous uncertainties inherent in estimating
quantities of proved reserves and projecting future rates of production and
timing of development expenditures. The following reserve information represents
estimates only and should not be construed as being exact.
 
                                       13
<PAGE>   16
 
     The following table sets forth the Company's estimated proved developed and
undeveloped reserves as of December 31, 1998, 1997 and 1996:
 
<TABLE>
<CAPTION>
                                                                         OIL, NGL
                                                              NATURAL      AND
                                                                GAS     CONDENSATE
                                                               (BCF)     (MMBBLS)
                                                              -------   ----------
<S>                                                           <C>       <C>
1998
Developed...................................................  1,450.1     178.0
Undeveloped.................................................    722.1      73.0
                                                              -------     -----
          Total.............................................  2,172.2     251.0
                                                              =======     =====
1997
Developed...................................................  1,554.3     203.1
Undeveloped.................................................    317.5      70.7
                                                              -------     -----
          Total.............................................  1,871.8     273.8
                                                              =======     =====
1996
Developed...................................................  1,435.3     183.2
Undeveloped.................................................    190.0      52.1
                                                              -------     -----
          Total.............................................  1,625.3     235.3
                                                              =======     =====
</TABLE>
 
     The following table sets forth the estimated future value of all the
Company's proved reserves, and proved developed reserves, as of December 31,
1998, 1997 and 1996. Future reserve values are based on year-end prices except
in those instances where the sale of gas and oil is covered by contract terms
providing for determinable escalations. Operating costs, production and ad
valorem taxes, and future development costs are based on current costs with no
escalations.
 
<TABLE>
<CAPTION>
                                                                 PRESENT VALUE OF ESTIMATED
                                                                     FUTURE NET REVENUES
                                          ESTIMATED FUTURE           BEFORE INCOME TAXES
                                            NET REVENUES         (DISCOUNTED AT 10 PERCENT)
                                       -----------------------   ---------------------------
                                                      PROVED                       PROVED
DECEMBER 31,                             PROVED     DEVELOPED       PROVED       DEVELOPED
- ------------                           ----------   ----------   ------------   ------------
                                                          (IN THOUSANDS)
<S>                                    <C>          <C>          <C>            <C>
1998.................................  $3,994,612   $2,793,698    $2,395,888     $1,764,887
1997.................................   5,347,892    4,301,768     3,272,618      2,728,747
1996.................................   7,936,924    6,713,252     4,568,475      4,041,065
</TABLE>
 
     At December 31, 1998, estimated future net revenues expected to be received
from all the Company's proved reserves and proved developed reserves were as
follows:
 
<TABLE>
<CAPTION>
                                                                             PROVED
DECEMBER 31,                                                    PROVED     DEVELOPED
- ------------                                                  ----------   ----------
                                                                  (IN THOUSANDS)
<S>                                                           <C>          <C>
1999........................................................  $  394,777   $  441,946
2000........................................................     431,644      400,389
2001........................................................     446,532      305,005
Thereafter..................................................   2,721,659    1,646,358
                                                              ----------   ----------
          Total.............................................  $3,994,612   $2,793,698
                                                              ==========   ==========
</TABLE>
 
     The Company believes that no major discovery or other favorable or adverse
event has occurred since December 31, 1998, which would cause a significant
change in the estimated proved reserves reported herein. The estimates above are
based on year-end pricing in accordance with the SEC guidelines and do not
reflect current prices. Since January 1, 1999, no oil or gas reserve information
has been filed with, or included in any report to, any U.S. authority or agency
other than the SEC and the Energy Information Administration
 
                                       14
<PAGE>   17
 
(EIA). The basis of reporting reserves to the EIA for the Company's reserves is
identical to that set forth in the foregoing table.
 
  Title to Interests
 
     The Company believes that its title to the various interests set forth
above is satisfactory and consistent with the standards generally accepted in
the oil and gas industry, subject only to immaterial exceptions which do not
detract substantially from the value of the interests or materially interfere
with their use in the Company's operations. The interests owned by the Company
may be subject to one or more royalty, overriding royalty and other outstanding
interests customary in the industry. The interests may additionally be subject
to obligations or duties under applicable laws, ordinances, rules, regulations
and orders of arbitral or governmental authorities. In addition, the interests
may be subject to burdens such as net profits interests, liens incident to
operating agreements and current taxes, development obligations under oil and
gas leases and other encumbrances, easements and restrictions, none of which
detract substantially from the value of the interests or materially interfere
with their use in the Company's operations.
 
ITEM 3. LEGAL PROCEEDINGS
 
     The information set forth under the caption "Litigation" in Note 10 to the
Company's financial statements under Item 8 below is incorporated herein by
reference.
 
ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
 
     No matters were submitted for a vote of security holders during the fourth
quarter of 1998.
 
                                    PART II
 
ITEM 5. MARKET FOR THE REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER
MATTERS
 
     Apache's common stock, par value $1.25 per share, is traded on the New York
Stock Exchange and the Chicago Stock Exchange under the symbol APA. The table
below provides certain information regarding Apache common stock for 1998 and
1997. Prices shown are from the New York Stock Exchange Composite Transactions
Reporting System.
 
<TABLE>
<CAPTION>
                                                        1998                         1997
                                             --------------------------   --------------------------
                                              PRICE RANGE                  PRICE RANGE
                                             --------------   DIVIDENDS   --------------   DIVIDENDS
                                              HIGH     LOW    PER SHARE    HIGH     LOW    PER SHARE
                                             ------   -----   ---------   ------   -----   ---------
<S>                                          <C>      <C>     <C>         <C>      <C>     <C>
First Quarter..............................  $38 3/4 $31 3/16  $.07      $39 3/8 $31 1/4    $.07
Second Quarter.............................   38 1/8  30 3/8   $.07       35 5/8  30 1/8    $.07
Third Quarter..............................   32 3/8  22 1/2   $.07       42 7/8  32 1/16   $.07
Fourth Quarter.............................   29 5/16 21 3/8   $.07       45 1/16 32 11/16  $.07
</TABLE>
 
     The closing price per share of Apache common stock, as reported on the New
York Stock Exchange Composite Transactions Reporting System for February 26,
1999, was $19.9375. At December 31, 1998, there were 97,769,122 shares of Apache
common stock outstanding, held by approximately 10,000 shareholders of record
and 45,000 beneficial owners.
 
     The Company has paid cash dividends on its common stock for 128 consecutive
quarters through December 31, 1998, and expects to continue the payment of
dividends at current levels, although future dividend payments will depend upon
the Company's level of earnings, financial requirements and other relevant
factors.
 
     In December 1995, the Company declared a dividend of one right (a Right)
for each share of Apache common stock outstanding on January 31, 1996. Each
Right entitles the registered holder to purchase from the Company one
ten-thousandth (1/10,000) of a share of Series A Preferred Stock at a price of
$100 per one ten-thousandth of a share, subject to adjustment. The Rights are
exercisable 10 calendar days following a
 
                                       15
<PAGE>   18
 
public announcement that certain persons or groups have acquired 20 percent or
more of the outstanding shares of Apache common stock or 10 business days
following commencement of an offer for 30 percent or more of the outstanding
shares of Apache common stock. In addition, if the Company engages in certain
business combinations or a 20 percent shareholder engages in certain
transactions with the Company, the Rights become exercisable for Apache common
stock or common stock of the corporation acquiring the Company (as the case may
be) at 50 percent of the then-market price. Any Rights that are or were
beneficially owned by a person who has acquired 20 percent or more of the
outstanding shares of Apache common stock and who engages in certain
transactions or realizes the benefits of certain transactions with the Company
will become void. The Company may redeem the Rights at $.01 per Right at any
time until 10 business days after public announcement that a person has acquired
20 percent or more of the outstanding shares of Apache common stock. The Rights
will expire on January 31, 2006, unless earlier redeemed by the Company. Unless
the Rights have been previously redeemed, all shares of Apache common stock
issued by the Company after January 31, 1996 will include Rights. Unless and
until the Rights become exercisable, they will be transferred with and only with
the shares of Apache common stock.
 
     In August 1998, the Company issued 100,000 shares of 5.68 percent Series B
Cumulative Preferred Stock (the Series B Preferred Stock) in the form of one
million depositary shares, each representing one-tenth (1/10) of a share of
Series B Preferred Stock. Neither the shares of Series B Preferred Stock nor the
depositary shares are traded on any stock exchange. These shares are not
convertible into common equity.
 
                                       16
<PAGE>   19
 
ITEM 6. SELECTED FINANCIAL DATA
 
     The following table sets forth selected financial data of the Company and
its consolidated subsidiaries for each of the years in the five-year period
ended December 31, 1998, which information has been derived from the Company's
audited financial statements. Apache's previously reported data for 1994 has
been restated to reflect the merger with DEKALB in May 1995 under the pooling of
interests method of accounting. This information should be read in connection
with, and is qualified in its entirety by, the more detailed information in the
Company's financial statements under Item 8 below.
 
<TABLE>
<CAPTION>
                                              AS OF OR FOR THE YEAR ENDED DECEMBER 31,
                                   --------------------------------------------------------------
                                    1998(1)      1997(2)      1996(3)      1995(4)        1994
                                   ----------   ----------   ----------   ----------   ----------
                                              (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
<S>                                <C>          <C>          <C>          <C>          <C>
INCOME STATEMENT DATA
Total revenues...................  $  875,715   $1,176,273   $  977,151   $  750,702   $  592,626
Net income (loss)................    (129,387)     154,896      121,427       20,207       45,583
Income (loss) attributable to
  common stock...................    (131,391)     154,896      121,427       20,207       45,583
Net income (loss) per common
  share
  Basic..........................       (1.34)        1.71         1.42          .28          .65
  Diluted........................       (1.34)        1.65         1.38          .28          .65
Cash dividends per common
  share(5).......................         .28          .28          .28          .28          .28
BALANCE SHEET DATA
Working capital (deficit)........  $  (78,804)  $    4,546   $  (41,501)  $  (22,013)  $   (3,203)
Total assets.....................   3,996,062    4,138,633    3,432,430    2,681,450    2,036,627
Long-term debt...................   1,343,258    1,501,380    1,235,706    1,072,076      719,033
Shareholders' equity.............   1,801,833    1,729,177    1,518,516    1,091,805      891,087
Common shares outstanding at end
  of year........................      97,769       93,305       90,059       77,379       69,666
</TABLE>
 
     For a discussion of significant acquisitions, reference is made to Item 7,
"Management's Discussion and Analysis of Financial Condition and Results of
Operations" and to Note 2 to the Company's consolidated financial statements
under Item 8 below.
 
- ---------------
 
(1) Includes the results of the acquisitions of certain subsidiaries and oil and
    gas properties from Novus after December 18, 1998.
 
(2) Includes financial data after November 20, 1997, relating to the acquisition
    from Mobil of three companies owning interests in certain oil and gas
    properties and production facilities offshore Western Australia (the Ampolex
    Group Transaction.)
 
(3) Includes financial data after May 20, 1996, for Apache PHN Company, Inc.
    (Phoenix, formerly known as The Phoenix Resource Companies, Inc.)
 
(4) Includes the results of the acquisitions of certain oil and gas properties
    from Texaco Exploration and Production, Inc. (Texaco) and Aquila Energy
    Resources Corporation (Aquila) after March 1, 1995 and September 1995,
    respectively, and the sale of a substantial portion of the Company's Rocky
    Mountain properties in September 1995.
 
(5) No cash dividends were paid on outstanding DEKALB common stock in 1995 and
    1994.
                                       17
<PAGE>   20
 
ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATIONS
 
OVERVIEW
 
     In anticipation of lower commodity prices, Apache entered 1998 with a
primary objective being to strengthen its balance sheet in order to take
advantage of lower cost drilling and acquisition opportunities that accompany
cyclical downturns in product prices. To accomplish this, high cost properties
were sold, drilling capital was curtailed, subordinated debentures were
converted into common equity, and non-convertible preferred stock and public
debt were issued. As a result of these efforts during 1998, Apache reduced debt
by $160 million, from 47 percent to 43 percent of capitalization; the ratio
would have been reduced to 41 percent absent the non-cash, full-cost ceiling
write-down. Debt maturities were also lengthened to an average of 26 years with
approximately three percent of Apache's total debt due over the next three
years. As a result, Apache is in its strongest financial position ever to take
advantage of opportunities brought about by the current industry downturn.
 
     Apache's results of operations and financial position for 1998 were also
significantly impacted by the following factors:
 
     Additional Depreciation, Depletion and Amortization (DD&A) Expense -- Low
oil and gas prices resulted in a non-cash full-cost ceiling write-down of $158.1
million after-tax ($243.2 million pre-tax). There were no such charges in 1997
and 1996.
 
     Commodity Prices -- Apache's average realized oil price decreased $6.54 per
barrel from $19.20 per barrel in 1997 to $12.66 per barrel in 1998, reducing
revenues by $158.9 million. The average realized price for natural gas decreased
$.36 per Mcf from $2.28 per Mcf in 1997 to $1.92 per Mcf in 1998, negatively
impacting revenues by $78.6 million.
 
RESULTS OF OPERATIONS
 
     Apache reported a 1998 loss attributable to common stock of $131.4 million
as opposed to 1997 income attributable to common stock of $154.9 million. The
1998 loss resulted from a full-cost ceiling write-down at year end. Results for
1998 were further hampered by sharp declines in oil and gas prices. Basic net
income (loss) per common share was $(1.34) for 1998, as compared to $1.71 in
1997. Income attributable to common stock increased $33.5 million in 1997 from
$121.4 million in 1996. Basic net income per common share increased 20 percent
in 1997 from $1.42 in 1996. Diluted net income per common share was $1.65 for
1997, 20 percent above 1996. The increase from 1996 to 1997 was primarily due to
higher oil and gas production, higher natural gas prices and lower operating
costs per unit of production.
 
     Revenues declined $300.6 million in 1998, driven by a 23 percent decrease
in oil and gas production revenues. The decrease in oil and gas production
revenues resulted from a 34 percent decrease in the average realized oil price,
a 16 percent decrease in the average realized price for natural gas and a three
percent decrease in gas production. Crude oil, including natural gas liquids,
contributed 45 percent and natural gas contributed 55 percent of oil and gas
production revenues during 1998. Revenues increased 20 percent in 1997 to $1.2
billion from $977.2 million in 1996. In 1997, crude oil and natural gas liquids
contributed 49 percent and natural gas contributed 51 percent of oil and gas
production revenues.
 
                                       18
<PAGE>   21
 
     The table below presents, for the years indicated, the revenues, production
and average prices received from sales of natural gas, oil and natural gas
liquids.
 
<TABLE>
<CAPTION>
                                                                 YEAR ENDED DECEMBER 31,
                                                              ------------------------------
                                                                1998       1997       1996
                                                              --------   --------   --------
<S>                                                           <C>        <C>        <C>
Revenues (in thousands):
  Natural gas...............................................  $413,870   $505,604   $415,736
  Oil.......................................................   336,813    466,291    405,724
  Natural gas liquids.......................................     8,355     11,878     11,704
                                                              --------   --------   --------
          Total.............................................  $759,038   $983,773   $833,164
                                                              ========   ========   ========
Natural Gas Volume -- Mcf per day:
  United States.............................................   432,059    492,594    472,171
  Canada....................................................   105,871     89,699     74,598
  Egypt.....................................................     1,554        563        302
  Australia.................................................    50,624     26,016     13,869
                                                              --------   --------   --------
          Total.............................................   590,108    608,872    560,940
                                                              ========   ========   ========
Average Natural Gas price -- Per Mcf:
  United States.............................................  $   2.11   $   2.47   $   2.17
  Canada....................................................      1.36       1.33       1.09
  Egypt.....................................................      1.91       2.94       3.21
  Australia.................................................      1.51       1.78       1.96
          Total.............................................      1.92       2.28       2.02
Oil Volume -- Barrels per day:
  United States.............................................    34,067     40,638     40,600
  Canada....................................................     2,090      2,120      1,969
  Egypt.....................................................    27,911     19,372      8,295
  Australia.................................................     8,838      4,417      2,318
                                                              --------   --------   --------
          Total.............................................    72,906     66,547     53,182
                                                              ========   ========   ========
Average Oil Price -- Per barrel:
  United States.............................................  $  12.63   $  19.31   $  20.67
  Canada....................................................     12.55      19.27      20.84
  Egypt.....................................................     12.57      18.65      21.29
  Australia.................................................     13.07      20.51      22.33
          Total.............................................     12.66      19.20      20.84
NGL Volume -- Barrels per day:
  United States.............................................     2,267      1,684      1,308
  Canada....................................................       616        627        641
                                                              --------   --------   --------
          Total.............................................     2,883      2,311      1,949
                                                              ========   ========   ========
Average NGL Price -- Per barrel:
  United States.............................................  $   8.38   $  14.50   $  17.23
  Canada....................................................      6.32      12.98      14.73
          Total.............................................      7.94      14.08      16.41
</TABLE>
 
     Natural gas revenues decreased by 18 percent from 1997 to 1998 due to lower
natural gas prices and production. The average realized gas price received in
1998 was $1.92 per Mcf, 16 percent lower than 1997, negatively affecting revenue
by $78.6 million. The Company periodically engages in hedging activities,
including fixed-price physical contracts and financial contracts. Apache
realized gains from open hedging positions favorably impacting the gas price by
$.01 per Mcf in 1998. Gains under long-term fixed-price physical contracts
increased the gas price by $.05 per Mcf in 1998. Prices declined in the United
States due to
 
                                       19
<PAGE>   22
 
unfavorable market conditions. Natural gas prices in Australia declined 15
percent from 1997 resulting from the devaluation of the Australian dollar.
 
     Natural gas production for the United States decreased 12 percent from 1997
to 1998 due to the impact of property sales in the Gulf and Midcontinent
regions, tropical storms in the Gulf of Mexico and natural depletion. In
Australia, natural gas production increased 95 percent driven by a full year of
incremental production from properties acquired in the year-end 1997 Ampolex
Group Transaction. The 18 percent uplift in Canadian production resulted from
development activity and Alberta royalty recoupments received for 1998. Alberta
allows reduction in royalty for costs to build processing and transportation
facilities.
 
     Natural gas revenues increased 22 percent from 1996 to 1997. Average
natural gas prices were $.26 per Mcf, or 13 percent, higher in 1997 than 1996.
The Company's net hedging activity, including fixed-price physical contracts and
financial contracts, had no impact on gas prices in 1997 and reduced prices by
$.09 per Mcf in 1996. Natural gas production increased nine percent from 1996 to
1997 from acquisitions and drilling activity.
 
     The Company's crude oil sales totaled $336.8 million in 1998, a 28 percent
decrease from 1997 due to lower average realized oil prices, which were
partially offset by production increases. On a worldwide basis, average oil
prices decreased 34 percent to $12.66 per barrel negatively impacting oil sales
by $158.9 million. Oil production increased 6,359 barrels per day (approximately
10 percent), in 1998 due to increases in Egypt and Australia. Australian oil
production increased 4,421 barrels per day over 1997 with additional production
from the Ampolex Group Transaction and initial sales from the Stag field.
Egyptian oil production increased 8,539 barrels per day, or 44 percent, as a
result of the price-driven dynamics of certain production sharing contracts and
to a lesser extent, drilling and development activity. U.S. oil production
decreased by 6,571 barrels per day, or 16 percent, primarily due to marginal
property sales in the first half of 1998 and natural reservoir depletion of
mature fields.
 
     Oil revenues increased 15 percent from 1996 to 1997. Egyptian oil
production more than doubled in 1997 due to development activity and the first
full year of production from the Company's Egyptian properties acquired in 1996.
Australian oil production increased 90 percent from 1996 to 1997 primarily due
to first production at the Agincourt field. These production increases were
partially offset by an eight percent decrease in average oil prices received
during 1997.
 
     Natural gas liquid revenues decreased 30 percent from 1997. Natural gas
liquid production increased 572 barrels per day, or 25 percent, while natural
gas liquid prices declined by $6.14 per barrel, or 44 percent due to
deteriorating market conditions. Natural gas liquid revenues were slightly
higher in 1997 than in 1996. Natural gas liquid production increased 19 percent
from 1996 to 1997, which was offset by a 14 percent decrease in average prices.
 
  Other Revenues and Operating Expenses
 
     Gas gathering, processing and marketing revenues decreased 40 percent to
$117.4 million in 1998 from 1997. Lower gas prices in 1998 contributed to the
decrease. Gas gathering, processing and marketing costs decreased by 41 percent
to $114.5 million resulting in a slight increase to 1998 margins. During 1997,
gas gathering, processing and marketing revenues increased 38 percent to $197.0
million. Lower margins were realized in 1997 as compared to 1996.
 
     Equity in loss of affiliates represents Apache's share of ProEnergy losses.
Equity in loss of affiliates was $1.6 million, $1.7 million and $.3 million in
1998, 1997 and 1996, respectively. Apache sold its 57 percent interest in
ProEnergy in June 1998.
 
     Recurring DD&A expense increased marginally to $382.8 million in 1998 from
$381.4 million in 1997. On an equivalent barrel basis, recurring full cost DD&A
expense decreased $.11 per boe, from $5.77 per boe in 1997 to $5.66 per boe in
1998. The Company's recurring DD&A expense increased to $381.4 million in 1997
from $315.1 million in 1996. On an equivalent barrel basis, recurring full cost
DD&A expense increased $.33 per boe, from $5.44 per boe in 1996 to $5.77 per boe
in 1997. Reserve revisions due to price declines and an increased cost
environment in North America negatively impacted the 1997 rates.
                                       20
<PAGE>   23
 
     Apache limits, on a country-by-country basis, the capitalized cost of
proved oil and gas properties, net of accumulated DD&A and deferred income
taxes, to estimated future net cash flows from proved oil and gas reserves
discounted at 10 percent, net of related tax effects, plus the lower of cost or
fair value of unproved properties included in the costs being amortized. As a
result of low oil and gas prices at December 31, 1998, Apache's capitalized
costs of U.S. oil and gas properties exceeded the ceiling limitation and the
Company reported a $243.2 million pre-tax ($158.1 million net of tax) non-cash
write-down. No additional DD&A was recorded during 1997 or 1996. If oil and gas
prices deteriorate from the Company's year-end realized prices, it is likely
that additional write-downs will occur in 1999. Write-downs required by these
rules do not impact cash flow from operating activities.
 
     Apache's operating costs decreased nine percent in 1998 to $211.6 million
from $231.4 million in 1997. Lease operating expense (LOE), excluding severance
taxes, decreased from $190.8 million in 1997 to $182.9 million in 1998. On an
equivalent barrel basis, LOE for 1998 averaged $2.88 per boe, a $.19 decline
from $3.07 per boe in 1997. Domestic per unit costs were significantly reduced
by the sale of marginal North American properties, and by lower Western and Gulf
region repairs and maintenance costs. Operating costs increased three percent to
$231.4 million in 1997 from $225.5 million in 1996. LOE, excluding severance
taxes, increased from $186.4 million in 1996 to $190.8 million in 1997. LOE
increased as a result of Egyptian oil production enhancements and North American
gas production gains. On an equivalent barrel basis, LOE for 1997 averaged $3.07
per boe, a $.36 decline from $3.43 per boe in 1996.
 
     Administrative, selling and other costs (G&A) increased $2.5 million, or
seven percent from 1997 to 1998. On an equivalent barrel basis, G&A expense
increased to $.64 per boe in 1998 compared to $.62 per boe in 1997. The increase
in G&A expense was primarily the result of employee separation payments
associated with the sale of marginal North American properties. G&A expense
increased $2.3 million, or six percent, from 1996 to 1997. A new bonus plan
initiated in 1997, under which Apache provided incentive compensation to all
employees based on the achievement of targeted performance, was the primary
reason for the increase. On an equivalent barrel basis, G&A expense declined
from $.66 per boe in 1996 to $.62 per boe in 1997. Production increases were not
met with rising administrative costs.
 
     Net financing costs for 1998 decreased $1.8 million, or two percent, from
1997 primarily due to higher capitalized interest. Gross interest expense
increased $14.6 million due to a slightly higher interest rate on average
outstanding debt in 1998 compared to 1997 and higher imputed interest on
advances from gas purchasers. This was offset by an increase in capitalized
interest, interest income and lower amortization of deferred loan costs. The
Company's weighted average interest rate on outstanding debt was approximately
7.2 percent at December 31, 1998 compared to 7.1 percent at December 31, 1997.
The capitalized interest increase is associated with Egyptian pipeline projects
under construction. The increase in interest income was due to a higher average
cash balance during 1998. Net financing costs for 1997 increased $10.7 million,
or 17 percent, over 1996. Gross interest expense increased by $15.3 million due
to higher average aggregate debt outstanding at higher average interest rates,
which resulted from the extension of Apache's debt maturities. In 1997, Apache
wrote off $1.2 million in deferred loan costs related to the Company's election
to cancel two secured credit facilities with the International Finance
Corporation (IFC). Additional capitalized interest of $5.8 million in 1997
mitigated these increases. Capitalized interest associated with higher
international unevaluated costs caused the increase in 1997.
 
MARKET RISK
 
  Commodity Risk
 
     The Company's major market risk exposure is in the pricing applicable to
its oil and gas production. Realized pricing is primarily driven by the
prevailing worldwide price for crude oil and spot prices applicable to its
United States and Canadian natural gas production. Historically, prices received
for oil and gas production have been volatile and unpredictable. Pricing
volatility is expected to continue. Oil price realizations ranged from a low of
$9.42 per barrel to a high of $15.11 per barrel during 1998. Gas price
realizations ranged from a monthly low of $1.73 per Mcf to a monthly high of
$2.08 per Mcf during the same period.
 
                                       21
<PAGE>   24
 
     The Company periodically enters into hedging activities on a portion of its
projected oil and natural gas production through a variety of financial and
physical arrangements intended to support oil and natural gas prices at targeted
levels and to manage its exposure to oil and gas price fluctuations. Apache may
use futures contracts, swaps, options and fixed-price physical contracts to
hedge its commodity prices. Realized gains or losses from the Company's price
risk management activities are recognized in oil and gas production revenues
when the associated production occurs. Apache does not hold or issue derivative
instruments for trading purposes. In 1998, Apache recognized a net gain of $11.5
million from hedging activities that increased oil and gas production revenues.
The net gain in 1998 includes $1.3 million in derivative income and $10.2
million in gains from fixed-price physical gas contracts. Gains or losses on
natural gas derivative contracts are expected to be offset by sales at the spot
market price or to preserve the margin on existing physical contracts. A 10
percent improvement in year-end spot market prices would increase the fair value
of derivative contracts in effect at December 31, 1998 by $21.4 million, while a
10 percent drop in spot prices would decrease the fair value of these
instruments by $21.4 million.
 
  Interest Rate Risk
 
     The Company considers its interest rate risk exposure to be minimal as a
result of fixing interest rates on over three-fourths of the Company's debt.
Total debt at December 31, 1998, included about $337.3 million of floating-rate
debt. As a result, Apache's annual interest costs in 1999 will fluctuate based
on short-term interest rates on approximately 25 percent of its total debt
outstanding at December 31, 1998. The impact on annual cash flow of a 10 percent
change in the floating rate (approximately 57 basis points) would be $1.9
million.
 
  Foreign Currency Risk
 
     The Company's cash flow stream relating to certain international operations
is based on the U.S. dollar equivalent of cash flows measured in foreign
currencies. Australian gas production is sold under fixed-price Australian
dollar contracts and over half the costs incurred are paid in Australian
dollars. Revenue and disbursement transactions denominated in Australian dollars
are converted to U.S. dollar equivalents based on the exchange rate on the
transaction date. Reported cash flow relating to Canadian operations is based on
cash flows measured in Canadian dollars converted to the U.S. dollar equivalent
based on the average of the Canadian and U.S. dollar exchange rates for the
period reported. Substantially all of the Company's international transactions,
outside of Canada and Australia, are denominated in U.S. dollars.
 
     The Company's Canadian and Australian subsidiaries have net financial
obligations that are denominated in a currency other than the functional
reporting currency of the subsidiaries. A decrease in value of 10 percent in the
Australian and Canadian dollars relative to the U.S. dollar from the year-end
exchange rates would result in a foreign currency loss of approximately $.4
million, based on December 31, 1998 amounts. The Company considers its current
risk exposure to exchange rate movements, based on net cash flows, to be
immaterial. The Company did not have any open derivative contracts relating to
foreign currencies at December 31, 1998.
 
CASH FLOW, LIQUIDITY AND CAPITAL RESOURCES
 
  Capital Commitments
 
     Apache's primary needs for cash are for exploration, development and
acquisition of oil and gas properties, repayment of principal and interest on
outstanding debt, payment of dividends, and capital obligations for affiliated
ventures. The Company funds its exploration and development activities primarily
through internally generated cash flows. Apache budgets capital expenditures
based upon projected cash flows. The Company routinely adjusts its capital
expenditures in response to changes in oil and natural gas prices and cash flow.
The Company cannot accurately predict future product prices.
 
                                       22
<PAGE>   25
 
     Capital Expenditures -- Apache's oil and gas capital expenditures over the
last three years are summarized below:
 
<TABLE>
<CAPTION>
                                                         1998       1997       1996
                                                       --------   --------   --------
                                                               (IN THOUSANDS)
<S>                                                    <C>        <C>        <C>
Exploration and Development:
  United States......................................  $238,140   $375,015   $302,494
  Canada.............................................    71,467     57,669     58,768
  Egypt..............................................   124,657    152,564     63,597
  Australia..........................................    86,453     70,802     46,838
  Ivory Coast........................................    24,356      1,077      7,914
  Other International................................    45,626     28,293     14,084
                                                       --------   --------   --------
          Total......................................  $590,699   $685,420   $493,695
                                                       ========   ========   ========
Acquisitions of Oil and Gas Properties...............  $ 58,402   $225,934   $446,205
                                                       ========   ========   ========
</TABLE>
 
     Expenditures for exploration and development totaled $590.7 million in 1998
compared to $685.4 million in 1997. Apache's drilling program in 1998 added
105.6 MMboe of proved reserves (including revisions) and replaced 166 percent of
production. In the United States, Apache completed 183 gross wells as producers
out of 233 gross wells drilled during the year, compared with 261 gross
producers out of 318 gross wells drilled in 1997. In Canada, Apache completed 47
gross wells as producers out of 66 gross wells drilled during the year, compared
with 60 gross producers out of 81 gross wells drilled in 1997.
 
     Internationally, the Company completed 46 gross producers out of 84 gross
wells drilled in 1998, compared to 41 gross producers out of 73 gross wells in
1997. Successful international wells drilled in 1998 included 38 in Egypt, seven
in Australia and one in China.
 
     The total capital expenditures budget for 1999 is $270.0 million, including
$122.8 million for North America. Estimated U.S. exploration and development
expenditures for 1999 are $89.1 million, which includes $37.3 million in the
Gulf region, $36.2 million in the Midcontinent region and $15.6 million in the
Western region. Apache expects to spend $33.7 million in Canada in 1999. The
Company expects its other international exploration and development expenditures
in 1999, exclusive of facilities, to total approximately $109.9 million. Capital
expenditures will be reviewed and possibly adjusted throughout the year in light
of changing industry conditions.
 
     On November 13, 1998, the Company entered into agreements to acquire
certain oil and gas interests and companies holding oil and gas interests in the
Carnarvon Basin, Western Australia, from subsidiaries of Novus for approximately
$55 million. The interests have proved reserves of approximately 5.8 MMboe and
daily production of 2,400 barrels of oil equivalent. They are within the
Apache-operated Harriet Joint Venture (which includes production, processing and
pipeline infrastructure associated with the Varanus Island hub), the Airlie
Joint Venture (in which the Company held a prior interest and became operator)
and three other exploration permit areas. The transaction closed in two stages,
on December 18, 1998 for approximately $49 million and on January 29, 1999 for
approximately $6 million. Under the terms of an agreement with Novus, the
Company may be required to make additional payments to Novus based on proved and
probable recoverable oil and condensate reserves, as determined by independent
engineers, on a defined geological structure in the Gipsy-Rose-Lee area,
offshore Western Australia. If required, such payments would be calculated using
$2.50 for each barrel of proved and $1.25 for each barrel of probable oil and
condensate reserves. A payment becomes due if and when a decision is made to
construct facilities for the production of oil or condensate from the designated
area.
 
     In 1998, the Company also completed tactical regional acquisitions for cash
consideration totaling $19.4 million. These acquisitions added approximately 9.1
MMboe to the Company's reserves.
 
     On November 20, 1997, the Company acquired, in the Ampolex Group
Transaction, all the capital stock of three companies owning interests in
certain oil and gas properties (including 31.9 MMboe of proved oil and natural
gas reserves) and production facilities offshore Western Australia for
approximately $300 million
 
                                       23
<PAGE>   26
 
pursuant to three agreements with subsidiaries of Mobil. Funds for the Ampolex
Group Transaction were obtained principally from borrowings under the Company's
global credit facility.
 
     The Ampolex Group Transaction acquisition, net of the sale of certain
properties to Hardy, increased the Company's interest to 47.5 percent from 22.5
percent in the Carnarvon Basin's Harriet area, which included the Varanus Island
pipeline, processing and production complex and eight existing oil and gas
fields. In addition, the Company's interest in the East Spar field, which
produces through the Varanus Island facilities, increased to 45 percent from 20
percent. Apache operates both the Harriet and East Spar properties.
 
     In conjunction with the closing of the Ampolex Group Transaction on
December 9, 1997, the Company entered into an agreement under which Hardy agreed
to purchase a 10 percent interest in the Company's East Spar gas field and
related production facilities in Western Australia. The transaction closed on
January 28, 1998 with a total sales price of approximately $63 million in cash.
 
     In 1997, the Company also completed 45 tactical regional acquisitions for
cash consideration totaling $33.6 million. These acquisitions added
approximately 6.6 MMboe to the Company's proved reserves.
 
     Expenditures for acquisitions of proved oil and gas properties during 1996
totaled $446.2 million. The Company added 52 MMboe of proved oil and gas
reserves through purchases in 1996. The most significant transaction completed
in 1996 was the merger with Phoenix. Apache acquired oil and gas properties
totaling $331.2 million from Phoenix. Apache also acquired $115.0 million of
other oil and gas properties located primarily in the Company's existing focus
areas. This amount included the purchase of certain oil and gas properties from
Hall-Houston Oil Company for $46 million in cash. Funds for the acquisitions
were obtained principally from borrowings under the Company's revolving bank
credit facility.
 
     Debt and Interest Commitments -- At December 31, 1998, Apache had
outstanding debt of $153.0 million under its global credit facility and an
aggregate of $1.2 billion of other debt. This other debt included notes and
debentures maturing in the years 2000 through 2096. Debt outstanding at December
31, 1998 of $1.4 billion was comparable to the $1.5 billion outstanding at
December 31, 1997. The Company's debt-to-capitalization ratio improved from 46.8
percent at December 31, 1997 to 43.0 percent at December 31, 1998. Interest
payments on the Company's debt for 1999 are projected to be $129.0 million
(using weighted average balances for floating rate obligations). Scheduled
principal payments for 1999 total $15.5 million.
 
     Dividend Payments -- Apache paid $1.0 million in dividends during 1998 on
its Series B Preferred Stock issued in August 1998. Common dividends paid during
1998 totaled $27.2 million, up 8 percent from 1997, due to the increased number
of common shares outstanding. The Company has paid cash dividends on its common
stock for 128 consecutive quarters through December 31, 1998, and expects to
continue payment of dividends at current levels. Future dividend payments will
depend on the Company's level of earnings, financial requirements and other
relevant factors.
 
  Capital Resources and Liquidity
 
     The Company's primary capital resources are net cash provided by operating
activities, proceeds from financing activities and proceeds from sales of
non-strategic assets.
 
     Net Cash Provided by Operating Activities -- Apache's net cash provided by
operating activities during 1998 totaled $471.5 million, a decrease of 35
percent from the $723.8 million provided in 1997. This decrease was due
primarily to lower oil and gas prices and lower gas production in 1998, offset
by the receipt of $71.8 million from a purchaser as an advance. The advance was
for future natural gas deliveries over a ten-year period commencing August 1998.
Net cash provided by operating activities in 1997 rose $233.3 million from 1996
primarily due to higher product prices. The receipt of $115.2 million from a
purchaser as an advance also impacted 1997 net cash provided by operating
activities. This advance was for future natural gas deliveries of 20,000 MMBtu
per day over a ten-year period commencing September 1997.
 
     Long-Term Borrowings -- In February 1998, Apache issued $150 million
principal amount, $148.2 million net of discount, of senior unsecured 7-percent
notes maturing on February 1, 2018. The notes are not
 
                                       24
<PAGE>   27
 
redeemable prior to maturity. Net proceeds from the sale were used to reduce
existing short-term obligations and for general corporate purposes.
 
     In March 1999, Apache Finance Pty Ltd, the Company's Australian finance
subsidiary, issued $100 million principal amount, $99.3 million net of discount,
of senior unsecured 7.0-percent notes due March 15, 2009. The notes are
irrevocably and unconditionally guaranteed by Apache. The Company has the right
to redeem the notes prior to maturity, under certain conditions related to
changes in relevant tax laws.
 
     Stock Transactions -- In January 1998, approximately 90 percent, or $155.6
million, of the Company's 6-percent debentures were converted into 5.1 million
shares of Apache common stock at a conversion price of $30.68 per share. The
remaining $16.9 million principal amount was redeemed for $17.4 million in cash,
plus accrued and unpaid interest. The Company recorded a $.8 million loss on the
early extinguishment of debt in January 1998.
 
     Preferred Stock Issuance -- In August 1998, Apache issued $100 million of
Series B Preferred Stock. The net proceeds of approximately $98.4 million were
used to repay debt outstanding under money market lines of credit and to reduce
outstanding borrowings under the Canadian portion of the Company's global credit
facility. The Series B Preferred Stock has no stated maturity, is not subject to
a sinking fund and is not convertible into Apache common stock or any other
securities of the Company. Apache has the option to redeem the Series B
Preferred Stock at $1,000 per share on or after August 25, 2008.
 
     Asset Sales -- Apache received $131.1 million in 1998 and $30.1 million in
1997 from the sale of non-strategic oil and gas properties in a number of
separate transactions. An additional $63 million was received in 1998 for a 10
percent interest in Apache's East Spar field and related production facilities.
These assets were reported as assets held for resale at December 31, 1997. The
proceeds were used to reduce debt.
 
     Liquidity -- The Company had $14.5 million in cash and cash equivalents on
hand at December 31, 1998, up from $9.7 million at December 31, 1997. Apache's
ratio of current assets to current liabilities decreased from 1.01:1 at December
31, 1997, to .74:1 at December 31, 1998.
 
     Management believes that cash on hand, net cash generated from operations
and unused committed borrowing capacity under its global credit facility will be
adequate to satisfy the Company's financial obligations to meet future liquidity
needs for at least the next two fiscal years. As of December 31, 1998, Apache's
available borrowing capacity under its global credit facility was $788 million.
 
                                       25
<PAGE>   28
 
IMPACT OF THE YEAR 2000 ISSUE
 
     The inability of some computer programs and embedded computer chips to
distinguish between the year 1900 and the year 2000 (the Year 2000 issue) poses
a serious threat of business disruption to any organization that utilizes
computer technology and computer chip technology in their business systems or
equipment. Apache has formed a Year 2000 Task Force with representation from
major business units to inventory and assess the risk associated with hardware,
software, telecommunications systems, office equipment, embedded chip controls
and systems, process control systems, facility control systems and dependencies
on external trading partners. The project phases, expected completion dates and
percentage complete as of March 1999 are as follows:
 
<TABLE>
<CAPTION>
                                                                              PERCENT
PHASE                                                       COMPLETION DATE   COMPLETE
- -----                                                       ---------------   --------
<S>                                                         <C>               <C>
Organization..............................................       July 1998      100%
Assessment................................................   November 1998      100%
  Desktop Computers
  Network Hardware
  Software
  Embedded Systems
  External Trading Partners
  Building/Infrastructure Systems
  Telecommunications Systems
Implementation/Replacement................................  September 1999       75%
  Computer Hardware
  Core Business Software
  Desktop Software
  Embedded Systems
  Building Systems
Contact External Trading Partners.........................      March 1999      100%
Contingency Planning......................................      April 1999       70%
</TABLE>
 
     To date, the Company is not aware of any significant Year 2000 issues that
would cause problems in the area of safety, environmental or business
interruption. The Company will assess the risks associated with hardware,
software, infrastructure, embedded chips and external trading partners that are
not Year 2000 compliant. While Apache is confident that Year 2000 remediation
efforts will succeed in minimizing exposure to business disruption, plans are
being developed that will allow continuation of business in all but the worst
case scenarios. All remediation and replacement efforts and contingency planning
are expected to be complete by September 1999. All critical external trading
partners have been contacted to determine Year 2000 readiness and contingency
plans will be developed where assurance of Year 2000 compliance is not received
by March 31, 1999.
 
     In 1997, the Company initiated a project to replace existing business
software as it relates to Apache's production, land, marketing, accounting and
financial systems to more effectively and efficiently meet its business needs.
Replacement computer systems selected by the Company from SAP America, Inc.,
PricewaterhouseCoopers LLP, Innovative Business Solutions and Landmark Graphics
will properly recognize dates beyond December 31, 1999. The Company plans to
implement the replacement software by March 31, 1999. The business system
replacement project is 90 percent complete and the Company believes that the
March 31, 1999 deadline is attainable.
 
     The Company expects the cost to achieve Year 2000 compliance will not
exceed $4 million excluding the cost of implementing business replacement
systems.
 
                                       26
<PAGE>   29
 
     The Company presently believes that with conversions to new software and
completion of efforts planned by the Year 2000 Task Force, the risk associated
with Year 2000 will be significantly reduced. However, the Company is unable to
assure that the consequences of Year 2000 failures of systems maintained by the
Company or by third parties will not materially adversely impact the Company's
results of operations, liquidity or financial condition.
 
FUTURE TRENDS
 
     Apache's strategy is to increase its oil and gas reserves, production, cash
flow and earnings by continuing to explore on and develop its inventory of
existing projects and making carefully targeted acquisitions of new assets.
Crude oil prices have fallen to the lowest level in over a decade. Drilling
costs and acquisition prices have also declined. As one of few companies to have
reduced debt in 1998, Apache is well positioned to execute the second phase of
its long-term strategy, which is to complete a meaningful acquisition in 1999
that builds shareholder value. Accordingly, Apache's 1999 plans include:
 
          1. Controlling G&A and LOE expense;
 
          2. Curtailing drilling costs; and
 
          3. Pursuing opportunities to acquire properties.
 
     Although no specific opportunity has as yet been identified as likely, the
Company believes that the number of quality acquisition, merger and joint
venture opportunities has increased dramatically.
 
     Apache's international properties should continue to grow in importance
with respect to Apache's financial results and future growth prospects. Apache's
international efforts remain focused on development of its discoveries in Egypt,
offshore Western Australia, China and the Ivory Coast, and exploration efforts
on the Company's concessions in Egypt and in Poland. While international
exploration is recognized as higher risk than Apache's North American
activities, the Company believes it offers potential for greater rewards and
significant reserve additions. Apache also believes that reserve additions in
these international areas may be made through higher risk exploration and
through improved production practices and recovery techniques.
 
     Under the full cost accounting rules of the SEC, the Company reviews the
carrying value of its proved oil and gas properties each quarter on a
country-by-country basis. Under these rules, capitalized costs of proved oil and
gas properties, net of accumulated DD&A and deferred income taxes, may not
exceed the present value of estimated future net cash flows from proved oil and
gas reserves, discounted at 10 percent, plus the lower of cost or fair value of
unproved properties included in the costs being amortized, net of related tax
effects. These rules generally require pricing future oil and gas production at
the unescalated oil and gas prices in effect at the end of each fiscal quarter
and require a write-down if the "ceiling" is exceeded, even if prices declined
for only a short period of time. The Company recorded a $243.2 million pre-tax
($158.1 million net of tax) non-cash write-down of the carrying value of the
Company's U.S. proved oil and gas properties as of December 31, 1998, due to
these ceiling test limitations. If oil and gas prices deteriorate from the
Company's year-end realized prices, it is likely that additional write-downs
will occur in 1999. Write-downs required by these rules do not impact cash flow
from operating activities.
 
FORWARD-LOOKING STATEMENTS AND RISK
 
     Certain statements in this report, including statements of the future
plans, objectives, and expected performance of the Company, are forward-looking
statements that are dependent upon certain events, risks and uncertainties that
may be outside the Company's control, and which could cause actual results to
differ materially from those anticipated. Some of these include, but are not
limited to, the market prices of oil and gas, economic and competitive
conditions, inflation rates, legislative and regulatory changes, financial
market conditions, political and economic uncertainties of foreign governments,
future business decisions, and other uncertainties, all of which are difficult
to predict.
 
     There are numerous uncertainties inherent in estimating quantities of
proved oil and gas reserves and in projecting future rates of production and the
timing of development expenditures. The total amount or timing
                                       27
<PAGE>   30
 
of actual future production may vary significantly from reserves and production
estimates. The drilling of exploratory wells can involve significant risks,
including those related to timing, success rates and cost overruns. Lease and
rig availability, complex geology and other factors can affect these risks.
Although Apache makes use of futures contracts, swaps, options and fixed-price
physical contracts to mitigate risk, fluctuations in oil and gas prices, or a
prolonged continuation of the current low price of crude oil, may substantially
adversely affect the Company's financial position, results of operations and
cash flows.
 
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA
 
     The financial statements and supplementary financial information required
to be filed under this item are presented on pages F-1 through F-35 of this Form
10-K, and are incorporated herein by reference.
 
ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
        FINANCIAL DISCLOSURE
 
     None.
 
                                    PART III
 
ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT
 
     The information set forth under the captions "Nominees for Election as
Directors," "Continuing Directors," "Executive Officers of the Company," and
"Voting Securities and Principal Holders" in the proxy statement relating to the
Company's 1999 annual meeting of stockholders (the Proxy Statement) is
incorporated herein by reference.
 
ITEM 11. EXECUTIVE COMPENSATION
 
     The information set forth under the captions "Summary Compensation Table,"
"Option/SAR Grants Table," "Option/SAR Exercises and Year-End Value Table,"
"Employment Contracts and Termination of Employment and Change-in-Control
Arrangements," and "Director Compensation" in the Proxy Statement is
incorporated herein by reference.
 
ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT
 
     The information set forth under the caption "Voting Securities and
Principal Holders" in the Proxy Statement is incorporated herein by reference.
 
ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
 
     The information set forth under the caption "Certain Business Relationships
and Transactions" in the Proxy Statement is incorporated herein by reference.
 
                                       28
<PAGE>   31
 
                                    PART IV
 
ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K
 
     (a) Documents included in this report:
 
        1. Financial Statements
 
<TABLE>
           <S>                                                           <C>
           Report of independent public accountants....................   F-1
           Report of management........................................   F-2
           Statement of consolidated operations for each of the three
             years in the period ended December 31, 1998...............   F-3
           Statement of consolidated cash flows for each of the three
             years in the period ended December 31, 1998...............   F-4
           Consolidated balance sheet as of December 31, 1998 and
             1997......................................................   F-5
           Statement of consolidated shareholders' equity for each of
             the three years in the period ended December 31, 1998.....   F-6
           Notes to consolidated financial statements..................   F-7
           Supplemental oil and gas disclosures........................  F-29
           Supplemental quarterly financial data.......................  F-35
</TABLE>
 
        2. Financial Statement Schedules
 
          Financial statement schedules have been omitted because they are
          either not required, not applicable or the information required to be
          presented is included in the Company's financial statements and
          related notes.
 
        3. Exhibits
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
           2.1           -- Stock Purchase Agreement, dated July 1, 1991, between
                            Registrant and Amoco Production Company (incorporated by
                            reference to Exhibit 10.1 to Registrant's Current Report
                            on Form 8-K, dated July 1, 1991, SEC File No. 1-4300).
           2.2           -- Form of Acquisition Agreement between Registrant, HERC
                            Acquisition Corporation and Hadson Energy Resources
                            Corporation, dated August 26, 1993, and amended September
                            28, 1993 (incorporated by reference to Exhibit 2.1 to
                            Registrant's Registration Statement on Form S-4,
                            Registration No. 33-67954, filed September 29, 1993).
           2.3           -- Purchase and Sale Agreement by and between Texaco
                            Exploration and Production Inc., as seller, and
                            Registrant, as buyer, dated December 22, 1994
                            (incorporated by reference to Exhibit 99.3 to
                            Registrant's Current Report on Form 8-K, dated November
                            29, 1994, SEC File No. 1-4300).
           2.4           -- Amended and Restated Agreement and Plan of Merger among
                            Registrant, XPX Acquisitions, Inc and DEKALB Energy
                            Company, dated December 21, 1994 (incorporated by
                            reference to Exhibit 2.1 to Amendment No. 3 to
                            Registrant's Registration Statement on Form S-4,
                            Registration No. 33-57321, filed April 14, 1995).
           2.5           -- Agreement and Plan of Merger among Registrant, YPY
                            Acquisitions, Inc. and The Phoenix Resource Companies,
                            Inc., dated March 27, 1996 (incorporated by reference to
                            Exhibit 2.1 to Registrant's Registration Statement on
                            Form S-4, Registration No. 333-02305, filed April 5,
                            1996).
</TABLE>
 
                                       29
<PAGE>   32
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
           3.1           -- Restated Certificate of Incorporation of Registrant,
                            dated December 1, 1993, as filed with the Secretary of
                            State of Delaware on December 16, 1993 (incorporated by
                            reference to Exhibit 3.1 to Registrant's Annual Report on
                            Form 10-K for year ended December 31, 1993, SEC File No.
                            1-4300).
           3.2           -- Certificate of Ownership and Merger Merging Apache Energy
                            Resources Corporation into Registrant, effective December
                            31, 1995, as filed with the Secretary of State of
                            Delaware on December 21, 1995 (incorporated by reference
                            to Exhibit 3.2 to Registrant's Annual Report on Form 10-K
                            for year ended December 31, 1995, SEC File No. 1-4300).
           3.3           -- Certificate of Designations, Preferences and Rights of
                            Series A Junior Participating Preferred Stock of
                            Registrant, effective January 31, 1996, as filed with the
                            Secretary of State of Delaware on January 22, 1996
                            (incorporated by reference to Exhibit 3.3 to Registrant's
                            Annual Report on Form 10-K for year ended December 31,
                            1995, SEC File No. 1-4300).
          *3.4           -- Certificate of Ownership and Merger merging Apache PHN
                            Company, Inc. into Registrant, effective July 1, 1998, as
                            filed with the Secretary of State of Delaware on July 1,
                            1998.
          *3.5           -- Agreement and Plan of Merger merging MWJR Petroleum
                            Corporation into Registrant, effective September 1, 1998,
                            as filed with the Secretary of State of Delaware on
                            August 19, 1998.
          *3.6           -- Certificate of Ownership and Merger merging MW Petroleum
                            Corporation into Registrant, effective September 1, 1998,
                            as filed with the Secretary of State of Delaware on
                            August 19, 1998.
          *3.7           -- Certificate of Designations, Preferences and Rights of
                            5.68% Cumulative Preferred Stock, Series B, of
                            Registrant, as filed with the Secretary of State of
                            Delaware on August 21, 1998.
          *3.8           -- Certificate of Correction to Certificate of Designations,
                            Preferences and Rights of 5.68% Cumulative Preferred
                            Stock, Series B, of Registrant, as filed with the
                            Secretary of State of Delaware on August 24, 1998.
           3.9           -- Bylaws of Registrant, as amended September 17, 1998
                            (incorporated by reference to Exhibit 3.2 to Registrant's
                            Quarterly Report on Form 10-Q for quarter ended September
                            30, 1998, SEC File No. 1-4300).
           4.1           -- Form of Certificate for Registrant's Common Stock
                            (incorporated by reference to Exhibit 4.1 to Registrant's
                            Annual Report on Form 10-K for year ended December 31,
                            1995, SEC File No. 1-4300).
           4.2           -- Form of Certificate for Registrant's 5.68% Cumulative
                            Preferred Stock, Series B (incorporated by reference to
                            Exhibit 4.2 to Amendment No. 2 on Form 8-K/A to
                            Registrant's Current Report on Form 8-K, dated August 18,
                            1998, SEC File No. 1-4300).
           4.3           -- Rights Agreement, dated January 31, 1996, between
                            Registrant and Norwest Bank Minnesota, N.A., rights
                            agent, relating to the declaration of a rights dividend
                            to Registrant's common shareholders of record on January
                            31, 1996 (incorporated by reference to Exhibit (a) to
                            Registrant's Registration Statement on Form 8-A, dated
                            January 24, 1996, SEC File No. 1-4300).
</TABLE>
 
                                       30
<PAGE>   33
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
          10.1           -- Credit Agreement, dated June 12, 1997, among the
                            Registrant, the lenders named therein, Morgan Guaranty
                            Trust Company, as Global Documentation Agent and U.S.
                            Syndication Agent, The First National Bank of Chicago, as
                            U.S. Documentation Agent, NationsBank of Texas, N.A., as
                            Co-Agent, Union Bank of Switzerland, Houston Agency, as
                            Co-Agent, and The Chase Manhattan Bank, as Global
                            Administrative Agent (incorporated by reference to
                            Exhibit 10.1 to Registrant's Current Report on Form 8-K,
                            dated June 13, 1997, SEC File No. 1-4300).
          10.2           -- Credit Agreement, dated June 12, 1997, among Apache
                            Canada Ltd., a wholly-owned subsidiary of the Registrant,
                            the lenders named therein, Morgan Guaranty Trust Company,
                            as Global Documentation Agent, Royal Bank of Canada, as
                            Canadian Documentation Agent, The Chase Manhattan Bank of
                            Canada, as Canadian Syndication Agent, Bank of Montreal,
                            as Canadian Administrative Agent, and The Chase Manhattan
                            Bank, as Global Administrative Agent (incorporated by
                            reference to Exhibit 10.2 to Registrant's Current Report
                            on Form 8-K, dated June 13, 1997, SEC File No. 1-4300).
          10.3           -- Credit Agreement, dated June 12, 1997, among Apache
                            Energy Limited and Apache Oil Australia Pty Limited,
                            wholly-owned subsidiaries of the Registrant, the lenders
                            named therein, Morgan Guaranty Trust Company, as Global
                            Documentation Agent, Bank of America National Trust and
                            Savings Association, Sydney Branch, as Australian
                            Documentation Agent, The Chase Manhattan Bank, as
                            Australian Syndication Agent, Citisecurities Limited, as
                            Australian Administrative Agent, and The Chase Manhattan
                            Bank, as Global Administrative Agent (incorporated by
                            reference to Exhibit 10.3 to Registrant's Current Report
                            on Form 8-K, dated June 13, 1997, SEC File No. 1-4300).
          10.4           -- Fiscal Agency Agreement, dated January 4, 1995, between
                            Registrant and Chemical Bank, as fiscal agent, relating
                            to Registrant's 6% Convertible Subordinated Debentures
                            due 2002 (incorporated by reference to Exhibit 99.2 to
                            Registrant's Current Report on Form 8-K, dated December
                            6, 1994, SEC File No. 1-4300).
          10.5           -- Concession Agreement for Petroleum Exploration and
                            Exploitation in the Khalda Area in Western Desert of
                            Egypt by and among Arab Republic of Egypt, the Egyptian
                            General Petroleum Corporation and Phoenix Resources
                            Company of Egypt, dated April 6, 1981 (incorporated by
                            reference to Exhibit 19(g) to Phoenix's Annual Report on
                            Form 10-K for year ended December 31, 1984, SEC File No.
                            1-547).
          10.6           -- Amendment, dated July 10, 1989, to Concession Agreement
                            for Petroleum Exploration and Exploitation in the Khalda
                            Area in Western Desert of Egypt by and among Arab
                            Republic of Egypt, the Egyptian General Petroleum
                            Corporation and Phoenix Resources Company of Egypt
                            (incorporated by reference to Exhibit 10(d)(4) to
                            Phoenix's Quarterly Report on Form 10-Q for quarter ended
                            June 30, 1989, SEC File No. 1-547).
          10.7           -- Farmout Agreement, dated September 13, 1985 and relating
                            to the Khalda Area Concession, by and between Phoenix
                            Resources Company of Egypt and Conoco Khalda
                            Inc(incorporated by reference to Exhibit 10.1 to
                            Phoenix's Registration Statement on Form S-1,
                            Registration No. 33-1069, filed October 23, 1985).
</TABLE>
 
                                       31
<PAGE>   34
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
          10.8           -- Amendment, dated March 30, 1989, to Farmout Agreement
                            relating to the Khalda Area Concession, by and between
                            Phoenix Resources Company of Egypt and Conoco Khalda
                            Inc(incorporated by reference to Exhibit 10(d)(5) to
                            Phoenix's Quarterly Report on Form 10-Q for quarter ended
                            June 30, 1989, SEC File No. 1-547).
          10.9           -- Amendment, dated May 21, 1995, to Concession Agreement
                            for Petroleum Exploration and Exploitation in the Khalda
                            Area in Western Desert of Egypt between Arab Republic of
                            Egypt, the Egyptian General Petroleum Corporation, Repsol
                            Exploracion Egipto S.A., Phoenix Resources Company of
                            Egypt and Samsung Corporation (incorporated by reference
                            to exhibit 10.12 to Registrant's Annual Report on Form
                            10-K for year ended December 31, 1997, SEC File No.
                            1-4300).
          10.10          -- Concession Agreement for Petroleum Exploration and
                            Exploitation in the Qarun Area in Western Desert of
                            Egypt, between Arab Republic of Egypt, the Egyptian
                            General Petroleum Corporation, Phoenix Resources Company
                            of Qarun and Apache Oil Egypt, Inc., dated May 17, 1993
                            (incorporated by reference to Exhibit 10(b) to Phoenix's
                            Annual Report on Form 10-K for year ended December 31,
                            1993, SEC File No. 1-547).
          10.11          -- Agreement for Amending the Gas Pricing Provisions under
                            the Concession Agreement for Petroleum Exploration and
                            Exploitation in the Qarun Area, effective June 16, 1994
                            (incorporated by reference to Exhibit 10.18 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1996, SEC File No. 1-4300).
         +10.12          -- 1982 Employee Stock Option Plan, as updated in January
                            1987 to conform to the Tax Reform Act of 1986
                            (incorporated by reference to Exhibit 10.7 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1990, SEC File No. 1-4300).
        +*10.13          -- Apache Corporation Corporate Incentive Compensation Plan
                            A (Senior Officers' Plan), dated July 16, 1998.
        +*10.14          -- Apache Corporation Corporate Incentive Compensation Plan
                            B (Strategic Objectives Format), dated July 16, 1998.
         +10.15          -- Apache Corporation 401(k) Savings Plan, dated August 1,
                            1997, effective January 1, 1997 (incorporated by
                            reference to Exhibit 10.1 to Registrant's Current Report
                            on Form 8-K, dated August 8, 1997, SEC File No. 1-4300).
         +10.16          -- Apache Corporation Money Purchase Retirement Plan, dated
                            December 31, 1997, effective January 1, 1997
                            (incorporated by reference to Exhibit 10.19 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1997, SEC File No. 1-4300).
        +*10.17          -- Non-Qualified Retirement/Savings Plan of Apache
                            Corporation, restated as of January 1, 1997, and
                            amendments effective as of January 1, 1997, January 1,
                            1998 and January 1, 1999.
         +10.18          -- Apache International, Inc. Common Stock Award Plan, dated
                            February 12, 1990 (incorporated by reference to Exhibit
                            10.13 to Registrant's Annual Report on Form 10-K for year
                            ended December 31, 1989, SEC File No. 1-4300).
        +*10.19          -- Apache Corporation 1990 Stock Incentive Plan, as amended
                            and restated December 17, 1998.
        +*10.20          -- Apache Corporation 1995 Stock Option Plan, as amended and
                            restated December 17, 1998.
</TABLE>
 
                                       32
<PAGE>   35
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
         +10.21          -- Apache Corporation 1996 share Price Appreciation Plan, as
                            amended and restated January 14, 1997 (incorporated by
                            reference to Appendix A to Registrant's definitive 14A
                            Proxy Statement, SEC File No. 1-4300, filed March 28,
                            1997).
         +10.22          -- Apache Corporation 1996 Performance Stock Option Plan, as
                            amended and restated January 14, 1997 (incorporated by
                            reference to Exhibit 10.32 to Registrant's Annual Report
                            on Form 10-K for year ended December 31, 1996, SEC File
                            No. 1-4300).
        +*10.23          -- Apache Corporation 1998 Stock Option Plan, as amended and
                            restated December 17, 1998.
         +10.24          -- 1990 Employee Stock Option Plan of The Phoenix Resource
                            Companies, Inc., as amended through September 29, 1995,
                            effective April 9, 1990 (incorporated by reference to
                            Exhibit 10.33 to Registrant's Annual Report on Form 10-K
                            for year ended December 31, 1996, SEC File No. 1-4300).
         +10.25          -- Apache Corporation Income Continuance Plan, as amended
                            and restated February 24, 1988 (incorporated by reference
                            to Exhibit 10.19 to Registrant's Annual Report on Form
                            10-K for year ended December 31, 1990, SEC File No.
                            1-4300).
        +*10.26          -- Apache Corporation Non-Employee Directors' Compensation
                            Plan, as amended and restated December 17, 1998.
         +10.27          -- Apache Corporation Outside Directors' Retirement Plan, as
                            amended and restated September 11, 1997 (incorporated by
                            reference to Exhibit 10.31 to Registrant's Annual Report
                            on Form 10-K for year ended December 31, 1997, SEC File
                            No. 1-4300).
         +10.28          -- Apache Corporation Equity Compensation Plan for
                            Non-Employee Directors, adopted February 9, 1994, and
                            form of Restricted Stock Award Agreement (incorporated by
                            reference to Exhibit 10.26 to Registrant's Annual Report
                            on Form 10-K for year ended December 31, 1993, SEC File
                            No. 1-4300).
         +10.29          -- Amended and Restated Employment Agreement, dated December
                            5, 1990, between Registrant and Raymond Plank
                            (incorporated by reference to Exhibit 10.39 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1996, SEC File No. 1-4300).
         +10.30          -- First Amendment, dated April 4, 1996, to Restated
                            Employment Agreement between Registrant and Raymond Plank
                            (incorporated by reference to Exhibit 10.40 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1996, SEC File No. 1-4300).
         +10.31          -- Amended and Restated Employment Agreement, dated December
                            20, 1990, between Registrant and John A. Kocur
                            (incorporated by reference to Exhibit 10.10 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1990, SEC File No. 1-4300).
         +10.32          -- Employment Agreement, dated June 6, 1988, between
                            Registrant and G. Steven Farris (incorporated by
                            reference to Exhibit 10.6 to Registrant's Annual Report
                            on Form 10-K for year ended December 31, 1989, SEC File
                            No. 1-4300).
        +*10.33          -- Conditional Stock Grant Agreement, dated December 17,
                            1998, between Registrant and G. Steven Farris.
</TABLE>
 
                                       33
<PAGE>   36
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
          10.34          -- Amended and Restated Gas Purchase Agreement, effective
                            July 1, 1998, by and among Registrant and MW Petroleum
                            Corporation, as Seller, and Producers Energy Marketing,
                            LLC, as Buyer (incorporated by reference to Exhibit 10.1
                            to Registrant's Current Report on Form 8-K, dated June
                            18, 1998, SEC File No. 1-4300).
          12.1           -- Statement of Computation of Ratio of Earnings to Combined
                            Fixed Charges and Preferred Stock Dividends (incorporated
                            by reference to Exhibit 99.1 to Registrant's Current
                            Report on Form 8-K, dated March 2, 1999, SEC File No.
                            1-4300).
         *21.1           -- Subsidiaries of Registrant
         *23.1           -- Consent of Arthur Andersen LLP
         *23.2           -- Consent of Ryder Scott Company Petroleum Engineers
         *23.3           -- Consent of Netherland, Sewell & Associates, Inc.
         *24.1           -- Power of Attorney (included as a part of the signature
                            pages to this report)
         *27.1           -- Financial Data Schedule
</TABLE>
 
- ---------------
 
*     Filed herewith.
 
+     Management contracts or compensatory plans or arrangements required to be
      filed herewith pursuant to Item 14 hereof.
 
Note: Debt instruments of the Registrant defining the rights of long-term debt
      holders in principal amounts not exceeding 10 percent of the Registrant's
      consolidated assets have been omitted and will be provided to the
      Commission upon request.
 
     (b) Reports on Form 8-K
 
          There were no reports on Form 8-K filed by Apache during the fiscal
     quarter ended December 31, 1998.
 
                                       34
<PAGE>   37
 
                                   SIGNATURES
 
     Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.
 
                                            APACHE CORPORATION
 
                                                    /s/ RAYMOND PLANK
 
                                            ------------------------------------
                                                       Raymond Plank
                                            Chairman and Chief Executive Officer
Dated: March 24, 1999
 
                               POWER OF ATTORNEY
 
     The officers and directors of Apache Corporation, whose signatures appear
below, hereby constitute and appoint Raymond Plank, G. Steven Farris, Z. S.
Kobiashvili and Roger B. Plank, and each of them (with full power to each of
them to act alone), the true and lawful attorney-in-fact to sign and execute, on
behalf of the undersigned, any amendment(s) to this report and each of the
undersigned does hereby ratify and confirm all that said attorneys shall do or
cause to be done by virtue thereof.
 
     Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
registrant and in the capacities and on the dates indicated.
 
<TABLE>
<CAPTION>
NAME                                                                 TITLE                        DATE
- ----                                                                 -----                        ----
<C>                                                    <S>                                <C>
                  /s/ RAYMOND PLANK                    Chairman and Chief Executive          March 24, 1999
- -----------------------------------------------------    Officer (Principal Executive
                    Raymond Plank                        Officer)
 
                 /s/ ROGER B. PLANK                    Vice President and Chief Financial    March 24, 1999
- -----------------------------------------------------    Officer (Principal Financial
                   Roger B. Plank                        Officer)
 
               /s/ THOMAS L. MITCHELL                  Vice President and Controller         March 24, 1999
- -----------------------------------------------------    (Principal Accounting Officer)
                 Thomas L. Mitchell
</TABLE>
<PAGE>   38
 
<TABLE>
<CAPTION>
NAME                                                                 TITLE                        DATE
- ----                                                                 -----                        ----
<C>                                                    <S>                                <C>
               /s/ FREDERICK M. BOHEN                  Director                              March 24, 1999
- -----------------------------------------------------
                 Frederick M. Bohen
 
                /s/ G. STEVEN FARRIS                   Director                              March 24, 1999
- -----------------------------------------------------
                  G. Steven Farris
 
               /s/ RANDOLPH M. FERLIC                  Director                              March 24, 1999
- -----------------------------------------------------
                 Randolph M. Ferlic
 
               /s/ EUGENE C. FIEDOREK                  Director                              March 24, 1999
- -----------------------------------------------------
                 Eugene C. Fiedorek
 
               /s/ A. D. FRAZIER, JR.                  Director                              March 24, 1999
- -----------------------------------------------------
                 A. D. Frazier, Jr.
 
               /s/ STANLEY K. HATHAWAY                 Director                              March 24, 1999
- -----------------------------------------------------
                 Stanley K. Hathaway
 
                  /s/ JOHN A. KOCUR                    Director                              March 24, 1999
- -----------------------------------------------------
                    John A. Kocur
 
             /s/ GEORGE D. LAWRENCE JR.                Director                              March 24, 1999
- -----------------------------------------------------
               George D. Lawrence Jr.
 
                 /s/ MARY RALPH LOWE                   Director                              March 24, 1999
- -----------------------------------------------------
                   Mary Ralph Lowe
 
                  /s/ F. H. MERELLI                    Director                              March 24, 1999
- -----------------------------------------------------
                    F. H. Merelli
 
                 /s/ JOSEPH A. RICE                    Director                              March 24, 1999
- -----------------------------------------------------
                   Joseph A. Rice
</TABLE>
<PAGE>   39
 
                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS
 
To the Shareholders of Apache Corporation:
 
     We have audited the accompanying consolidated balance sheet of Apache
Corporation (a Delaware corporation) and Subsidiaries as of December 31, 1998
and 1997, and the related consolidated statements of operations, shareholders'
equity, and cash flows for each of the three years in the period ended December
31, 1998. These financial statements are the responsibility of the Company's
management. Our responsibility is to express an opinion on these financial
statements based on our audits.
 
     We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
     In our opinion, the consolidated financial statements referred to above
present fairly, in all material respects, the financial position of Apache
Corporation and Subsidiaries as of December 31, 1998 and 1997, and the results
of their operations and their cash flows for each of the three years in the
period ended December 31, 1998, in conformity with generally accepted accounting
principles.
 
                                            ARTHUR ANDERSEN LLP
 
Houston, Texas
March 5, 1999
 
                                       F-1
<PAGE>   40
 
                              REPORT OF MANAGEMENT
 
     The financial statements and related financial information of Apache
Corporation and Subsidiaries were prepared by and are the responsibility of
management. The statements have been prepared in conformity with generally
accepted accounting principles and include amounts that are based on
management's best estimates and judgments.
 
     Management maintains and places reliance on systems of internal control
designed to provide reasonable assurance, weighing the costs with the benefits
sought, that all transactions are properly recorded in the Company's books and
records, that policies and procedures are adhered to, and that assets are
safeguarded. The systems of internal controls are supported by written policies
and guidelines, internal audits and the selection and training of qualified
personnel.
 
     The consolidated financial statements of Apache Corporation and
Subsidiaries have been audited by Arthur Andersen LLP, independent public
accountants. Their audits included developing an overall understanding of the
Company's accounting systems, procedures and internal controls and conducting
tests and other auditing procedures sufficient to support their opinion on the
fairness of the consolidated financial statements.
 
     The Apache Corporation Board of Directors exercises its oversight
responsibility for the financial statements through its Audit Committee,
composed solely of directors who are not current or former employees of Apache.
The Audit Committee meets periodically with management, internal auditors and
the independent public accountants to ensure that they are successfully
completing designated responsibilities. The internal auditors and independent
public accountants have open access to the Audit Committee to discuss auditing
and financial reporting issues.
 
Houston, Texas
March 5, 1999
 
                                            Raymond Plank
                                            Chairman of the Board
                                            and Chief Executive Officer
 
                                            Roger B. Plank
                                            Vice President and Chief Financial
                                            Officer
 
                                            Thomas L. Mitchell
                                            Vice President and Chief Accounting
                                            Officer
 
                                       F-2
<PAGE>   41
 
                      APACHE CORPORATION AND SUBSIDIARIES
 
                      STATEMENT OF CONSOLIDATED OPERATIONS
 
<TABLE>
<CAPTION>
                                                                     FOR THE YEAR ENDED DECEMBER 31,
                                                              ---------------------------------------------
                                                                  1998             1997            1996
                                                              -------------    -------------    -----------
                                                              (IN THOUSANDS, EXCEPT PER COMMON SHARE DATA)
<S>                                                           <C>              <C>              <C>
 
REVENUES:
  Oil and gas production revenues...........................   $  759,038       $  983,773       $833,164
  Gathering, processing and marketing revenues..............      117,395          196,951        142,868
  Equity in loss of affiliates..............................       (1,558)          (1,683)          (281)
  Other revenues............................................          840           (2,768)         1,400
                                                               ----------       ----------       --------
                                                                  875,715        1,176,273        977,151
                                                               ----------       ----------       --------
OPERATING EXPENSES:
  Depreciation, depletion and amortization:
     Recurring..............................................      382,807          381,416        315,144
     Additional.............................................      243,178               --             --
  Operating costs...........................................      211,554          231,370        225,527
  Gathering, processing and marketing costs.................      114,471          194,279        138,768
  Administrative, selling and other.........................       40,731           38,243         35,911
  Financing costs:
     Interest expense.......................................      119,703          105,148         89,829
     Amortization of deferred loan costs....................        4,496            6,438          5,118
     Capitalized interest...................................      (49,279)         (36,493)       (30,712)
     Interest income........................................       (4,383)          (2,768)        (2,629)
                                                               ----------       ----------       --------
                                                                1,063,278          917,633        776,956
                                                               ----------       ----------       --------
INCOME (LOSS) BEFORE INCOME TAXES...........................     (187,563)         258,640        200,195
  Provision (benefit) for income taxes......................      (58,176)         103,744         78,768
                                                               ----------       ----------       --------
NET INCOME (LOSS)...........................................     (129,387)         154,896        121,427
  Preferred stock dividends.................................        2,004               --             --
                                                               ----------       ----------       --------
INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCK..................   $ (131,391)      $  154,896       $121,427
                                                               ==========       ==========       ========
NET INCOME (LOSS) PER COMMON SHARE:
  Basic.....................................................   $    (1.34)      $     1.71       $   1.42
                                                               ==========       ==========       ========
  Diluted...................................................   $    (1.34)      $     1.65       $   1.38
                                                               ==========       ==========       ========
</TABLE>
 
The accompanying notes to consolidated financial statements are an integral part
                               of this statement.
                                       F-3
<PAGE>   42
 
                      APACHE CORPORATION AND SUBSIDIARIES
 
                      STATEMENT OF CONSOLIDATED CASH FLOWS
 
<TABLE>
<CAPTION>
                                                                FOR THE YEAR ENDED DECEMBER 31,
                                                              -----------------------------------
                                                                1998         1997         1996
                                                              ---------   -----------   ---------
                                                                        (IN THOUSANDS)
<S>                                                           <C>         <C>           <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
  Net income (loss).........................................  $(129,387)  $   154,896   $ 121,427
  Adjustments to reconcile net income (loss) to net cash
     provided by operating activities:
       Depreciation, depletion and amortization.............    625,985       381,416     315,144
       Amortization of deferred loan costs..................      4,496         6,438       5,118
       Provision (benefit) for deferred income taxes........    (81,856)       68,280      61,336
  Cash distributions in excess of (less than) earnings of
     affiliates.............................................      1,523         1,768        (163)
  Loss (gain) on sale of stock held for investment..........        364           (13)       (770)
  Changes in operating assets and liabilities, net of
     effects of acquisitions:
     (Increase) decrease in receivables.....................     65,487        12,556     (55,645)
     (Increase) decrease in advances to oil and gas ventures
      and other.............................................      3,879        (7,728)      5,737
     (Increase) decrease in deferred charges and other......     13,238           447      (3,321)
     Increase (decrease) in payables........................    (65,851)        1,920      35,998
     Increase (decrease) in accrued expenses................    (12,161)        9,579      (3,433)
     Increase (decrease) in advance from gas purchaser......     50,922       102,748      (8,540)
     Increase (decrease) in deferred credits and noncurrent
      liabilities...........................................     (5,128)       (8,499)     17,616
                                                              ---------   -----------   ---------
            NET CASH PROVIDED BY OPERATING ACTIVITIES.......    471,511       723,808     490,504
                                                              ---------   -----------   ---------
CASH FLOWS FROM INVESTING ACTIVITIES:
  Additions to property and equipment.......................   (699,509)     (771,419)   (642,021)
  Non-cash portion of net oil and gas property additions....     38,774         6,208      46,268
  Acquisition of Novus, net of cash acquired................    (48,499)           --          --
  Acquisition of Ampolex Group, net of cash acquired........         --      (299,852)         --
  Acquisition of Phoenix, net of cash acquired..............         --            --     (43,294)
  Proceeds from sales of oil and gas properties.............    131,149        30,134      30,144
  Purchase of stock held for investment.....................         --        (1,170)         --
  Proceeds from sale of stock held for investment...........     26,147         1,183       7,193
  Proceeds from sale of assets held for resale..............     62,998            --          --
  Other, net................................................    (23,180)      (31,309)    (16,517)
                                                              ---------   -----------   ---------
            NET CASH USED IN INVESTING ACTIVITIES...........   (512,120)   (1,066,225)   (618,227)
                                                              ---------   -----------   ---------
CASH FLOWS FROM FINANCING ACTIVITIES:
  Long-term borrowings......................................    551,897     1,168,201     765,895
  Payments on long-term debt................................   (556,141)     (812,327)   (615,765)
  Dividends paid............................................    (28,204)      (25,275)    (23,420)
  Proceeds from issuance of preferred stock.................     98,630            --          --
  Proceeds from issuance of common stock....................      1,240        11,623       8,145
  Payments to acquire treasury stock........................    (21,418)         (386)     (1,698)
  Cost of debt and equity transactions......................       (544)       (2,894)     (5,906)
                                                              ---------   -----------   ---------
            NET CASH PROVIDED BY FINANCING ACTIVITIES.......     45,460       338,942     127,251
                                                              ---------   -----------   ---------
NET INCREASE (DECREASE) IN CASH AND
  CASH EQUIVALENTS..........................................      4,851        (3,475)       (472)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR..............      9,686        13,161      13,633
                                                              ---------   -----------   ---------
CASH AND CASH EQUIVALENTS AT END OF YEAR....................  $  14,537   $     9,686   $  13,161
                                                              =========   ===========   =========
</TABLE>
 
The accompanying notes to consolidated financial statements are an integral part
                               of this statement.
                                       F-4
<PAGE>   43
 
                      APACHE CORPORATION AND SUBSIDIARIES
 
                           CONSOLIDATED BALANCE SHEET
 
<TABLE>
<CAPTION>
                                                                    DECEMBER 31,
                                                              -------------------------
                                                                 1998          1997
                                                              -----------   -----------
                           ASSETS                                  (IN THOUSANDS)
<S>                                                           <C>           <C>
CURRENT ASSETS:
  Cash and cash equivalents.................................  $    14,537   $     9,686
  Receivables...............................................      159,806       224,025
  Inventories...............................................       40,948        36,041
  Advances to oil and gas ventures and other................       11,679        15,579
  Assets held for resale....................................           --        62,998
                                                              -----------   -----------
                                                                  226,970       348,329
                                                              -----------   -----------
PROPERTY AND EQUIPMENT:
  Oil and gas, on the basis of full cost accounting:
     Proved properties......................................    5,901,863     5,530,991
     Unproved properties and properties under development,
      not being amortized...................................      637,854       532,556
  Gas gathering, transmission and processing facilities.....      354,506       246,049
  Other.....................................................       88,422        71,067
                                                              -----------   -----------
                                                                6,982,645     6,380,663
  Less: Accumulated depreciation, depletion and
     amortization...........................................   (3,255,104)   (2,647,478)
                                                              -----------   -----------
                                                                3,727,541     3,733,185
                                                              -----------   -----------
OTHER ASSETS:
  Deferred charges and other................................       41,551        57,119
                                                              -----------   -----------
                                                              $ 3,996,062   $ 4,138,633
                                                              ===========   ===========
 
            LIABILITIES AND SHAREHOLDERS' EQUITY
 
CURRENT LIABILITIES:
  Current maturities of long-term debt......................  $    15,500   $    17,200
  Accounts payable..........................................      115,111       178,361
  Accrued operating expense.................................       18,990        20,153
  Accrued exploration and development.......................      120,855        82,392
  Accrued compensation and benefits.........................       10,692        17,600
  Accrued interest..........................................       19,054        20,598
  Other accrued expenses....................................        5,572         7,479
                                                              -----------   -----------
                                                                  305,774       343,783
                                                              -----------   -----------
LONG-TERM DEBT..............................................    1,343,258     1,501,380
                                                              -----------   -----------
DEFERRED CREDITS AND OTHER NONCURRENT LIABILITIES:
  Income taxes..............................................      270,493       355,619
  Advances from gas purchaser...............................      205,468       154,546
  Other.....................................................       69,236        54,128
                                                              -----------   -----------
                                                                  545,197       564,293
                                                              -----------   -----------
COMMITMENTS AND CONTINGENCIES (Note 10)
SHAREHOLDERS' EQUITY:
  Preferred stock, no par value, 5,000,000 shares
     authorized, 100,000 shares of 5.68% Cumulative Series B
     issued and outstanding in 1998.........................       98,387            --
  Common stock, $1.25 par, 215,000,000 shares authorized,
     99,790,337 and 94,478,788 shares issued,
     respectively...........................................      124,738       118,098
  Paid-in capital...........................................    1,245,738     1,085,063
  Retained earnings.........................................      403,098       561,981
  Treasury stock, at cost, 2,021,215 and 1,174,247 shares,
     respectively...........................................      (36,924)      (15,506)
  Accumulated other comprehensive income....................      (33,204)      (20,459)
                                                              -----------   -----------
                                                                1,801,833     1,729,177
                                                              -----------   -----------
                                                              $ 3,996,062   $ 4,138,633
                                                              ===========   ===========
</TABLE>
 
The accompanying notes to consolidated financial statements are an integral part
                               of this statement.
                                       F-5
<PAGE>   44
 
                      APACHE CORPORATION AND SUBSIDIARIES
 
                 STATEMENT OF CONSOLIDATED SHAREHOLDERS' EQUITY
<TABLE>
<CAPTION>
                                                                                                   ACCUMULATED                 
                                                                                                      OTHER           TOTAL
                             COMPREHENSIVE  PREFERRED   COMMON    PAID-IN    RETAINED   TREASURY  COMPREHENSIVE   SHAREHOLDERS
                                INCOME        STOCK     STOCK     CAPITAL    EARNINGS    STOCK       INCOME          EQUITY
                             -------------  ---------  --------  ----------  ---------  --------  -------------   ------------
                                                                       (IN THOUSANDS)                                   
<S>                          <C>           <C>        <C>       <C>         <C>        <C>       <C>             <C>
                                                                                                  
BALANCE, DECEMBER 31, 1995..                $    --   $ 98,124  $  687,465  $ 335,470  $(13,478)   $(15,776)      $1,091,805
  Comprehensive income:                                                                                                     
    Net income..............   $ 121,427         --         --          --    121,427        --          --          121,427
    Currency translation
      adjustments...........         286         --         --          --         --        --         286              286 
                               ---------                                                                                    
  Comprehensive income......   $ 121,713                                                                                       
                               =========                                                                                       
  Dividends ($.28 per                                                                                                          
    common share)...........                     --         --          --    (24,309)       --          --          (24,309)
  Common shares issued......                     --     15,906     315,075         --        --          --          330,981
  Treasury shares                                                                                                              
    purchased, net..........                     --         --          --         --    (1,674)         --           (1,674)
                                            -------   --------  ----------  ---------  --------    --------       ----------
BALANCE, DECEMBER 31, 1996..                     --    114,030   1,002,540    432,588   (15,152)    (15,490)       1,518,516   
  Comprehensive income:                                                                                                        
    Net income..............   $ 154,896         --         --          --    154,896        --          --          154,896   
    Currency translation                                                                                                       
      adjustments...........      (4,969)        --         --          --         --        --      (4,969)          (4,969)  
                               ---------                                                                                     
  Comprehensive income......   $ 149,927                                                                                     
                               =========
  Dividends ($.28 per
    common share)...........                     --         --          --    (25,503)       --          --          (25,503)
  Common shares issued......                     --      4,068      82,523         --        --          --           86,591 
  Treasury shares                                                                                                              
    purchased, net..........                     --         --          --         --      (354)         --             (354)
                                            -------   --------  ----------  ---------  --------   ---------       ----------   
BALANCE, DECEMBER 31, 1997..                     --    118,098   1,085,063    561,981   (15,506)    (20,459)       1,729,177    
  Comprehensive income:                                                                                                      
    Net loss................   $(129,387)        --         --          --   (129,387)       --          --         (129,387)   
    Currency translation
      adjustments...........     (12,745)        --         --          --         --        --     (12,745)         (12,745)
                               ---------
  Comprehensive loss........   $(142,132)
                               =========
  Dividends:
    Preferred...............                     --         --          --     (2,004)       --          --           (2,004)  
    Common ($.28 per share).                     --         --          --    (27,492)       --          --          (27,492)  
  Preferred shares issued...                 98,387         --          --         --        --          --           98,387 
  Common shares issued......                     --      6,640     160,675         --        --          --          167,315 
  Treasury shares
    purchased, net..........                     --         --          --         --   (21,418)         --          (21,418)  
                                            -------   --------  ----------  ---------  --------   ---------       ---------- 
BALANCE, DECEMBER 31, 1998..                $98,387   $124,738  $1,245,738  $ 403,098  $(36,924)   $(33,204)      $1,801,833  
                                            =======   ========  ==========  =========  ========   =========       ==========
</TABLE>

 
The accompanying notes to consolidated financial statements are an integral part
                               of this statement.

                                       F-6
<PAGE>   45
 
                      APACHE CORPORATION AND SUBSIDIARIES
 
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
 
1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
     Nature of Operations -- Apache Corporation (Apache or the Company) is an
independent energy company that explores for, develops and produces natural gas,
crude oil and natural gas liquids. The Company's North American exploration and
production activities are divided into three U.S. operating regions (Gulf,
Midcontinent and Western), plus a Canadian region. Approximately 62 percent of
the Company's proved reserves are located in North America. Internationally,
Apache has exploration and production interests in Egypt, offshore Western
Australia and offshore Ivory Coast, and exploration interests in Poland and
offshore The People's Republic of China (China).
 
     The Company's future financial condition and results of operations will
depend upon prices received for its oil and natural gas production and the costs
of finding, acquiring, developing and producing reserves. A substantial portion
of the Company's production is sold under market-sensitive contracts. Prices for
oil and natural gas are subject to fluctuations in response to changes in
supply, market uncertainty and a variety of other factors beyond the Company's
control. These factors include worldwide political instability (especially in
the Middle East), the foreign supply of oil and natural gas, the price of
foreign imports, the level of consumer demand, and the price and availability of
alternative fuels. With natural gas accounting for 56 percent of Apache's 1998
production on an energy equivalent basis, the Company is affected more by
fluctuations in natural gas prices than in oil prices.
 
     Principles of Consolidation -- The accompanying consolidated financial
statements include the accounts of Apache and its subsidiaries after elimination
of intercompany balances and transactions. The Company's interests in oil and
gas exploration and production ventures and partnerships are proportionately
consolidated. Apache's investment in Producers Energy Marketing LLC (ProEnergy)
and a pipeline partnership in Western Australia are accounted for using the
equity method for the periods of ownership. Certain reclassifications have been
made to the 1997 and 1996 financial statements to conform to the classifications
used in the current year.
 
     Cash Equivalents -- The Company considers all highly liquid debt
instruments purchased with an original maturity of three months or less to be
cash equivalents. These investments are carried at cost, which approximates
market.
 
     Inventories -- Inventories consist principally of tubular goods and
production equipment, stated at the lower of weighted average cost or market,
and oil produced but not sold, stated at current market value net of costs to
sell.
 
     Property and Equipment -- The Company uses the full cost method of
accounting for its investment in oil and gas properties. Under this method, the
Company capitalizes all acquisition, exploration and development costs incurred
for the purpose of finding oil and gas reserves, including salaries, benefits
and other internal costs directly attributable to these activities. Exclusive of
field-level costs, Apache capitalized $12.2 million, $11.9 million and $12.1
million of internal costs in 1998, 1997 and 1996, respectively. Costs associated
with production and general corporate activities are expensed in the period
incurred. Internal costs attributable to the management of the Company's
producing properties, before recoveries from industry partners, totaled $23.1
million, $22.5 million and $17.0 million in 1998, 1997, and 1996, respectively,
and are included in operating costs in the Company's statement of consolidated
operations. Interest costs related to unproved properties and properties under
development are also capitalized to oil and gas properties. Unless a significant
portion of the Company's reserve quantities are sold (greater than 25 percent),
proceeds from the sale of oil and gas properties are accounted for as reductions
to capitalized costs, and gains and losses are not recognized.
 
     Apache computes the provision for recurring depreciation, depletion and
amortization (DD&A) of oil and gas properties on a quarterly basis using the
unit-of-production method based upon production and estimates of proved reserve
quantities. Unevaluated costs and related capitalized interest costs are
excluded
                                       F-7
<PAGE>   46
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
from the amortization base until the properties associated with these costs are
evaluated. The amortizable base includes estimated future development costs and
dismantlement, restoration and abandonment costs, net of estimated salvage
values. These future costs are generally estimated by engineers employed by
Apache.
 
     Apache limits, on a country-by-country basis, the capitalized costs of
proved oil and gas properties, net of accumulated DD&A and deferred income
taxes, to the estimated future net cash flows from proved oil and gas reserves
discounted at 10 percent, net of related tax effects, plus the lower of cost or
fair value of unproved properties included in the costs being amortized. If
capitalized costs exceed this limit, the excess is charged to additional DD&A
expense. Included in the estimated future net cash flows are Canadian provincial
tax credits expected to be realized beyond the date at which the legislation,
under its provisions, could be repealed. To date, the Canadian provincial
government has not indicated an intention to repeal this legislation.
 
     As a result of low oil and gas prices at December 31, 1998, Apache's
capitalized costs of U.S. oil and gas properties exceeded the ceiling limitation
and the Company reported a $243.2 million pre-tax ($158.1 million net of tax)
non-cash write-down. The write-down is reflected as additional DD&A expense in
the accompanying statement of consolidated operations.
 
     The costs of certain unevaluated leasehold acreage and wells being drilled
are not being amortized. Costs not being amortized are periodically assessed for
possible impairments or reductions in value. If a reduction in value has
occurred, costs being amortized are increased or a charge is made against
earnings for those international operations where a reserve base is not yet
established.
 
     Buildings, equipment and gas gathering, transmission and processing
facilities are depreciated on a straight-line basis over the estimated useful
lives of the assets, which range from two to 15 years. Accumulated depreciation
for these assets totaled $70.0 million and $51.8 million at December 31, 1998
and 1997, respectively.
 
     Accounts Payable -- Included in accounts payable at December 31, 1998 and
1997, are liabilities of approximately $24.0 million and $36.3 million,
respectively, representing the amount by which checks issued, but not presented
to the Company's banks for collection, exceeded balances in applicable bank
accounts.
 
     Revenue Recognition -- Apache uses the sales method of accounting for
natural gas revenues. Under this method, revenues are recognized based on actual
volumes of gas sold to purchasers. The volumes of gas sold may differ from the
volumes to which Apache is entitled based on its interests in the properties.
Differences between volumes sold and entitled volumes create gas imbalances
which are generally reflected as adjustments to reported proved gas reserves and
future cash flows in the Company's supplemental oil and gas disclosures.
Adjustments for gas imbalances totaled approximately one percent of Apache's
proved gas reserves at December 31, 1998. Revenue is deferred and a liability is
recorded for those properties where the estimated remaining reserves will not be
sufficient to enable the underproduced owner to recoup its entitled share
through production.
 
     Derivative Instruments and Hedging Activities -- Apache periodically enters
into commodity derivatives contracts and fixed-price physical contracts to
manage its exposure to oil and gas price volatility. Commodity derivatives
contracts, which are usually placed with major financial institutions that the
Company believes are minimal credit risks, may take the form of futures
contracts, swaps or options. The oil and gas reference prices upon which these
commodity derivatives contracts are based reflect various market indices that
have a high degree of historical correlation with actual prices received by the
Company. The Company accounts for its commodity derivatives contracts using the
hedge (or deferral) method of accounting. Under this method, realized gains and
losses from the Company's price risk management activities are recognized in oil
and gas production revenues when the associated production occurs and the
resulting cash flows are reported as cash flows from operating activities. Gains
and losses on commodity derivatives contracts that are closed before the hedged
production occurs are deferred until the production month originally hedged. In
the event of a loss of correlation between changes in oil and gas reference
prices under a commodity derivatives contract and actual
                                       F-8
<PAGE>   47
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
oil and gas prices, a gain or loss is recognized currently to the extent the
commodity derivatives contract has not offset changes in actual oil and gas
prices.
 
     In June 1998, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards (SFAS) No. 133, "Accounting for Derivative
Instruments and Hedging Activities." SFAS No. 133 establishes accounting and
reporting standards requiring that every derivative instrument (including
certain derivative instruments embedded in other contracts) be recorded in the
balance sheet as either an asset or liability measured at its fair value, and
requires that changes in a derivative's fair value be recognized currently in
earnings unless specific hedge accounting criteria are met. Special accounting
for qualifying hedges allows a derivative's gains and losses to offset related
results on the hedged item in the statement of consolidated operations, and
requires that a company formally document, designate, and assess the
effectiveness of transactions that receive hedge accounting treatment. SFAS No.
133 is required to be adopted on January 1, 2000, although earlier adoption is
permitted. The Company is analyzing the effects of SFAS No. 133, but has not yet
quantified the impact on its financial statements or determined the timing or
method of adoption. Management does not believe that the adoption of SFAS No.
133 will have a material impact on the Company's financial condition or results
of operations.
 
     Income Taxes -- The Company follows the liability method of accounting for
income taxes under which deferred tax assets and liabilities are recognized for
the future tax consequences of (i) temporary differences between the tax bases
of assets and liabilities and their reported amounts in the financial statements
and (ii) operating loss and tax credit carryforwards for tax purposes. Deferred
tax assets are reduced by a valuation allowance when, based upon management's
estimates, it is more likely than not that a portion of the deferred tax assets
will not be realized in a future period.
 
     Foreign Currency Translation -- The U.S. dollar is considered the
functional currency for each of the Company's international operations, except
for its Canadian subsidiary whose functional currency is the Canadian dollar.
Translation adjustments resulting from translating the Canadian subsidiary's
foreign currency financial statements into U.S. dollar equivalents are reported
separately and accumulated in other comprehensive income. For other
international operations, transaction gains or losses are recognized in net
income.
 
     Net Income (Loss) Per Common Share -- Basic and diluted net income (loss)
per common share have been computed in accordance with SFAS No. 128, "Earnings
per Share." Basic net income (loss) per common share is computed by dividing
income (loss) attributable to common stock by the weighted average number of
common shares outstanding for the period. Diluted net income per common share
reflects the potential dilution that could occur if securities or other
contracts to issue common stock were exercised or converted into common stock.
Diluted net loss per common share does not reflect dilution from potential
common shares, because to do so would have been antidilutive. Calculations of
basic and diluted net income (loss) per common share are illustrated in Note 7.
 
     Stock-Based Compensation -- The Company accounts for employee stock-based
compensation using the intrinsic value method prescribed by Accounting
Principles Board (APB) Opinion No. 25, "Accounting for Stock Issued to
Employees" and related interpretations. Nonemployee stock-based compensation is
accounted for using the fair value method in accordance with SFAS No. 123,
"Accounting for Stock-Based Compensation."
 
     Comprehensive Income -- In the first quarter of 1998, the Company adopted
SFAS No. 130, "Reporting Comprehensive Income," which requires companies to
report the components of comprehensive income in a financial statement with the
same prominence as other financial statements. The Company has chosen to
disclose comprehensive income, which is comprised of net income (loss) and
foreign currency translation adjustments, in the accompanying statement of
consolidated shareholders' equity. This information is shown for all periods
presented.
 
                                       F-9
<PAGE>   48
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     Segment Information -- In June 1997, the Financial Accounting Standards
Board issued SFAS No. 131, "Disclosures about Segments of an Enterprise and
Related Information" which established standards for the way that enterprises
report information about operating segments and related information. The Company
adopted the disclosure requirements of SFAS No. 131 at year-end 1998 and
restated prior-year comparative information.
 
     Use of Estimates -- The preparation of financial statements in conformity
with generally accepted accounting principles requires management to make
estimates and assumptions that affect the reported amounts of assets and
liabilities and disclosure of contingent assets and liabilities at the date of
the financial statements and the reported amounts of revenues and expenses
during the reporting period. Actual results could differ from those estimates.
Significant estimates with regard to these financial statements include the
estimate of proved oil and gas reserve quantities and the related present value
of estimated future net cash flows therefrom (see supplemental oil and gas
disclosures).
 
2. ACQUISITIONS AND DIVESTITURES
 
  Acquisitions
 
     On November 13, 1998, the Company entered into agreements to acquire
certain oil and gas interests and companies holding oil and gas interests in the
Carnarvon Basin, offshore Western Australia, from subsidiaries of Novus
Petroleum Limited (Novus) for approximately $55 million. The interests have
estimated proved reserves of approximately 5.8 MMboe and daily production of
2,400 barrels of oil equivalent. They are within the Apache-operated Harriet
Joint Venture (which includes production, processing and pipeline infrastructure
associated with the Varanus Island hub), the Airlie Joint Venture (in which the
Company held a prior interest and became operator) and three other exploration
permit areas. The transaction closed in two stages, on December 18, 1998
(approximately $49 million) and on January 29, 1999 (approximately $6 million).
Under the terms of an agreement with Novus, the Company may be required to make
additional payments to Novus based on proved and probable recoverable oil and
condensate reserves, as determined by independent engineers, on a defined
geological structure in the Gipsy-Rose-Lee area, offshore Western Australia. If
required, such payments would be calculated using $2.50 for each barrel of
proved and $1.25 for each barrel of probable oil and condensate reserves. A
payment becomes due if and when a decision is made to construct facilities for
the production of oil or condensate from the designated area.
 
     The purchase price for the portion of the transaction completed in 1998 was
allocated to the assets purchased and the liabilities assumed based upon the
fair values on the date of acquisition, as follows:
 
<TABLE>
<CAPTION>
                                                              (IN THOUSANDS)
<S>                                                           <C>
Value of properties acquired, including gathering and
  transportation facilities.................................     $55,223
Working capital acquired, net...............................       2,658
Deferred income tax liability...............................      (9,382)
                                                                 -------
Cash paid, net of cash acquired.............................     $48,499
                                                                 =======
</TABLE>
 
     In 1998, the Company also completed tactical regional acquisitions for cash
consideration totaling $19.4 million. These acquisitions added approximately 9.1
MMboe to the Company's proved reserves.
 
     In November 1997, the Company acquired all the capital stock of three
companies owning interests in certain oil and gas properties (including 31.9
MMboe of proved oil and natural gas reserves) and production facilities offshore
Western Australia for approximately $300 million from subsidiaries of Mobil
Exploration & Producing Australia Pty Ltd (Ampolex Group Transaction). The
Ampolex Group Transaction, net of the subsequent sale of certain properties to
Hardy Petroleum Limited (Hardy), increased the Company's interest to 47.5
percent from 22.5 percent in the Carnarvon Basin's Harriet area, which includes
the Varanus Island
 
                                      F-10
<PAGE>   49
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
pipeline, processing and production complex and eight existing oil and gas
fields. The transaction also increased the Company's interest in the East Spar
field, which produces through the Varanus Island facilities, to 45 percent from
20 percent. Apache operates the Harriet and East Spar properties.
 
     The purchase price was allocated to the assets purchased and the
liabilities assumed based upon the fair values on the date of acquisition, as
follows:
 
<TABLE>
<CAPTION>
                                                              (IN THOUSANDS)
<S>                                                           <C>
Value of properties acquired, including gathering and
  transportation facilities.................................     $264,539
Assets held for resale......................................       63,058
Working capital acquired, net...............................        6,692
Deferred income tax liability...............................      (34,437)
                                                                 --------
Cash paid, net of cash acquired.............................     $299,852
                                                                 ========
</TABLE>
 
     In conjunction with the closing of the Ampolex Group Transaction, the
Company entered into an agreement with Hardy on December 9, 1997, under which
Hardy agreed to purchase a 10 percent interest in the Company's East Spar field
and related production facilities. The transaction closed on January 28, 1998,
with a total sales price of approximately $63 million in cash. The assets sold
to Hardy were reported as assets held for resale in the accompanying
consolidated balance sheet at December 31, 1997.
 
     In 1997, the Company also completed tactical regional acquisitions for cash
consideration totaling $33.6 million. These acquisitions added approximately 6.6
MMboe to the Company's proved reserves.
 
     In May 1996, Apache acquired, for approximately $396.3 million, The Phoenix
Resource Companies, Inc. (Phoenix, now known as Apache PHN Company, Inc.), an
oil and gas company operating primarily in the Arab Republic of Egypt, through a
merger (Phoenix Merger) which resulted in Phoenix becoming a wholly owned
subsidiary of Apache. Pursuant to the Merger Agreement, shares of Phoenix common
stock then outstanding and outstanding Phoenix stock options (which were assumed
by Apache) were converted into the right to receive (a) .75 shares of Apache
common stock with any fractional shares paid in cash, without interest, and (b)
$4.00 in cash. As a result, 12.2 million shares of Apache common stock, valued
at $26 per share, were issued and approximately $65 million was paid to former
Phoenix shareholders.
 
     In 1996, the Company also completed tactical regional acquisitions for cash
consideration totaling $115.0 million. These acquisitions added approximately
18.9 MMboe to the Company's proved reserves.
 
     Each transaction described above has been accounted for using the purchase
method of accounting and has been included in the financial statements of Apache
since the date of acquisition.
 
     The following unaudited pro forma financial information shows the effect on
the Company's consolidated results of operations as if the Phoenix Merger
occurred on January 1, 1996. The pro forma data is based on numerous assumptions
and is not necessarily indicative of future results of operations.
 
<TABLE>
<CAPTION>
                                                                 FOR THE YEAR ENDED
                                                                  DECEMBER 31, 1996
                                                              -------------------------
                                                              AS REPORTED    PRO FORMA
                                                              ------------   ----------
                                                              (IN THOUSANDS, EXCEPT PER
(UNAUDITED)                                                      COMMON SHARE DATA)
<S>                                                           <C>            <C>
Revenues....................................................    $977,151      $992,077
Net income..................................................     121,427       125,040
Net income per common share:
  Basic.....................................................    $   1.42      $   1.39
  Diluted...................................................        1.38          1.36
</TABLE>
 
                                      F-11
<PAGE>   50
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     On February 1, 1999, the Company acquired oil and gas properties located in
the Gulf of Mexico from Petsec Energy Inc. (Petsec) for an adjusted purchase
price of approximately $66.7 million. The Petsec transaction included estimated
proved reserves of approximately 10.4 MMboe on the effective date.
 
  Divestitures
 
     In 1998, Apache sold marginal properties, primarily in North America,
containing 29.6 MMboe of proved reserves, for $131.1 million. Apache used the
sales proceeds to reduce bank debt.
 
     Apache received $30.1 million in each of 1997 and 1996 from the sale of
non-strategic oil and gas properties in a number of separate transactions.
 
3. INVESTMENTS IN EQUITY SECURITIES
 
     At December 31, 1998 and 1997, Apache had no investments in equity
securities.
 
     The Company realized losses from the sale of equity securities totaling
approximately $364,000 during 1998, and gains totaling approximately $13,000 and
$770,000 during 1997 and 1996, respectively. Apache utilizes the average cost
method in computing realized gains or losses, which are included in other
revenues in the accompanying statement of consolidated operations.
 
4. DEBT
  Long-Term Debt
 
<TABLE>
<CAPTION>
                                                                   DECEMBER 31,
                                                              -----------------------
                                                                 1998         1997
                                                              ----------   ----------
                                                                  (IN THOUSANDS)
<S>                                                           <C>          <C>
Apache:
  Global credit facility -- U.S.............................  $       --   $       --
  Money market lines of credit..............................      15,500       17,200
  Commercial paper, expected to be refinanced...............      59,000       50,800
  6-percent convertible subordinated debentures due 2002....          --      172,500
  9.25-percent notes due 2002, net of discount..............      99,842       99,805
  7-percent notes due 2018, net of discount.................     148,246           --
  7.7-percent notes due 2026, net of discount...............      99,642       99,638
  7.95-percent notes due 2026, net of discount..............     178,544      178,531
  7.375-percent debentures due 2047, net of discount........     147,988      147,984
  7.625-percent debentures due 2096, net of discount........     149,175      149,175
                                                              ----------   ----------
                                                                 897,937      915,633
                                                              ----------   ----------
Subsidiary and other obligations:
  Global credit facility -- Australia.......................     148,000      139,000
  Global credit facility -- Canada..........................       5,000      116,000
  Revolving credit facility -- Egypt........................     109,780      150,000
  DEKALB 9.875-percent notes due 2000.......................      29,225       29,225
  Apache Finance 6.5-percent notes due 2007, net of
     discount...............................................     168,816      168,722
                                                              ----------   ----------
                                                                 460,821      602,947
                                                              ----------   ----------
Total debt..................................................   1,358,758    1,518,580
Less: current maturities....................................     (15,500)     (17,200)
                                                              ----------   ----------
Long-term debt..............................................  $1,343,258   $1,501,380
                                                              ==========   ==========
</TABLE>
 
                                      F-12
<PAGE>   51
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     In June 1997, Apache replaced its $1 billion global borrowing-base credit
facility with a new $1 billion global corporate credit facility (global credit
facility). The global credit facility consists of three separate bank
facilities: a $700 million facility in the United States; a $175 million
facility in Australia; and a $125 million facility in Canada. The global credit
facility enables Apache to draw on the entire $1 billion facility without
restrictions tied to periodic revaluation of the Company's oil and gas reserves.
As of December 31, 1998, Apache's available borrowing capacity under the global
credit facility was $788 million. Under the financial covenants of the global
credit facility, the Company must (i) maintain a consolidated tangible net
worth, as defined, of at least $1.1 billion as of December 31, 1998, which is
adjusted for subsequent earnings, and (ii) maintain a ratio of debt to
capitalization of not greater than 60 percent at the end of any fiscal quarter.
The Company was in compliance with all financial covenants at December 31, 1998.
 
     The global credit facility is scheduled to mature on June 12, 2002, in the
amount of $40 million and the remaining $960 million on June 12, 2003. The
agreement provides for perpetual one-year extensions as requested by the
Company, subject to the approval of the lenders. At the Company's option, the
interest rate is based on (i) the greater of (a) The Chase Manhattan Bank's
prime rate or (b) the federal funds rate plus one-half of one percent, (ii) the
London Interbank Offered Rate (LIBOR) plus a margin determined by the Company's
senior long-term debt rating, or (iii) a margin that is determined by
competitive bids from the participating banks. At December 31, 1998, the margin
over LIBOR for committed loans was .185 percent. The Company also pays a
quarterly facility fee of .09 percent on the total amount of each of the three
facilities, which fee varies based upon the Company's senior long-term debt
rating.
 
     At December 31, 1998, the Company also had certain uncommitted money market
lines of credit which are used from time to time for working capital purposes.
As of December 31, 1998, an aggregate of $15.5 million was outstanding under
such credit lines.
 
     In January 1997, the Company established a $300 million commercial paper
program which enables Apache to borrow funds for up to 270 days at competitive
interest rates. In June 1997, Apache expanded its commercial paper program to
$700 million from $300 million to provide access to additional low-cost, short-
term funds. Since its inception in January 1997, the Company's commercial paper
program has been rated A-2, Prime-2 and D-1- (D-One-Minus) by Standard & Poor's,
Moody's and Duff and Phelps, respectively. As of December 31, 1998, $59.0
million was outstanding under Apache's commercial paper program. The commercial
paper is classified as long-term debt in the accompanying consolidated balance
sheet as the Company has the ability and intent to refinance such amounts on a
long-term basis through either the rollover of commercial paper or available
borrowing capacity under the global credit facility.
 
     In January 1998, approximately 90 percent, or $155.6 million, of the
Company's 6-percent convertible subordinated debentures was converted into
approximately 5.1 million shares of Apache common stock at a conversion price of
$30.68 per share. The remaining $16.9 million of principal amount was redeemed
for $17.4 million in cash, plus accrued and unpaid interest. The Company
recorded a $.8 million loss on the early extinguishment of debt in January 1998.
 
     The 9.25-percent notes totaling $100 million were issued by Apache in May
1992 and are redeemable at maturity in June 2002.
 
     In February 1998, Apache issued $150 million principal amount, $148.2
million net of discount, of senior unsecured 7-percent notes maturing on
February 1, 2018. The notes are not redeemable prior to maturity.
 
     In February 1996, Apache issued $100 million principal amount, $99.6
million net of discount, of senior unsecured 7.7-percent notes due March 15,
2026. In April 1996, the Company issued $180 million principal amount, $178.5
million net of discount, of senior unsecured 7.95-percent notes maturing on
April 15, 2026. The notes are not redeemable prior to maturity; however, under
certain conditions, Apache has the right to advance maturity of these notes.
 
                                      F-13
<PAGE>   52
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     In August 1997, Apache issued $150 million principal amount, $148 million
net of discount, of senior unsecured 7.375-percent debentures maturing on August
15, 2047. The debentures are not redeemable prior to maturity; however, Apache
has the right to advance maturity, under certain conditions.
 
     In November 1996, Apache issued $150 million principal amount, $149.2
million net of discount, of senior unsecured 7.625-percent debentures maturing
on November 1, 2096. The debentures are not redeemable prior to maturity;
however, under certain conditions, Apache has the right to advance maturity of
these debentures.
 
     Upon certain changes in control, the debt instruments described in the
preceding five paragraphs are subject to mandatory repurchase.
 
     In October 1997, three of the Company's Egyptian subsidiaries entered into
a secured, revolving credit facility with a group of banks. The facility
provides for total commitments of $250 million, with availability determined by
a borrowing base formula predicated upon those subsidiaries' oil and gas reserve
quantities, forecast rates of production, and future oil and gas prices. The
borrowing base is $121.8 million at December 31, 1998 and will be redetermined
semi-annually. The total amount of commitments under the facility is currently
scheduled to be reduced by set increments every six months, beginning two and
one-half years after the effective date of the facility. The facility is
presently secured solely by assets associated with the Company's Qarun and
Khalda concessions and shares of stock of the Company's subsidiaries holding
those concessions, with provisions that will permit the inclusion of other of
the Company's Egyptian subsidiaries as borrowers with security interests on such
subsidiaries' assets and shares of stock. Interest is assessed at LIBOR plus a
margin of .375 percent, which is scheduled to increase to .625 percent on the
third anniversary of the facility; however, if the facility is extended the rate
increase would occur two years from the end of the facility's extended term. A
quarterly fee of .375 percent is payable on the available portion of the
commitments, while a quarterly fee of .1875 percent is payable on the difference
between the borrowing base and the total amount of commitments under the
facility. The facility is scheduled to mature on January 3, 2003.
 
     The DEKALB 9.875-percent notes mature on July 15, 2000 and are not
redeemable prior to their maturity.
 
     In December 1997, Apache Finance Pty Ltd (Apache Finance), the Company's
Australian finance subsidiary, issued $170 million principal amount, $168.7
million net of discount, of senior unsecured 6.5-percent notes due December 15,
2007. In March 1999, Apache Finance issued $100 million principal amount, $99.3
million net of discount, of senior unsecured 7.0-percent notes due March 15,
2009. These notes are irrevocably and unconditionally guaranteed by Apache. The
Company has the right to redeem these notes prior to maturity, under certain
conditions related to changes in relevant tax laws. Also, upon certain changes
in control, these notes are subject to mandatory repurchase.
 
     As of December 31, 1998 and 1997, the Company had approximately $13.4
million and $18.2 million, respectively, of unamortized costs associated with
its various debt obligations. These costs are reflected as deferred charges in
the accompanying consolidated balance sheet and are being amortized over the
life of the related debt.
 
     The indentures for the notes and debentures described above place certain
restrictions on the Company, including limits on Apache's ability to incur debt
secured by certain liens and its ability to enter into certain sale and
leaseback transactions.
 
                                      F-14
<PAGE>   53
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
  Aggregate Maturities of Debt
 
<TABLE>
<CAPTION>
                                                              (IN THOUSANDS)
<S>                                                           <C>
1999........................................................    $   15,500
2000........................................................        29,225
2001........................................................            --
2002........................................................       209,622
2003........................................................       212,000
Thereafter..................................................       892,411
                                                                ----------
                                                                $1,358,758
                                                                ==========
</TABLE>
 
5. INCOME TAXES
 
     Income (loss) before income taxes is composed of the following:
 
<TABLE>
<CAPTION>
                                                      FOR THE YEAR ENDED DECEMBER 31,
                                                      -------------------------------
                                                        1998        1997       1996
                                                      ---------   --------   --------
                                                              (IN THOUSANDS)
<S>                                                   <C>         <C>        <C>
United States.......................................  $(241,861)  $171,304   $154,759
International.......................................     54,298     87,336     45,436
                                                      ---------   --------   --------
          Total.....................................  $(187,563)  $258,640   $200,195
                                                      =========   ========   ========
</TABLE>
 
     The total provision (benefit) for income taxes consists of the following:
 
<TABLE>
<CAPTION>
                                                        FOR THE YEAR ENDED DECEMBER 31,
                                                        --------------------------------
                                                          1998        1997        1996
                                                        ---------   ---------   --------
                                                                 (IN THOUSANDS)
<S>                                                     <C>         <C>         <C>
Current taxes:
  Federal.............................................  $     --    $    300    $    --
  Foreign.............................................    23,680      35,164     17,432
Deferred taxes........................................   (81,856)     68,280     61,336
                                                        --------    --------    -------
          Total.......................................  $(58,176)   $103,744    $78,768
                                                        ========    ========    =======
</TABLE>
 
     A reconciliation of the federal statutory income tax amounts to the
effective amounts is shown below:
 
<TABLE>
<CAPTION>
                                                        FOR THE YEAR ENDED DECEMBER 31,
                                                        --------------------------------
                                                          1998        1997        1996
                                                        ---------   ---------   --------
                                                                 (IN THOUSANDS)
<S>                                                     <C>         <C>         <C>
Statutory income tax..................................  $(65,647)   $ 90,524    $70,068
State income tax, less federal benefit................        38       3,987      4,558
Taxation of foreign operations........................     8,710      10,842      5,226
All other, net........................................    (1,277)     (1,609)    (1,084)
                                                        --------    --------    -------
                                                        $(58,176)   $103,744    $78,768
                                                        ========    ========    =======
</TABLE>
 
                                      F-15
<PAGE>   54
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     The net deferred tax liability is comprised of the following:
 
<TABLE>
<CAPTION>
                                                                  DECEMBER 31,
                                                              ---------------------
                                                                1998        1997
                                                              ---------   ---------
                                                                 (IN THOUSANDS)
<S>                                                           <C>         <C>
Deferred tax assets:
  Deferred income...........................................  $  (9,087)  $  (2,259)
  Federal net operating loss carryforwards..................    (88,411)    (79,009)
  State net operating loss carryforwards....................    (12,670)    (12,562)
  Statutory depletion carryforwards.........................     (3,720)     (3,316)
  Alternative minimum tax credits...........................     (9,141)     (9,141)
  Accrued expenses and liabilities..........................     (5,590)     (5,452)
  Other.....................................................     (5,374)    (12,090)
                                                              ---------   ---------
          Total deferred tax assets.........................   (133,993)   (123,829)
Valuation allowance.........................................      1,704       1,704
                                                              ---------   ---------
          Net deferred tax assets...........................   (132,289)   (122,125)
                                                              ---------   ---------
Deferred tax liabilities:
  Depreciation, depletion and amortization..................    391,624     471,403
  Other.....................................................     11,158       6,341
                                                              ---------   ---------
          Total deferred tax liabilities....................    402,782     477,744
                                                              ---------   ---------
Deferred income tax liability...............................  $ 270,493   $ 355,619
                                                              =========   =========
</TABLE>
 
     U.S. deferred taxes have not been provided on foreign earnings totaling
$211.7 million, which are permanently reinvested abroad. Presently, limited
foreign tax credits are available to reduce the U.S. taxes on such amounts if
repatriated.
 
     At December 31, 1998, the Company had U.S. federal net operating loss
carryforwards of $237.0 million that will expire beginning in 1999, and U.S. and
foreign statutory depletion carryforwards totaling $9.9 million that can be
carried forward indefinitely. The Company has alternative minimum tax (AMT)
credit carryforwards of $9.1 million that can be carried forward indefinitely,
but which can be used only to reduce regular tax liabilities in excess of AMT
liabilities. The Company has investment and other tax credit carryforwards of
$1.7 million that will expire beginning in 1999, which have been fully reserved
through the valuation allowance.
 
6. ADVANCES FROM GAS PURCHASERS
 
     In July 1998, Apache received $71.8 million from a purchaser as an advance
payment for future natural gas deliveries ranging from 6,726 MMBtu per day to
24,669 MMBtu per day, for a total of 45,330,949 MMBtu, over a ten-year period
commencing August 1998. As a condition of the arrangement with the purchaser,
Apache entered into three gas price swap contracts with a third party under
which Apache became a fixed price payor for identical volumes at prices ranging
from $2.34 per MMBtu to $2.56 per MMBtu. In addition, the purchaser pays Apache
a monthly fee of $.08 per MMBtu on the contracted volumes. The net result of
these related transactions is that gas delivered to the purchaser is reported as
revenue at prevailing spot prices with Apache realizing a premium associated
with the monthly fee paid by the purchaser.
 
     In August 1997, Apache received $115.2 million from a purchaser as an
advance payment for future natural gas deliveries of 20,000 MMBtu per day over a
ten-year period commencing September 1997. As a condition of the arrangement
with the purchaser, Apache entered into two gas price swap contracts with a
third party under which Apache became a fixed price payor for identical volumes
at average prices starting at
 
                                      F-16
<PAGE>   55
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
$2.19 per MMBtu in 1997 and escalating to $2.59 per MMBtu in 2007. In addition,
the purchaser pays Apache a monthly fee of $.07 per MMBtu on the contracted
volumes. The net result of these related transactions is that gas delivered to
the purchaser is reported as revenue at prevailing spot prices with Apache
realizing a premium associated with the monthly fee paid by the purchaser.
 
     In December 1994, Apache received $67.4 million from a purchaser as an
advance payment for future natural gas deliveries of 20,000 MMBtu per day over a
six-year period commencing January 1995. As a condition of the arrangement with
the purchaser, Apache entered into a gas price swap contract with a third party
under which Apache became a fixed price payor for identical volumes at prices
starting at $1.81 per MMBtu in 1995 and escalating at $.10 per MMBtu per year
through the year 2000. The net result of these related transactions is that gas
delivered to the purchaser is reported as revenue at prevailing spot prices with
Apache realizing a $.05 per MMBtu premium associated with a monthly fee paid by
the purchaser.
 
     The Company, through its marketing subsidiaries, may purchase gas from
third parties to satisfy gas delivery requirements under these arrangements.
Contracted volumes relating to these arrangements are included in the Company's
supplemental oil and gas disclosures.
 
     These advance payments have been classified as advances on the balance
sheet and are being reduced as gas is delivered to the purchasers under the
terms of the contracts. At December 31, 1998 and 1997, advances of $205.5
million and $154.5 million, respectively, were outstanding. Gas volumes
delivered to the purchaser are reported as revenue at prices used to calculate
the amount advanced, before imputed interest, plus or minus amounts paid or
received by Apache applicable to the price swap agreements. Interest expense is
recorded based on a rate of 8 percent on the 1998 and 1997 advances, and 9.5
percent on the 1994 advances.
 
7. CAPITAL STOCK
 
  Common Stock Outstanding
 
<TABLE>
<CAPTION>
                                                              1998         1997         1996
                                                           ----------   ----------   ----------
<S>                                                        <C>          <C>          <C>
Balance, beginning of year...............................  93,304,541   90,058,797   77,378,958
Treasury shares acquired, net............................    (846,968)      (9,016)     (45,297)
Shares issued for:
  Conversion of 6-percent convertible debentures.........   5,070,914           --           --
  Acquisition of oil and gas property interests..........     176,836           --           --
  Conversion of 3.93-percent convertible notes...........          --    2,777,777           --
  Phoenix merger.........................................          --           --   12,189,918
  Dividend reinvestment plan.............................          --       34,249       25,148
  401(k) savings plan....................................      10,477      182,742      183,059
  Stock option plans.....................................      53,322      259,992      317,775
  Other..................................................          --           --        9,236
                                                           ----------   ----------   ----------
Balance, end of year.....................................  97,769,122   93,304,541   90,058,797
                                                           ==========   ==========   ==========
</TABLE>
 
                                      F-17
<PAGE>   56
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     Net Income (Loss) Per Common Share -- A reconciliation of the components of
basic and diluted net income (loss) per common share for the years ended
December 31, 1998, 1997 and 1996 is presented in the table below:
 
<TABLE>
<CAPTION>
                                                       1998                         1997                        1996
                                            ---------------------------   -------------------------   -------------------------
                                                                  PER                          PER                         PER
                                             INCOME     SHARES   SHARE     INCOME    SHARES   SHARE    INCOME    SHARES   SHARE
                                            ---------   ------   ------   --------   ------   -----   --------   ------   -----
                                                                 (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
<S>                                         <C>         <C>      <C>      <C>        <C>      <C>     <C>        <C>      <C>
Basic:
  Income (loss) attributable to common
    stock.................................  $(131,391)  98,066   $(1.34)  $154,896   90,677   $1.71   $121,427   85,777   $1.42
                                                                 ======                       =====                       =====
Effect of Dilutive Securities:
  Stock options...........................         --       --                  --      519                 --      374
  3.93%-convertible notes.................         --       --               1,859    2,435              2,114    2,778
  6%-convertible debentures...............         --       --               6,919    5,623              6,916    5,623
                                            ---------   ------            --------   ------           --------   ------
Diluted:
  Income (loss) attributable to common
    stock, including assumed
    conversions...........................  $(131,391)  98,066   $(1.34)  $163,674   99,254   $1.65   $130,457   94,552   $1.38
                                            =========   ======   ======   ========   ======   =====   ========   ======   =====
</TABLE>
 
     The effect of stock options and the 6-percent convertible subordinated
debentures were not included in the computation of diluted net income (loss) per
common share during 1998, because to do so would have been antidilutive.
 
     Stock Option Plans -- At December 31, 1998, officers and certain key
employees had been granted options to purchase the Company's common stock under
employee stock option plans adopted in 1990, 1995 and 1998 and under certain
predecessor plans (collectively, the Stock Option Plans). Under the Stock Option
Plans, the exercise price of each option equals the market price of Apache's
common stock on the date of grant. Options generally become exercisable ratably
over a four-year period and expire after 10 years. The Company may issue up to
6,489,031 shares of common stock under the Stock Option Plans, of which options
to acquire 2,006,350 shares of common stock remained available for grant at
December 31, 1998.
 
     On October 31, 1996, the Company established the 1996 Performance Stock
Option Plan (the Performance Plan) for substantially all full-time employees,
excluding officers and certain key employees. Under the Performance Plan, the
exercise price of each option equals the market price of Apache common stock on
the date of grant. All options become exercisable after nine and one-half years
and expire ten years from the date of grant; however, exercisability will be
accelerated if share price goals of $50 and $60 per share are attained before
January 1, 2000. Under the terms of the Performance Plan, no grants may be made
after December 31, 1998.
 
                                      F-18
<PAGE>   57
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     A summary of the status of the plans described above as of December 31,
1998, 1997, and 1996, and changes during the years then ended, is presented in
the table and narrative below (shares in thousands):
 
<TABLE>
<CAPTION>
                                            1998                1997                1996
                                      -----------------   -----------------   -----------------
                                               WEIGHTED            WEIGHTED            WEIGHTED
                                      SHARES   AVERAGE    SHARES   AVERAGE    SHARES   AVERAGE
                                      UNDER    EXERCISE   UNDER    EXERCISE   UNDER    EXERCISE
                                      OPTION    PRICE     OPTION    PRICE     OPTION    PRICE
                                      ------   --------   ------   --------   ------   --------
<S>                                   <C>      <C>        <C>      <C>        <C>      <C>
Outstanding, beginning of year......   3,629    $32.20     2,885    $30.82     1,218    $23.91
Granted.............................   1,243     32.53     1,228     34.59     2,032     33.26
Exercised...........................     (20)    26.68      (145)    23.02      (224)    17.58
Forfeited...........................    (431)    33.98      (339)    33.08      (141)    27.30
                                      ------              ------              ------
Outstanding, end of year(1).........   4,421     32.15     3,629     32.20     2,885     30.82
                                      ======              ======              ======
Exercisable, end of year............   1,223     28.86       729     26.96       467     23.88
                                      ======              ======              ======
Available for grant, end of year....   2,006                 603               1,503
                                      ======              ======              ======
Weighted average fair value of
  options granted during the
  year(2)...........................  $10.87              $11.73              $ 9.80
                                      ======              ======              ======
</TABLE>
 
     The following table summarizes information about stock options covered by
the plans described above that are outstanding at December 31, 1998 (shares in
thousands):
 
<TABLE>
<CAPTION>
                                                      OPTIONS OUTSTANDING             OPTIONS EXERCISABLE
                                              ------------------------------------   ----------------------
                                               NUMBER OF     WEIGHTED                 NUMBER OF
                                                SHARES        AVERAGE     WEIGHTED     SHARES      WEIGHTED
                                                 UNDER       REMAINING    AVERAGE       UNDER      AVERAGE
                                              OUTSTANDING   CONTRACTUAL   EXERCISE   EXERCISABLE   EXERCISE
          RANGE OF EXERCISE PRICES              OPTIONS        LIFE        PRICE       OPTIONS      PRICE
          ------------------------            -----------   -----------   --------   -----------   --------
<S>                                           <C>           <C>           <C>        <C>           <C>
$ 2.393 - $19.625...........................        67         2.50        $16.80          67       $16.80
 21.000 -  29.875...........................     1,272         7.26         27.22         677        27.03
 30.250 -  36.000...........................     2,952         8.37         34.24         457        32.74
 36.375 -  42.438...........................       130         8.71         40.66          22        41.00
                                                 -----                                  -----
                                                 4,421                                  1,223
                                                 =====                                  =====
</TABLE>
 
- ---------------
 
(1) Excludes 449,600, 496,900 and 644,100 shares as of December 31, 1998, 1997
    and 1996, respectively, issuable under stock options assumed by Apache in
    connection with the Phoenix Merger.
 
(2) The fair value of each option is estimated as of the date of grant using the
    Black-Scholes option-pricing model with the following weighted-average
    assumptions used for grants in 1998, 1997 and 1996, respectively: (i)
    risk-free interest rates of 5.46, 6.33 and 6.19 percent; (ii) expected lives
    of five years for the Stock Option Plans, and 2.5 years for the Performance
    Plan; (iii) expected volatility of 31.17, 31.21 and 30.50 percent, and (iv)
    expected dividend yields of .88, .82 and .85 percent.
                                      F-19
<PAGE>   58
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     In May 1997, Apache's shareholders approved the 1996 Share Price
Appreciation Plan (the Appreciation Plan) for officers and certain key
employees. The Appreciation Plan provides for conditional grants denominated in
shares of Apache common stock that vest upon attainment of share price goals of
$50 and $60 per share before January 1, 2000. Between 30 and 50 percent of the
conditional grants will be paid in cash at the market value of the stock on the
date of payment, and the balance (up to a total of 2,000,000 shares in the
aggregate) will be issued in Apache common stock. Generally, any vested amounts
will be distributed in three installments over the 36-month period following
attainment of the share price goals. When and if the share price goals are
achieved, the Company will recognize compensation expense over the 36-month
period equal to the value of the stock as of the date the share price goal is
achieved (i.e., $50 or $60 per share, as appropriate) and the actual amount of
cash paid. The shares of Apache common stock contingently issuable under the
Appreciation Plan will be excluded from the computation of net income (loss) per
common share until the stated share price goals of $50 and $60 per share are
achieved. Under the terms of the Appreciation Plan, no conditional grants may be
made after December 31, 1998.
 
     A summary of the status of the Appreciation Plan as of December 31, 1998
and 1997, and changes during the years then ended, is presented in the table and
narrative below (shares in thousands):
 
<TABLE>
<CAPTION>
                                                               SHARES SUBJECT TO
                                                              CONDITIONAL GRANTS
                                                              -------------------
                                                                1998       1997
                                                              --------   --------
<S>                                                           <C>        <C>
Outstanding, beginning of year..............................    1,719         --
Granted.....................................................      190      1,965
Forfeited...................................................     (200)      (246)
                                                               ------     ------
Outstanding, end of year....................................    1,709      1,719
                                                               ======     ======
Exercisable, end of year....................................       --         --
                                                               ======     ======
Available for grant, end of year............................       --        281
                                                               ======     ======
Weighted average fair value of conditional grants(1)........   $ 6.72     $13.50
                                                               ======     ======
</TABLE>
 
- ---------------
 
(1) The fair value of each conditional grant is estimated as of the date of
    grant using a Monte Carlo simulation with the following weighted-average
    assumptions used for grants in 1998 and 1997, respectively: (i) risk-free
    interest rates of 5.37 and 6.45 percent; (ii) expected volatility of 33.11
    and 28.63 percent; and (iii) expected dividend yields of .82 and .84
    percent.
                                      F-20
<PAGE>   59
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     The Company accounts for its stock-based compensation plans under APB
Opinion No. 25 and related interpretations, under which no compensation cost has
been recognized for the Stock Option Plans, the Performance Plan, or the
Appreciation Plan. If compensation costs for these plans had been determined in
accordance with SFAS No. 123, the Company's net income and net income per common
share would approximate the following pro forma amounts:
 
<TABLE>
<CAPTION>
                                                          1998          1997          1996
                                                      ------------   -----------   -----------
                                                      (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
<S>                                                   <C>            <C>           <C>
Income (Loss) Attributable to Common Stock:
  As reported.......................................   $(131,391)     $154,896      $121,427
  Pro forma.........................................    (141,306)      147,152       119,536
Net Income (Loss) per Common Share:
  Basic:
     As reported....................................   $   (1.34)     $   1.71      $   1.42
     Pro forma......................................       (1.44)         1.62          1.39
  Diluted:
     As reported....................................   $   (1.34)     $   1.65      $   1.38
     Pro forma......................................       (1.44)         1.55          1.36
</TABLE>
 
     The pro forma amounts shown above may not be representative of future
results, as the SFAS No. 123 method of accounting has not been applied to
options granted prior to January 1, 1995.
 
  Preferred Stock
 
     The Company has five million shares of no par preferred stock authorized,
of which 25,000 shares have been "designated" as Series A Junior Participating
Preferred Stock (the Series A Preferred Stock) and 100,000 shares have been
designated as the 5.68 percent Series B Cumulative Preferred Stock (the Series B
Preferred Stock). The shares of Series A Preferred Stock are authorized for
issuance pursuant to certain rights that trade with Apache common stock
outstanding and are reserved for issuance upon the exercise of the Rights as
defined and discussed below.
 
     Series B Preferred Stock -- In August 1998, Apache issued 100,000 shares of
Series B Preferred Stock in the form of one million depositary shares, each
representing one-tenth (1/10) of a share of Series B Preferred Stock. The Series
B Preferred Stock has no stated maturity, is not subject to a sinking fund and
is not convertible into Apache common stock or any other securities of the
Company. Apache has the option to redeem the Series B Preferred Stock at $1,000
per share on or after August 25, 2008. Holders of the shares are entitled to
receive cumulative cash dividends at an annual rate of $5.68 per depositary
share when, and if, declared by Apache's board of directors. The net proceeds of
approximately $98.4 million were used to repay debt outstanding under money
market lines of credit and to reduce outstanding borrowings under the Canadian
portion of the Company's global credit facility.
 
     Rights to Purchase Series A Preferred Stock -- In December 1995, the
Company declared a dividend of one right (a Right) for each share of Apache
common stock outstanding on January 31, 1996. Each Right entitles the registered
holder to purchase from the Company one ten-thousandth (1/10,000) of a share of
Series A Preferred Stock at a price of $100 per one ten-thousandth of a share,
subject to adjustment. The Rights are exercisable 10 calendar days following a
public announcement that certain persons or groups have acquired 20 percent or
more of the outstanding shares of Apache common stock or 10 business days
following commencement of an offer for 30 percent or more of the outstanding
shares of Apache common stock. In addition, if the Company engages in certain
business combinations or a 20 percent shareholder engages in certain
transactions with the Company, the Rights become exercisable for Apache common
stock or common stock of the corporation acquiring the Company (as the case may
be) at 50 percent of the then-market price.
 
                                      F-21
<PAGE>   60
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
Any Rights that are or were beneficially owned by a person who has acquired 20
percent or more of the outstanding shares of Apache common stock and who engages
in certain transactions or realizes the benefits of certain transactions with
the Company will become void. The Company may redeem the Rights at $.01 per
Right at any time until 10 business days after public announcement that a person
has acquired 20 percent or more of the outstanding shares of Apache common
stock. The Rights will expire on January 31, 2006, unless earlier redeemed by
the Company. Unless the Rights have been previously redeemed, all shares of
Apache common stock issued by the Company after January 31, 1996 will include
Rights. Unless and until the Rights become exercisable, they will be transferred
with and only with the shares of Apache common stock.
 
8. NON-CASH INVESTING AND FINANCING ACTIVITIES
 
     A summary of non-cash investing and financing activities is presented
below:
 
     In December 1998, the Company acquired certain oil and gas interests from
subsidiaries of Novus for cash and the assumption of certain liabilities. The
accompanying financial statements include the amounts detailed in Note 2.
 
     In June 1998, Apache formed a strategic alliance with Cinergy Corp.
(Cinergy) and sold its 57 percent interest in ProEnergy for 771,258 shares of
Cinergy common stock valued at $26.5 million.
 
     In March 1998, Apache acquired certain oil and gas property interests for
approximately 177,000 shares of Apache common stock valued at $6.1 million.
 
     In January 1998, approximately 90 percent, or $155.6 million principal
amount, of the Company's 6-percent convertible subordinated debentures was
converted into approximately 5.1 million shares of Apache common stock at a
conversion price of $30.68 per share.
 
     In November 1997, Apache acquired certain assets through the Ampolex Group
Transaction for cash and the assumption of certain liabilities. The accompanying
financial statements include the amounts detailed in Note 2.
 
     In November 1997, the Company's $75 million principal amount of
3.93-percent convertible notes were converted into approximately 2.8 million
shares of Apache common stock at a conversion price of $27 per share.
 
     In May 1996, Apache acquired Phoenix for cash and shares of Apache common
stock, and assumed certain outstanding Phoenix stock options. The accompanying
financial statements include the following attributable to the Phoenix Merger:
 
<TABLE>
<CAPTION>
                                                              (IN THOUSANDS)
<S>                                                           <C>
Value of properties acquired, including gathering
  facilities................................................    $ 386,237
Other non-cash assets acquired..............................        7,901
Common stock issued and options to purchase common stock
  assumed (12.2 million and .8 million shares,
  respectively).............................................     (322,860)
Liabilities assumed.........................................      (27,984)
                                                                ---------
Cash paid, net of cash acquired.............................    $  43,294
                                                                =========
</TABLE>
 
                                      F-22
<PAGE>   61
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
Supplemental Disclosure of Cash Flow Information:
 
<TABLE>
<CAPTION>
                                                           FOR THE YEAR ENDED DECEMBER 31,
                                                          ---------------------------------
                                                            1998        1997        1996
                                                          ---------   ---------   ---------
                                                                   (IN THOUSANDS)
<S>                                                       <C>         <C>         <C>
Cash paid during the year for:
  Interest, net of amounts capitalized..................   $71,968     $63,633     $53,228
  Income and other taxes, net of refunds................    23,680      35,464       6,241
</TABLE>
 
9. FINANCIAL INSTRUMENTS AND OFF-BALANCE-SHEET RISK
 
     The following table presents the carrying amounts and estimated fair values
of the Company's financial instruments at December 31, 1998 and 1997.
 
<TABLE>
<CAPTION>
                                                            1998                  1997
                                                     -------------------   -------------------
                                                     CARRYING     FAIR     CARRYING     FAIR
                                                      AMOUNT     VALUE      AMOUNT     VALUE
                                                     --------   --------   --------   --------
                                                                  (IN THOUSANDS)
<S>                                                  <C>        <C>        <C>        <C>
Cash and cash equivalents..........................  $ 14,537   $ 14,537   $  9,686   $  9,686
Long-term debt:
  Bank debt........................................   262,780    262,780    405,000    405,000
  Commercial paper.................................    59,000     59,000     50,800     50,800
  7.95-percent notes...............................   178,544    195,624    178,531    203,868
  7.625-percent debentures.........................   149,175    147,749    149,175    159,510
  7-percent notes..................................   148,246    148,410         --         --
  7.375-percent debentures.........................   147,988    152,055    147,984    159,825
  9.25-percent notes...............................    99,842    109,290     99,805    111,210
  7.7-percent notes................................    99,642    105,660     99,638    110,140
  6-percent convertible subordinated debentures....        --         --    172,500    197,944
  Money market lines of credit.....................    15,500     15,500     17,200     17,200
  Apache Finance 6.5-percent notes.................   168,816    171,530    168,722    169,881
  DEKALB 9.875-percent notes.......................    29,225     30,589     29,225     31,598
Hedging financial instruments:
  Commodity price swaps
     -- Natural gas(1).............................        --    (13,066)        --      3,319
     -- Oil........................................        --          3         --         --
</TABLE>
 
- ---------------
 
(1) The fair value of natural gas price swaps at December 31, 1998 and 1997
    reflects fixed-to-floating price swaps where there is an offsetting position
    with a physical contract. See Commodity Price Hedges.
                                      F-23
<PAGE>   62
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     The following methods and assumptions were used to estimate the fair value
of the financial instruments summarized in the table above. The carrying values
of trade receivables and trade payables included in the accompanying
consolidated balance sheet approximated market value at December 31, 1998 and
1997.
 
     Cash and Cash Equivalents -- The carrying amounts approximated fair value
due to the short maturity of these instruments.
 
     Long-Term Debt -- The fair values of the 7.95-percent, 7.7-percent,
9.25-percent, 6.5-percent and 7-percent notes and the 7.375-percent debentures
are based on the quoted market prices for those issues. The fair values of the
9.875-percent notes and 7.625-percent debentures are, and the 6-percent
convertible subordinated debentures were, based upon estimates provided to the
Company by independent investment banking firms. The carrying amount of the bank
debt, commercial paper and money market lines of credit approximates fair value
because the interest rates are variable and reflective of market rates.
 
     Commodity Price Hedges -- Apache periodically enters into commodity
derivative contracts and fixed-price physical contracts to manage its exposure
to oil and gas price volatility. Commodity derivatives contracts, which are
usually placed with major financial institutions that the Company believes are
minimal credit risks, may take the form of futures contracts, swaps or options.
The derivative contracts call for Apache to receive, or make, payments based
upon the differential between a fixed and a variable commodity price as
specified in the contract. As a result of these activities, Apache recognized
hedging gains of $1.3 million and $14.5 million in 1998 and 1997, respectively,
and hedging losses of $23.0 million in 1996. The hedging gains and losses are
included in oil and gas production revenues in the statement of consolidated
operations.
 
     Apache's consolidated balance sheet includes deferred credits totaling $1.0
million and $2.2 million at December 31, 1998 and 1997, respectively, for gains
realized on the early termination of commodity derivative contracts in 1998 and
prior years. These gains will be recognized as oil and gas production revenues
over periods ranging from one to 12 months as the hedged production occurs.
 
     The following table and note thereto cover the Company's pricing and
notional volumes on open natural gas commodity derivative contracts as of
December 31, 1998:
 
<TABLE>
<CAPTION>
                                               1999    2000    2001    2002    2003    THEREAFTER
                                               -----   -----   -----   -----   -----   ----------
<S>                                            <C>     <C>     <C>     <C>     <C>     <C>
New York Mercantile Exchange Based Swap
  Positions:
  Pay fixed price (thousand MMBtu/d)(1)......     50      50      30      30      30        30
  Average swap price, per MMBtu(1)...........  $2.22   $2.27   $2.27   $2.31   $2.35     $2.49
</TABLE>
 
- ---------------
 
(1) The Company has various contracts to supply gas at fixed prices. In order to
    lock in a margin on a portion of the volumes, the Company is a fixed price
    payor on swap transactions. The average physical contract price ranges from
    $2.26 in 1999 to $2.56 in 2008. The fair value of these hedges was $(13.1)
    million at December 31, 1998, all of which is related to the arrangements
    discussed in Note 6.
                                      F-24
<PAGE>   63
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
10. COMMITMENTS AND CONTINGENCIES
 
     Litigation -- The Company is involved in litigation and is subject to
governmental and regulatory controls arising in the ordinary course of business.
It is the opinion of the Company's management that all claims and litigation
involving the Company are not likely to have a material adverse effect on its
financial position or results of operations.
 
     Environmental -- Apache, as an owner and operator of oil and gas
properties, is subject to various federal, state, local and foreign country laws
and regulations relating to discharge of materials into, and protection of, the
environment. These laws and regulations may, among other things, impose
liability on the lessee under an oil and gas lease for the cost of pollution
clean-up resulting from operations and subject the lessee to liability for
pollution damages. Apache maintains insurance coverage, which it believes, is
customary in the industry, although it is not fully insured against all
environmental risks.
 
     As part of the Company's due diligence review for acquisitions, Apache
conducts an extensive environmental evaluation of purchased properties.
Depending on the extent of an identified environmental problem, the Company may
exclude a property from the acquisition, require the seller to remediate the
property to Apache's satisfaction, or agree to assume liability for remediation
of the property. As of December 31, 1998, Apache had a reserve for environmental
remediation of approximately $6.1 million. The Company is not aware of any
environmental claims existing as of December 31, 1998, which have not been
provided for or would otherwise have a material impact on its financial position
or results of operations. There can be no assurance, however, that current
regulatory requirements will not change, or past non-compliance with
environmental laws will not be discovered on the Company's properties.
 
     International Commitments -- The Company, through its subsidiaries, has
acquired or has been conditionally or unconditionally granted exploration rights
in Australia, Egypt, China, Poland and the Ivory Coast. In order to comply with
the contracts and agreements granting these rights, the Company, through various
wholly-owned subsidiaries, is committed to expend approximately $154.5 million
through 2002.
 
     Retirement and Deferred Compensation Plans -- The Company provides a 401(k)
savings plan for employees which allows participating employees to elect to
contribute up to 12 percent of their salaries, with Apache making matching
contributions up to a maximum of six percent of each employee's salary. In
addition, the Company annually contributes six percent of each participating
employee's compensation, as defined, to a money purchase retirement plan. The
401(k) plan and the money purchase retirement plan are subject to certain
annually-adjusted, government-mandated restrictions which limit the amount of
each employee's contributions.
 
     For certain eligible employees, the Company also provides a non-qualified
retirement/savings plan which allows the deferral of up to 50 percent of each
such employee's salary, and which accepts employee contributions and the
Company's matching contributions in excess of the above-referenced restrictions
on the 401(k) savings plan and money purchase retirement plan. Additionally,
Apache Energy Limited and Apache Canada Ltd. maintain separate retirement plans,
as required under the laws of Australia and Canada, respectively.
 
     Vesting in the Company's contributions to the 401(k) savings plan, the
money purchase retirement plan and the non-qualified retirement/savings plan
occurs at the rate of 20 percent per year. Total expenses under all plans were
$7.3 million, $6.3 million and $6.5 million for 1998, 1997 and 1996,
respectively. The unfunded liability for all plans has been accrued in the
consolidated balance sheet.
 
     Lease Commitments -- The Company has leases for buildings, facilities and
equipment with varying expiration dates through 2007. Net rental expense was
$8.1 million, $5.8 million and $6.5 million for 1998, 1997 and 1996,
respectively.
 
                                      F-25
<PAGE>   64
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     As of December 31, 1998, minimum rental commitments under long-term
operating leases, net of sublease rentals, and long-term pipeline transportation
commitments, ranging from one to 25 years, are as follows:
 
<TABLE>
<CAPTION>
                                                                NET MINIMUM
                                                                COMMITMENTS
                                                               --------------
                                                               (IN THOUSANDS)
<S>                                                            <C>
1999........................................................      $ 12,422
2000........................................................        10,112
2001........................................................         8,866
2002........................................................         8,694
2003........................................................         9,097
Thereafter..................................................        55,147
                                                                  --------
                                                                  $104,338
                                                                  ========
</TABLE>
 
     Partnership in Western Australia -- Apache is a partner in a partnership
formed to construct and operate a 62-mile pipeline from Varanus Island to
onshore facilities in Western Australia. Apache has a 50 percent interest in the
partnership and has guaranteed 50 percent of the partnership's share of
construction costs, and any related debt incurred by the partnership, during the
construction phase of the pipeline up to the time pipeline certification is
obtained. After certification and the finalization of certain documentation
related to the partnership's debt, partnership debt will be non-recourse to
Apache. The Company has dedicated the production volumes of six take-or-pay gas
sales contracts to the pipeline. Apache will be required to prepay
transportation tariffs in the event Apache receives payments under the
take-or-pay provisions of these contracts, or in the event the Company fails to
deliver the volumes required by the contracts and requested by the purchasers.
 
11. TRANSACTIONS WITH RELATED PARTIES AND MAJOR CUSTOMERS
 
     Strategic Alliance with Cinergy -- In June 1998, Apache formed a strategic
alliance with Cinergy to market substantially all the Company's natural gas
production from North America and sold its 57 percent interest in ProEnergy for
771,258 shares of Cinergy common stock subsequently sold for $26.1 million.
ProEnergy will continue to market Apache's North American natural gas production
for 10 years, with an option to terminate after six years, under an amended and
restated gas purchase agreement effective July 1, 1998. During this period,
Apache is generally obligated to deliver most of its North American gas
production to Cinergy and, under certain circumstances, reimburse Cinergy if
certain gas throughput thresholds are not met. Accordingly, Apache recorded a
deferred gain of $20.0 million, subject to adjustment, on the sale of ProEnergy
that is being amortized over six years.
 
     Related Parties -- F.H. Merelli, a member of the Company's board of
directors since July 1997, is chairman, president and chief executive officer of
Key Production Company, Inc. (Key). In the normal course of business, Key paid
to Apache during 1998 approximately $7.7 million for Key's proportionate share
of drilling and workover costs, mineral interests and routine expenses relating
to 369 oil and gas wells in which Key owns interests and for which Apache is the
operator. Key received approximately $5.7 million in 1998 for its proportionate
share of revenues from such interests, of which approximately $3.4 million was
paid directly to Key by Apache or related entities.
 
     Major Purchasers -- In 1998, purchases by ProEnergy and the Egyptian
General Petroleum Corporation (EGPC) accounted for 38 percent and 17 percent of
the Company's oil and gas production revenues, respectively. In 1997, purchases
by ProEnergy and EGPC accounted for 40 percent and 13 percent of the Company's
oil and gas production revenues, respectively. In 1996, purchases by ProEnergy
accounted for 35 percent of the Company's oil and gas production revenues.
 
                                      F-26
<PAGE>   65
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
     Concentration of Credit Risk -- The Company's revenues are derived
principally from uncollateralized sales to customers in the oil and gas
industry; therefore, customers may be similarly affected by changes in economic
and other conditions within the industry. Apache has not experienced significant
credit losses on such sales. Sales of natural gas by Apache to ProEnergy are
similarly uncollateralized.
 
12. BUSINESS SEGMENT INFORMATION
 
     Apache has five reportable segments which are primarily in the business of
natural gas and crude oil exploration and production. The accounting policies of
the segments are the same as those described in the summary of significant
accounting policies. The Company evaluates performance based on profit or loss
from oil and gas operations before income and expense items incidental to oil
and gas operations and income taxes. Apache's reportable segments are managed
separately because of their geographic locations. Financial information by
operating segment is presented below:
 
<TABLE>
<CAPTION>
                                      UNITED                                           OTHER
                                      STATES      CANADA     EGYPT     AUSTRALIA   INTERNATIONAL     TOTAL
                                    ----------   --------   --------   ---------   -------------   ----------
                                                                 (IN THOUSANDS)
<S>                                 <C>          <C>        <C>        <C>         <C>             <C>
1998
Oil and Gas Production Revenues...  $  496,238   $ 63,620   $129,123   $ 70,057      $     --      $  759,038
Operating Expenses:
  Depreciation, depletion and
     amortization
       Recurring..................     256,507     30,514     59,825     35,961            --         382,807
       Additional.................     243,178         --         --         --            --         243,178
  Operating costs.................     154,264     17,216     23,436     16,638            --         211,554
  Gathering, processing and
     marketing, net...............      (2,924)        --         --         --            --          (2,924)
                                    ----------   --------   --------   --------      --------      ----------
Operating Income (Loss)...........  $ (154,787)  $ 15,890   $ 45,862   $ 17,458      $     --         (75,577)
                                    ==========   ========   ========   ========      ========
Other Income (Expense):
  Equity in loss of affiliates....                                                                     (1,558)
  Other revenues..................                                                                        840
  Administrative, selling and
     other........................                                                                    (40,731)
  Financing costs, net............                                                                    (70,537)
                                                                                                   ----------
Income (Loss) Before Income
  Taxes...........................                                                                 $ (187,563)
                                                                                                   ==========
Total Long-Lived Assets...........  $1,892,020   $290,341   $809,075   $592,979      $143,126      $3,727,541
                                    ==========   ========   ========   ========      ========      ==========
Total Assets......................  $2,046,628   $305,238   $853,561   $633,981      $156,654      $3,996,062
                                    ==========   ========   ========   ========      ========      ==========
Additions to Long-Lived Assets....  $  274,395   $ 73,327   $219,162   $145,037      $ 70,251      $  782,172
                                    ==========   ========   ========   ========      ========      ==========
</TABLE>
 
                                      F-27
<PAGE>   66
                      APACHE CORPORATION AND SUBSIDIARIES
 
           NOTES TO CONSOLIDATED FINANCIAL STATEMENTS -- (CONTINUED)
 
<TABLE>
<CAPTION>
                                      UNITED                                           OTHER
                                      STATES      CANADA     EGYPT     AUSTRALIA   INTERNATIONAL     TOTAL
                                    ----------   --------   --------   ---------   -------------   ----------
                                                                 (IN THOUSANDS)
<S>                                 <C>          <C>        <C>        <C>         <C>             <C>
1997
Oil and Gas Production Revenues...  $  740,037   $ 61,328   $132,493   $ 49,915      $     --      $  983,773
Operating Expenses:
  Depreciation, depletion and
     amortization.................     292,531     26,028     43,945     18,912            --         381,416
  Operating costs.................     187,753     16,687     16,212     10,718            --         231,370
  Gathering, processing and
     marketing, net...............      (2,672)        --         --         --            --          (2,672)
                                    ----------   --------   --------   --------      --------      ----------
Operating Income..................  $  262,425   $ 18,613   $ 72,336   $ 20,285      $     --         373,659
                                    ==========   ========   ========   ========      ========
Other Income (Expense):
  Equity in loss of affiliates....                                                                     (1,683)
  Other revenues..................                                                                     (2,768)
  Administrative, selling and
     other........................                                                                    (38,243)
  Financing costs, net............                                                                    (72,325)
                                                                                                   ----------
Income Before Income Taxes........                                                                 $  258,640
                                                                                                   ==========
Total Long-Lived Assets...........  $2,243,489   $270,604   $649,758   $483,817      $ 85,517      $3,733,185
                                    ==========   ========   ========   ========      ========      ==========
Total Assets......................  $2,492,233   $285,214   $687,784   $582,487      $ 90,915      $4,138,633
                                    ==========   ========   ========   ========      ========      ==========
Additions to Long-Lived Assets....  $  409,167   $ 69,881   $205,001   $335,986      $ 29,365      $1,049,400
                                    ==========   ========   ========   ========      ========      ==========
1996
Oil and Gas Production Revenues...  $  691,065   $ 48,204   $ 64,990   $ 28,905      $     --      $  833,164
Operating Expenses:
  Depreciation, depletion and
     amortization.................     265,649     20,882     18,113     10,500            --         315,144
  Operating costs.................     188,367     17,234     11,665      8,261            --         225,527
  Gathering, processing and
     marketing, net...............      (4,100)        --         --         --            --          (4,100)
                                    ----------   --------   --------   --------      --------      ----------
Operating Income..................  $  241,149   $ 10,088   $ 35,212   $ 10,144      $     --         296,593
                                    ==========   ========   ========   ========      ========
Other Income (Expense):
  Equity in loss of affiliates....                                                                       (281)
  Other revenues..................                                                                      1,400
  Administrative, selling and
     other........................                                                                    (35,911)
  Financing costs, net............                                                                    (61,606)
                                                                                                   ----------
Income Before Income Taxes........                                                                 $  200,195
                                                                                                   ==========
Total Long-Lived Assets...........  $2,145,398   $243,003   $488,703   $166,735      $ 56,222      $3,100,061
                                    ==========   ========   ========   ========      ========      ==========
Total Assets......................  $2,410,180   $260,818   $512,213   $190,867      $ 58,352      $3,432,430
                                    ==========   ========   ========   ========      ========      ==========
Additions to Long-Lived Assets....  $  428,208   $ 61,710   $493,088   $ 46,838      $ 21,998      $1,051,842
                                    ==========   ========   ========   ========      ========      ==========
</TABLE>
 
                                      F-28
<PAGE>   67
 
                      APACHE CORPORATION AND SUBSIDIARIES
 
                      SUPPLEMENTAL OIL AND GAS DISCLOSURES
                                  (UNAUDITED)
 
     Oil and Gas Operations -- The following table sets forth revenue and direct
cost information relating to the Company's oil and gas exploration and
production activities. Apache has no long-term agreements to purchase oil or gas
production from foreign governments or authorities.
 
<TABLE>
<CAPTION>
                                             UNITED
                                             STATES    CANADA     EGYPT     AUSTRALIA    TOTAL
                                            --------   -------   --------   ---------   --------
                                                               (IN THOUSANDS)
<S>                                         <C>        <C>       <C>        <C>         <C>
1998
Oil and gas production revenues...........  $496,238   $63,620   $129,123    $70,057    $759,038
                                            --------   -------   --------    -------    --------
Operating costs:
  Depreciation, depletion and amortization
     Recurring............................   246,994    29,967     59,825     35,219     372,005
     Additional...........................   243,178        --         --         --     243,178
  Lease operating expenses................   129,585    16,419     23,436     13,472     182,912
  Production taxes........................    21,503        --         --      3,166      24,669
  Income tax (benefit)....................   (54,383)    7,686     22,014      6,552     (18,131)
                                            --------   -------   --------    -------    --------
                                             586,877    54,072    105,275     58,409     804,633
                                            --------   -------   --------    -------    --------
Results of operations.....................  $(90,639)  $ 9,548   $ 23,848    $11,648    $(45,595)
                                            ========   =======   ========    =======    ========
Amortization rate per boe(1)..............  $   6.21   $  4.03   $   5.22    $  4.86    $   5.66
                                            ========   =======   ========    =======    ========
1997
Oil and gas production revenues...........  $740,037   $61,328   $132,493    $49,915    $983,773
                                            --------   -------   --------    -------    --------
Operating costs:
  Depreciation, depletion and
     amortization.........................   283,866    25,592     43,945     18,210     371,613
  Lease operating expenses................   151,236    16,122     16,212      7,226     190,796
  Production taxes........................    33,539        --         --      3,492      37,031
  Income tax..............................   101,774     8,748     34,721      7,555     152,798
                                            --------   -------   --------    -------    --------
                                             570,415    50,462     94,878     36,483     752,238
                                            --------   -------   --------    -------    --------
Results of operations.....................  $169,622   $10,866   $ 37,615    $13,432    $231,535
                                            ========   =======   ========    =======    ========
Amortization rate per boe(1)..............  $   6.12   $  3.96   $   5.47    $  5.23    $   5.77
                                            ========   =======   ========    =======    ========
1996
Oil and gas production revenues...........  $691,065   $48,204   $ 64,990    $28,905    $833,164
                                            --------   -------   --------    -------    --------
Operating costs:
  Depreciation, depletion and
     amortization.........................   256,243    20,511     17,930      9,146     303,830
  Lease operating expenses................   152,187    16,439     11,665      6,108     186,399
  Production taxes........................    33,571        --         --      2,153      35,724
  Income tax..............................    94,644     5,022     16,990      4,139     120,795
                                            --------   -------   --------    -------    --------
                                             536,645    41,972     46,585     21,546     646,748
                                            --------   -------   --------    -------    --------
Results of operations.....................  $154,420   $ 6,232   $ 18,405    $ 7,359    $186,416
                                            ========   =======   ========    =======    ========
Amortization rate per boe(1)..............  $   5.68   $  3.73   $   5.17    $  5.40    $   5.44
                                            ========   =======   ========    =======    ========
</TABLE>
 
- ---------------
 
(1) Amortization rate per boe reflects only depreciation, depletion and
    amortization (DD&A) of capitalized costs of proved oil and gas properties
    (and excludes the additional DD&A recorded in 1998).
                                      F-29
<PAGE>   68
                      APACHE CORPORATION AND SUBSIDIARIES
 
              SUPPLEMENTAL OIL AND GAS DISCLOSURES -- (CONTINUED)
                                  (UNAUDITED)
 
     Costs Not Being Amortized -- The following table sets forth a summary of
oil and gas property costs not being amortized at December 31, 1998, by the year
in which such costs were incurred:
 
<TABLE>
<CAPTION>
                                                                                1995
                                   TOTAL       1998       1997       1996     AND PRIOR
                                  --------   --------   --------   --------   ---------
                                                     (IN THOUSANDS)
<S>                               <C>        <C>        <C>        <C>        <C>
Property acquisition costs......  $423,549   $ 65,404   $117,375   $149,970   $ 90,800
Exploration and development.....   214,305    119,765     64,216         --     30,324
                                  --------   --------   --------   --------   --------
          Total.................  $637,854   $185,169   $181,591   $149,970   $121,124
                                  ========   ========   ========   ========   ========
</TABLE>
 
     Capitalized Costs Incurred -- The following table sets forth the
capitalized costs incurred in oil and gas producing activities:
 
<TABLE>
<CAPTION>
                                                                                                OTHER
                             UNITED STATES   CANADA     EGYPT     AUSTRALIA   IVORY COAST   INTERNATIONAL     TOTAL
                             -------------   -------   --------   ---------   -----------   -------------   ---------
                                                                  (IN THOUSANDS)
<S>                          <C>             <C>       <C>        <C>         <C>           <C>             <C>
1998
Acquisition of proved
  properties(1)............    $  13,240     $ 1,034   $  2,249   $ 41,608      $   271       $     --      $  58,402
Acquisition of unproved
  properties...............       20,819       5,458         --         --           --             --         26,277
Exploration................       27,482      20,054     65,696     39,578           --         30,563        183,373
Development................      174,449      44,245     39,735     40,521       23,527          9,293        331,770
Capitalized interest.......       15,390       1,710     19,226      6,354          829          5,770         49,279
Property sales.............     (123,861)     (4,943)        --         --           --        (12,645)      (141,449)
                               ---------     -------   --------   --------      -------       --------      ---------
                               $ 127,519     $67,558   $126,906   $128,061      $24,627       $ 32,981      $ 507,652
                               =========     =======   ========   ========      =======       ========      =========
1997
Acquisition of proved
  properties(1)............    $  21,927     $11,635   $     --   $192,372      $    --       $     --      $ 225,934
Acquisition of unproved
  properties...............       34,487       6,061      7,744      7,975           --            136         56,403
Exploration................       55,997      21,270     41,910     18,744           67         24,199        162,187
Development................      268,788      28,932     90,284     41,844          489             --        430,337
Capitalized interest.......       15,743       1,406     12,626      2,239          521          3,958         36,493
Property sales.............      (24,609)     (5,525)        --         --           --             --        (30,134)
                               ---------     -------   --------   --------      -------       --------      ---------
                               $ 372,333     $63,779   $152,564   $263,174      $ 1,077       $ 28,293      $ 881,220
                               =========     =======   ========   ========      =======       ========      =========
1996
Acquisition of proved
  properties(1)............    $ 109,872     $ 2,499   $333,834   $     --      $    --       $     --      $ 446,205
Acquisition of unproved
  properties...............       26,055       5,385         --         --           --             --         31,440
Exploration................       48,578      30,153     31,805     11,012        7,674         11,687        140,909
Development................      211,658      21,970     23,056     33,950           --             --        290,634
Capitalized interest.......       16,203       1,260      8,736      1,876          240          2,397         30,712
Property sales.............      (29,459)       (685)        --         --           --             --        (30,144)
                               ---------     -------   --------   --------      -------       --------      ---------
                               $ 382,907     $60,582   $397,431   $ 46,838      $ 7,914       $ 14,084      $ 909,756
                               =========     =======   ========   ========      =======       ========      =========
</TABLE>
 
- ---------------
 
(1) Acquisition of proved properties includes unevaluated costs of $15.7
    million, $53.8 million and $203.6 million for transactions completed in
    1998, 1997 and 1996, respectively.
                                      F-30
<PAGE>   69
                      APACHE CORPORATION AND SUBSIDIARIES
 
              SUPPLEMENTAL OIL AND GAS DISCLOSURES -- (CONTINUED)
                                  (UNAUDITED)
 
     Capitalized Costs -- The following table sets forth the capitalized costs
and associated accumulated depreciation, depletion and amortization, including
impairments, relating to the Company's oil and gas production, exploration and
development activities:
 
<TABLE>
<CAPTION>
                                                                                              OTHER
                        UNITED STATES    CANADA       EGYPT     AUSTRALIA   IVORY COAST   INTERNATIONAL      TOTAL
                        -------------   ---------   ---------   ---------   -----------   -------------   -----------
                                                               (IN THOUSANDS)
<S>                     <C>             <C>         <C>         <C>         <C>           <C>             <C>
1998
Proved properties.....   $ 4,430,504    $ 480,836   $ 454,434   $465,009      $21,409       $ 49,671      $ 5,901,863
Unproved properties...       137,775       21,996     236,568    119,812       13,497        108,206          637,854
                         -----------    ---------   ---------   --------      -------       --------      -----------
                           4,568,279      502,832     691,002    584,821       34,906        157,877        6,539,717
Accumulated DD&A......    (2,717,135)    (213,615)   (108,491)   (96,229)          --        (49,671)      (3,185,141)
                         -----------    ---------   ---------   --------      -------       --------      -----------
                         $ 1,851,144    $ 289,217   $ 582,511   $488,592      $34,906       $108,206      $ 3,354,576
                         ===========    =========   =========   ========      =======       ========      ===========
1997
Proved properties.....   $ 4,279,089    $ 445,314   $ 379,552   $375,037      $ 2,328       $ 49,671      $ 5,530,991
Unproved properties...       161,671       21,443     184,544     81,723        7,951         75,224          532,556
                         -----------    ---------   ---------   --------      -------       --------      -----------
                           4,440,760      466,757     564,096    456,760       10,279        124,895        6,063,547
Accumulated DD&A......    (2,228,575)    (197,067)    (54,789)   (65,605)          --        (49,671)      (2,595,707)
                         -----------    ---------   ---------   --------      -------       --------      -----------
                         $ 2,212,185    $ 269,690   $ 509,307   $391,155      $10,279       $ 75,224      $ 3,467,840
                         ===========    =========   =========   ========      =======       ========      ===========
</TABLE>
 
                                      F-31
<PAGE>   70
                      APACHE CORPORATION AND SUBSIDIARIES
 
              SUPPLEMENTAL OIL AND GAS DISCLOSURES -- (CONTINUED)
                                  (UNAUDITED)
 
     Oil and Gas Reserve Information -- Proved oil and gas reserve quantities
are based on estimates prepared by the Company's engineers in accordance with
guidelines established by the Securities and Exchange Commission (SEC). The
Company's estimates of proved reserve quantities of its U.S., Canadian and
international properties are subject to review by Ryder Scott Company Petroleum
Engineers, independent petroleum engineers. In 1996, the proved reserve
quantities of certain of the Company's Egyptian properties were subject to
review by Netherland, Sewell & Associates, Inc., independent petroleum
engineers.
 
     There are numerous uncertainties inherent in estimating quantities of
proved reserves and projecting future rates of production and timing of
development expenditures. The following reserve data represents estimates only
and should not be construed as being exact.
<TABLE>
<CAPTION>
                                                      CRUDE OIL, CONDENSATE AND NATURAL GAS LIQUIDS       
                                                -------------------------------------------------------- 
                                                                 (THOUSANDS OF BARRELS)                  
                                                UNITED                                   IVORY           
                                                STATES    CANADA    EGYPT    AUSTRALIA   COAST    TOTAL  
                                                -------   ------   -------   ---------   -----   ------- 
<S>                                             <C>       <C>      <C>       <C>         <C>     <C>     
PROVED DEVELOPED RESERVES:
 
 December 31, 1995...........................   123,726   9,597         --     4,141        --   137,464
 December 31, 1996...........................   129,551   10,351    38,213     5,106        --   183,221
 December 31, 1997...........................   133,035   11,313    42,714    15,690       393   203,145
 December 31, 1998...........................   107,306   10,962    33,705    24,674     1,352   177,999

TOTAL PROVED RESERVES:

Balance December 31, 1995....................   153,121   9,816         --     7,392        --   170,329
 Extensions, discoveries
   and other additions.......................     9,065   1,123     18,909    14,562        --    43,659
 Purchases of minerals
   in-place..................................     3,547     128     30,706        --        --    34,381
 Revisions of previous
   estimates.................................    12,547     320         --    (1,679)       --    11,188
 Production..................................   (15,338)   (955)    (3,036)     (849)       --   (20,178)
 Sales of properties.........................    (4,019)    (66)        --        --        --    (4,085)
                                                -------   ------   -------    ------     -----   -------
Balance December 31, 1996....................   158,923   10,366    46,579    19,426        --   235,294
 Extensions, discoveries
   and other additions.......................    32,530   2,677     10,492    12,814       393    58,906
 Purchases of minerals
   in-place..................................     1,818     278         --     9,116        --    11,212
 Revisions of previous
   estimates.................................    (7,283)   (379)     4,696        --        --    (2,966)
 Production..................................   (15,448)  (1,003)   (7,071)   (1,612)       --   (25,134)
 Sales of properties.........................    (2,923)   (611)        --        --        --    (3,534)
                                                -------   ------   -------    ------     -----   -------
Balance December 31, 1997....................   167,617   11,328    54,696    39,744       393   273,778
 Extensions, discoveries
   and other additions.......................    36,655   1,917      5,906    11,765       930    57,173
 Purchases of minerals
   in-place..................................     4,768      59         --     1,214        --     6,041
 Revisions of previous
   estimates.................................   (40,868)   (155)     4,739    (3,121)       29   (39,376)
 Production..................................   (13,262)   (988)   (10,188)   (3,225)       --   (27,663)
 Sales of properties.........................   (18,726)   (219)        --        --        --   (18,945)
                                                -------   ------   -------    ------     -----   -------
Balance December 31, 1998....................   136,184   11,942    55,153    46,377     1,352   251,008
                                                =======   ======   =======    ======     =====   =======
 
<CAPTION>
                                                                       NATURAL GAS
                                               --------------------------------------------------------------
                                                                 (MILLIONS OF CUBIC FEET)
                                                 UNITED                                     IVORY
                                                 STATES     CANADA     EGYPT    AUSTRALIA   COAST      TOTAL
                                               ---------   -------   -------   ---------   ------   ---------
<S>                                            <C>         <C>       <C>       <C>         <C>      <C>
PROVED DEVELOPED RESERVES:                               

 December 31, 1995...........................  1,003,853   274,306        --     20,308        --   1,298,467
 December 31, 1996...........................  1,087,694   274,498     6,977     66,174        --   1,435,343
 December 31, 1997...........................  1,009,080   326,237     8,825    183,962    26,208   1,554,312
 December 31, 1998...........................    869,464   322,576     4,790    173,764    79,515   1,450,109

TOTAL PROVED RESERVES:

Balance December 31, 1995....................  1,140,341   288,420        --     73,159        --   1,501,920
 Extensions, discoveries
   and other additions.......................    140,208    44,584    59,329      8,346        --     252,467
 Purchases of minerals
   in-place..................................     88,023     3,039    12,964         --        --     104,026
 Revisions of previous
   estimates.................................     35,026   (25,747)       --     (5,276)       --       4,003
 Production..................................   (172,815)  (27,303)     (111)    (5,076)       --    (205,305)
 Sales of properties.........................    (29,231)   (2,576)       --         --        --     (31,807)
                                               ---------   -------   -------    -------    ------   ---------
Balance December 31, 1996....................  1,201,552   280,417    72,182     71,153        --   1,625,304
 Extensions, discoveries ....................
   and other additions.......................    187,270    68,877    58,685     42,936    26,208     383,976
 Purchases of minerals 
   in-place..................................     13,295    13,897        --    136,817        --     164,009
 Revisions of previous 
   estimates.................................    (56,632)    4,257    13,584         --        --     (38,791)
 Production..................................   (179,796)  (32,740)     (205)    (9,496)       --    (222,237)
 Sales of properties.........................    (33,940)   (6,500)       --         --        --     (40,440)
                                               ---------   -------   -------    -------    ------   ---------
Balance December 31, 1997....................  1,131,749   328,208   144,246    241,410    26,208   1,871,821
 Extensions, discoveries 
   and other additions.......................    146,112    60,660    31,201    267,533    50,406     555,912
 Purchases of minerals
   in-place..................................     25,188       599        --     27,373        --      53,160
 Revisions of previous   
   estimates.................................    (43,778)   (7,812)   19,550        (76)    2,901     (29,215)
 Production..................................   (157,701)  (38,643)     (567)   (18,478)       --    (215,389)
 Sales of properties.........................    (52,995)  (11,068)       --         --        --     (64,063)
                                               ---------   -------   -------    -------    ------   ---------
Balance December 31, 1998....................  1,048,575   331,944   194,430    517,762    79,515   2,172,226
                                               =========   =======   =======    =======    ======   =========
</TABLE>
 
                                      F-32
<PAGE>   71
                      APACHE CORPORATION AND SUBSIDIARIES
 
              SUPPLEMENTAL OIL AND GAS DISCLOSURES -- (CONTINUED)
                                  (UNAUDITED)
 
     Future Net Cash Flows -- Future cash inflows are based on year-end oil and
gas prices except in those instances where future natural gas or oil sales are
covered by physical or derivative contract terms providing for higher or lower
amounts. Operating costs, production and ad valorem taxes and future development
costs are based on current costs with no escalation.
 
     The following table sets forth unaudited information concerning future net
cash flows for oil and gas reserves, net of income tax expense. Income tax
expense has been computed using expected future tax rates and giving effect to
tax deductions and credits available, under current laws, and which relate to
oil and gas producing activities. This information does not purport to present
the fair market value of the Company's oil and gas assets, but does present a
standardized disclosure concerning possible future net cash flows that would
result under the assumptions used.
 
<TABLE>
<CAPTION>
                                               UNITED                                             IVORY
                                               STATES      CANADA(1)     EGYPT      AUSTRALIA     COAST        TOTAL
                                             -----------   ---------   ----------   ----------   --------   -----------
                                                                           (IN THOUSANDS)
<S>                                          <C>           <C>         <C>          <C>          <C>        <C>
1998
Cash inflows...............................  $ 3,523,294   $763,349    $  877,861   $1,208,235   $129,965   $ 6,502,704
Production and development costs...........   (1,496,382)  (240,166)     (263,199)    (479,627)   (28,718)   (2,508,092)
Income tax expense.........................     (327,470)  (127,405)     (166,751)    (156,409)   (29,211)     (807,246)
                                             -----------   ---------   ----------   ----------   --------   -----------
Net cash flows.............................    1,699,442    395,778       447,911      572,199     72,036     3,187,366
10 percent discount rate...................     (675,035)  (165,220)     (127,723)    (209,448)   (45,889)   (1,223,315)
                                             -----------   ---------   ----------   ----------   --------   -----------
Discounted future net cash flows(2)........  $ 1,024,407   $230,558    $  320,188   $  362,751   $ 26,147   $ 1,964,051
                                             ===========   =========   ==========   ==========   ========   ===========
1997
Cash inflows...............................  $ 5,585,925   $610,359    $1,196,054   $1,108,969   $ 58,589   $ 8,559,896
Production and development costs...........   (2,151,076)  (186,328)     (427,608)    (415,282)   (31,710)   (3,212,004)
Income tax expense.........................     (776,649)   (89,852)     (235,560)    (131,017)        --    (1,233,078)
                                             -----------   ---------   ----------   ----------   --------   -----------
Net cash flows.............................    2,658,200    334,179       532,886      562,670     26,879     4,114,814
10 percent discount rate...................   (1,049,380)  (145,899)     (179,290)    (157,385)   (19,598)   (1,551,552)
                                             -----------   ---------   ----------   ----------   --------   -----------
Discounted future net cash flows(2)........  $ 1,608,820   $188,280    $  353,596   $  405,285   $  7,281   $ 2,563,262
                                             ===========   =========   ==========   ==========   ========   ===========
1996
Cash inflows...............................  $ 8,839,819   $761,657    $1,272,104   $  553,781   $     --   $11,427,361
Production and development costs...........   (2,542,757)  (204,610)     (484,143)    (240,451)        --    (3,471,961)
Income tax expense.........................   (1,751,611)  (148,745)     (260,598)     (83,593)        --    (2,244,547)
                                             -----------   ---------   ----------   ----------   --------   -----------
Net cash flows.............................    4,545,451    408,302       527,363      229,737         --     5,710,853
10 percent discount rate...................   (1,928,723)  (182,645)     (208,272)     (71,696)        --    (2,391,336)
                                             -----------   ---------   ----------   ----------   --------   -----------
Discounted future net cash flows(2)........  $ 2,616,728   $225,657    $  319,091   $  158,041   $     --   $ 3,319,517
                                             ===========   =========   ==========   ==========   ========   ===========
</TABLE>
 
- ---------------
 
(1) Included in cash inflows is approximately $27.9 million, $27.3 million and
    $16.2 million ($9.1 million, $9.3 million and $5.3 million after discount at
    10 percent per annum) for 1998, 1997 and 1996, respectively, of Canadian
    provincial tax credits expected to be realized beyond the date at which the
    legislation, under its provisions, could be repealed.
 
(2) Estimated future net cash flows before income tax expense, discounted at 10
    percent per annum, totaled approximately $2.4 billion, $3.3 billion and $4.6
    billion as of December 31, 1998, 1997 and 1996, respectively.
                                      F-33
<PAGE>   72
                      APACHE CORPORATION AND SUBSIDIARIES
 
              SUPPLEMENTAL OIL AND GAS DISCLOSURES -- (CONTINUED)
                                  (UNAUDITED)
 
     The following table sets forth the principal sources of change in the
discounted future net cash flows:
 
<TABLE>
<CAPTION>
                                                    FOR THE YEAR ENDED DECEMBER 31,
                                                 --------------------------------------
                                                    1998          1997          1996
                                                 -----------   -----------   ----------
                                                             (IN THOUSANDS)
<S>                                              <C>           <C>           <C>
Sales, net of production costs.................  $  (551,457)  $  (755,946)  $ (611,041)
Net change in prices and production costs......   (1,253,213)   (1,904,236)   1,336,340
Discoveries and improved recovery, net of
  related costs................................      620,153       644,652      775,136
Change in future development costs.............      251,638       120,462       54,236
Revision of quantities.........................     (149,859)      (40,121)     113,819
Purchases of minerals in-place.................       52,785       242,958      522,123
Accretion of discount..........................      327,262       456,848      234,436
Change in income taxes.........................      277,518       545,424     (779,980)
Sales of properties............................     (132,337)      (48,353)     (46,056)
Change in production rates and other...........      (41,701)      (17,943)    (149,055)
                                                 -----------   -----------   ----------
                                                 $  (599,211)  $  (756,255)  $1,449,958
                                                 ===========   ===========   ==========
</TABLE>
 
     Impact of Pricing -- The estimates of cash flows and reserve quantities
shown above are based on year-end oil and gas prices, except in those cases
where future natural gas or oil sales are covered by contracts at specified
prices. Estimates of future liabilities and receivables applicable to oil and
gas commodity hedges are reflected in future cash flows from proved reserves
with such estimates based on prices in effect as of the date of the reserve
report. Fluctuations are largely due to supply and demand perceptions for
natural gas and volatility in oil prices.
 
     Under the full cost accounting rules of the SEC, the Company reviews the
carrying value of its proved oil and gas properties each quarter on a
country-by-country basis. Under these rules, capitalized costs of proved oil and
gas properties, net of accumulated DD&A and deferred income taxes, may not
exceed the present value of estimated future net cash flows from proved oil and
gas reserves, discounted at 10 percent, plus the lower of cost or fair value of
unproved properties included in the costs being amortized, net of related tax
effects. These rules generally require pricing future oil and gas production at
the unescalated oil and gas prices at the end of each fiscal quarter and require
a write-down if the "ceiling" is exceeded, even if prices declined for only a
short period of time. The Company recorded a $243.2 million pre-tax ($158.1
million net of tax) non-cash write-down of the carrying value of Apache's U.S.
proved oil and gas properties as of December 31, 1998, due to these ceiling test
limitations. If oil and gas prices deteriorate from the Company's year-end
realized prices, it is likely that additional write-downs will occur in 1999.
Write-downs required by these rules do not impact cash flow from operating
activities.
 
                                      F-34
<PAGE>   73
 
                      APACHE CORPORATION AND SUBSIDIARIES
 
                     SUPPLEMENTAL QUARTERLY FINANCIAL DATA
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                         FIRST      SECOND     THIRD     FOURTH(2)     TOTAL
                                        --------   --------   --------   ---------   ----------
                                               (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
<S>                                     <C>        <C>        <C>        <C>         <C>
1998
Revenues..............................  $245,941   $220,132   $211,683   $ 197,959   $  875,715
Expenses, net.........................   228,585    210,896    208,482     357,139    1,005,102
                                        --------   --------   --------   ---------   ----------
Net income (loss).....................  $ 17,356   $  9,236   $  3,201   $(159,180)  $ (129,387)
                                        ========   ========   ========   =========   ==========
Income (loss) attributable to common
  stock...............................  $ 17,356   $  9,236   $  2,617   $(160,600)  $ (131,391)
                                        ========   ========   ========   =========   ==========
Net income (loss) per common share(1)
  Basic...............................  $    .18   $    .09   $    .03   $   (1.64)  $    (1.34)
                                        ========   ========   ========   =========   ==========
  Diluted.............................  $    .18   $    .09   $    .03   $   (1.64)  $    (1.34)
                                        ========   ========   ========   =========   ==========
1997
Revenues..............................  $321,828   $258,841   $276,748   $ 318,856   $1,176,273
Expenses, net.........................   268,951    233,095    245,963     273,368    1,021,377
                                        --------   --------   --------   ---------   ----------
Net income............................  $ 52,877   $ 25,746   $ 30,785   $  45,488   $  154,896
                                        ========   ========   ========   =========   ==========
Net income per common share(1)
  Basic...............................  $    .59   $    .29   $    .34   $     .50   $     1.71
                                        ========   ========   ========   =========   ==========
  Diluted.............................  $    .56   $    .28   $    .33   $     .48   $     1.65
                                        ========   ========   ========   =========   ==========
</TABLE>
 
- ---------------
 
(1) The sum of the individual quarterly net income (loss) per common share
    amounts may not agree with year-to-date net income (loss) per common share
    as each quarterly computation is based on the weighted average number of
    common shares outstanding during that period. In addition, certain
    potentially dilutive securities were not included in certain of the
    quarterly computations of diluted net income (loss) per common share because
    to do so would have been antidilutive.
 
(2) As a result of low oil and gas prices at December 31, 1998, the carrying
    value of Apache's U.S. oil and gas properties exceeded the ceiling
    limitation and the Company reported a $243.2 million pre-tax ($158.1 million
    net of tax) non-cash write-down in the fourth quarter of 1998.
                                      F-35
<PAGE>   74
 
                               INDEX TO EXHIBITS
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
           2.1           -- Stock Purchase Agreement, dated July 1, 1991, between
                            Registrant and Amoco Production Company (incorporated by
                            reference to Exhibit 10.1 to Registrant's Current Report
                            on Form 8-K, dated July 1, 1991, SEC File No. 1-4300).
           2.2           -- Form of Acquisition Agreement between Registrant, HERC
                            Acquisition Corporation and Hadson Energy Resources
                            Corporation, dated August 26, 1993, and amended September
                            28, 1993 (incorporated by reference to Exhibit 2.1 to
                            Registrant's Registration Statement on Form S-4,
                            Registration No. 33-67954, filed September 29, 1993).
           2.3           -- Purchase and Sale Agreement by and between Texaco
                            Exploration and Production Inc., as seller, and
                            Registrant, as buyer, dated December 22, 1994
                            (incorporated by reference to Exhibit 99.3 to
                            Registrant's Current Report on Form 8-K, dated November
                            29, 1994, SEC File No. 1-4300).
           2.4           -- Amended and Restated Agreement and Plan of Merger among
                            Registrant, XPX Acquisitions, Inc and DEKALB Energy
                            Company, dated December 21, 1994 (incorporated by
                            reference to Exhibit 2.1 to Amendment No. 3 to
                            Registrant's Registration Statement on Form S-4,
                            Registration No. 33-57321, filed April 14, 1995).
           2.5           -- Agreement and Plan of Merger among Registrant, YPY
                            Acquisitions, Inc. and The Phoenix Resource Companies,
                            Inc., dated March 27, 1996 (incorporated by reference to
                            Exhibit 2.1 to Registrant's Registration Statement on
                            Form S-4, Registration No. 333-02305, filed April 5,
                            1996).
           3.1           -- Restated Certificate of Incorporation of Registrant,
                            dated December 1, 1993, as filed with the Secretary of
                            State of Delaware on December 16, 1993 (incorporated by
                            reference to Exhibit 3.1 to Registrant's Annual Report on
                            Form 10-K for year ended December 31, 1993, SEC File No.
                            1-4300).
           3.2           -- Certificate of Ownership and Merger Merging Apache Energy
                            Resources Corporation into Registrant, effective December
                            31, 1995, as filed with the Secretary of State of
                            Delaware on December 21, 1995 (incorporated by reference
                            to Exhibit 3.2 to Registrant's Annual Report on Form 10-K
                            for year ended December 31, 1995, SEC File No. 1-4300).
           3.3           -- Certificate of Designations, Preferences and Rights of
                            Series A Junior Participating Preferred Stock of
                            Registrant, effective January 31, 1996, as filed with the
                            Secretary of State of Delaware on January 22, 1996
                            (incorporated by reference to Exhibit 3.3 to Registrant's
                            Annual Report on Form 10-K for year ended December 31,
                            1995, SEC File No. 1-4300).
          *3.4           -- Certificate of Ownership and Merger merging Apache PHN
                            Company, Inc. into Registrant, effective July 1, 1998, as
                            filed with the Secretary of State of Delaware on July 1,
                            1998.
          *3.5           -- Agreement and Plan of Merger merging MWJR Petroleum
                            Corporation into Registrant, effective September 1, 1998,
                            as filed with the Secretary of State of Delaware on
                            August 19, 1998.
          *3.6           -- Certificate of Ownership and Merger merging MW Petroleum
                            Corporation into Registrant, effective September 1, 1998,
                            as filed with the Secretary of State of Delaware on
                            August 19, 1998.
          *3.7           -- Certificate of Designations, Preferences and Rights of
                            5.68% Cumulative Preferred Stock, Series B, of
                            Registrant, as filed with the Secretary of State of
                            Delaware on August 21, 1998.
</TABLE>
<PAGE>   75
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
          *3.8           -- Certificate of Correction to Certificate of Designations,
                            Preferences and Rights of 5.68% Cumulative Preferred
                            Stock, Series B, of Registrant, as filed with the
                            Secretary of State of Delaware on August 24, 1998.
           3.9           -- Bylaws of Registrant, as amended September 17, 1998
                            (incorporated by reference to Exhibit 3.2 to Registrant's
                            Quarterly Report on Form 10-Q for quarter ended September
                            30, 1998, SEC File No. 1-4300).
           4.1           -- Form of Certificate for Registrant's Common Stock
                            (incorporated by reference to Exhibit 4.1 to Registrant's
                            Annual Report on Form 10-K for year ended December 31,
                            1995, SEC File No. 1-4300).
           4.2           -- Form of Certificate for Registrant's 5.68% Cumulative
                            Preferred Stock, Series B (incorporated by reference to
                            Exhibit 4.2 to Amendment No. 2 on Form 8-K/A to
                            Registrant's Current Report on Form 8-K, dated August 18,
                            1998, SEC File No. 1-4300).
           4.3           -- Rights Agreement, dated January 31, 1996, between
                            Registrant and Norwest Bank Minnesota, N.A., rights
                            agent, relating to the declaration of a rights dividend
                            to Registrant's common shareholders of record on January
                            31, 1996 (incorporated by reference to Exhibit (a) to
                            Registrant's Registration Statement on Form 8-A, dated
                            January 24, 1996, SEC File No. 1-4300).
          10.1           -- Credit Agreement, dated June 12, 1997, among the
                            Registrant, the lenders named therein, Morgan Guaranty
                            Trust Company, as Global Documentation Agent and U.S.
                            Syndication Agent, The First National Bank of Chicago, as
                            U.S. Documentation Agent, NationsBank of Texas, N.A., as
                            Co-Agent, Union Bank of Switzerland, Houston Agency, as
                            Co-Agent, and The Chase Manhattan Bank, as Global
                            Administrative Agent (incorporated by reference to
                            Exhibit 10.1 to Registrant's Current Report on Form 8-K,
                            dated June 13, 1997, SEC File No. 1-4300).
          10.2           -- Credit Agreement, dated June 12, 1997, among Apache
                            Canada Ltd., a wholly-owned subsidiary of the Registrant,
                            the lenders named therein, Morgan Guaranty Trust Company,
                            as Global Documentation Agent, Royal Bank of Canada, as
                            Canadian Documentation Agent, The Chase Manhattan Bank of
                            Canada, as Canadian Syndication Agent, Bank of Montreal,
                            as Canadian Administrative Agent, and The Chase Manhattan
                            Bank, as Global Administrative Agent (incorporated by
                            reference to Exhibit 10.2 to Registrant's Current Report
                            on Form 8-K, dated June 13, 1997, SEC File No. 1-4300).
          10.3           -- Credit Agreement, dated June 12, 1997, among Apache
                            Energy Limited and Apache Oil Australia Pty Limited,
                            wholly-owned subsidiaries of the Registrant, the lenders
                            named therein, Morgan Guaranty Trust Company, as Global
                            Documentation Agent, Bank of America National Trust and
                            Savings Association, Sydney Branch, as Australian
                            Documentation Agent, The Chase Manhattan Bank, as
                            Australian Syndication Agent, Citisecurities Limited, as
                            Australian Administrative Agent, and The Chase Manhattan
                            Bank, as Global Administrative Agent (incorporated by
                            reference to Exhibit 10.3 to Registrant's Current Report
                            on Form 8-K, dated June 13, 1997, SEC File No. 1-4300).
          10.4           -- Fiscal Agency Agreement, dated January 4, 1995, between
                            Registrant and Chemical Bank, as fiscal agent, relating
                            to Registrant's 6% Convertible Subordinated Debentures
                            due 2002 (incorporated by reference to Exhibit 99.2 to
                            Registrant's Current Report on Form 8-K, dated December
                            6, 1994, SEC File No. 1-4300).
</TABLE>
<PAGE>   76
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
          10.5           -- Concession Agreement for Petroleum Exploration and
                            Exploitation in the Khalda Area in Western Desert of
                            Egypt by and among Arab Republic of Egypt, the Egyptian
                            General Petroleum Corporation and Phoenix Resources
                            Company of Egypt, dated April 6, 1981 (incorporated by
                            reference to Exhibit 19(g) to Phoenix's Annual Report on
                            Form 10-K for year ended December 31, 1984, SEC File No.
                            1-547).
          10.6           -- Amendment, dated July 10, 1989, to Concession Agreement
                            for Petroleum Exploration and Exploitation in the Khalda
                            Area in Western Desert of Egypt by and among Arab
                            Republic of Egypt, the Egyptian General Petroleum
                            Corporation and Phoenix Resources Company of Egypt
                            (incorporated by reference to Exhibit 10(d)(4) to
                            Phoenix's Quarterly Report on Form 10-Q for quarter ended
                            June 30, 1989, SEC File No. 1-547).
          10.7           -- Farmout Agreement, dated September 13, 1985 and relating
                            to the Khalda Area Concession, by and between Phoenix
                            Resources Company of Egypt and Conoco Khalda
                            Inc(incorporated by reference to Exhibit 10.1 to
                            Phoenix's Registration Statement on Form S-1,
                            Registration No. 33-1069, filed October 23, 1985).
          10.8           -- Amendment, dated March 30, 1989, to Farmout Agreement
                            relating to the Khalda Area Concession, by and between
                            Phoenix Resources Company of Egypt and Conoco Khalda
                            Inc(incorporated by reference to Exhibit 10(d)(5) to
                            Phoenix's Quarterly Report on Form 10-Q for quarter ended
                            June 30, 1989, SEC File No. 1-547).
          10.9           -- Amendment, dated May 21, 1995, to Concession Agreement
                            for Petroleum Exploration and Exploitation in the Khalda
                            Area in Western Desert of Egypt between Arab Republic of
                            Egypt, the Egyptian General Petroleum Corporation, Repsol
                            Exploracion Egipto S.A., Phoenix Resources Company of
                            Egypt and Samsung Corporation (incorporated by reference
                            to exhibit 10.12 to Registrant's Annual Report on Form
                            10-K for year ended December 31, 1997, SEC File No.
                            1-4300).
          10.10          -- Concession Agreement for Petroleum Exploration and
                            Exploitation in the Qarun Area in Western Desert of
                            Egypt, between Arab Republic of Egypt, the Egyptian
                            General Petroleum Corporation, Phoenix Resources Company
                            of Qarun and Apache Oil Egypt, Inc., dated May 17, 1993
                            (incorporated by reference to Exhibit 10(b) to Phoenix's
                            Annual Report on Form 10-K for year ended December 31,
                            1993, SEC File No. 1-547).
          10.11          -- Agreement for Amending the Gas Pricing Provisions under
                            the Concession Agreement for Petroleum Exploration and
                            Exploitation in the Qarun Area, effective June 16, 1994
                            (incorporated by reference to Exhibit 10.18 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1996, SEC File No. 1-4300).
         +10.12          -- 1982 Employee Stock Option Plan, as updated in January
                            1987 to conform to the Tax Reform Act of 1986
                            (incorporated by reference to Exhibit 10.7 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1990, SEC File No. 1-4300).
        +*10.13          -- Apache Corporation Corporate Incentive Compensation Plan
                            A (Senior Officers' Plan), dated July 16, 1998.
        +*10.14          -- Apache Corporation Corporate Incentive Compensation Plan
                            B (Strategic Objectives Format), dated July 16, 1998.
         +10.15          -- Apache Corporation 401(k) Savings Plan, dated August 1,
                            1997, effective January 1, 1997 (incorporated by
                            reference to Exhibit 10.1 to Registrant's Current Report
                            on Form 8-K, dated August 8, 1997, SEC File No. 1-4300).
</TABLE>
<PAGE>   77
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
         +10.16          -- Apache Corporation Money Purchase Retirement Plan, dated
                            December 31, 1997, effective January 1, 1997
                            (incorporated by reference to Exhibit 10.19 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1997, SEC File No. 1-4300).
        +*10.17          -- Non-Qualified Retirement/Savings Plan of Apache
                            Corporation, restated as of January 1, 1997, and
                            amendments effective as of January 1, 1997, January 1,
                            1998 and January 1, 1999.
         +10.18          -- Apache International, Inc. Common Stock Award Plan, dated
                            February 12, 1990 (incorporated by reference to Exhibit
                            10.13 to Registrant's Annual Report on Form 10-K for year
                            ended December 31, 1989, SEC File No. 1-4300).
        +*10.19          -- Apache Corporation 1990 Stock Incentive Plan, as amended
                            and restated December 17, 1998.
        +*10.20          -- Apache Corporation 1995 Stock Option Plan, as amended and
                            restated December 17, 1998.
         +10.21          -- Apache Corporation 1996 share Price Appreciation Plan, as
                            amended and restated January 14, 1997 (incorporated by
                            reference to Appendix A to Registrant's definitive 14A
                            Proxy Statement, SEC File No. 1-4300, filed March 28,
                            1997).
         +10.22          -- Apache Corporation 1996 Performance Stock Option Plan, as
                            amended and restated January 14, 1997 (incorporated by
                            reference to Exhibit 10.32 to Registrant's Annual Report
                            on Form 10-K for year ended December 31, 1996, SEC File
                            No. 1-4300).
        +*10.23          -- Apache Corporation 1998 Stock Option Plan, as amended and
                            restated December 17, 1998.
         +10.24          -- 1990 Employee Stock Option Plan of The Phoenix Resource
                            Companies, Inc., as amended through September 29, 1995,
                            effective April 9, 1990 (incorporated by reference to
                            Exhibit 10.33 to Registrant's Annual Report on Form 10-K
                            for year ended December 31, 1996, SEC File No. 1-4300).
         +10.25          -- Apache Corporation Income Continuance Plan, as amended
                            and restated February 24, 1988 (incorporated by reference
                            to Exhibit 10.19 to Registrant's Annual Report on Form
                            10-K for year ended December 31, 1990, SEC File No.
                            1-4300).
        +*10.26          -- Apache Corporation Non-Employee Directors' Compensation
                            Plan, as amended and restated December 17, 1998.
         +10.27          -- Apache Corporation Outside Directors' Retirement Plan, as
                            amended and restated September 11, 1997 (incorporated by
                            reference to Exhibit 10.31 to Registrant's Annual Report
                            on Form 10-K for year ended December 31, 1997, SEC File
                            No. 1-4300).
         +10.28          -- Apache Corporation Equity Compensation Plan for
                            Non-Employee Directors, adopted February 9, 1994, and
                            form of Restricted Stock Award Agreement (incorporated by
                            reference to Exhibit 10.26 to Registrant's Annual Report
                            on Form 10-K for year ended December 31, 1993, SEC File
                            No. 1-4300).
         +10.29          -- Amended and Restated Employment Agreement, dated December
                            5, 1990, between Registrant and Raymond Plank
                            (incorporated by reference to Exhibit 10.39 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1996, SEC File No. 1-4300).
</TABLE>
<PAGE>   78
 
<TABLE>
<CAPTION>
      EXHIBIT NO.                                DESCRIPTION
      -----------                                -----------
<C>                      <S>
         +10.30          -- First Amendment, dated April 4, 1996, to Restated
                            Employment Agreement between Registrant and Raymond Plank
                            (incorporated by reference to Exhibit 10.40 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1996, SEC File No. 1-4300).
         +10.31          -- Amended and Restated Employment Agreement, dated December
                            20, 1990, between Registrant and John A. Kocur
                            (incorporated by reference to Exhibit 10.10 to
                            Registrant's Annual Report on Form 10-K for year ended
                            December 31, 1990, SEC File No. 1-4300).
         +10.32          -- Employment Agreement, dated June 6, 1988, between
                            Registrant and G. Steven Farris (incorporated by
                            reference to Exhibit 10.6 to Registrant's Annual Report
                            on Form 10-K for year ended December 31, 1989, SEC File
                            No. 1-4300).
        +*10.33          -- Conditional Stock Grant Agreement, dated December 17,
                            1998, between Registrant and G. Steven Farris.
          10.34          -- Amended and Restated Gas Purchase Agreement, effective
                            July 1, 1998, by and among Registrant and MW Petroleum
                            Corporation, as Seller, and Producers Energy Marketing,
                            LLC, as Buyer (incorporated by reference to Exhibit 10.1
                            to Registrant's Current Report on Form 8-K, dated June
                            18, 1998, SEC File No. 1-4300).
          12.1           -- Statement of Computation of Ratio of Earnings to Combined
                            Fixed Charges and Preferred Stock Dividends (incorporated
                            by reference to Exhibit 99.1 to Registrant's Current
                            Report on Form 8-K, dated March 2, 1999, SEC File No.
                            1-4300).
         *21.1           -- Subsidiaries of Registrant
         *23.1           -- Consent of Arthur Andersen LLP
         *23.2           -- Consent of Ryder Scott Company Petroleum Engineers
         *23.3           -- Consent of Netherland, Sewell & Associates, Inc.
         *24.1           -- Power of Attorney (included as a part of the signature
                            pages to this report)
         *27.1           -- Financial Data Schedule
</TABLE>
 
- ---------------
 
*     Filed herewith.
 
+     Management contracts or compensatory plans or arrangements required to be
      filed herewith pursuant to Item 14 hereof.
 
Note: Debt instruments of the Registrant defining the rights of long-term debt
      holders in principal amounts not exceeding 10 percent of the Registrant's
      consolidated assets have been omitted and will be provided to the
      Commission upon request.

<PAGE>   1
                                                                     EXHIBIT 3.4

                                                                 PAGE 1

                                STATE OF DELAWARE
                        OFFICE OF THE SECRETARY OF STATE
                      ------------------------------------


         I, EDWARD J. FREEL, SECRETARY OF STATE OF THE STATE OF DELAWARE, DO
HEREBY CERTIFY THE ATTACHED IS A TRUE AND CORRECT COPY OF THE CERTIFICATE OF
OWNERSHIP, WHICH MERGES:

         "APACHE PHN COMPANY, INC.", A DELAWARE CORPORATION,

         WITH AND INTO "APACHE CORPORATION" UNDER THE NAME OF" APACHE
CORPORATION", A CORPORATION ORGANIZED AND EXISTING UNDER THE LAWS OF THE STATE
OF DELAWARE, AS RECEIVED AND FILED IN THIS OFFICE THE FIRST DAY OF JULY, A.D.
1998, AT 4:30 O'CLOCK P.M.

         A FILED COPY OF THIS CERTIFICATE HAS BEEN FORWARDED TO THE NEW CASTLE
COUNTY RECORDER OF DEEDS.


                                          /s/ Edward J. Freel
                                          -----------------------------------
                                          Edward J. Freel, Secretary of State

                                     [SEAL]


0482215 8100M                             AUTHENTICATION:        9175881
981258093                                           DATE:        07-02-98


<PAGE>   2


                       CERTIFICATE OF OWNERSHIP AND MERGER
                                     MERGING
                            APACHE PHN COMPANY, INC.
                                      INTO
                               APACHE CORPORATION


         Apache Corporation, a corporation organized and existing under the laws
of the State of Delaware, DOES HEREBY CERTIFY:

         FIRST: That Apache Corporation was incorporated on the 6th day of
December, 1954, pursuant to the General Corporation Law of the State of
Delaware.

         SECOND: That Apache Corporation owns all of the issued and outstanding
shares of the capital stock of Apache PHN Company, Inc., a corporation which was
incorporated on the 19th day of May, 1930, pursuant to the General Corporation
Law of the State of Delaware.

         THIRD: That Apache Corporation, by the following resolutions of its
Board of Directors, duly adopted by unanimous written consent dated June 29,
1998, determined to and did merge into itself said Apache PHN Company, Inc.:

                  RESOLVED that Apache PHN Company, Inc. ("Apache PHN"), a
         wholly owned subsidiary of Apache Corporation, be merged with and into
         Apache Corporation ("Apache"), with Apache being the surviving
         corporation.

                  FURTHER RESOLVED that the merger shall be effective as of July
         1, 1998.

                  FURTHER RESOLVED that all of the shares of the capital stock
         of Apache PHN issued and outstanding as of the effective date of the
         merger shall be cancelled without consideration.

                  FURTHER RESOLVED that upon the merger taking effect, Apache
         shall thereupon and thereafter possess all the rights, privileges,
         immunities, and franchises, of a public as well as a private nature, of
         each of Apache and Apache PHN; that all property, real, personal, and
         mixed, and all debts due on whatever account, including subscriptions
         to shares, and all other chooses in action, and every other interest of
         or belonging to or due to Apache PHN shall be deemed to be transferred
         to and vested in Apache without further act or deed; that the title to
         any real estate, or any interest therein vested in either of Apache or
         Apache PHN shall not revert or be in any way impaired by reason of the
         merger; and that such transfer to and vesting in Apache shall be deemed
         to occur by operation of law, and no consent or approval of any other
         person shall be required in connection with any such transfer or
         vesting unless such consent or approval is specifically required in the
         event of merger by law or by express 



                                       2
<PAGE>   3

         provision in any contract, agreement, decree, order, or other
         instrument to which either of Apache or Apache PHN is a party or by
         which either is bound.

                  FURTHER RESOLVED that upon the merger taking effect, Apache
         shall be responsible and liable for all the liabilities and obligations
         of Apache PHN; that any claim existing or action or proceeding, whether
         civil or criminal, pending by or against Apache PHN may be prosecuted
         as if the merger had not taken place; and that neither the rights of
         creditors nor any liens upon the property of either of Apache or Apache
         PHN shall be impaired by such merger.

                  FURTHER RESOLVED that the proper officers of Apache are hereby
         authorized and directed, in the name and on behalf of Apache, to
         prepare and execute a Certificate of Ownership and Merger setting forth
         a copy of the resolutions authorizing the merger of Apache PHN with and
         into Apache and the assumption by Apache of the liabilities and
         obligations of Apache PHN, and the date of adoption thereof, and to
         cause such Certificate of Ownership and Merger to be filed with the
         Delaware Secretary of State and a certified copy of same recorded in
         the office of the Recorder of Deeds of New Castle County.

                  FURTHER RESOLVED that the proper officers of Apache be, and
         they hereby are, authorized and directed to take such further action
         and to execute such certificates and other documents as they, in their
         discretion, shall deem necessary or advisable to consummate the merger
         and effect the foregoing resolutions.

         FOURTH: Anything herein or elsewhere to the contrary notwithstanding,
this merger may be amended or terminated and abandoned by the Board of Directors
of Apache Corporation at any time prior to the date of filing the merger with
the Delaware Secretary of State.

         IN WITNESS WHEREOF, Apache Corporation has caused this Certificate of
Ownership and Merger to be executed by its duly authorized officers as of this
29th day of June, 1998.

                                           APACHE CORPORATION


                                           By:  /s/ G. STEVEN FARRIS
                                                -------------------------------
                                                    G. Steven Farris
                                                    President and Chief 
                                                    Operating Officer

ATTEST:


/s/ CHERI L. PEPER
- ------------------------------------
Cheri L. Peper
Corporate Secretary



                                       3
<PAGE>   4






STATE OF TEXAS      )
                    )
COUNTY OF HARRIS    )


         The foregoing instrument was acknowledged before me this 29th day of
June, 1998, on behalf of Apache Corporation, by G. Steven Farris, President and
Chief Operating Officer of Apache Corporation, a Delaware corporation.



[Seal]                                     /s/ SUSAN CHARBA
                                           -----------------------------------
                                           Susan Charba, Notary Public in and
                                           for the State of Texas

                                           My Commission Expires
                                           November 21, 1999



                                       4


<PAGE>   1
                                                                     EXHIBIT 3.5

                                                                  PAGE 1

                                STATE OF DELAWARE
                        OFFICE OF THE SECRETARY OF STATE
                      ------------------------------------


         I, EDWARD J. FREEL, SECRETARY OF STATE OF THE STATE OF DELAWARE, DO
HEREBY CERTIFY THE ATTACHED IS A TRUE AND CORRECT COPY OF THE CERTIFICATE OF
AGREEMENT OF MERGER, WHICH MERGES:

         "MWJR PETROLEUM CORPORATION", A DELAWARE CORPORATION,

         WITH AND INTO "APACHE CORPORATION" UNDER THE NAME OF" APACHE
CORPORATION", A CORPORATION ORGANIZED AND EXISTING UNDER THE LAWS OF THE STATE
OF DELAWARE, AS RECEIVED AND FILED IN THIS OFFICE THE NINETEENTH DAY OF AUGUST,
A.D. 1998, AT 8:30 O'CLOCK A.M.

         AND I DO HEREBY FURTHER CERTIFY THAT THE EFFECTIVE DATE OF THE
AFORESAID CERTIFICATE OF AGREEMENT OF MERGER IS THE FIRST DAY OF SEPTEMBER, A.D.
1998.

         A FILED COPY OF THIS CERTIFICATE HAS BEEN FORWARDED TO THE NEW CASTLE
COUNTY RECORDER OF DEEDS.


                                       /s/ Edward J. Freel
                                       -----------------------------------------
                                       Edward J. Freel, Secretary of State

                                     [SEAL]

     0482215  8100M                               AUTHENTICATION:  9260798
     981324877                                              DATE:  08-19-98



<PAGE>   2


                          AGREEMENT AND PLAN OF MERGER


                                     BETWEEN
                               APACHE CORPORATION
                                       AND
                           MWJR PETROLEUM CORPORATION


AGREEMENT AND PLAN OF MERGER ("Agreement"), dated this 7th day of August, 1998,
pursuant to Section 251 of the General Corporation Law of the State of Delaware,
between Apache Corporation, a Delaware corporation, and MWJR Petroleum
Corporation, a Delaware corporation (together, the "Constituent Corporations").

WITNESSETH that:

WHEREAS, both of the Constituent Corporations desire to merge into a single
corporation; and

NOW THEREFORE, the corporations, parties to this Agreement, in consideration of
the mutual covenants, agreements and provisions hereinafter contained do hereby
prescribe the terms and conditions of said merger and the mode of carrying the
same into effect as follows:

         FIRST: MWJR Petroleum Corporation (the "Merged Corporation") at the
effective time shall be merged with and into Apache Corporation, which shall be
the surviving corporation (the "Surviving Corporation").

         SECOND: The Restated Certificate of Incorporation of Apache
Corporation, as heretofore amended and as in effect on the date of the merger
provided for in this Agreement, shall continue in full force and effect as the
Restated Certificate of Incorporation of the Surviving Corporation.

         THIRD: The effect on the capital stock of each of the Constituent
Corporations shall be as follows:

         (a)  Each share of capital stock of the Surviving Corporation issued
              and outstanding on the effective date of the merger shall remain
              issued and outstanding.

         (b)  Each share of capital stock of the Merged Corporation issued and
              outstanding on the effective date of the merger shall be cancelled
              without consideration, and no shares of the capital stock of the
              Surviving Corporation shall be issued in respect thereof.

         FOURTH: The bylaws of Apache Corporation as they exist on the effective
date of the merger shall be and remain the bylaws of the Surviving Corporation
until the same shall be altered, amended or repealed as therein provided.

                                      -1-

<PAGE>   3


         FIFTH: The directors and officers of Apache Corporation on the
effective date of the merger shall be the directors and officers of the
Surviving Corporation and shall continue in office until the next annual meeting
of stockholders and until their successors shall have been elected and
qualified.

         SIXTH:  This merger shall become on September 1, 1998.

         SEVENTH: Upon the merger becoming effective, all the property, rights
privileges, franchises, patents, trademarks, licenses, registrations and other
assets of every kind and description of the Merged Corporation shall, by
operation of law, be transferred to, vested in, and devolve upon, the Surviving
Corporation without further act or deed, and all property, rights, and every
other interest of the Constituent Corporations shall be as effectively the
property of the Surviving Corporation as they were of the Surviving Corporation
and the Merged Corporation, respectively. The proper officers and directors of
the Surviving Corporation are fully authorized in the name of the Merged
Corporation or otherwise to take any and all action, from time to time, to
execute and deliver or cause to be executed and delivered all such deeds and
instruments and to take or cause to be taken such further or other action as the
Surviving Corporation may deem necessary or desirable in order to vest in and
confirm to the Surviving Corporation title to and possession of any property of
the Merged Corporation acquired or to be acquired by reason of or as a result of
the merger herein provided for and otherwise to carry out the intent and
purposes hereof.

         EIGHTH: Anything herein or elsewhere to the contrary notwithstanding,
this merger may be amended or terminated and abandoned by the Board of Directors
of either of the Constituent Corporations at any time prior to the date of
filing this Agreement with the Delaware Secretary of State.

IN WITNESS WHEREOF, the parties to this Agreement, pursuant to the approval and
authority duly given by resolutions duly adopted by their respective Boards of
Directors, have caused these presents to be executed by the president and
attested by the corporate secretary of each party hereto as the respective act,
deed and agreement of each of said corporations, on this 7th day of August,
1998.


ATTEST:                                APACHE CORPORATION


/s/ Cheri L. Peper                     By: /s/ G. Steven Farris
- -----------------------------------       --------------------------------------
Cheri L. Peper                            G. Steven Farris
Corporate Secretary                       President and Chief Operating Officer


ATTEST:                                MWJR PETROLEUM CORPORATION


/s/ Cheri L. Peper                     By: /s/ G. Steven Farris      
- -----------------------------------       --------------------------------------
Cheri L. Peper                            G. Steven Farris
Corporate Secretary                       President

                                      -2-

<PAGE>   4


         I, Cheri L. Peper, Corporate Secretary of Apache Corporation, a
corporation organized and existing under the laws of the State of Delaware,
hereby certify that the Agreement and Plan of Merger to which this Certificate
is attached, after having been first duly signed on behalf of said Apache
Corporation and having been signed on behalf of MWJR Petroleum Corporation, a
corporation organized and existing under the laws of the State of Delaware, was
duly adopted by action of the Board of Directors of said Apache Corporation and
without any vote of its stockholders pursuant to Section 251(f) of the General
Corporation Law of Delaware and that the conditions specified in the first
sentence of such Section 251(f) have been satisfied.


WITNESS my hand on this 7th day of August, 1998.


                                       /s/ Cheri L. Peper
                                       -----------------------------------------
         [Seal]                        Cheri L. Peper
                                       Corporate Secretary

                                      -3-

<PAGE>   1
                                                                     EXHIBIT 3.6

                                                                  PAGE 1

                                STATE OF DELAWARE
                        OFFICE OF THE SECRETARY OF STATE
                      ------------------------------------


         I, EDWARD J. FREEL, SECRETARY OF STATE OF THE STATE OF DELAWARE, DO
HEREBY CERTIFY THE ATTACHED IS A TRUE AND CORRECT COPY OF THE CERTIFICATE OF
AGREEMENT OF MERGER, WHICH MERGES:

         "MW PETROLEUM CORPORATION", A COLORADO CORPORATION,

         WITH AND INTO "APACHE CORPORATION" UNDER THE NAME OF" APACHE
CORPORATION", A CORPORATION ORGANIZED AND EXISTING UNDER THE LAWS OF THE STATE
OF DELAWARE, AS RECEIVED AND FILED IN THIS OFFICE THE NINETEENTH DAY OF AUGUST,
A.D. 1998, AT 8:31 O'CLOCK A.M.

         AND I DO HEREBY FURTHER CERTIFY THAT THE EFFECTIVE DATE OF THE
AFORESAID CERTIFICATE OF AGREEMENT OF MERGER IS THE FIRST DAY OF SEPTEMBER, A.D.
1998.

         A FILED COPY OF THIS CERTIFICATE HAS BEEN FORWARDED TO THE NEW CASTLE
COUNTY RECORDER OF DEEDS.


                                       /s/ Edward J. Freel                  
                                       -----------------------------------------
                                       Edward J. Freel, Secretary of State

                                     [SEAL]


     0482215  8100M                            AUTHENTICATION:    9261680
     981324886                                           DATE:    8-19-98



<PAGE>   2


                       CERTIFICATE OF OWNERSHIP AND MERGER


                                     MERGING
                            MW PETROLEUM CORPORATION
                                      INTO
                               APACHE CORPORATION


         Apache Corporation, a corporation organized and existing under the laws
of the State of Delaware, DOES HEREBY CERTIFY:

         FIRST: That Apache Corporation was incorporated on the 6th day of
December, 1954, pursuant to the General Corporation Law of the State of
Delaware.

         SECOND: That Apache Corporation owns all of the issued and outstanding
shares of the capital stock of MW Petroleum Corporation, a corporation formerly
known as MW Acquisition Corporation and which was incorporated on the 20th day
of December, 1991, pursuant to the Revised Statutes of the State of Colorado.

         THIRD: That Apache Corporation, by the following resolutions of its
Board of Directors, duly adopted at a meeting held on the 30th day of April,
1998, determined to and did merge into itself said MW Petroleum Corporation:

         RESOLVED: That MW Petroleum Corporation ("MW"), a wholly owned
         subsidiary of Apache Corporation, be merged with and into Apache
         Corporation ("Apache"), with Apache being the surviving corporation.

         FURTHER RESOLVED: That the merger shall be effective on September 1,
         1998.

         FURTHER RESOLVED: That the Restated Certificate of Incorporation of
         Apache, as heretofore amended and as in effect on the date of the
         merger, shall continue in full force and effect as the Restated
         Certificate of Incorporation of the surviving corporation.

         FURTHER RESOLVED: That each share of the capital stock of Apache, the
         surviving corporation, issued and outstanding on the effective date of
         the merger shall remain issued and outstanding.

         FURTHER RESOLVED: That each share of the capital stock of MW issued and
         outstanding on the effective date of the merger shall be cancelled
         without consideration, and no shares of the capital stock of Apache,
         the surviving corporation, shall be issued in exchange therefore.

                                       1

<PAGE>   3


         FURTHER RESOLVED: That the bylaws of Apache, as they exist on the
         effective date of the merger, shall be and remain the bylaws of Apache,
         the surviving corporation, until the same shall be altered, amended or
         repealed as therein provided.

         FURTHER RESOLVED: That the directors and officers of Apache on the
         effective date of the merger shall be the directors and officers of the
         surviving corporation and shall continue in office until the next
         annual meeting of stockholders and until their successors have been
         elected and qualified.

         FURTHER RESOLVED: That, upon the merger taking effect, Apache shall
         thereupon and thereafter possess all the rights, privileges,
         immunities, and franchises, of a public as well as a private nature, of
         each of Apache and MW; that all property, real, personal, and mixed,
         and all debts due on whatever account, including subscriptions to
         shares, and all other chooses in action, and every other interest of or
         belonging to or due to MW shall be deemed to be transferred to and
         vested in Apache without further act or deed; that the title to any
         real estate, or any interest therein vested in either of Apache or MW
         shall not revert or be in any way impaired by reason of the merger; and
         that such transfer to and vesting in Apache shall be deemed to occur by
         operation of law, and no consent or approval of any other person shall
         be required in connection with any such transfer or vesting unless such
         consent or approval is specifically required in the event of merger by
         law or by express provision in any contract, agreement, decree, order,
         or other instrument to which either of Apache or MW is a party or by
         which either is bound.

         FURTHER RESOLVED: That, upon the merger taking effect, Apache shall be
         responsible and liable for all the liabilities and obligations of MW;
         that any claim existing or action or proceeding, whether civil or
         criminal, pending by or against MW may be prosecuted as if the merger
         had not taken place; and that neither the rights of creditors nor any
         liens upon the property of either of Apache or MW shall be impaired by
         such merger.

         FURTHER RESOLVED: That the proper officers of Apache are hereby
         authorized and directed, in the name and on behalf of Apache, to
         prepare and execute a Certificate of Ownership and Merger setting forth
         a copy of the resolutions authorizing the merger of MW with and into
         Apache and the assumption by Apache of the liabilities and obligations
         of MW, and the date of adoption thereof, and to cause such Certificate
         of Ownership and Merger to be filed with the Delaware Secretary of
         State and a certified copy of same recorded in the office of the
         Recorder of Deeds of New Castle County.

                                       2

<PAGE>   4


         FURTHER RESOLVED: That the proper officers of Apache be, and they
         hereby are, authorized and directed to take such further action and to
         execute and file such certificates and other documents as they, in
         their discretion, shall deem necessary or advisable to consummate the
         merger and effect the foregoing resolutions including, without
         limitation, articles of merger or share exchange for filing with the
         Colorado Secretary of State.

         FURTHER RESOLVED: This merger may be amended or terminated and
         abandoned by the Board of Directors of Apache at any time prior to the
         date of filing the merger with the Secretary of State of Delaware and
         of Colorado.

         IN WITNESS WHEREOF, Apache Corporation has caused this Certificate of
Ownership and Merger to be executed by its duly authorized officers as of this
7th day of August, 1998.

                                       APACHE CORPORATION


                                       By: /s/ G. Steven Farris              
                                           -------------------------------------
                                           G. Steven Farris
                                           President and Chief Operating Officer

ATTEST:


/s/ Cheri L. Peper                          
- -----------------------------------
Cheri L. Peper
Corporate Secretary

                                       3

<PAGE>   1
                                                                     EXHIBIT 3.7

                                                                          PAGE 1

                                STATE OF DELAWARE
                        OFFICE OF THE SECRETARY OF STATE
                      ------------------------------------


         I, EDWARD J. FREEL, SECRETARY OF STATE OF THE STATE OF DELAWARE, DO
HEREBY CERTIFY THE ATTACHED IS A TRUE AND CORRECT COPY OF THE CERTIFICATE OF
DESIGNATION OF "APACHE CORPORATION", FILED IN THIS OFFICE ON THE TWENTY-FIRST
DAY OF AUGUST, A.D. 1998, AT 1:30 O'CLOCK P.M.

         A FILED COPY OF THIS CERTIFICATE HAS BEEN FORWARDED TO THE NEW CASTLE
COUNTY RECORDER OF DEEDS.


                                          /s/ Edward J. Freel
                                          --------------------------------------
                                          Edward J. Freel, Secretary of State


                                     [SEAL]


         0482215  8100                           AUTHENTICATION:      9265795
         981328934                                         DATE:      08-21-98



<PAGE>   2



                          CERTIFICATE OF DESIGNATIONS,
                             PREFERENCES AND RIGHTS

                                       OF

                   5.68% CUMULATIVE PREFERRED STOCK, SERIES B

                                       OF

                               APACHE CORPORATION

             PURSUANT TO SECTION 151 OF THE GENERAL CORPORATION LAW
                            OF THE STATE OF DELAWARE


Apache Corporation, a corporation organized and existing under the General
Corporation Law of the State of Delaware (the "Corporation"), in accordance with
the provisions of Section 103 thereof, DOES HEREBY CERTIFY:

That pursuant to the authority vested in the Board of Directors in accordance
with the provisions of the Restated Certificate of Incorporation of the
Corporation, which authorizes the issuance by the Corporation of up to five
million (5,000,000) shares of no par value preferred stock, which authority was
delegated by the Board of Directors to a committee of the Board of Directors
(the "Committee") pursuant to resolutions adopted by unanimous written consent
dated June 18, 1998, the Committee by unanimous written consent dated August 25,
1998, adopted the following resolution creating and providing for the issuance
of a series of preferred stock of the Corporation:

         RESOLVED: That, pursuant to the authority delegated by the Board of
         Directors of the Corporation, the Committee hereby creates a series of
         preferred stock of the Corporation and hereby states the designation
         and number of shares, and fixes the relative rights, preferences and
         limitations thereof (in addition to the provisions set forth in the
         Restated Certificate of Incorporation of the Corporation, which are
         applicable to all series of the Corporation's preferred stock) as
         follows:

                   5.68% CUMULATIVE PREFERRED STOCK, SERIES B

         1. Number of Shares and Designation. One hundred thousand (100,000)
shares of the five million (5,000,000) authorized shares of no par value
preferred stock of the Corporation are hereby constituted as a series of
preferred stock, no par value per share, designated as "5.68% Cumulative
Preferred Stock, Series B" (hereinafter called the "Series B Preferred Stock").



                                       1

<PAGE>   3


         2. Ranking. The Series B Preferred Stock shall rank prior and superior
to all of the Common Stock of the Corporation now or hereafter outstanding, and
the Series A Junior Participating Preferred Stock of the Corporation as to
payment of dividends and distribution of assets upon dissolution, liquidation or
winding up of the Corporation.

         3. Dividends.

                  (i) General. Cumulative cash dividends shall be payable on
each share of Series B Preferred Stock when, as and if declared by the Board of
Directors of the Corporation or a duly authorized committee thereof, out of the
assets of the Corporation legally available therefor.

                  The initial dividend for the dividend period commencing on
         August 25, 1998, to but excluding October 30, 1998, will be $10.26 per
         share and shall be payable on October 30, 1998. Thereafter, dividends
         on the Series B Preferred Stock shall be payable quarterly, when, as
         and if declared by the Board of Directors of the Corporation or a duly
         authorized committee thereof on the last business day of January,
         April, July and October of each year (each a "Dividend Payment Date")
         at the annual rate of 5.68% or $56.80 per share. The amount of
         dividends payable on each share of Series B Preferred Stock for each
         full quarterly period shall be computed by dividing the annual dividend
         rate by four. The amount of dividends payable for any other period that
         is shorter or longer than a full quarterly dividend period will be
         computed on the basis of a 360-day year consisting of twelve 30-day
         months.


                  If a Dividend Payment Date is not a business day, dividends
(if declared) on the Series B Preferred Stock shall be paid on the next business
day, without interest. As used herein, the term "business day" means any day
other than a Saturday or Sunday or any other day on which banks in The City of
New York are authorized or required by law or executive order to close. A
dividend period with respect to a Dividend Payment Date is the period commencing
on the preceding Dividend Payment Date and ending on the day immediately prior
to the next Dividend Payment Date. Dividends payable, if declared, on a Dividend
Payment Date shall be payable to holders of record as they appear on the stock
books of the Corporation on the record date, which shall be the fifteenth day of
the calendar month in which the applicable Dividend Payment Date falls (each, a
"Dividend Record Date").

                  Dividends on the Series B Preferred Stock shall be cumulative
if the Corporation fails to declare one or more dividends on the Series B
Preferred Stock in any amount, whether or not the earnings or financial
condition of the Corporation were sufficient to pay such dividends in whole or
in part.

                  Holders of shares of Series B Preferred Stock shall not be
entitled to any dividend, whether payable in cash, property or stock, in excess
of full dividends (including accrued dividends, if any) on shares of Series B
Preferred Stock. No interest or sum of money in lieu of interest shall be
payable in respect of any dividend or payment which may be in arrears.

                  Dividends in arrears on the Series B Preferred Stock payable,
if declared, but not declared for payment or paid on any Dividend Payment Date
may be declared by the Board of Directors of the Corporation or a duly
authorized committee thereof and paid on any date fixed by the 



                                       2

<PAGE>   4

Board of Directors of the Corporation or a duly authorized committee thereof,
whether or not a Dividend Payment Date, to the holders of record of the shares
of Series B Preferred Stock, as they appear on the stock register of the
Corporation on such record date, which shall be not less than ten nor more than
30 days prior to the payment date therefor, as shall be fixed by the Board of
Directors of the Corporation or a duly authorized committee thereof.

                  (ii) Changes in the Dividends Received Percentage. If, prior
to 18 months after the date of the original issuance of the Series B Preferred
Stock, one or more amendments to the U. S. Internal Revenue Code of 1986, as
amended (the "Code"), are enacted which change the percentage of the dividends
received deduction as specified in Section 243(a)(1) of the Code or any
successor provision (the "Dividends Received Percentage"), the amount of each
dividend on each share of the Series B Preferred Stock for dividend payments
made on or after the date of enactment of such change shall be adjusted by
multiplying the amount of the dividend payable determined as described above
(before adjustment) by a factor, which shall be the number determined in
accordance with the following formula (the "DRD Formula"), and rounding the
result to the nearest cent (with one-half cent and above rounded up):

                                 1-[.35 (1-.70)]
                                 ---------------
                                 1-[.35 (1-DRP)]

                  For the purposes of the DRD Formula, "DRP" means the Dividends
Received Percentage applicable to the dividend in question; provided however,
that if the Dividends Received Percentage applicable to the dividend in question
shall be less than 50%, then the DRP shall equal .50. No amendment to the Code,
other than a change in the percentage of the dividends received deduction set
forth in Section 243(a)(1) of the Code or any successor provision, shall give
rise to such an adjustment. Notwithstanding the foregoing provisions, in the
event that, with respect to any such amendment, the Corporation receives either
an unqualified opinion from a nationally recognized independent tax counsel
selected by the Corporation or a private letter ruling or similar form of
authorization from the U.S. Internal Revenue Service ("IRS") to the effect that
such an amendment does not apply to dividends payable on the Series B Preferred
Stock, then any such amendment shall not result in the adjustment provided for
pursuant to the DRD Formula. The opinion referenced in the previous sentence
shall be based upon a specific exception in the legislation amending the DRP or
upon a published pronouncement of the IRS addressing such legislation. Unless
the context otherwise requires, references to dividends herein shall mean
dividends as adjusted by the DRD Formula. The Corporation's calculation of the
dividends payable as so adjusted, and as certified accurate as to calculation
and reasonable as to method by the independent certified public accountants then
regularly engaged by the Corporation, shall be final and not subject to review.

                  If any amendment to the Code which reduces the Dividends
Received Percentage is enacted after a Dividend Record Date and before the next
Dividend Payment Date, the amount of dividend payable on such Dividend Payment
Date shall not be increased; but instead, an amount equal to the excess of (x)
the product of the dividends paid by the Corporation on such Dividend Payment
Date and the DRD Formula (where the DRP used in the DRD Formula would be equal
to the greater of the Dividends Received Percentage applicable to the dividend
in question and .50) over (y) the dividends paid by the Corporation on such
Dividend Payment Date, shall be payable (if declared) to holders of record on
the next succeeding Dividend Payment Date in addition to any other amounts
payable on such date.



                                       3

<PAGE>   5

                  In addition, if any such amendment to the Code is enacted that
reduces the Dividends Received Percentage and such reduction retroactively
applies to a Dividend Payment Date as to which the Corporation previously paid
dividends on the Series B Preferred Stock (each an "Affected Dividend Payment
Date"), the Corporation shall pay (if declared) additional dividends (the
"Additional Dividends") on the next succeeding Dividend Payment Date (or if such
amendment is enacted after the dividend payable on such Dividend Payment Date
has been declared, on the second succeeding Dividend Payment Date following the
date of enactment) to holders of record on such succeeding Dividend Payment Date
in an amount equal to the excess of (x) the product of the dividends paid by the
Corporation on each Affected Dividend Payment Date and the DRD Formula (where
the DRP used in the DRD Formula would be equal to the greater of the Dividends
Received Percentage and .50 applied to each Affected Dividend Payment Date) over
(y) the dividends paid by the Corporation on each Affected Dividend Payment
Date.

                  Notwithstanding the foregoing, Additional Dividends shall not
be paid as a result of the enactment of any amendment to the Code 18 months or
more after the date of original issuance of the Series B Preferred Stock which
retroactively reduces the Dividends Received Percentage, or if such amendment
would not result in an adjustment due to the Corporation having received either
an opinion of counsel or tax ruling referred to in the third preceding
paragraph. The Corporation shall make only one payment of Additional Dividends.

                  In the event that the amount of dividend payable per share of
the Series B Preferred Stock shall be adjusted pursuant to the DRD Formula
and/or Additional Dividends are to be paid, the Corporation will cause notice of
each adjustment and, if applicable, any Additional Dividends, to be sent to the
holders of the Series B Preferred Stock with the payment of dividends on the
next Dividend Payment Date after the date of such adjustment.

                  In the event that, prior to 18 months after the date of the
original issuance of the Series B Preferred Stock, the Dividends Received
Percentage is reduced to 50% or less, the Corporation may, at its option, redeem
the Series B Preferred Stock in whole, but not in part, as described below.

                  (iii)    Payment Restrictions. The Corporation may not declare
                           or pay any dividend or make any distribution of
                           assets (other than dividends paid or other
                           distributions made in stock of the Corporation
                           ranking junior to the Series B Preferred Stock as to
                           the payment of dividends and the distribution of
                           assets upon liquidation, dissolution or winding up)
                           on, or redeem, purchase or otherwise acquire (except
                           upon conversion or exchange for stock of the
                           Corporation ranking junior to the Series B Preferred
                           Stock as to the payment of dividends and the
                           distribution of assets upon liquidation, dissolution
                           or winding up), shares of Common Stock, of Series A
                           Preferred Stock or of any other stock of the
                           Corporation ranking junior to the Series B Preferred
                           Stock as to the payment of dividends or the
                           distribution of assets upon liquidation, dissolution
                           or winding up, unless all accrued and unpaid
                           dividends on the Series B Preferred Stock for all
                           prior dividend periods have been or contemporaneously
                           are declared and paid and the full quarterly dividend
                           on the Series B Preferred Stock for the current
                           dividend period has been or contemporaneously is
                           declared and set apart for payment.



                                       4

<PAGE>   6

                  Whenever all accrued dividends on the Series B Preferred Stock
are not paid in full, the Corporation may not declare or pay dividends or make
any distribution of assets (other than dividends paid or other distributions
made in stock of the Corporation ranking junior to the Series B Preferred Stock
as to the payment of dividends and the distribution of assets upon liquidation,
dissolution or winding up) on any other stock of the Corporation ranking on a
parity with the Series B Preferred Stock as to the payment of dividends unless
(i) all accrued and unpaid dividends on the Series B Preferred Stock for all
prior dividend periods are contemporaneously declared and paid or (ii) all
dividends declared and paid or set apart for payment or other distributions made
on the Series B Preferred Stock and any other stock of the Corporation ranking
on a parity with the Series B Preferred Stock as to the payment of dividends are
declared and paid or set apart for payment or made pro rata so that the amount
of dividends declared and paid or set apart for payment or other distributions
made per share on the Series B Preferred Stock and such other stock of the
Corporation will bear the same ratio that accrued and unpaid dividends per share
on the Series B Preferred Stock and such other stock of the Corporation bear to
each other.

                  Whenever all accrued dividends on the Series B Preferred Stock
are not paid in full, the Corporation may not redeem, purchase or otherwise
acquire (except upon conversion or exchange for stock of the Corporation ranking
junior to the Series B Preferred Stock as to the payment of dividends and the
distribution of assets upon liquidation, dissolution or winding up) other stock
of the Corporation ranking on a parity with the Series B Preferred Stock as to
the payment of dividends or the distribution of assets upon liquidation,
dissolution or winding up unless (i) all outstanding shares of the Series B
Preferred Stock are contemporaneously redeemed or (ii) a pro rata redemption is
made of shares of Series B Preferred Stock and such other stock of the
Corporation, with the amount allocable to each series of such stock determined
on the basis of the aggregate liquidation preference of the outstanding shares
of each series and the shares of each series being redeemed only on a pro rata
basis.

         4. Liquidation Preference. In the event of any voluntary or involuntary
liquidation, dissolution or winding up of the Corporation, the holders of shares
of Series B Preferred Stock shall be entitled to receive out of the assets of
the Corporation available for distribution to stockholders, before any
distribution of assets is made on the Common Stock of the Corporation or any
other class or series of stock of the Corporation ranking junior to the Series B
Preferred Stock, upon liquidation, a liquidating distribution in the amount of
$1,000 per share, plus an amount equal to the sum of all accrued and unpaid
dividends including any increase in dividends payable due to changes in the
Dividends Received Percentage and Additional Dividends (whether or not earned or
declared) for the then-current dividend period and all dividend periods prior
thereto.

                  Neither the sale of all or substantially all of the property
         or business of the Corporation, nor the merger, conversion or
         consolidation of the Corporation into or with any other corporation,
         nor the merger, conversion or consolidation of any other corporation
         into or with the Corporation shall constitute a liquidation,
         dissolution or winding up, voluntary or involuntary, for the purposes
         of the foregoing paragraph. After the payment to the holders of the
         shares of Series B Preferred Stock of the full preferential amounts
         provided for above, the holders of the shares of Series B Preferred
         Stock as such shall have no right or claim to any of the remaining
         assets of the Corporation.


                  In the event the assets of the Corporation available for
distribution to the holders of the shares of Series B Preferred Stock upon any
liquidation, dissolution or winding up of the Corporation, 



                                       5

<PAGE>   7

whether voluntary or involuntary, shall be insufficient to pay in full all
amounts to which such holders are entitled as provided above, no such
distribution shall be made on account of any other stock of the Corporation
ranking on a parity with the Preferred Stock as to the distribution of assets
upon such liquidation, dissolution or winding up unless a pro rata distribution
is made on the Series B Preferred Stock and such other stock of the Corporation,
with the amount allocable to each series of such stock determined on the basis
of the aggregate liquidation preference of the outstanding shares of each series
and distributions to the shares of each series being made on a pro rata basis.

         5. Voting Rights.

                  (i)      The holders of shares of Series B Preferred Stock
                           will not be entitled to vote, except as set forth
                           below or as expressly required by applicable law. In
                           exercising any such vote, each outstanding share of
                           Series B Preferred Stock shall be entitled to one
                           vote.

                  (ii)     If the equivalent of six quarterly dividends payable
                           on the Series B Preferred Stock or any other class or
                           series of preferred stock ranking on a parity with
                           the Series B Preferred Stock as to the payment of
                           dividends have not been paid, the Corporation has
                           resolved to increase the number of directors of the
                           Corporation by two (without duplication of any
                           increase made pursuant to the terms of any other
                           series of preferred stock of the Corporation), and
                           the holders of the Series B Preferred Stock, voting
                           as a single class with the holders of shares of any
                           other class of the preferred stock of the Corporation
                           ranking on a parity with the Series B Preferred Stock
                           either as to dividends or distribution of assets and
                           upon which like voting rights have been conferred and
                           are exercisable, will be entitled to elect two
                           directors at any meeting of stockholders of the
                           Corporation at which directors are to be elected held
                           during the period such dividends remain in arrears.
                           Each class or series of preferred stock entitled to
                           vote for the additional directors shall have a number
                           of votes proportionate to the aggregate liquidation
                           preference of its outstanding shares. Such voting
                           right shall continue until full cumulative dividends
                           for all past dividend periods on all such preferred
                           stock of the Corporation, including any shares of the
                           Series B Preferred Stock, have been paid or declared
                           and set apart for payment. Any such elected directors
                           shall serve until the Corporation's next annual
                           meeting of stockholders (notwithstanding that prior
                           to the end of such term the right to elect directors
                           shall cease to exist) or until their respective
                           successors shall be elected and qualify.

                  (iii)    Whenever such right shall vest, it may be exercised
                           initially either at a special meeting of holders of
                           Series B Preferred Stock or at any annual
                           stockholders' meeting, but thereafter it shall be
                           exercised only at annual stockholders' meetings. Any
                           director who shall have been elected by the holders
                           of Series B Preferred Stock as a class pursuant to
                           this subparagraph (iii) may be removed at any time,
                           either for or without cause by, and only by, the
                           affirmative votes of the holders of record of a
                           majority of the outstanding shares of Series B
                           Preferred Stock given at a special meeting of such
                           stockholders called for such purpose, and any vacancy
                           created by such removal may also be filled at such
                           meeting. Any vacancy 


                                       6

<PAGE>   8

                           caused by the death or resignation of a director who
                           shall have been elected by the holders of Series B
                           Preferred Stock as a class pursuant to this
                           subparagraph (iii) may be filled only by the holders
                           of all outstanding Series B Preferred Stock at a
                           meeting called for such purpose.

                  Any meeting of the holders of all outstanding Series B
Preferred Stock entitled to vote as a class for the election or removal of
directors shall be held at the place at which the last annual meeting of
stockholders was held. At such meeting, the presence in person or by proxy of
the holders of a majority of the outstanding shares of all outstanding Series B
Preferred Stock shall be required to constitute a quorum; in the absence of a
quorum, a majority of the holders present in person or by proxy shall have the
power to adjourn the meeting from time to time without notice, other than
announcement at the meeting, until a quorum shall be present.

                  (iv) So long as any Series B Preferred Stock is outstanding,
the affirmative vote or consent of the holders of at least 80% of the
outstanding shares of the Series B Preferred Stock will be required for any
amendment of the Restated Certificate of Incorporation of the Corporation (or
any certificate supplemental thereto) which will adversely affect the powers,
preferences, privileges or rights of the Series B Preferred Stock. The
affirmative vote or consent of the holders of at least 80% of the outstanding
shares of the Series B Preferred Stock and any other series of the preferred
stock of the Corporation ranking on a parity with the Series B Preferred Stock
either as to dividends or upon liquidation, voting as a single class without
regard to series, will be required to issue, authorize or increase the
authorized amount of, or issue or authorize any obligation or security
convertible into or evidencing a right to purchase, any additional class or
series of stock ranking prior to the Series B Preferred Stock as to dividends or
upon liquidation, or to reclassify any authorized stock of the Corporation into
such prior shares, but such vote will not be required for the Corporation to
take any such actions with respect to any stock ranking on a parity with or
junior to the Series B Preferred Stock.

                  The affirmative vote or consent of the holders of a majority
of all the outstanding shares of Series B Preferred Stock, voting or consenting
separately as a class, shall be required to approve any merger, conversion,
consolidation or compulsory share exchange to which the Corporation is a party,
unless (i) the terms of such merger, conversion, consolidation or compulsory
share exchange do not provide for a change in the terms of the Series B
Preferred Stock and (ii) the Series B Preferred Stock is on a parity with or
prior to (in respect of the payment of dividends and the distribution of assets
upon liquidation, dissolution or winding up) any other class or series of
capital stock authorized by the surviving corporation, other than any class or
series of stock of the Corporation ranking senior as to the Series B Preferred
Stock either as to the payment of dividends or the distribution of assets upon
liquidation, dissolution or winding up of the Corporation and previously
authorized with the consent of holders of Series B Preferred Stock as described
herein (or other than any capital stock into which such prior stock is converted
as a result of such merger, consolidation or compulsory share exchange).

                  In addition, if the holders of the shares of the Series B
  Preferred Stock are entitled to vote upon or consent to a merger,
  consolidation, conversion or compulsory share exchange of the Corporation, and
  if the Corporation offers to purchase all of the outstanding shares of the
  Series B Preferred Stock (the "Offer"), then each holder of the Series B
  Preferred Stock who does not sell its shares of Series B Preferred Stock
  pursuant to the Offer shall be deemed irrevocably to have voted or consented
  all shares of Series B Preferred Stock owned by such holder in favor of the
  merger or consolidation of the Corporation without any further action by the
  holder. The Offer shall be at a price 



                                       7

<PAGE>   9

of $1,000 per share, together with accrued and unpaid dividends (whether or not
declared) to the date fixed for repurchase including any increase in dividends
payable due to changes in the Dividends Received Percentage and Additional
Dividends. The Offer shall remain open for acceptance for a period of at least
30 days.

6. Redemption. Prior to August 25, 2008, the Series B Preferred Stock is not
redeemable, except as set forth herein. On or after such date, each share of
Series B Preferred Stock shall be redeemable, in whole or in part, at the option
of the Corporation, at any time and from time to time, out of funds legally
available therefor, at a redemption price of $1,000 per share, plus accrued and
unpaid dividends (whether or not declared) to the date fixed for redemption,
including any increase in dividends payable due to changes in the Dividends
Received Percentage and Additional Dividends. If fewer than all the outstanding
shares of Series B Preferred Stock are to be redeemed, the Corporation will
select those to be redeemed by lot or pro rata or by any other method as may be
determined by the Board of Directors to be equitable.

         If, prior to 18 months after the date of the original issuance of the
Series B Preferred Stock, one or more amendments to the Code are enacted which
result in a reduction of the Dividend Received Percentage to 50% or less, the
Corporation, at its option may redeem all, but not less than all, of the
outstanding shares of Series B Preferred Stock provided that, within 60 days of
the date on which an amendment to the Code is enacted which changes the Dividend
Received Percentage to 50% or less, the Corporation sends notice to holders of
the Series B Preferred Stock of such redemption. Any redemption of the Series B
Preferred Stock pursuant to this paragraph will take place on the date specified
in the notice, which date shall not be less than 30 or more than 60 days from
the date such notice is sent to holders of the Series B Preferred Stock. Any
redemption of the Series B Preferred Stock in accordance with this paragraph
shall be at a redemption price equal to the greater of (i) $1,000 per share of
the Series B Preferred Stock (the "Liquidation Value") to be redeemed or (ii)
the sum of the present values of the Remaining Scheduled Dividends prior to
August 25, 2028 and the Liquidation Value assuming payment on August 25, 2028,
discounted to the redemption date on a quarterly basis (assuming a 360-day year
consisting of twelve 30-day months) at the Treasury Yield plus zero basis
points, excluding any increase in dividends payable due to changes in the
Dividend Received Deduction Percentage, if any, plus in the case of (i) or (ii)
accrued and unpaid dividends (whether or not declared) to the date fixed for
redemption.

                  "Treasury Yield" means, with respect to any redemption date,
the rate per annum equal to the semiannual equivalent yield to maturity of the
Comparable Treasury Issue, assuming a price for the Comparable Treasury Issue
(expressed as a percentage of its principal amount) equal to the Comparable
Treasury Rate for such redemption date.

         "Comparable Treasury Issue" means the United States Treasury security
selected by an Independent Investment Banker as having a maturity of August 25,
2028 that would be utilized, at the time of selection and in accordance with
customary financial practice, in pricing new issues of corporate debt securities
maturing on or about August 25, 2028. "Independent Investment Banker" means
Smith Barney Inc. or, if such firm is unwilling or unable to select the
Comparable Treasury Issue, an independent investment banking institution of
national standing appointed by the Corporation.

         "Comparable Treasury Rate" means, as of any date of determination, the
yield to maturity implied by (i) the yields reported, as of 10:00 A.M. (New York
City time) on the second business day preceding such date of determination on
the display designated as "Page 678" on the Telerate Access Service (or such
other display as may replace Page 678 on Telerate Access Service) for 


                                       8

<PAGE>   10

actively traded U.S. Treasury securities having a 30-year maturity as of such
date of determination, or (ii) if such yields are not reported as of such time
or the yields reported as of such time are not ascertainable, the Treasury
Constant Maturity Series Yields reported, for the latest day for which such
yields have been so reported as of the second business day preceding the date of
determination in Federal Reserve Statistical Release H.15 (519) (or any
comparable successor publication) for actively traded U.S. Treasury securities
having a 30-year constant maturity as of such date of determination.

         "Remaining Scheduled Dividends" means cumulative cash dividends at a
rate of 5.68% of the Liquidation Value per share of Series B Preferred Stock
equivalent to $56.80 per annum per share of Series B Preferred Stock from the
date specified in the notice until August 25, 2028.

         Not more than 60 nor less than 30 days prior to the redemption date,
notice by first class mail, postage prepaid, shall be given to the holders of
record of the Series B Preferred Stock to be redeemed, addressed to such
stockholders at their last addresses as shown on the books of the Corporation.
Each such notice of redemption shall specify the date fixed for redemption, the
redemption price, the place or places of payment, that payment will be made upon
presentation and surrender of the shares of Series B Preferred Stock and that on
and after the redemption date, dividends will cease to accumulate on such
shares.

         Any notice which is mailed as herein provided shall be conclusively
presumed to have been duly given, whether or not the holder of Series B
Preferred Stock receives such notice; and failure to give such notice by mail,
or any defect in such notice, to the holders of any shares designated for
redemption shall not affect the validity of the proceedings for the redemption
any other shares of Series B Preferred Stock. On or after the date fixed for
redemption as stated in such notice, each holder of the shares called for
redemption shall surrender the certificate evidencing such shares to the
Corporation at the place designated in such notice and shall thereupon be
entitled to receive payment of the redemption price. If less than all the shares
represented by any such surrendered certificate are redeemed, a new certificate
shall be issued representing the unredeemed shares. If, on the date fixed for
redemption, funds necessary for the redemption shall be available therefor and
shall have been irrevocably deposited or set aside, then, notwithstanding that
the certificates evidencing any shares so called for redemption shall not have
been surrendered, the dividends with respect to the shares so called shall cease
to accumulate after the date fixed for redemption, the shares shall no longer be
deemed outstanding, the holders thereof shall cease to be stockholders with
respect to such shares, and all rights whatsoever with respect to the shares so
called for redemption (except the right of the holders to receive the redemption
price without interest upon surrender of their certificates therefor) shall
terminate.

         The Series B Preferred Stock is not subject to any mandatory
redemption, sinking fund or other similar provisions.

         7. Outstanding Shares. For purposes of this Certificate of
Designations, all shares of Series B Preferred Stock shall be deemed
outstanding, except (i) from the date fixed for redemption pursuant to Section 6
hereof, all shares of Series B Preferred Stock that have been so called for
redemption under Section 6; and (ii) from the date of registration of transfer,
all shares of Series B Preferred Stock held of record by the Corporation or any
subsidiary of the Corporation.



                                       9

<PAGE>   11

         8. Preemptive Rights. The Series B Preferred Stock is not entitled to
any preemptive or subscription rights in respect of any securities of the
Corporation.

         9. Severability of Provisions. Whenever possible, each provision hereof
shall be interpreted in a manner as to be effective and valid under applicable
law, but if any provision hereof is held to be prohibited by or invalid under
applicable law, such provision shall be ineffective only to the extent of such
prohibition or invalidity, without invalidating or otherwise adversely affecting
the remaining provisions hereof. If a court of competent jurisdiction should
determine that a provision hereof would be valid or enforceable if a period of
time were extended or shortened or a particular percentage were increased or
decreased, then such court may make such change as shall be necessary to render
the provision in question effective and valid under applicable law.

         10. Fractional Shares. The Series B Preferred Stock may be issued in
fractions of a share which shall entitle the holder, in proportion to such
holder's fractional shares, to exercise voting rights, receive dividends,
participate in distributions and have the benefit of all other rights of holders
of Series B Preferred Stock.

         11. Reversion to Corporation. Subject to applicable escheat laws, any
monies set aside by the Corporation in respect of any payment with respect to
shares of the Series B Preferred Stock, or dividends thereon, and unclaimed at
the end of two years from the date upon which such payment is due and payable
shall revert to the general funds of the Corporation, after which reversion the
holders of such shares shall look only to the general funds of the Company for
the payment thereof. Any interest accrued on funds so deposited shall be paid to
the Corporation from time to time.




                                       10

<PAGE>   12



This Certificate shall be effective as of August 21, 1998.

IN WITNESS WHEREOF, said Apache Corporation has caused this Certificate to be
signed by Raymond Plank, its Chairman and Chief Executive Officer, and attested
by Cheri L. Peper, its Corporate Secretary, this 20th day of August, 1998.



ATTEST:                                        APACHE CORPORATION



/s/ Cheri L. Peper                             /s/ Raymond Plank
- --------------------------------               --------------------------------
Name:    Cheri L. Peper                        Name: Raymond Plank
Title:   Corporate Secretary                   Title: Chairman and Chief 
                                                        Executive Officer






                                       11




<PAGE>   1
                                                                     EXHIBIT 3.8

                                                                PAGE 1

                                STATE OF DELAWARE
                        OFFICE OF THE SECRETARY OF STATE
                      ------------------------------------


         I, EDWARD J. FREEL, SECRETARY OF STATE OF THE STATE OF DELAWARE, DO
HEREBY CERTIFY THE ATTACHED IS A TRUE AND CORRECT COPY OF THE CERTIFICATE OF
CORRECTION OF "APACHE CORPORATION", FILED IN THIS OFFICE ON THE TWENTY-FOURTH
DAY OF AUGUST, A.D. 1998, AT 1:00 O'CLOCK P.M.

         A FILED COPY OF THIS CERTIFICATE HAS BEEN FORWARDED TO THE NEW CASTLE
COUNTY RECORDER OF DEEDS.


                                             /s/ EDWARD J. FREEL
                                             ----------------------------------
                                             Edward J. Freel, Secretary of State

                                     [SEAL]
0482215  8100                                AUTHENTICATION:        9267715
981330420                                              DATE:        08-24-98



<PAGE>   2
                            CERTIFICATE OF CORRECTION
                        FILED TO CORRECT A CERTAIN ERROR
                                       IN
               CERTIFICATE OF DESIGNATIONS, PREFERENCES AND RIGHTS
                                       OF
                   5.68% CUMULATIVE PREFERRED STOCK, SERIES B
                                       OF
                               APACHE CORPORATION

            FILED IN THE OFFICE OF THE SECRETARY OF STATE OF DELAWARE
                               ON AUGUST 21, 1998


Apache Corporation, a corporation organized and existing under and by virtue of
the General Corporation Law of the State of Delaware,

DOES HEREBY CERTIFY:

         1.       The name of the corporation is Apache Corporation.

         2. That a Certificate of Designations, Preferences and Rights was filed
with the Secretary of State of Delaware on August 21, 1998, and that said
Certificate requires correction as permitted by Section 103 of the General
Corporation Law of the State of Delaware.

         3. The inaccuracy or defect of said Certificate to be corrected is as
follows: In the preamble of said Certificate, the date of the unanimous written
consent of the Committee of the Board of Directors adopting the resolutions that
created the 5.68% Cumulative Preferred Stock, Series B of Apache Corporation, is
stated as being August 25, 1998. The correct date of such written consent of the
Committee is August 20, 1998.

         4. As corrected the preamble of said Certificate reads as follows:

         "Apache Corporation, a corporation organized and existing under the
         General Corporation Law of the State of Delaware (the "Corporation"),
         in accordance with the provisions of Section 103 thereof, DOES HEREBY
         CERTIFY:

         That pursuant to the authority vested in the Board of Directors in
         accordance with the provisions of the Restated Certificate of
         Incorporation of the Corporation, which authorizes the issuance by the
         Corporation of up to five million (5,000,000) shares of no par value
         preferred stock, which authority was delegated by the Board of
         Directors to a committee of the Board of Directors (the "Committee")
         pursuant to resolutions adopted by unanimous written consent dated June
         18, 1998, the Committee by unanimous written consent dated August 20,
         1998, adopted the following resolution creating and providing for the
         issuance of a series of preferred stock of the Corporation:"


                                  Page 1 of 2

<PAGE>   3

IN WITNESS WHEREOF, said Apache Corporation has caused this Certificate of
Correction to be signed by Cheri L. Peper, its Corporate Secretary, this 24th
day of August, 1998.



                                        APACHE CORPORATION



                                        By:  /s/ CHERI L. PEPER 
                                             ---------------------------------
                                             Cheri L. Peper
                                             Corporate Secretary


                                  Page 2 of 2

<PAGE>   1


                                                                   EXHIBIT 10.13




                    CORPORATE INCENTIVE COMPENSATION PLAN "A"
                             (SENIOR OFFICERS' PLAN)


1.       Purpose of the Plan 

         Apache Corporation (the "Company") adopts this Corporate Incentive
         Compensation Plan "A" (the "Plan") effective January 1, 1998. The
         purpose of this Plan is to provide incentive to certain senior officers
         of the Company to achieve certain financial and operational objectives
         of the financial plan of the Company. Senior Officers are in a unique
         position to shape the company's strategic direction and to put in place
         the tools -incentives, capital, etc., to support it's development or
         endorse the company's long range strategy, and have the power and
         authority to allocate resources and measure and reward goal
         achievement. The Corporate IC Plan "A" is intended to incentivize
         results that will:

         o  Enhance shareholder value,

         o  Enhance the Company's financial position, and

         o  Create interaction and involvement through the management of the
            Corporate IC Plan "B".

2.       Administration

         The Plan shall be administered by the Company's Board of Directors (the
         "Board"), except to the extent that the Plan delegates authority to the
         Management Development and Compensation Committee (the "Committee") of
         the Board, and except to the extent that the Board otherwise delegates
         or provides.

         The Committee shall administer the Plan and make recommendations to the
         Board concerning selection of employees eligible to participate in the
         Plan (the "Participants") and the funding of the Plan.

         All actions, decisions, and determinations of the Committee concerning
         the Plan and its administration shall be subject only to review by the
         Board to the extent the Board deems review appropriate, and shall
         otherwise be final, conclusive and binding upon the Company, its
         shareholders, subsidiaries, affiliates, employees and officers, and
         upon all Participants and all other affected persons.

3.       Eligible Participants

         The Committee will designate certain senior officers of the Company as
         Participants, but will include the Chairman/CEO and COO/President.



<PAGE>   2


4.       Assessment

         Assessment of the performance of the Participants and subsequent
         recommendations for payment of incentive compensation will rest with
         the Committee. The recommendation will be made to the Board for final
         approval.
         The Committee's assessment will include the following areas:

         1.    Comparison of company's performance for one year against that of
               a defined peer group of "tier one independents." (Attachment I)

         2.    Assessment of Participant's strategic management as evidenced by
               selection of and achievement of the tasks identified as the
               annual component of the strategic plan.

         3.    Other factors, such as participant's individual objectives which
               are deemed by the committee and the Board to bear on the annual
               incentive opportunity for the Participants.

         Comprehensive comparative information on defined peer group to be made
available to the Committee by Management.

5.       Distribution

         Awards under the Plan shall be determined as follows:

         a)    Eligible salary equal to 50% of base compensation,

         b)    Up to 75% of eligible salary be recommended by achievement as
               reviewed and approved by the Committee, and

         c)    Up to 25% of eligible percent of salary be recommended by
               achievement of personal objectives.

         Distribution of a Participant's award, if any, shall be made on or
         before 90 days after the end of the Plan year (the "Distribution
         Date".) A portion(s) of the award may be deferred to future years
         dependent upon the payout/funding mechanism as recommended annually by
         the Committee.

6.       Miscellaneous Provisions

         Neither the Plan nor any action taken hereunder shall be construed as
         giving any Participant any right to be retained in the employ of the
         Company or interfere in any way with the right of the Company to
         determine a Participant's compensation or any other terms of
         employment.

         A Participant's rights and interests under this Plan may not be
         assigned, transferred, attached, pledged, mortgaged or hypothecated.

         The Company has the right to offset from a Participant's award any
         amounts due from the Participant to the Company.



<PAGE>   3


         A Participant shall be entitled to an award under the Plan only if the
         Participant is employed by the Company or an affiliated company on the
         Distribution Date for the applicable Plan year. If a Participant dies,
         retires, or suffers a disability after receiving an award allocation,
         but prior to the Distribution Date, special provisions may be granted
         for that Participant by the Committee.

         This Plan, in combination with the Corporate Incentive Plan "B",
         supercedes and replaces the Company's Corporate Administrative Group
         Incentive Plan, as amended effective January 1, 1990.

7.       Amendment and Termination

         The Board, upon recommendation by the Committee, may at any time
         suspend, amend, modify or terminate the Plan; provided that no
         suspension, amendment, modification, or termination shall alter or
         impair any rights or obligations to any award distributed previously
         under the Plan. If this Plan is terminated during any incentive period
         for which Participants have been selected to participate, the Board
         may, in its sole discretion, make provision for payment of awards as it
         deems appropriate.

8.       Governing Law

         The Plan shall be construed in accordance with and governed by the laws
         of the State of Texas.



<PAGE>   4


Dated this 16th day of July, 1998.



Attest:

/s/ Cheri L. Peper                     /s/ Raymond Plank                   
- -----------------------------------    -----------------------------------------
CORPORATE SECRETARY                    RAYMOND PLANK
                                       CHAIRMAN & CHIEF EXECUTIVE OFFICER



/s/ Cheri L. Peper                     /s/ G. Steven Farris             
- -----------------------------------    -----------------------------------------
CORPORATE SECRETARY                    G. STEVEN FARRIS
                                       PRESIDENT & CHIEF OPERATING OFFICER


/s/ Cheri L. Peper                     /s/ Daniel L. Schaeffer          
- -----------------------------------    -----------------------------------------
CORPORATE SECRETARY                    DANIEL L. SCHAEFFER
                                       VICE PRESIDENT, HUMAN RESOURCES



<PAGE>   5


                                                                  ATTACHMENT "I"


                          LISTING OF PEER COMPANIES FOR
                             COMPARATIVE ASSESSMENT




                             NOBLE AFFILIATES, INC.

                             VASTAR RESOURCES, INC.

                         ANADARKO PETROLEUM CORPORATION

                             ENRON OIL & GAS COMPANY

                           BURLINGTON RESOURCES, INC.

                               ORYX ENERGY COMPANY

                                PENNZOIL COMPANY

                       UNION PACIFIC RESOURCES GROUP, INC.

<PAGE>   1
                                                                   EXHIBIT 10.14



                    CORPORATE INCENTIVE COMPENSATION PLAN "B"
                          (Strategic Objectives Format)


1.       PURPOSE OF THE PLAN 

         Apache Corporation (the "Company") adopts this Corporate Incentive
         Compensation Plan "B" (the "Plan") effective January 1, 1998. The
         purpose of this Plan is to provide incentive to certain officers,
         directors, managers and key personnel to achieve specified strategic
         objectives. The Corporate Incentive Compensation Plan "B" is intended
         to incentivize the accomplishment of specified strategic objectives
         that will:

         o Enhance the Company's financial position,

         o Create greater interaction and involvement by management, and

         o Encourage and develop a longer term strategic perspective.

2.       ADMINISTRATION

         The Plan shall be administered by the Company's Board of Directors (the
         "Board"), except to the extent that the Plan delegates authority to the
         Management Development and Compensation Committee (the "Committee") of
         the Board, and except to the extent that the Board otherwise delegates
         or provides.

         The Committee shall administer the Plan and make recommendations to the
         Board concerning selection of employees eligible to participate in the
         Plan (the "Participants") and the funding of the Plan.

         Senior management as designated by the Committee ("Senior Management")
         shall be responsible for the management of the Plan including the
         development and on-going monitoring of the strategic objectives. The
         Committee will review the status of the objectives at their regular
         meetings as appropriate. The Committee's assessment of achievement of
         the objectives shall be made at their first regular meeting of each
         calendar year based on a review by Senior Management.

         All actions, decisions, and determinations of the Committee concerning
         the Plan and its administration shall be subject only to review by the
         Board to the extent the Board deems review appropriate, and shall
         otherwise be final, conclusive and binding upon the Company, its
         shareholders, subsidiaries, affiliates, employees and officers, and
         upon all Participants and all other affected persons.

3.       ELIGIBLE DEPARTMENTS

         The Committee upon recommendation of the Chairman and/or the
         President/COO will designate Participants in the Plan from the
         following listing of departments of the Company (the "Departments").
         The Committee may, as appropriate, add individual departments to or
         remove individual departments from the listing.

<PAGE>   2

<TABLE>

<S>                                 <C>                      <C> 
         Accounting                 Gas Flow                 Legal
         Administrative Services    Human Resources          Public & Int'l. Affairs
         Business Development       Information Technology   Reservoir Engineering
         Corporate Planning         Internal Audit           Technical Services
         Crude Oil Marketing        Investor Relations       Treasury
         Environmental Health       Land Administration      Officers (as specified)
         & Safety
</TABLE>


4.       PARTICIPATION

         The Vice President of each Department will recommend the employees of
         that Department eligible to be Participants in the Plan and the maximum
         percent of each Participant's salary that may be awarded if the Plan is
         funded for that year. The Chairman and/or President/COO shall review
         the Department recommendations and submit the final list of
         Participants and salary allocations to the Committee.

5.       CORPORATE AND PERSONAL OBJECTIVES

         -CORPORATE OBJECTIVES-

         Senior Management shall be responsible for the development and
         administration of the objective listing, although all eligible
         personnel are expected to contribute to the listing and completion of
         the objectives. The listing of the objectives shall be dynamic and
         responsive to changing business conditions. The Company's officers
         shall meet regularly to assess the completeness and appropriateness of
         the current listing and recommend to Senior Management additions,
         deletions or modifications to the listing of objectives.

         The objectives shall be annualized for incentive purposes, but be broad
         enough to have potential impact beyond the current year. Each objective
         shall have written, defined, measurable outcomes, timeframes for
         achievement and assigned responsibility. Additionally, objectives shall
         be weighted numerically to designate overall importance and impact in
         corporate achievement.

         Each objective shall have a corresponding percent of total weighting,
         based on a maximum percent total equal to 133% (100% goal attainment
         equals maximum 133% pool funding). As the number of objectives and
         numerical weighting totals change during the year, the corresponding
         percent, based on weighting will change.

         -PERSONAL GOALS-

         Each of the Company's executive officers will establish personal goals
         relating to cost reduction, operational improvements, program or
         project enhancements or other objectively determinable goals that
         support the strategic and financial goals of the Company. Personal
         goals will be approved by the officer's superior.


<PAGE>   3


         All non-officer Participants will establish personal objectives each
         year by March 1. All objectives must be agreed upon and approved by the
         Participant, his immediate supervisor and the Department Vice
         President.

6.       DISTRIBUTION

         Awards under the Plan shall be determined as follows:

         Officers as designated by the Committee who are Participants in this
         Plan shall have:

         a)       eligible salary equal to 50% of base compensation,

         b)       up to 75% of eligible salary be recommended by achievement of
                  corporate objectives as reviewed and approved by the
                  Committee,

         c)       up to 25% of eligible percent of salary be recommended by
                  achievement of personal objectives, and

         d)       when a Participant demonstrates extraordinary performance
                  contributing directly to the substantial achievement of a
                  corporate objective, the CEO and/or the President/COO may
                  recommend that the Committee approve an award greater than the
                  Participant's allotted maximum.

         All non-officer participants shall have:

         a)       eligible salary from 10 to 40% of base compensation as
                  recommended by the Department Vice President and approved by
                  the Chairman and/or the President/COO and the Committee
                  (Eligible salary shall be determined by position level in the
                  Company),

         b)       up to 50% of eligible percent of salary as recommended by
                  achievement of corporate objectives, as reviewed and approved
                  by the Committee,

         c)       up to 50% of eligible percent of salary as recommended by
                  achievement of personal objectives, and

         d)       when a Participant demonstrates extraordinary performance
                  contributing directly to the substantial achievement of a
                  corporate objective, the CEO and/or the President/COO may
                  recommend that the Committee approve an award greater than the
                  Participant's allotted maximum.

Recommendations concerning achievement of personal goals shall be made by the
Vice President of the Participant's Department after the review with the
Participant and shall be approved by the Chairman and/or the President/COO
within 45 days of the end of the Plan year.



<PAGE>   4


Distribution of a Participant's award, if any, shall be made on or before 90
days after the end of the Plan year (the "Distribution Date"). A portion(s) of
the award may be deferred to future years, dependent upon the payout/funding
mechanism as recommended annually by the Committee.

7.       MISCELLANEOUS PROVISIONS

         Neither this Plan nor any action taken hereunder shall be construed as
         giving any Participant any right to be retained in the employ of the
         Company or interfere in any way with the right of the Company to
         determine a Participant's compensation or any other terms of
         employment.

         A Participant's rights and interests under this Plan may not be
         assigned, transferred, attached, pledged, mortgaged or hypothecated.

         The Company has the right to offset from a Participant's award any
         amounts due from the Participant to the Company.

A Participant shall be entitled to an award under the Plan only if the
Participant is employed by the Company or an affiliated company on the
Distribution Date for the applicable Plan year. If a Participant dies, retires,
or suffers a disability after receiving an award allocation, but prior to the
Distribution Date, special provisions may be granted for that Participant by the
Committee.

This Plan, in combination with the Corporate Incentive Plan "A", supercedes and
replaces the Company's Corporate Administrative Group Incentive Plan, as amended
effective January 1, 1990.


8.       AMENDMENT AND TERMINATION

         The Board, upon recommendation by the Committee, may at any time
         suspend, amend, modify or terminate the Plan; provided that no
         suspension, amendment, modification, or termination shall alter or
         impair any rights or obligations to any award distributed previously
         under the Plan. If this Plan is terminated during any incentive period
         for which Participants have been selected to participate, the Board
         may, in its sole discretion, make provision for payment of awards as it
         deems appropriate.

9.       GOVERNING LAW

         The Plan shall be construed in accordance with and governed by the laws
         of the State of Texas.



<PAGE>   5

Dated this 16th day of July, 1998.



Attest:

/s/ CHERI L. PEPER                          /s/ RAYMOND PLANK      
- -------------------------------             -----------------------------------
Corporate Secretary                         Raymond Plank
                                            Chairman & Chief Executive Officer



/s/ CHERI L. PEPER                          /s/ G. STEVEN FARRIS   
- -------------------------------             -----------------------------------
Corporate Secretary                         G. Steven Farris
                                            President & Chief Operating Officer


/s/ CHERI L. PEPER                          /s/ DANIEL L. SCHAEFFER
- -------------------------------             -----------------------------------
Corporate Secretary                         Daniel L. Schaeffer
                                            Vice President, Human Resources









<PAGE>   1
                                                                   EXHIBIT 10.17







                      NON-QUALIFIED RETIREMENT/SAVINGS PLAN

                                       OF

                               APACHE CORPORATION


                        As restated as of January 1, 1997



<PAGE>   2



                                TABLE OF CONTENTS


<TABLE>
<S>                                                                                                              <C>
ARTICLE I DEFINITIONS.............................................................................................1
1.01 Account......................................................................................................1
1.02 Affiliated Entity............................................................................................1
1.03 Committee....................................................................................................2
1.04 Company......................................................................................................2
1.05 Company Deferrals............................................................................................2
1.06 Compensation.................................................................................................2
1.07 Deferred Contributions.......................................................................................3
1.08 Enrollment Agreement.........................................................................................3
1.09 Participant..................................................................................................3
1.10 Plan Year....................................................................................................4
1.11 Trust........................................................................................................4
1.12 Trust Agreement..............................................................................................4
1.13 Trustee......................................................................................................4
1.14 Valuation Date...............................................................................................4

ARTICLE II ELIGIBILITY AND PARTICIPATION..........................................................................4
2.01 Eligibility and Participation................................................................................4
2.02 Enrollment...................................................................................................4
2.03 Failure of Eligibility.......................................................................................5

ARTICLE III CONTRIBUTION DEFERRALS................................................................................5
3.01 Participant Deferrals........................................................................................5
3.02 Company Deferrals............................................................................................6

ARTICLE IV INVESTMENT OF DEFERRALS AND ACCOUNTING.................................................................8
4.01 Investments..................................................................................................8

ARTICLE V DISTRIBUTIONS...........................................................................................8
5.01 Vesting......................................................................................................8
5.02 Distribution After Termination of Employment................................................................10
5.03 Distributions After Participant's Death.....................................................................11
5.04 Hardship Distributions......................................................................................12
5.05 Withholding.................................................................................................13

ARTICLE VI ADMINISTRATION........................................................................................13
6.01 The Committee -- Plan Administrator.........................................................................13
6.02 Committee to Administer and Interpret Plan..................................................................13
6.03 Organization of Committee...................................................................................13
6.04 Indemnification.............................................................................................13
6.05 Agent for Process...........................................................................................14
6.06 Determination of Committee Final............................................................................14
</TABLE>




<PAGE>   3

<TABLE>
<S>                                                                                                             <C>
ARTICLE VI TRUST.................................................................................................14
7.01 Trust Agreement.............................................................................................14
7.02 Expenses of Trust...........................................................................................14

ARTICLE VIII AMENDMENT AND TERMINATION...........................................................................14
8.01 Termination of Plan.........................................................................................14
8.02 Amendment...................................................................................................14

ARTICLE IX MISCELLANEOUS.........................................................................................15
9.01 Funding of Benefits -- No Fiduciary Relationship............................................................15
9.02 Right to Terminate Employment...............................................................................15
9.03 Inalienability of Benefits..................................................................................15
9.04 Claims Procedure............................................................................................15
9.05 Disposition of Unclaimed Distributions......................................................................16
9.06 Distributions Due Infants or Incompetents...................................................................16
9.07 Use and Form of Words.......................................................................................17
9.08 Headings....................................................................................................17
9.09 Governing Law...............................................................................................17
</TABLE>



<PAGE>   4
                      NON-QUALIFIED RETIREMENT/SAVINGS PLAN
                                       OF
                               APACHE CORPORATION



         Apache Corporation ("Apache") established the Non-Qualified
Retirement/Savings Plan of Apache Corporation (the "Plan") effective as of
November 16, 1989. Apache is now restating the Plan in its entirety as of
January 1, 1997.

         Apache has also established the Apache Corporation 401(k) Savings Plan
(the "Savings Plan"), a profit sharing plan that satisfies the qualification
requirements of section 401(a) of the Internal Revenue Code of 1986, as amended
(the "Code"), and which contains a cash or deferred arrangement that satisfies
the requirements of Code section 401(k). Apache has also established the Apache
Corporation Money Purchase Retirement Plan (the "Retirement Plan"), a money
purchase pension plan that satisfies the qualification requirements of Code
section 401(a).

         Apache intends for this Plan to provide a select group of management or
highly compensated employees of the Company (as that term is defined in Article
I) with deferred retirement benefits, in addition to the retirement benefits
provided under the Retirement Plan and the Savings Plan, in consideration of the
valuable services provided by such employees to the Company and to induce such
employees to remain in the employ of the Company. The Company intends that the
Plan shall not be treated as a "funded" plan for purposes of either the Code or
the Employee Retirement Income Security Act of 1974, as amended ("ERISA").


                                    ARTICLE I
                                   DEFINITIONS

         Defined terms used in this Plan shall have the meanings set forth below
or the same meanings as in the Retirement Plan or the Savings Plan, as the case
may be:

1.01     Account

         "Account" means the account maintained for each Participant to which
         shall be credited all Deferred Contributions made by a Participant, all
         Company Deferrals on behalf of a Participant, and all adjustments
         thereto.

1.02     Affiliated Entity

         "Affiliated Entity" means any legal entity that is treated as a single
         employer with Apache pursuant to Code section 414(b), 414(c), 414(m),
         or 414(o).



                                  Page 1 of 17
<PAGE>   5

1.03     Committee

         "Committee" means the administrative committee provided for in Section
         6.01.

1.04     Company

         "Company" means (i) Apache, and (ii) any Affiliated Entity that, with
         approval of the Board of Directors of Apache, has adopted the Plan.

1.05     Company Deferrals

         "Company Deferrals" means the allocations to a Participant's Account
         made pursuant to Section 3.02.

1.06     Compensation

         "Compensation" shall generally mean regular compensation paid by the
         Company.

         (a)      Specifically, Compensation shall include:

                  (i)      regular salary or wages,

                  (ii)     overtime pay,

                  (iii)    bonuses,

                  (iv)     salary reductions pursuant to the Savings Plan,

                  (v)      salary reductions that are excludable from an
                           Employee's gross income pursuant to Code section 125,
                           and

                  (vi)     amounts contributed as salary deferrals to this Plan.

         (b)      Compensation shall exclude:

                  (i)      commissions,

                  (ii)     severance pay,

                  (iii)    moving expenses,

                  (iv)     any gross-up of moving expenses to account for
                           increased income taxes,



                                  Page 2 of 17
<PAGE>   6

                  (v)      foreign service premiums paid as an inducement to
                           work outside of the United States,

                  (vi)     Company contributions under the Retirement Plan

                  (vii)    Company contributions under the Savings Plan,

                  (viii)   other contingent compensation,

                  (ix)     contributions to any other fringe benefit plan
                           (including, but not limited to, overriding royalty
                           payments or any other exploration-related payments),

                  (x)      any amounts relating to the granting of a stock
                           option by the Company or an Affiliated Entity, the
                           exercise of such a stock option, or the sale or
                           deemed sale of any shares thereby acquired,

                  (x)      bonuses paid as an inducement to enter the employment
                           of the Company, and

                  (xi)     Any amount paid in cash or Company Stock pursuant to
                           the Apache Corporation 1996 Share Price Appreciation
                           Plan.

         Compensation shall include only those amounts paid while the employee
         is a Participant in the Plan, except for the purpose of determining the
         size of the Participant's retirement-6 allocation under Section
         3.02(b), in which case Compensation shall include all amounts paid to
         the Participant during the entire Plan Year.

1.07     Deferred Contributions

         "Deferred Contributions" means the amounts of a Participant's
         Compensation which he elects to defer and have allocated to his Account
         pursuant to Section 3.01.

1.08     Enrollment Agreement

         "Enrollment Agreement" means an application for participation in the
         Plan, execution of which by an eligible employee is required under
         Article II for the employee to make Deferred Contributions.

1.09     Participant

         "Participant" means any eligible employee selected to participate in
         this Plan.



                                  Page 3 of 17
<PAGE>   7

1.10     Plan Year

         "Plan Year" means the period during which the Plan records are kept.
         The Plan Year shall be the calendar year.

1.11     Trust

         "Trust" means the trust or trusts, if any, created by the Company to
         provide funding for the distribution of benefits in accordance with the
         provisions of the Plan. The assets of any such Trust shall remain
         subject to the claims of the Company's general creditors in the event
         of the Company's insolvency.

1.12     Trust Agreement

         "Trust Agreement" means the written instrument pursuant to which each
         separate Trust is created.

1.13     Trustee

         "Trustee" means one or more banks, trust companies or insurance
         companies designated by the Company to hold and invest the Trust Fund
         and to pay benefits and expenses as authorized by the Committee in
         accordance with the terms and provisions of the Trust Agreement.

1.14     Valuation Date

         "Valuation Date" means the last day of the Plan Year or any other date
         specified by the Committee for the valuation of the Participants'
         Accounts.


                                   ARTICLE II
                          ELIGIBILITY AND PARTICIPATION

2.01     Eligibility and Participation

         The Committee shall from time to time in its sole discretion select
         those employees of the Company who are eligible to participate in the
         Plan from those employees who are among a select group of management or
         highly compensated employees.

2.02     Enrollment

         Employees who have been selected by the Committee to participate in the
         Plan shall complete the enrollment procedure specified by the
         Committee. The enrollment procedure may include form(s) for the
         employee to (a) designate his beneficiary (pursuant to Section 



                                  Page 4 of 17
<PAGE>   8

         5.03), (b) provide instructions regarding the investment of his Account
         (pursuant to Section 4.01), (c) make Deferred Contributions by entering
         into an Enrollment Agreement with the Company (pursuant to Section
         3.01), (d) select a payment option for the eventual distribution of his
         Account (pursuant to Section 5.02), and (e) provide such other
         information as the Committee may reasonably require.

2.03     Failure of Eligibility

         The Committee shall have the authority to determine that a Participant
         is no longer eligible to participate in the Plan. No Company Deferrals
         shall be accrued, nor any Deferred Contributions withheld from an
         employee's Compensation after the Participant ceases to be eligible to
         participate in the Plan. The determination of the Committee with
         respect to the termination of participation in the Plan shall be final
         and binding on all parties affected thereby. Any benefits accrued
         hereunder, however, at the time the Participant becomes ineligible to
         continue participation, shall be distributable in accordance with the
         provisions of the Plan.

                                   ARTICLE III
                             CONTRIBUTION DEFERRALS

3.01     Participant Deferrals

         (a)      General. A Participant may elect to defer a portion of his
                  Compensation by filing the appropriate Enrollment Agreement
                  with the Committee. Deferred Contributions shall be deducted
                  through payroll withholding from the Participant's cash
                  Compensation payable by the Company. Deferred Contributions
                  shall be credited to the Participant's Account on or about the
                  date the amount is withheld from the Participant's
                  Compensation.

         (b)      Initial Enrollment. When an employee first becomes eligible to
                  participate in the Plan, pursuant to Section 2.01, the
                  Committee shall provide him with an enrollment form, which,
                  when properly completed and timely returned to the Committee
                  shall constitute an Enrollment Agreement. To be effective, the
                  Enrollment Agreement must be completed and returned to the
                  Committee before the 31st day after the employee becomes
                  eligible to participate in the Plan. The employee may elect to
                  defer up to 50% of each pay period's Compensation (excluding
                  bonuses) to this Plan (in addition to his salary deferrals to
                  the Savings Plan). The Enrollment Agreement shall be effective
                  on the first day of the payroll period after the Committee
                  receives the completed Enrollment Agreement. The Enrollment
                  Agreement shall be irrevocable for the remainder of the Plan
                  Year, except as provided in Subsections 3.01(e) through
                  3.01(g).

         (c)      Continuing Enrollment. An eligible employee may enter into a
                  new Enrollment Agreement for each Plan Year. To be effective,
                  the Enrollment Agreement must be completed and returned to the
                  Committee by the deadline established by the 



                                  Page 5 of 17
<PAGE>   9

                  Committee. The deadline must be before the first day of the
                  Plan Year. The employee may elect to defer up to 50% of each
                  pay period's Compensation (excluding bonuses) to this Plan (in
                  addition to his salary deferrals to the Savings Plan). The
                  Participant may also elect to defer an additional amount equal
                  to any corrective distribution made to him during the Plan
                  Year by the Retirement Plan or the Savings Plan, pursuant to
                  the terms of Article III of either plan. The Enrollment
                  Agreement shall be irrevocable for the Plan Year, except as
                  provided in Subsections 3.01(e) through 3.01(g). If a
                  Participant fails to timely complete a new Enrollment
                  Agreement for the following Plan Year, the Participant's old
                  Enrollment Agreement shall be extended for another Plan Year.

         (d)      Deferrals from Bonuses. In addition to the Deferred
                  Contributions that are provided for in Subsections 3.01(b) and
                  3.01(c) above, a Participant may also elect to defer up to 75%
                  of any performance bonus by filing an Enrollment Agreement
                  with the Committee. The Committee must receive the
                  Participant's signed Agreement by the date specified by the
                  Committee, which date shall be no later than the day before
                  the size of the bonus is determined.

         (e)      Suspension of Deferred Contributions Following a Hardship
                  Withdrawal. A Participant's Deferred Contributions shall be
                  suspended as specified in Section 5.04 following a hardship
                  withdrawal from this Plan and shall also be suspended, for the
                  number of months required by Section 7.1 of the Savings Plan,
                  following a hardship withdrawal from that plan. If the
                  suspension extends beyond the end of the Plan Year, the
                  Participant may enter into an Enrollment Agreement for the
                  remainder of the following Plan Year, provided that he
                  completes the Enrollment Agreement and returns it to the
                  Committee before his suspension has ended. If he does not
                  timely complete a new Enrollment Agreement, his prior
                  Enrollment Agreement shall be reinstated for the remainder of
                  the new Plan Year.

         (f)      Participant Becomes Ineligible. A Participant's Enrollment
                  Agreement shall be canceled immediately when he becomes
                  ineligible to participate in the Plan.

         (g)      Committee-Initiated Changes in Enrollment Agreement. The
                  Committee may adjust any Participant's Enrollment Agreement
                  for the remainder of any Plan Year by reducing the amount of
                  the Participant's future Deferred Contributions, provided that
                  the Committee believes that such reduction will assist either
                  the Retirement Plan or the Savings Plan in satisfying any
                  legal requirement.

3.02     Company Deferrals

         The Company shall credit to a Participant's Account a matching
         contribution for each payroll period and a retirement-6 contribution
         for the Plan Year. The matching contributions shall be credited on the
         last day of each pay period. The retirement-6 contribution shall be
         credited on the last day of the Plan Year. Company Deferrals shall
         begin to share in the investment earnings (or losses) at the time
         specified in Article IV.



                                  Page 6 of 17
<PAGE>   10

         (a)      Matching Contribution.

                  (i)      Through October 31, 1997. This Paragraph applies
                           through October 31, 1997. The matching contribution
                           for this Plan shall be calculated each pay period,
                           after the Savings Plan's matching contribution is
                           calculated. The "total match" each pay period shall
                           be equal to the "applicable percentage" multiplied by
                           the Participant's "total deferrals" for the pay
                           period; the maximum total match for a pay period is
                           6% of the pay period's Compensation.

                  (ii)     November 1, 1997 and Thereafter. This Paragraph
                           applies after October 31, 1997. The matching
                           contribution for this Plan shall be calculated each
                           pay period, after the Savings Plan's matching
                           contribution is calculated. The "total match" each
                           pay period shall be equal to the Participant's "total
                           deferrals" for the pay period, up to a maximum total
                           match for a pay period of 6% of the pay period's
                           Compensation.

                  (iii)    Definitions.

                           The "total match" is equal to the matching
                           contribution to the Participant's Account in this
                           Plan plus the Company Matching Contribution allocated
                           to the Participant's accounts in the Savings Plan.

                           The "applicable percentage" is equal to that pay
                           period's matching percentage in the Savings Plan, as
                           determined under subparagraph 3.1(b)(i)(A) of that
                           plan.

                           The "total deferrals" for a pay period are equal to
                           (i) the Participant's Deferred Contributions for the
                           pay period, including any Deferred Contributions from
                           a bonus paid during the pay period, plus (ii) the
                           Participant's salary deferrals to the Savings Plan
                           for the pay period.

         (b)      Retirement-6. In order to receive an allocation of the
                  retirement-6 contribution, an employee must be eligible to
                  participate in the Plan on the last day of the Plan Year. The
                  retirement-6 contribution shall be calculated each Plan Year
                  after the Company Mandatory Contribution is calculated in the
                  Retirement Plan for the Plan Year. The sum of the
                  Participant's retirement-6 contribution in this Plan and his
                  Company Mandatory Contribution in the Retirement Plan shall be
                  equal to 6% of the Participant's Compensation for the Plan
                  Year.


                                  Page 7 of 17
<PAGE>   11

                                   ARTICLE IV
                     INVESTMENT OF DEFERRALS AND ACCOUNTING

4.01     Investments

         All amounts credited to a Participant's Account, together with the
         earnings thereon, shall be credited with income and loss as if invested
         in one or more investment alternatives selected by the Committee. At
         such times and under such procedures as the Committee shall designate,
         each Participant shall have the right to elect among investment
         alternatives made available by the Committee, including without
         limitation the right to transfer all or a portion of the funds in the
         Participant's Account among such available investment alternatives. The
         Committee shall give written notice to the Participants of the
         investment alternatives, if any, available to them for election. The
         Committee may change, add to or subtract from the investment
         alternatives available at any time. Nothing contained in this Section
         shall be construed to give any Participant any power or control to make
         investment directions or otherwise influence in any manner the
         investment and reinvestment of assets contained within any investment
         alternative, such control being at all times retained in the full
         discretion of the Committee. Nothing contained in this Section shall be
         construed to require the Committee to make investment choices available
         to Participants, and in lieu thereof the investment alternative may be
         selected by the Committee. Company Deferrals and Deferred Contributions
         may be deemed to remain uninvested for a reasonable period of time
         following payroll withdrawal, as determined from time to time by the
         Committee, without interest. Nothing contained in this Section shall be
         construed to require the Company or the Committee to fund any
         Participant's Account, and the investment alternatives discussed herein
         may be used solely as a means to establish income and loss without the
         actual funding of the Participants' Accounts.


                                    ARTICLE V
                                  DISTRIBUTIONS

5.01     Vesting

         (a)      A Participant shall be fully vested in the portion of his Plan
                  Account that is attributable to his Deferred Contributions.

         (b)      A Participant shall vest in the portion of his Plan Account
                  that is attributable to Company Deferrals according to the
                  following schedule, unless Subsection 5.01(c) provides for
                  faster vesting:



                                  Page 8 of 17
<PAGE>   12

<TABLE>
<CAPTION>
                      Years of Completed Service          Vested Portion
                      --------------------------          --------------
                      
<S>                                                       <C>
                              Less than 1                        0%
                                    1                           20%
                                    2                           40%
                                    3                           60%
                                    4                           80%
                              5 or more                        100%
</TABLE>              

         (c)      A Participant shall be fully vested in the portion of his Plan
                  Account that is attributable to Company Deferrals in the
                  following circumstances.

                  (i)      The Participant shall be fully vested if he attains
                           age 65 while employed by the Company or an Affiliated
                           Entity.

                  (ii)     The Participant shall be fully vested if he is hired
                           by the Company after attaining age 65.

                  (iii)    The Participant shall be fully vested if he incurs a
                           Disability while employed by the Company or an
                           Affiliated Entity.

                  (iv)     The Participant shall be fully vested if he dies
                           while employed by the Company or an Affiliated
                           Entity.

                  (v)      All Participants shall be fully vested if a "Change
                           in Control" occurs. A "Change of Control" occurs when
                           an individual or legal entity, together with all
                           individuals and legal entities acting in concert with
                           such individual or legal entity, or any or all of
                           them, acquires more than 20% of Apache's outstanding
                           voting securities; except that a Change of Control
                           does not occur if, prior to the acquisition of more
                           than 20% of the voting securities, Apache's Board of
                           Directors by majority vote designates the individual
                           or legal entity as an approved acquiror and resolves
                           that a Change of Control will not have occurred for
                           purposes of this Plan.

                  (vi)     All Participants in the Plan who were employed by the
                           Company on July 1, 1992 became 100% vested with
                           respect to all Company Deferrals made to the Plan
                           prior to or as of July 1, 1992. If a Participant was
                           not previously 100% vested, then the amount that
                           becomes 100% vested pursuant to this paragraph shall
                           be allocated to a special account and a new account
                           shall be established for all Company Deferrals made
                           with respect to such Participant subsequent to July
                           1, 1992. Once any Participant becomes 100% vested in
                           both such accounts, the two separate accounts shall
                           be merged into one account. 




                                  Page 9 of 17
<PAGE>   13

                  (vii)    All Participants who were transferred to Producers
                           Energy Marketing LLC prior to April 1, 1996 became
                           fully vested. This special vesting rule applies only
                           to the Participant's Account at the time of his
                           transfer. If such a Participant was not previously
                           fully vested, returns to employment with the Company,
                           and recommences participation in the Plan, then the
                           amount that became 100% vested pursuant to this
                           paragraph shall be allocated to a special account and
                           a new account shall be established for all Company
                           Deferrals made with respect to such Participant after
                           his reemployment. Once a Participant becomes 100%
                           vested in both such accounts, the two separate
                           accounts shall be merged into one account.

         (d)      When a Participant terminates employment, the portion of his
                  Account that is not then vested shall be forfeited
                  immediately.

5.02     Distribution After Termination of Employment

         While a Participant is employed by the Company or an Affiliated Entity,
         the only available distribution is a hardship withdrawal pursuant to
         Section 5.04. Distributions after the Participant's death are discussed
         in Section 5.03. All other distributions are discussed in this Section.

         (a)      Timing. The Participant's vested Account shall be distributed
                  after the Participant terminates employment with the Company
                  and all Affiliated Entities. If the Participant terminates
                  employment before July 1, distribution shall commence in the
                  Plan Year of employment termination, as soon as
                  administratively convenient after the termination of
                  employment. If the Participant terminates employment on or
                  after July 1, distribution shall commence in the Plan Year
                  after the termination of employment, as soon as
                  administratively convenient.

         (b)      Form of Distribution. The Participant's entire vested Account
                  shall be paid in one payment if (i) the vested Account is less
                  than $100,000 when the Participant terminated employment, or
                  (ii) the Participant terminates employment in 1996 or 1997.
                  Otherwise, the distribution shall be paid in one to ten annual
                  installments, as elected by the Participant subject to the
                  following restrictions. The Participant shall make his
                  distribution election when he initially enrolls in the Plan,
                  except that Participants prior to January 1, 1997 shall make
                  their election no later than December 31, 1996. Regardless of
                  the Participant's election, the minimum annual installment
                  payment shall be $100,000, or, if less, the Participant's
                  remaining Account balance. Each installment will be equal to
                  the greater of (i) the minimum installment, or (ii) the vested
                  Account balance at the beginning of the Plan Year divided by
                  the number of remaining annual installments, except for the
                  final installment, which will be equal to the remaining
                  Account balance. Installments will be paid as soon as
                  administratively convenient during the Plan Year.



                                 Page 10 of 17
<PAGE>   14

                  For example, if the Participant had chosen 5 annual
                  installments, and terminates employment in February of 1999,
                  the unvested account balance shall be forfeited immediately;
                  his 1999 installment will be one-fifth of his January 1, 1999
                  vested Account balance; his 2000 installment will be
                  one-fourth of his January 1, 2000 Account balance; his 2001
                  installment will be one-third of his January 1, 2001 Account
                  balance; his 2002 installment will be one-half of his January
                  1, 2002 Account balance; and his final installment in 2003
                  will be the remainder of his Account balance.

         (c)      Reemployment. If a Participant is reemployed by the Company or
                  an Affiliated Entity before he is paid his entire vested
                  Account balance, his payments from the Plan shall be
                  suspended. Payments will resume after he again terminates
                  employment. The number of remaining payments shall be the
                  number of annual payments originally chosen, less the number
                  of payments received before he was reemployed. If the
                  Participant dies before receiving all installments, Section
                  5.03 shall apply.

5.03     Distributions After Participant's Death

         (a)      Each Participant shall designate one or more persons, trusts
                  or other entities as his beneficiary (the "Beneficiary") to
                  receive any amounts distributable hereunder at the time of the
                  Participant's death. In the absence of an effective
                  beneficiary designation as to part or all of a Participant's
                  interest in the Plan, such amount shall be distributed to the
                  Participant's surviving spouse, if any, otherwise to the
                  personal representative of the Participant's estate.

         (b)      A beneficiary designation may be changed by the Participant at
                  any time and without the consent of any previously designated
                  Beneficiary. However, if the Participant is married, his
                  spouse shall be his Beneficiary unless such spouse has
                  consented to the designation of a different beneficiary. To be
                  effective, the spouse's consent must be in writing, witnessed
                  by a notary public, and filed with the Committee. If a
                  Participant has designated his spouse as a Beneficiary or as a
                  contingent beneficiary, and the Participant and that spouse
                  subsequently divorce, then the beneficiary designation shall
                  be void and of no effect with respect to such spouse on the
                  day such divorce is final.

         (c)      When a Participant dies, his remaining vested Account balance
                  shall be distributed to his Beneficiary as soon as
                  administratively possible after his death, regardless of the
                  payment schedule the Participant elected, and regardless of
                  whether installment payments had begun.



                                 Page 11 of 17
<PAGE>   15

5.04     Hardship Distributions

         A Participant may request, and the Committee may approve or disapprove
         in its sole discretion, a withdrawal of part or all of the vested
         portion of the Participant's Account, subject to the following:

         (a)      The Participant must file a written request for withdrawal
                  with the Committee, along with such information as the
                  Committee may request for this purpose. The Committee shall
                  review the information filed as soon as practicable after it
                  is received and shall promptly inform the Participant of the
                  results of the Committee's determination.

         (b)      Such withdrawal may be made only for the purpose of meeting an
                  unforeseeable emergency, which shall be defined as a severe
                  financial hardship to the Participant resulting from a sudden
                  and unexpected illness or accident of the Participant or of a
                  dependent (as defined in Section 152 of the Code) of the
                  Participant, loss of the Participant's property due to
                  casualty, or other similar extraordinary and unforeseeable
                  circumstances arising as a result of events beyond the control
                  of the Participant, and only if and to the extent other
                  resources which could alleviate such need are not reasonably
                  available to the Participant.

         (c)      An unforeseeable emergency shall be determined to exist by the
                  Committee based on all relevant facts and circumstances.

         (d)      If the Committee determines that a hardship exists, the
                  Participant must represent to the Committee by written
                  certification that the need cannot be relieved through
                  reimbursement or compensation by insurance or otherwise; by
                  liquidation of the Participant's assets, to the extent that
                  liquidation of such assets would not itself cause severe
                  financial hardship; or by cessation of deferrals under the
                  Plan and any other plans maintained by the Company.

         (e)      If the Committee is satisfied that the foregoing requirements
                  are satisfied and determines, in its sole discretion, to
                  permit a hardship withdrawal, it will determine the amount of
                  hardship withdrawal necessary to satisfy the need of the
                  Participant and will distribute such amount to the
                  Participant.

         (f)      The Participant's Deferred Contributions shall be suspended
                  for six months following the date of his hardship withdrawal
                  from this Plan. If a Participant makes a hardship withdrawal
                  from this Plan and also makes a hardship withdrawal from the
                  Savings Plan, the suspension period under this Plan shall run
                  concurrently with the suspension period under the Savings
                  Plan, if any, and the suspension period under this Plan shall
                  be the longer of the suspension period provided under the
                  Savings Plan or the six-month suspension provided by this
                  Plan.



                                 Page 12 of 17
<PAGE>   16

5.05     Withholding

         The Plan shall withhold any taxes or other amounts that it is required
         to withhold pursuant to any applicable law. The Committee may direct
         the Plan to withhold additional amounts from any payment, either
         because the Participant so requested or to repay the Participant's debt
         or obligation to the Company or Affiliated Entities.


                                   ARTICLE VI
                                 ADMINISTRATION

6.01     The Committee -- Plan Administrator

         The Committee members for the Plan shall be the same committee members
         as for the Savings Plan.

6.02     Committee to Administer and Interpret Plan

         The Committee shall administer the Plan and shall have all discretion
         and powers necessary for that purpose, including, but not by way of
         limitation, full discretion and power to interpret the Plan, to
         determine the eligibility, status and rights of all persons under the
         Plan and, in general, to decide any dispute. The Committee shall direct
         the Company, the Trustee, or both, as the case may be, concerning
         distributions in accordance with the provisions of the Plan. The
         Committee shall maintain all Plan records except records of any Trust.

6.03     Organization of Committee

         The Committee shall adopt such rules as it deems desirable for the
         conduct of its affairs and for the administration of the Plan. It may
         appoint agents (who need not be members of the Committee) to whom it
         may delegate such powers as it deems appropriate, except that any
         dispute shall be determined by the Committee. The Committee may make
         its determinations with or without meetings. It may authorize one or
         more of its members or agents to sign instructions, notices and
         determinations on its behalf. The action of a majority of the Committee
         shall constitute the action of the Committee.

6.04     Indemnification

         The Committee and all of the agents and representatives of the
         Committee shall be indemnified and saved harmless by the Company
         against any claims, and the expenses of defending against such claims,
         resulting from any action or conduct relating to the administration of
         the Plan, except claims judicially determined to be attributable to
         gross negligence or willful misconduct.



                                 Page 13 of 17
<PAGE>   17

6.05     Agent for Process

         The Committee shall appoint an agent of the Plan for service of all
         process.

6.06     Determination of Committee Final

         The decisions made by the Committee shall be final and conclusive on
         all persons.


                                   ARTICLE VII
                                      TRUST

7.01     Trust Agreement

         The Company may, but shall not be required to, adopt a separate Trust
         Agreement for the holding, investment and administration of the funds
         contributed to Accounts under the Plan. The Trustee shall maintain and
         allocate assets to a separate account for each Participant under the
         Plan. The assets of any such Trust shall remain subject to the claims
         of the Company's general creditors in the event of the Company's
         insolvency.

7.02     Expenses of Trust

         The parties expect that any Trust created pursuant to Section 7.01 will
         be treated as a "grantor" trust for federal and state income tax
         purposes and that, as a consequence, such Trust will not be subject to
         income tax with respect to its income. However, if the Trust should be
         taxable, the Trustee shall pay all such taxes out of the Trust. All
         expenses of administering any such Trust shall be a charge against and
         shall be paid from the assets of such Trust.


                                  ARTICLE VIII
                            AMENDMENT AND TERMINATION

8.01     Termination of Plan

         The Company expects to continue the Plan indefinitely, but each Company
         may terminate its participation in the Plan at any time, and Apache may
         terminate the entire Plan at any time.

8.02     Amendment

         Apache may amend the Plan at any time and from time to time,
         retroactively or otherwise, on behalf of all Companies, but no
         amendment shall reduce any vested benefit that has accrued on the
         effective date of the amendment.



                                 Page 14 of 17
<PAGE>   18

         Each amendment shall be in writing. Each amendment shall be approved by
         Apache's Board of Directors or by an officer of Apache Corporation who
         is authorized by Apache's Board of Directors to amend the Plan. Each
         amendment shall be executed by an officer of Apache to whom Apache's
         Board of Directors has delegated the authority to execute the
         amendment.


                                   ARTICLE IX
                                  MISCELLANEOUS

9.01     Funding of Benefits -- No Fiduciary Relationship

         All benefits payable under the Plan shall be distributed in cash or in
         kind, in the discretion of the Committee. Benefits shall be paid either
         out of the Trust or, if no Trust is in existence or if the assets in
         the Trust are insufficient to provide fully for such benefits, then
         such benefits shall be distributed by the Company out of its general
         assets. Nothing contained in the Plan shall be deemed to create any
         fiduciary relationship between the Company and the Participants.
         Notwithstanding anything herein to the contrary, to the extent that any
         person acquires a right to receive benefits under the Plan, such right
         shall be no greater than the right of any unsecured general creditor of
         the Company, except to the extent provided in the Trust Agreement, if
         any.

9.02     Right to Terminate Employment

         The Company may terminate the employment of any Participant as freely
         and with the same effect as if the Plan were not in existence.

9.03     Inalienability of Benefits

         No Participant shall have the right to assign, transfer, hypothecate,
         encumber or anticipate his interest in any benefits under the Plan, nor
         shall the benefits under the Plan be subject to any legal process to
         levy upon or attach the benefits for payment for any claim against the
         Participant or his spouse. If, notwithstanding the foregoing provision,
         any Participant's benefits are garnished or attached by the order of
         any court, the Company may bring an action for declaratory judgment in
         a court of competent jurisdiction to determine the proper recipient of
         the benefits to be distributed pursuant to the Plan. During the
         pendency of the action, any benefits that become distributable shall be
         paid into the court as they become distributable, to be distributed by
         the court to the recipient it deems proper at the conclusion of the
         action.

9.04     Claims Procedure

         (a)      All claims shall be filed in writing by the Participant, his
                  spouse or the authorized representative of the claimant, by
                  completing such procedures as the Committee 



                                 Page 15 of 17
<PAGE>   19

                  shall require. Such procedures shall be reasonable and may
                  include the completion of forms and the submission of
                  documents and additional information.

         (b)      If a claim is denied, notice of denial shall be furnished by
                  the Committee to the claimant within 90 days after the receipt
                  of the claim by the Committee, unless special circumstances
                  require an extension of time for processing the claim, in
                  which event notification of the extension shall be provided to
                  the Participant or beneficiary and the extension shall not
                  exceed 90 days.

         (c)      The Committee shall provide adequate notice, in writing, to
                  any claimant whose claim as been denied, setting forth the
                  specific reasons for such denial, specific reference to
                  pertinent Plan provisions, a description of any additional
                  material or information necessary for the claimant to perfect
                  his claims and an explanation of why such material or
                  information is necessary, all written in a manner calculated
                  to be understood by the claimant. Such notice shall include
                  appropriate information as to the steps to be taken if the
                  claimant wishes to submit his claim for review. The claimant
                  or the claimant's authorized representative may request such
                  review within the reasonable period of time prescribed by the
                  Committee. In no event shall such a period of time be less
                  than 60 days. A decision on review shall be made not later
                  than 60 days after the Committee's receipt of the request for
                  review. If special circumstances require a further extension
                  of time for processing, a decision shall be rendered not later
                  than 120 days following the Committee's receipt of the request
                  for review. If such an extension of time for review is
                  required, written notice of the extension shall be furnished
                  to the claimant prior to the commencement of the extension.
                  The decision on review shall be furnished to the claimant.
                  Such decision shall be in writing and shall include specific
                  reasons for the decision, written in a manner calculated to be
                  understood by the claimant, as well as specific references to
                  the pertinent Plan provisions on which the decision is based.

9.05     Disposition of Unclaimed Distributions

         Each Participant must file with the Company from time to time in
         writing his post office address and each change of post office address.
         Any communication, statement or notice addressed to a Participant at
         his last post office address on file with the Company, or if no address
         is filed with the Company, then at his last post office address as
         shown on the Company's records, will be binding on the Participant and
         his spouse for all purposes of the Plan. The Company shall not be
         required to search for or locate a Participant or his spouse.

9.06     Distributions Due Infants or Incompetents

         If any person entitled to a distribution under the Plan is an infant,
         or if the Committee determines that any such person is incompetent by
         reason of physical or mental disability, whether or not legally
         adjudicated an incompetent, the Committee shall have the power to 



                                 Page 16 of 17
<PAGE>   20

         cause the distributions becoming due to such person to be made to
         another for his or her benefit, without responsibility of the Committee
         to see to the application of such distributions. Distributions made
         pursuant to such power shall operate as a complete discharge of the
         Company, the Trustee, if any, and the Committee.

9.07     Use and Form of Words

         When any words are used herein in the masculine gender, they shall be
         construed as though they were also used in the feminine gender in all
         cases where they would so apply, and vice versa. Whenever any words are
         used herein in the singular form, they shall be construed as though
         they were also used in the plural form in all cases where they would so
         apply, and vice versa.

9.08     Headings

         Headings of Articles and Sections are inserted solely for convenience
         and reference, and constitute no part of the Plan.

9.09     Governing Law

         The Plan shall be construed in accordance with ERISA, the Code, and, to
         the extent applicable, the laws of the State of Texas excluding any
         conflicts-of-law provisions.



                                        APACHE CORPORATION


                                        /s/ Daniel L. Schaeffer
                                        ----------------------------------------
                                        Daniel L. Schaeffer
                                        Vice President, Human Resources

                                        Date:    12/15/97
                                                -------------------


<PAGE>   21
                                    AMENDMENT
                                       TO

                    NON-QUALIFIED RETIREMENT/SAVINGS PLAN OF

                               APACHE CORPORATION

         Apache Corporation ("Apache") maintains the Non-Qualified
Retirement/Savings Plan of Apache Corporation (the "Plan"). Pursuant to section
8.02 of the Plan, Apache has retained the right to amend the Plan. Apache hereby
exercises that right, effective as of January 1, 1997, by adding the following
paragraph 3.02(a)(iv) to the Plan.

         (iv)     Exception. Notwithstanding paragraphs (i) and (ii) above, the
                  matching contribution for a Participant shall be $0 for any
                  Plan Year in which the Participant fails to make the maximum
                  possible salary deferral to the Savings Plan for that Plan
                  Year. If a matching contribution is made to the Participant's
                  Account in this Plan before he makes the maximum possible
                  salary deferral to the Savings Plan for the Plan Year, and the
                  Participant fails to contribute the maximum possible salary
                  deferral to the Savings Plan for the Plan Year, then the
                  Participant shall forfeit any matching contribution (adjusted
                  to reflect any investment gains or losses thereon) made to the
                  Participant's Accounts for the Plan Year.


         IN WITNESS WHEREOF, this Amendment has been executed the date set forth
below.


                                    APACHE CORPORATION


                                    By: /s/ D. L. Schaeffer
                                        ---------------------------------------

         Date:  December 22, 1998   Title: Vice President, Human Resources
               ------------------          ------------------------------------




Page 1 of 1
<PAGE>   22

                                    AMENDMENT
                                       TO

                    NON-QUALIFIED RETIREMENT/SAVINGS PLAN OF

                               APACHE CORPORATION

         Apache Corporation ("Apache") maintains the Non-Qualified
Retirement/Savings Plan of Apache Corporation (the "Plan"). Pursuant to section
8.02 of the Plan, Apache has retained the right to amend the Plan. Apache hereby
exercises that right, effective as of January 1, 1998, as follows.

1.       The following paragraph 3.02(a)(iv) shall be added to the Plan.

         (iv)     Additional Match. If a Participant's match in the Savings Plan
                  is reduced to comply with any requirement of federal law (such
                  as the ACP or multiple-use test of Code section 401(m) or the
                  limits imposed by Code section 415 or 401(a)(17)) after the
                  match for this Plan has been calculated, then the
                  Participant's match for this Plan shall be increased by the
                  amount of the reduction in the match in the Savings Plan.

2.       The existing paragraph 3.02(a)(iv) shall be renumbered paragraph 
         3.02(a)(v).

3.       The phrase "Notwithstanding paragraphs (i) and (ii) above," in the
         newly renumbered paragraph 3.02(a)(v) shall be replaced with the phrase
         "Notwithstanding paragraphs (i), (ii), and (iv) above."

4.       The following sentence shall be added to the end of subsection 3.02(b).

         If a Participant's Company Mandatory Contribution in the Retirement
         Plan is reduced to comply with any requirement of federal law after the
         retirement-6 contribution for this Plan has been calculated, then the
         Participant's retirement-6 contribution for this Plan shall be
         increased by the amount of the reduction in the Company Mandatory
         Contribution in the Retirement Plan.


         IN WITNESS WHEREOF, this Amendment has been executed the date set forth
below.

                                  APACHE CORPORATION


                                  By: /s/ D. L. Schaeffer
                                      ------------------------------------

         Date: December 22, 1998  Title: Vice president, Human Resources
               -----------------         ---------------------------------



Page 1 of 1
<PAGE>   23

                                    AMENDMENT
                                       TO

                    NON-QUALIFIED RETIREMENT/SAVINGS PLAN OF

                               APACHE CORPORATION

         Apache Corporation ("Apache") maintains the Non-Qualified
Retirement/Savings Plan of Apache Corporation (the "Plan"). Pursuant to section
8.02 of the Plan, Apache has retained the right to amend the Plan. Apache hereby
exercises that right, effective as of January 1, 1999, as follows.


1.       The introductory paragraph in Section 5.02 shall be replaced by the
         following.

         While a Participant is employed by the Company or an Affiliated Entity,
         the only available distributions are a hardship withdrawal pursuant to
         Section 5.04 and an age-70-and-older distribution pursuant to Section
         5.05. Distributions after the Participant's death are discussed in
         Section 5.03. This Section contains the rules that apply to all other
         distributions.

2.       Subsection 5.02(c) shall be replaced by the following.

         (c)      Reemployment. If a Participant is reemployed by the Company or
                  an Affiliated Entity before he is paid his entire vested
                  Account balance, his payments from the Plan pursuant to this
                  Section shall be suspended. If the reemployed Participant
                  receives a payment pursuant to Section 5.05 (regarding
                  payments to those age 70 and older), his payments after he
                  eventually terminates employment shall be determined pursuant
                  to Section 5.05. If the Participant does not receive a payment
                  pursuant to Section 5.05, payments under this Section will
                  resume after the Participant again terminates employment, with
                  the number of remaining payments equal to the number of annual
                  payments originally chosen, less the number of payments
                  received before he was reemployed. If the Participant dies
                  before receiving all installments, Section 5.03 shall apply.

3.       Section 5.05 shall be re-numbered as Section 5.06, and the following
         Section 5.05 shall be added to the Plan. For an employee who attained
         age 70 on or before the end of the Plan Year preceding the effective
         date of this amendment, the first distribution pursuant to this new
         Section 5.05 will occur as soon as administratively convenient after
         the effective date of this amendment.

         5.05     Age-70-and-Older Distributions.

         (a)      General. A Participant who is employed by the Company or an
                  Affiliated Entity after attaining age 70 shall receive annual
                  payments from the Plan. The first payment shall be paid in the
                  Plan Year after the Plan Year in which the Participant attains
                  age 70. Payments shall be made as early in the Plan Year as is
                  administratively convenient. Each payment shall be equal to
                  the Participant's 



Page 1 of 2
<PAGE>   24

                  Account balance at the end of the prior Plan Year, including
                  all amounts credited to the Participant's Account as of any
                  date in the prior Plan Year, and adjusted pursuant to Article
                  IV to reflect investment experience until the date the payment
                  is made. A payment shall not include any amount credited to
                  the Participant's Account as of any date within the current
                  Plan Year.

         (b)      Termination Before First Payment. If the Participant dies or
                  otherwise terminates employment before the first payment under
                  this Section is made, then this Section will not apply, and
                  Sections 5.02 and 5.03 will apply instead.

         (c)      Termination of Employment. When a Participant who has received
                  one or more payments pursuant to this Section terminates
                  employment, his remaining Account balance shall be paid as
                  soon as administratively convenient after his termination of
                  employment, but only after all Company Deferrals have been
                  credited to his Account.

         IN WITNESS WHEREOF, this Amendment has been executed the date set forth
below.

                                  APACHE CORPORATION


                                  By: /s/ D. L. Schaeffer
                                      --------------------------------------

         Date: December 22, 1998  Title: Vice President, Human Resources
               -----------------         -----------------------------------



Page 2 of 2

<PAGE>   1


                                                                   EXHIBIT 10.19
















                               APACHE CORPORATION

                            1990 STOCK INCENTIVE PLAN

                   (AS AMENDED AND RESTATED DECEMBER 17, 1998)















<PAGE>   2


                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                       PAGE
                                                                                                       ----

<S>                                                                                                     <C>
Section 1 - Introduction.................................................................................1

         1.1      Establishment..........................................................................1
         1.2      Purposes...............................................................................1
         1.3      Effective Date.........................................................................1

Section 2 - Definitions..................................................................................1

         2.1      Definitions............................................................................1
         2.2      Gender and Number......................................................................2

Section 3 - Plan Administration..........................................................................3

Section 4 - Stock Subject to the Plan....................................................................3

         4.1      Number of Shares.......................................................................3
         4.2      Other Shares of Stock..................................................................3
         4.3      Adjustments for Stock Split, Stock Dividend, Etc.......................................4
         4.4      Dividend Payable in Stock of Another Corporation, Etc..................................4
         4.5      Other Changes in Stock.................................................................4
         4.6      Rights to Subscribe....................................................................4
         4.7      General Adjustment Rules...............................................................5
         4.8      Determination by the Committee, Etc....................................................5

Section 5 - Reorganization or Liquidation................................................................5

Section 6 - Participation................................................................................6

Section 7 - Stock Options................................................................................6

         7.1      Grant of Stock Options.................................................................6
         7.2      Stock Option Agreements................................................................6
         7.3      Shareholder Privileges................................................................11

Section 8 - Change in Control...........................................................................11

         8.1      In General............................................................................11
         8.2      Limitation on Payments................................................................11
         8.3      Definition............................................................................11
</TABLE>

                                      -i-

<PAGE>   3


<TABLE>
<S>                                                                                                     <C>
Section 9 - Rights of Employees; Participants...........................................................12

         9.1      Employment............................................................................12
         9.2      Nontransferability....................................................................12

Section 10 - General Restrictions.......................................................................12

         10.1     Investment Representations............................................................12
         10.2     Compliance with Securities Laws.......................................................13

Section 11 - Other Employee Benefits....................................................................13

Section 12 - Plan Amendment, Modification and Termination...............................................13

Section 13 - Withholding................................................................................13

         13.1     Withholding Requirement...............................................................13
         13.2     Withholding With Stock................................................................14

Section 14 - Requirements of Law........................................................................14

         14.1     Requirements of Law...................................................................14
         14.2     Federal Securities Law Requirements...................................................14
         14.3     Governing Law.........................................................................14

Section 15 - Duration of the Plan.......................................................................15
</TABLE>

                                      -ii-

<PAGE>   4


                               APACHE CORPORATION

                            1990 STOCK INCENTIVE PLAN


                                    SECTION 1

                                  INTRODUCTION

1.1      Establishment. Apache Corporation, a Delaware corporation (hereinafter
referred to, together with its Affiliated Corporations (as defined in subsection
2.1(a)) as the "Company" except where the context otherwise requires), hereby
establishes the Apache Corporation 1990 Stock Incentive Plan (the "Plan") for
certain key employees of the Company. The Plan permits the grant of stock
options to certain key employees of the Company.

1.2      Purposes. The purposes of the Plan are to provide the key management
employees selected for participation in the Plan with added incentives to
continue in the long-term service of the Company and to create in such employees
a more direct interest in the future success of the operations of the Company by
relating incentive compensation to increases in shareholder value, so that the
income of the key management employees is more closely aligned with the income
of the Company's shareholders. The Plan is also designed to attract key
employees and to retain and motivate participating employees by providing an
opportunity for investment in the Company.

1.3      Effective Date. The Effective Date of the Plan (the "Effective Date")
shall be September 19, 1990. This Plan and each option granted hereunder is
conditioned on and shall be of no force or effect until approval of the Plan by
the holders of the shares of voting stock of the Company unless the Company, on
the advice of counsel, determines that shareholder approval is not necessary.

                                    SECTION 2

                                   DEFINITIONS

2.1      Definitions. The following terms shall have the meanings set forth
below:

         (a)      "Affiliated Corporation" means any corporation or other entity
(including but not limited to a partnership) which is affiliated with Apache
Corporation through stock ownership or otherwise and is treated as a common
employer under the provisions of Sections 414(b) and (c) of the Internal Revenue
Code.

         (b)      "Board" means the Board of Directors of the Company.

                                      -1-

<PAGE>   5


         (c)      "Committee" means a committee consisting of members of the
Board who are empowered hereunder to take actions in the administration of the
Plan. The Committee shall be constituted at all times as to permit the Plan to
comply with Rule 16b-3 or any successor rule promulgated under the Securities
Exchange Act of 1934 (the "1934 Act"). Members of the Committee shall be
appointed from time to time by the Board, shall serve at the pleasure of the
Board and may resign at any time upon written notice to the Board.

         (d)      "Effective Date" means the effective date of the Plan,
September 19, 1990.

         (e)      "Eligible Employees" means those full-time key employees
(including, without limitation, officers and directors who are also employees)
of the Company or any division thereof, upon whose judgment, initiative and
efforts the Company is, or will become, largely dependent for the successful
conduct of its business.

         (f)      "Fair Market Value" means the closing price of the Stock on
the composite tape on a particular date. If there are no Stock transactions on
such date, the Fair Market Value shall be determined as of the immediately
preceding date on which there were Stock transactions.

         (g)      "Internal Revenue Code" means the Internal Revenue Code of
1986, as it may be amended from time to time.

         (h)      "Option" means a right to purchase Stock at a stated price for
a specified period of time. All Options granted under the Plan shall be Options
which are not "incentive stock options" as described in Section 422A of the
Internal Revenue Code.

         (i)      "Option Price" means the price at which shares of Stock
subject to an Option may be purchased, determined in accordance with subsection
7.2(b).

         (j)      "Participant" means an Eligible Employee designated by the
Committee from time to time during the term of the Plan to receive one or more
Options under the Plan.

         (k)      "Stock" means the $1.25 par value Common Stock of the Company.

2.2      Gender and Number. Except when otherwise indicated by the context, the
masculine gender shall also include the feminine gender, and the definition of
any term herein in the singular shall also include the plural.

                                      -2-

<PAGE>   6


                                    SECTION 3

                               PLAN ADMINISTRATION

The Plan shall also be administered by the Committee. In accordance with the
provisions of the Plan, the Committee shall, in its sole discretion, select the
Participants from among the Eligible Employees, determine the Options to be
granted pursuant to the Plan, the number of shares of Stock to be issued
thereunder and the time at which such Options are to be granted, fix the Option
Price, and establish such other terms and requirements as the Committee may deem
necessary or desirable and consistent with the terms of the Plan. The Committee
shall determine the form or forms of the agreements with Participants which
shall evidence the particular provisions, terms, conditions, rights and duties
of the Company and the Participants with respect to Options granted pursuant to
the Plan, which provisions need not be identical except as may be provided
herein. The Committee may from time to time adopt such rules and regulations for
carrying out the purposes of the Plan as it may deem proper and in the best
interests of the Company. The Committee may correct any defect, supply any
omission or reconcile any inconsistency in the Plan or in any agreement entered
into hereunder in the manner and to the extent it shall deem expedient and it
shall be the sole and final judge of such expediency. No member of the Committee
shall be liable for any action or determination made in good faith. The
determination, interpretations and other actions of the committee pursuant to
the provisions of the Plan shall be binding and conclusive for all purposes and
on all persons.

                                    SECTION 4

                            STOCK SUBJECT TO THE PLAN

4.1      Number of Shares. Two Million Fifty Thousand (2,050,000) shares of
Stock are authorized for issuance under the Plan in accordance with the
provisions of the Plan and subject to such restrictions or other provisions as
the Committee may from time to time deem necessary. This authorization may be
increased from time to time by approval of the Board and by the shareholders of
the Company if, in the opinion of counsel for the Company, such shareholder
approval is required. Shares of Stock which may be issued upon exercise of
Options shall be applied to reduce the maximum number of shares of Stock
remaining available for use under the Plan. The Company shall at all times
during the term of the Plan and while any Options are outstanding retain as
authorized and unissued Stock, or as treasury Stock, at least the number of
shares from time to time required under the provisions of the Plan, or otherwise
assure itself of its ability to perform its obligations hereunder.

4.2      Other Shares of Stock. Any shares of Stock that are subject to an
Option which expires or for any reason is terminated unexercised, and any shares
of Stock that for any

                                      -3-

<PAGE>   7


other reason are not issued to an Eligible Employee or are forfeited shall
automatically become available for use under the Plan.

4.3      Adjustments for Stock Split, Stock Dividend, Etc. If the Company shall
at any time increase or decrease the number of its outstanding shares of Stock
or change in any way the rights and privileges of such shares by means of the
payment of a stock dividend or any other distribution upon such shares payable
in Stock, or through a stock split, subdivision, consolidation, combination,
reclassification or recapitalization involving the Stock, then in relation to
the Stock that is affected by one or more of the above events, the numbers,
rights and privileges of the following shall be increased, decreased or changed
in like manner as if they had been issued and outstanding, fully paid in
nonassessable at the time of such occurrence: (i) the shares of Stock as to
which Options may be granted under the Plan; and (ii) the shares of the Stock
then included in each outstanding Option granted hereunder.

4.4      Dividend Payable in Stock of Another Corporation, Etc. If the Company
shall at any time pay or make any dividend or other distribution upon the Stock
payable in securities or other property (except money or Stock), a proportionate
part of such securities or other property shall be set aside and delivered to
any Participant then holding an Option for the particular type of Stock for
which the dividend or other distribution was made, upon exercise thereof. Prior
to the time that any such securities or other property are delivered to a
Participant in accordance with the foregoing, the Company shall be the owner of
such securities or other property and shall have the right to vote the
securities, receive any dividends payable on such securities, and in all other
respects shall be treated as the owner. If securities or other property which
have been set aside by the Company in accordance with this Section are not
delivered to a Participant because an Option is not exercised, then such
securities or other property shall remain the property of the Company and shall
be dealt with by the Company as it shall determine in its sole discretion.

4.5      Other Changes in Stock. In the event there shall be any change, other
than as specified in Sections 4.3 and 4.4, in the number or kind of outstanding
shares of Stock or of any stock or other securities into which the Stock shall
be changed or for which it shall have been exchanged, and if the Committee shall
in its discretion determine that such change equitably requires an adjustment in
the number or kind of shares subject to outstanding Options or which have been
reserved for issuance pursuant to the Plan but are not then subject to an
Option, then such adjustments shall be made by the Committee and shall be
effective for all purposes of the Plan and on each outstanding Option that
involves the particular type of stock for which a change was effected.

4.6      Rights to Subscribe. If the Company shall at any time grant to the
holders of its Stock rights to subscribe pro rata for additional shares thereof
or for any other securities of the Company or of any other corporation, there
shall be reserved with respect to the

                                      -4-

<PAGE>   8


shares then under Option to any Participant of the particular class of Stock
involved the Stock or other securities which the Participant would have been
entitled to subscribe for if immediately prior to such grant the Participant had
exercised his entire Option. If, upon exercise of any such Option, the
Participant subscribes for the additional shares of other securities, the Option
Price shall be increased by the amount of the price that is payable by the
Participant for such Stock or other securities.

4.7      General Adjustment Rules. No adjustment or substitution provided for in
this Section 4 shall require the Company to sell a fractional share of Stock
under any Option, or otherwise issue a fractional share of Stock, and the total
substitution or adjustment with respect to each Option shall be limited by
deleting any fractional share. In the case of any such substitution or
adjustment, the total Option Price for the shares of Stock then subject to the
Option shall remain unchanged but the Option Price per share under each such
Option shall be equitably adjusted by the Committee to reflect the greater or
lesser number of shares of Stock or other securities into which the Stock
subject to the Option may have been changed.

4.8      Determination by the Committee, Etc. Adjustments under this Section 4
shall be made by the Committee, whose determinations with regard thereto shall
be final and binding upon all parties thereto.

                                    SECTION 5

                          REORGANIZATION OR LIQUIDATION

In the event that the Company is merged or consolidated with another corporation
and the Company is not the surviving corporation, or if all or substantially all
of the assets or more than 20% of the outstanding voting stock of the Company is
acquired by any other corporation, business entity or person, or in case of a
reorganization (other than a reorganization under the United States Bankruptcy
Code) or liquidation of the Company, and if the provisions of Section 9 do not
apply, the Committee, or the board of directors of any corporation assuming the
obligations of the Company, shall, as to the Plan and outstanding Options either
(i) make appropriate provision for the adoption and continuation of the Plan by
the acquiring or successor corporation and for the protection of any such
outstanding Options by the substitution on an equitable basis of appropriate
stock of the Company or of the merged, consolidated or otherwise reorganized
corporation which will be issuable with respect to the Stock, provided that no
additional benefits shall be conferred upon the Participants holding such
Options as a result of such substitution, and the excess of the aggregate Fair
Market Value of the shares subject to the Options immediately after such
substitution over the Option Price thereof is not more than the excess of the
aggregate Fair Market Value of the shares subject to such Options immediately
before such substitution over the Option Price thereof, or (ii) upon written
notice to the Participants, provide that all unexercised Options must be
exercised within a

                                      -5-

<PAGE>   9


specified number of days of the date of such notice or they will be terminated.
In the latter event, the Committee shall accelerate the exercise dates of
outstanding Options so that all Options become fully vested prior to any such
event.

                                    SECTION 6

                                  PARTICIPATION

Participants in the Plan shall be those Eligible Employees who, in the judgment
of the Committee, are performing, or during the term of their incentive
arrangement will perform, vital services in the management, operation and
development of the Company or an Affiliated Corporation, and significantly
contribute, or are expected to significantly contribute, to the achievement of
long-term corporate economic objectives. Participants may be granted from time
to time one or more Options; provided, however, that the grant of each such
Option shall be separately approved by the Committee, and receipt of one such
Option shall not result in automatic receipt of any other Option. Upon
determination by the Committee that an Option is to be granted to a Participant,
written notice shall be given to such person, specifying the terms, conditions,
rights and duties related thereto. Each Participant shall, if required by the
Committee, enter into an agreement with the Company, in such form as the
Committee shall determine and which is consistent with the provisions of the
Plan, specifying such terms, conditions, rights and duties. Options shall be
deemed to be granted as of the date specified in the grant resolution of the
Committee, which date shall be the date of any related agreement with the
Participant. In the event of any inconsistency between the provisions of the
Plan and any such agreement entered into hereunder, the provisions of the Plan
shall govern.

                                    SECTION 7

                                  STOCK OPTIONS

7.1      Grant of Stock Options. Coincident with or following designation for
participation in the Plan, a Participant may be granted one or more Options. In
no event shall the exercise of one Option affect the right to exercise any other
Option or affect the number of shares of Stock for which any other Option may be
exercised, except as provided in subsection 7.2(j).

7.2      Stock Option Agreements. Each Option granted under the Plan shall be
evidenced by a written stock option agreement which shall be entered into by the
Company and the Participant to whom the Option is granted (the "Option Holder"),
and which shall contain the following terms and conditions, as well as such
other terms and conditions, not inconsistent therewith, as the Committee may
consider appropriate in each case.

                                      -6-

<PAGE>   10


         (a)      Number of Shares. Each stock option agreement shall state that
it covers a specified number of shares of the Stock, as determined by the
Committee.

         (b)      Price. The price at which each share of Stock covered by an
Option may be purchased shall be determined in each case by the Committee and
set forth in the stock option agreement, but in no event shall the price be less
than the Fair Market Value of the Stock on the date the Option is granted.

         (c)      Duration of Options; Employment Required For Exercise. Each
stock option agreement shall state the period of time, determined by the
Committee, within which the Option may be exercised by the Option Holder (the
"Option Period"). The Option Period must end, in all cases, not more than ten
years from the date an Option is granted. Except as otherwise provided in
Sections 5 and 8 and subsection 7.2(d)(iv) hereof, each Option granted under the
Plan shall become exercisable in increments such that 25% of the Option will
become exercisable on each of the four subsequent one-year anniversaries of the
date the Option is granted, but each such additional 25% increment shall become
exercisable only if the Option Holder has been continuously employed by the
Company from the date the Option is granted through the date on which each such
additional 25% increment becomes exercisable.

         (d)      Termination of Employment, Death, Disability, Etc. Each stock
option agreement shall provide as follows with respect to the exercise of the
Option upon termination of the employment or the death of the Option Holder:

                  (i) If the employment of the Option Holder is terminated
within the Option Period for cause, as determined by the Company, the Option
shall thereafter be void for all purposes. As used in this subsection 7.2(d),
"cause" shall mean a gross violation, as determined by the Company, of the
Company's established policies and procedures, provided that the effect of this
subsection 7.2(d) (i) shall be limited to determining the consequences of a
termination and that nothing in this subsection 7.2(d) (i) shall restrict or
otherwise interfere with the Company's discretion with respect to the
termination of any employee.

                  (ii) If the Option Holder retires from employment by the
Company or its affiliates on or after attaining age 65, the Option may be
exercised by the Option Holder within 36 months following his or her retirement
(provided that such exercise must occur within the Option Period), but not
thereafter. In the event of the Option Holder's death during such 36-month
period, each Option may be exercised by those entitled to do so in the manner
referred to in (iv) below. In any such case, the Option may be exercised only as
to the shares as to which the Option had become exercisable on or before the
date of the Option Holder's retirement.

                                      -7-

<PAGE>   11


                  (iii) If the Option Holder becomes disabled (as determined
pursuant to the Company's Long-Term Disability Plan), during the Option Period
while still employed, or within the three-month period referred to in (v) below,
or within the 36-month period referred to in (ii) above, the Option may be
exercised by the Option Holder or by his or her guardian or legal
representative, within twelve months following the Option Holder's disability,
or within the 36-month period referred to in (ii) if applicable and if longer
(provided that such exercise must occur within the Option Period), but not
thereafter. In the event of the Option Holder's death during such twelve-month
period, each Option may be exercised by those entitled to do so in the manner
referred to in (iv) below. In any such case, the Option may be exercised only as
to the shares as to which the Option had become exercisable on or before the
date of the Option Holder's disability.

                  (iv) In the event of the Option Holder's death while still
employed by the Company, each Option of the deceased Option Holder may be
exercised by those entitled to do so under the Option Holder's will or under the
laws of descent and distribution within twelve months following the Option
Holder's death (provided that in any event such exercise must occur within the
Option Period), but not thereafter, as to all shares of Stock which are subject
to such Option, including each 25% increment of the Option, if any, which has
not yet become exercisable at the time of the Option Holder's death. In the
event of the Option Holder's death within the 36-month period referred to in
(ii) above or within the twelve-month period referred to in (iii) above, each
Option of the deceased Option Holder that is exercisable at the time of death
may be exercised by those entitled to do so under the Option Holder's will or
under the laws of descent and distribution within twelve months following the
Option Holder's death or within the 36-month period referred to in (ii), if
applicable and if longer (provided that in any event such exercise must occur
within the Option Period). The provisions of this paragraph (iv) of subsection
7.2(d) shall be applicable to each Stock Option Agreement as if set forth
therein word for word. Each Stock Option Agreement executed by the Company prior
to the adoption of this provision shall be deemed amended to include the
provisions of this paragraph and all Options granted pursuant to such Stock
Option Agreements shall be exercisable as provided herein.

                  (v) If the employment of the Option Holder by the Company is
terminated (which for this purpose means that the Option Holder is no longer
employed by the Company or by an Affiliated Corporation) within the Option
Period for any reason other than cause, retirement on or after attaining age 65,
disability or the Option Holder's death, the Option may be exercised by the
Option Holder within three months following the date of such termination
(provided that such exercise must occur within the Option Period), but not
thereafter. In any such case, the Option may be exercised only as to the shares
as to which the Option had become exercisable on or before the date of
termination of employment.

                                      -8-

<PAGE>   12


         (e)      Transferability. Each stock option agreement shall provide
that the Option granted therein is not transferable by the Option Holder except
by will or pursuant to the laws of descent and distribution, and that such
Option is exercisable during the Option Holder's lifetime only by him or her, or
in the event of disability or incapacity, by his or her guardian or legal
representative.

         (f)      Agreement to Continue in Employment. Each stock option
agreement shall contain the Option Holder's agreement to remain in the
employment of the Company, at the pleasure of the Company, for a continuous
period of at least one year after the date of such stock option agreement, at
the salary rate in effect on the date of such agreement or at such changed rate
as may be fixed, from time to time, by the Company.

         (g)      Exercise, Payments, Etc.

                  (i) Each stock option agreement shall provide that the method
for exercising the Option granted therein shall be by delivery to the Corporate
Secretary of the Company of written notice specifying the number of shares with
respect to which such Option is exercised and payment of the Option Price. Such
notice shall be in a form satisfactory to the Committee and shall specify the
particular Option (or portion thereof) which is being exercised and the number
of shares with respect to which the Option is being exercised. The exercise of
the Stock Option shall be deemed effective upon receipt of such notice by the
Corporate Secretary and payment to the Company. If requested by the Company,
such notice shall contain the Option Holder's representation that he or she is
purchasing the Stock for investment purposes only and his or her agreement not
to sell any stock so purchased in any manner that is in violation of the
Securities Act of 1933, as amended, or any applicable state law. Such
restriction, or notice thereof, shall be placed on the certificates representing
the Stock so purchased. The purchase of such Stock shall take place at the
principal offices of the Company upon delivery of such notice, at which time the
purchase price of the Stock shall be paid in full by any of the methods or any
combination of the methods set forth in (ii) below. A properly executed
certificate or certificates representing the Stock shall be issued by the
Company and delivered to the Option Holder. If certificates representing Stock
are used to pay all or part of the exercise price, separate certificates for the
same number of shares of Stock shall be issued by the Company and delivered to
the Option Holder representing each certificate used to pay the Option Price,
and an additional certificate shall be issued by the Company and delivered to
the Option Holder representing the additional shares, in excess of the Option
Price, to which the Option Holder is entitled as a result of the exercise of the
Option.

                                      -9-

<PAGE>   13


                  (ii) the exercise price shall be paid by any of the following
methods or any combination of the following methods:

                           (A)  in cash;

                           (B) by certified or cashier's check payable to the
order of the Company;

                           (C) by delivery to the Company of certificates
representing the number of shares then owned by the Option Holder, the Fair
Market Value of which equals the purchase price of the Stock purchased pursuant
to the Option, properly endorsed for transfer to the Company; provided however,
that shares of Stock used for this purpose must have been held by the Option
Holder for such minimum period of time as may be established from time to time
by the Committee; for purposes of this Plan, the Fair Market Value of any shares
of Stock delivered in payment of the purchase price upon exercise of the Option
shall be the Fair Market Value as of the exercise date; the exercise date shall
be the day of delivery of the certificates for the Stock used as payment of the
Option Price; or

                           (D) by delivery to the Company of a properly executed
notice of exercise together with irrevocable instructions to a broker to deliver
to the Company promptly the amount of the proceeds of the sale of all or a
portion of the Stock or of a loan from the broker to the Option Holder necessary
to pay the exercise price.

         (h)      Date of Grant. An option shall be considered as having been
granted on the date specified in the grant resolution of the Committee.

         (i)      Withholding. Each stock option agreement shall provide that,
upon exercise of the Option, the Option Holder shall make appropriate
arrangements with the Company to provide for the Amount of additional
withholding required by Sections 3102 and 3402 of the Internal Revenue Code and
applicable state income tax laws, including payment of such taxes through
delivery of shares of Stock or by withholding Stock to be issued under the
Option, as provided in Section 13.

         (j)      Adjustment of Options. Subject to the provisions of Sections
4, 5, 7, 8 and 12, the Committee may make any adjustment in the number of shares
covered by, or the terms of an outstanding Option and a subsequent granting of
an Option, by amendment or by substitution of an outstanding Option; however,
except as provided in Sections 4, 5, 8 and 12 hereof, the Committee may not
adjust the exercise price of any outstanding Option. Such amendment or
substitution may result in terms and conditions (including the number of shares
covered, vesting schedule or exercise period) that differ from the terms and
conditions of the original Option. The Committee may not, however, adversely
affect the rights of any Participant to previously granted Options without the
consent of

                                      -10-

<PAGE>   14


such Participant. If such action is effected by amendment, the effective date of
such amendment will be the date of the original grant.

7.3      Shareholder Privileges. No Option Holder shall have any rights as a
shareholder with respect to any shares of Stock covered by an Option until the
Option Holder becomes the holder of record of such Stock, and no adjustments
shall be made for dividends or other distributions or other rights as to which
there is a record date preceding the date such Option Holder becomes the holder
of record of such Stock, except as provided in Section 4.

                                    SECTION 8

                                CHANGE IN CONTROL

8.1      In General. In the event of a change in control of the Company as
defined in Section 8.3, then the Committee may, in its sole discretion, without
obtaining shareholder approval, to the extent permitted in Section 12, take any
or all of the following actions: (a) accelerate the exercise dates of any
outstanding Options or make all such Options fully vested and exercisable; (b)
grant a cash bonus award to any Option Holder in an amount necessary to pay the
exercise price of all or any portion of the Options then held by such Option
Holder; (c) pay cash to any or all Option Holders in exchange for the
cancellation of their outstanding Options in an amount equal to the difference
between the exercise price of such Options and the greater of the tender offer
price for the underlying Stock or the Fair Market Value of the Stock on the date
of the cancellation of the Options; and (d) make any other adjustments or
amendments to the outstanding Options.

8.2      Limitation on Payments. If the provisions of this Section 8 would
result in the receipt by any Participant of a payment within the meaning of
Section 280G of the Internal Revenue Code and the regulations promulgated
thereunder and if the receipt of such payment by any Participant would, in the
opinion of independent tax counsel of recognized standing selected by the
Company, result in the payment by such Participant of any excise tax provided
for in Sections 280G and 4999 of the Internal Revenue Code, then the amount of
such payment shall be reduced to the extent required, in the opinion of
independent tax counsel, to prevent the imposition of such excise tax; provided,
however, that the Committee, in its sole discretion, may authorize the payment
of all or any portion of the amount of such reduction to the Participant.

8.3      Definition. For purposes of the Plan, a "change in control" shall mean
any of the events specified in the Company's Income Continuance Plan which
constitute a change in control within the meaning of that Plan.

                                      -11-

<PAGE>   15


                                    SECTION 9

                        RIGHTS OF EMPLOYEES, PARTICIPANTS

9.1      Employment. Nothing contained in the Plan or in any Option granted
under the Plan shall confer upon any Participant any right with respect to the
continuation of his or her employment by the Company or any Affiliated
Corporation, or interfere in any way with the right of the Company or any
Affiliated Corporation, subject to the terms of any separate employment
agreement to the contrary, at any time to terminate such employment or to
increase or decrease the compensation of the Participant from the rate in
existence at the time of the grant of an Option. Whether an authorized leave of
absence, or absence in military or government service, shall constitute a
termination of employment shall be determined by the Committee at the time.

9.2      Nontransferability. No right or interest of any Participant in an
Option granted pursuant to the Plan shall be assignable or transferable during
the lifetime of the Participant, either voluntarily or involuntarily, or
subjected to any lien, directly or indirectly, by operation of law, or
otherwise, including execution, levy, garnishment, attachment, pledge or
bankruptcy. In the event of a Participant's death, a Participant's rights and
interests in Options shall, to the extent provided in Section 7, be transferable
by testamentary will or the laws of descent and distribution, and payment of any
amounts due under the Plan shall be made to, and exercise of any Options may be
made by, the Participant's legal representatives, heirs or legatees. If in the
opinion of the Committee a person entitled to payments or to exercise rights
with respect to the Plan is disabled from caring for his affairs because of
mental condition, physical condition or age, payment due such person may be made
to, and such rights shall be exercised by, such person's guardian, conservator
or other legal personal representative upon furnishing the Committee with
evidence satisfactory to the Committee of such status.

                                   SECTION 10

                              GENERAL RESTRICTIONS

10.1     Investment Representations. The Company may require any person to whom
an Option is granted, as a condition of exercising such Option, to give written
assurances in substance and form satisfactory to the Company and its counsel to
the effect that such person is acquiring the Stock subject to the Option for his
own account for investment and not with any present intention of selling or
otherwise distributing the same, and to such other effects as the Company deems
necessary or appropriate in order to comply with Federal and applicable state
securities laws.

                                      -12-

<PAGE>   16


10.2     Compliance with Securities Laws. Each Option shall be subject to the
requirement that, if at any time counsel to the Company shall determine that the
listing, registration or qualification of the shares subject to such Option upon
any securities exchange or under any state or federal law, or the consent or
approval of any governmental or regulatory body, is necessary as a condition of,
or in connection with, the issuance or purchase of shares thereunder, such
Option may not be accepted or exercised in whole or in part unless such listing,
registration, qualification, consent or approval shall have been effected or
obtained on conditions acceptable to the Committee. Nothing herein shall be
deemed to require the Company to apply for or to obtain such listing,
registration or qualification.

                                   SECTION 11

                             OTHER EMPLOYEE BENEFITS

The amount of any compensation deemed to be received by a Participant as a
result of the exercise of an Option shall not constitute "earnings" with respect
to which any other employee benefits of such employee are determined, including
without limitation benefits under any pension, profit sharing, life insurance or
salary continuation plan.

                                   SECTION 12

                  PLAN AMENDMENT, MODIFICATION AND TERMINATION

The Board may at any time terminate, and from time to time may amend or modify
the Plan provided, however, that no amendment or modification may become
effective without approval of the amendment or modification by the shareholders
if shareholder approval is required to enable the Plan to satisfy any applicable
statutory or regulatory requirements, or if the Company, on the advice of
counsel, determines that shareholder approval is otherwise necessary or
desirable.

No amendment, modification or termination of the Plan shall in any manner
adversely affect any Options theretofore granted under the Plan, without the
consent of the Participant holding such Options.

                                   SECTION 13

                                   WITHHOLDING

13.1     Withholding Requirement. The Company's obligations to deliver shares of
Stock upon the exercise of an Option shall be subject to the Participant's
satisfaction of all applicable federal, state and local income and other tax
withholding requirements.

                                      -13-

<PAGE>   17


13.2     Withholding With Stock. At the time the Committee grants an Option, it
may, in its sole discretion, grant the Participant an election to pay all such
amounts of tax withholding, or any part thereof, by electing to transfer to the
Company, or to have the Company withhold from shares otherwise issuable to the
Participant, shares of Stock having a value equal to the amount required to be
withheld or such lesser amount as may be elected by the Participant. All
elections shall be subject to the approval or disapproval of the Committee. The
value of shares of Stock to be withheld shall be based on the Fair Market Value
of the Stock on the date that the amount of tax to be withheld is to be
determined (the "Tax Date"). Any such elections by Participants to have shares
of Stock withheld for this purpose will be subject to the following
restrictions:

         (a)      All elections must be made prior to the Tax Date.

         (b)      All elections shall be irrevocable.

         (c)      If the Participant is an officer or director of the Company
within the meaning of Section 16 of the 1934 Act ("Section 16"), the Participant
must satisfy the requirements of such Section 16 and any applicable Rules
thereunder with respect to the use of Stock to satisfy such tax withholding
obligation.

                                   SECTION 14

                               REQUIREMENTS OF LAW

14.1     Requirements of Law. The issuance of stock and the payment of cash
pursuant to the Plan shall be subject to all applicable laws, rules and
regulations.

14.2     Federal Securities Law Requirements. If a Participant is an officer or
director of the Company within the meaning of Section 16, Options granted
hereunder shall be subject to all conditions required under Rule 16b-3, or any
successor rule promulgated under the 1934 Act, to qualify the Option for any
exception from the provisions of Section 16(b) of the 1934 Act available under
that Rule. Such conditions are hereby incorporated herein by reference and shall
be set forth in the agreement with the Participant which describes the Option.

14.3     Governing Law. The Plan and all agreements hereunder shall be construed
in accordance with and governed by the laws of the State of Colorado.

                                      -14-

<PAGE>   18


                                   SECTION 15

                              DURATION OF THE PLAN

The Plan shall terminate at such time as may be determined by the Board of
Directors, and no Option shall be granted after such termination. If not sooner
terminated under the preceding sentence, the Plan shall fully cease and expire
at midnight on September 18, 1995. Options outstanding at the time of the Plan
termination may continue to be exercised in accordance with their terms.



Dated: December 17, 1998

                                       APACHE CORPORATION

ATTEST:

/s/ Cheri L. Peper                     By: /s/ Daniel L. Schaeffer            
- -----------------------------------       -----------------------------------
Cheri L. Peper                            Daniel L. Schaeffer
Corporate Secretary                       Vice President

                                      -15-

<PAGE>   1
                                                                   EXHIBIT 10.20












                               APACHE CORPORATION

                             1995 STOCK OPTION PLAN

                   (AS AMENDED AND RESTATED DECEMBER 17, 1998)















<PAGE>   2

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                     PAGE

<S>               <C>                                                                                   <C>
Section 1 - Introduction................................................................................ 1

         1.1      Establishment......................................................................... 1
         1.2      Purposes.............................................................................. 1
         1.3      Effective Date........................................................................ 1

Section 2 - Definitions................................................................................. 1

         2.1      Definitions........................................................................... 1
         2.2      Headings; Gender and Number........................................................... 2

Section 3 - Plan Administration......................................................................... 3

Section 4 - Stock Subject to the Plan................................................................... 3

         4.1      Number of Shares...................................................................... 3
         4.2      Other Shares of Stock................................................................. 4
         4.3      Adjustments for Stock Split, Stock Dividend, Etc...................................... 4
         4.4      Dividend Payable in Stock of Another Corporation, Etc................................. 4
         4.5      Other Changes in Stock................................................................ 4
         4.6      Rights to Subscribe................................................................... 5
         4.7      General Adjustment Rules.............................................................. 5
         4.8      Determination by the Committee, Etc................................................... 5

Section 5 - Reorganization or Liquidation............................................................... 5

Section 6 - Participation............................................................................... 6

Section 7 - Stock Options............................................................................... 6

         7.1      Grant of Stock Options................................................................ 6
         7.2      Stock Option Agreements............................................................... 7
         7.3      Stockholder Privileges................................................................11

Section 8 - Change in Control...........................................................................11

         8.1      In General............................................................................11
         8.2      Limitation on Payments................................................................11
         8.3      Definition............................................................................12
</TABLE>


                                       i
<PAGE>   3

<TABLE>

<S>               <C>                                                                                   <C>
Section 9 - Rights of Employees; Participants...........................................................12

         9.1      Employment............................................................................12
         9.2      Nontransferability....................................................................12

Section 10 - General Restrictions.......................................................................12

         10.1     Investment Representations............................................................12
         10.2     Compliance with Securities Laws.......................................................13

Section 11 - Other Employee Benefits....................................................................13

Section 12 - Plan Amendment, Modification and Termination...............................................13

Section 13 - Withholding................................................................................14

         13.1     Withholding Requirement...............................................................14
         13.2     Withholding With Stock................................................................14

Section 14 - Requirements of Law........................................................................14

         14.1     Requirements of Law...................................................................14
         14.2     Federal Securities Laws Requirements..................................................14
         14.3     Governing Law.........................................................................15

Section 15 - Duration of the Plan.......................................................................15
</TABLE>


                                       ii
<PAGE>   4

                               APACHE CORPORATION

                             1995 STOCK OPTION PLAN


                                    SECTION 1

                                  INTRODUCTION

1.1. Establishment. Apache Corporation, a Delaware corporation (hereinafter
referred to, together with its Affiliated Corporations (as defined in Section
2.1 hereof) as the "Company" except where the context otherwise requires),
hereby establishes the Apache Corporation 1995 Stock Option Plan (the "Plan")
for certain key employees of the Company. The Plan permits the grant of stock
options to certain key employees of the Company.

1.2. Purposes. The purposes of the Plan are to provide the key management
employees selected for participation in the Plan with added incentives to
continue in the long-term service of the Company and to create in such employees
a more direct interest in the future success of the operations of the Company by
relating incentive compensation to increases in stockholder value, so that the
income of the key management employees is more closely aligned with the
interests of the Company's stockholders. The Plan is also designed to attract
key employees and to retain and motivate participating employees by providing an
opportunity for investment in the Company.

1.3. Effective Date. The Effective Date of the Plan (the "Effective Date")
shall be May 4, 1995. This Plan and each option granted hereunder is conditioned
on and shall be of no force or effect until approval of the Plan by the holders
of the shares of voting stock of the Company unless the Company, on the advice
of counsel, determines that stockholder approval is not necessary. The Committee
(as defined in Section 2.1 hereof) may grant options the exercise of which shall
be expressly subject to the condition that the Plan shall have been approved by
the stockholders of the Company.

                                    SECTION 2

                                   DEFINITIONS

2.1. Definitions.  The following terms shall have the meanings set forth below:

         (a)  "Affiliated Corporation" means any corporation or other entity
(including but not limited to a partnership) which is affiliated with Apache
Corporation through stock ownership or otherwise and is treated as a common
employer under the provisions of Sections 414(b) and (c) or any successor
section(s) of the Internal Revenue Code.



                                       1
<PAGE>   5

         (b) "Board" means the Board of Directors of the Company.

         (c) "Committee" means the Stock Option Plan Committee of the Board,
which is empowered hereunder to take actions in the administration of the Plan.
The Committee shall be constituted at all times as to permit the Plan to comply
with: (i) Rule 16b-3 or any successor rule(s) promulgated under the Securities
Exchange Act of 1934, as amended (the "1934 Act"), and (ii) Section 162(m) or
any successor section(s) of the Internal Revenue Code and the regulations
promulgated thereunder.

         (d) "Eligible Employees" means those full-time key employees
(including, without limitation, officers and directors who are also employees)
of the Company or any division thereof, upon whose judgment, initiative and
efforts the Company is, or will become, largely dependent for the successful
conduct of its business.

         (e) "Fair Market Value" means the closing price of the Stock as
reported on the New York Stock Exchange, Inc. Composite Transactions Reporting
System for a particular date. If there are no Stock transactions on such date,
the Fair Market Value shall be determined as of the immediately preceding date
on which there were Stock transactions.

         (f) "Internal Revenue Code" means the Internal Revenue Code of 1986, as
it may be amended from time to time.

         (g) "Option" means a right to purchase Stock at a stated price for a
specified period of time. All Options granted under the Plan shall be Options
which are not "incentive stock options" as described in Section 422 or any
successor section(s) of the Internal Revenue Code.

         (h) "Option Price" means the price at which shares of Stock subject to
an Option may be purchased, determined in accordance with subsection 7.2(b)
hereof.

         (i) "Participant" means an Eligible Employee designated by the
Committee from time to time during the term of the Plan to receive
one or more Options under the Plan.

         (j) "Stock" means the $1.25 par value Common Stock of the Company.

2.2  Headings; Gender and Number. The headings contained in the Plan are for
reference purposes only and shall not affect in any way the meaning or
interpretation of the Plan. Except when otherwise indicated by the context, the
masculine gender shall also include the feminine gender, and the definition of
any term herein in the singular shall also include the plural.




                                       2
<PAGE>   6

                                    SECTION 3

                               PLAN ADMINISTRATION

The Plan shall be administered by the Committee. In accordance with the
provisions of the Plan, the Committee shall, in its sole discretion, select the
Participants from among the Eligible Employees, determine the Options to be
granted pursuant to the Plan, the number of shares of Stock to be issued
thereunder, the time at which such Options are to be granted, fix the Option
Price, and establish such other terms and requirements as the Committee may deem
necessary, or desirable and consistent with the terms of the Plan. The Committee
shall determine the form or forms of the agreements with Participants which
shall evidence the particular provisions, terms, conditions, rights and duties
of the Company and the Participants with respect to Options granted pursuant to
the Plan, which provisions need not be identical except as may be provided
herein. The Committee may from time to time adopt such rules and regulations for
carrying out the purposes of the Plan as it may deem proper and in the best
interests of the Company. The Committee may correct any defect, supply any
omission or reconcile any inconsistency in the Plan, or in any agreement entered
into hereunder, in the manner and to the extent it shall deem expedient and it
shall be the sole and final judge of such expediency. No member of the Committee
shall be liable for any action or determination made in good faith. The
determination, interpretations and other actions of the Committee pursuant to
the provisions of the Plan shall be binding and conclusive for all purposes and
on all persons.

The Plan is intended to comply with the requirements of Section 162 or any
successor section(s) of the Internal Revenue Code ("Section 162") as to any
"covered employee" as defined in Section 162, and shall be administered,
interpreted and construed consistently therewith. In accordance with this
intent, the amount of compensation a Participant may receive from Options
granted under the Plan shall be based solely on an increase in the value of the
Stock after the date of the grant of the Option, or such other bases as may be
permitted by applicable law. The Committee is authorized to take such additional
action, if any, that may be required to ensure that the Plan satisfies the
requirements of Section 162 and the regulations promulgated or revenue rulings
published thereunder.

                                    SECTION 4

                            STOCK SUBJECT TO THE PLAN

4.1  Number of Shares. Subject to Section 7.1 and to adjustment pursuant to
Section 4.3 hereof, two million five hundred thousand (2,500,000) shares of
Stock are authorized for issuance under the Plan in accordance with the
provisions of the Plan and subject to such restrictions or other provisions as
the Committee may from time to time deem necessary. This authorization may be
increased from time to time by approval of the Board and the stockholders of the
Company if, in the opinion of counsel for the Company, such stockholder approval
is required. Shares of Stock which may be issued



                                       3
<PAGE>   7

upon exercise of Options shall be applied to reduce the maximum number of shares
of Stock remaining available for use under the Plan. The Company shall at all
times during the term of the Plan and while any Options are outstanding retain
as authorized and unissued Stock, or as Stock in the Company's treasury, at
least the number of shares from time to time required under the provisions of
the Plan, or otherwise assure itself of its ability to perform its obligations
hereunder.

4.2 Other Shares of Stock. Any shares of Stock that are subject to an Option
which expires, is forfeited, is cancelled, or for any reason is terminated
unexercised, and any shares of Stock that for any other reason are not issued to
a Participant or are forfeited shall automatically become available for use
under the Plan.

4.3 Adjustments for Stock Split, Stock Dividend, Etc. If the Company shall at
any time increase or decrease the number of its outstanding shares of Stock or
change in any way the rights and privileges of such shares by means of the
payment of a Stock dividend or any other distribution upon such shares payable
in Stock, or through a Stock split, subdivision, consolidation, combination,
reclassification or recapitalization involving the Stock, then in relation to
the Stock that is affected by one or more of the above events, the numbers,
rights and privileges of the following shall be increased, decreased or changed
in like manner as if they had been issued and outstanding, fully paid and
nonassessable at the time of such occurrence: (i) the shares of Stock as to
which Options may be granted under the Plan; and (ii) the shares of the Stock
then included in each outstanding Option granted hereunder.

4.4 Dividend Payable in Stock of Another Corporation, Etc. If the Company shall
at any time pay or make any dividend or other distribution upon the Stock
payable in securities or other property (except money or Stock), a proportionate
part of such securities or other property shall be set aside and delivered to
any Participant then holding an Option for the particular type of Stock for
which the dividend or other distribution was made, upon exercise thereof. Prior
to the time that any such securities or other property are delivered to a
Participant in accordance with the foregoing, the Company shall be the owner of
such securities or other property and shall have the right to vote the
securities, receive any dividends payable on such securities, and in all other
respects shall be treated as the owner. If securities or other property which
have been set aside by the Company in accordance with this Section are not
delivered to a Participant because an Option is not exercised, then such
securities or other property shall remain the property of the Company and shall
be dealt with by the Company as it shall determine in its sole discretion.

4.5 Other Changes in Stock. In the event there shall be any change, other than
as specified in Sections 4.3 and 4.4 hereof, in the number or kind of
outstanding shares of Stock or of any stock or other securities into which the
Stock shall be changed or for which it shall have been exchanged, and if the
Committee shall in its discretion determine that such change equitably requires
an adjustment in the number or kind of shares subject




                                       4
<PAGE>   8

to outstanding Options or which have been reserved for issuance pursuant to the
Plan but are not then subject to an Option, then such adjustments shall be made
by the Committee and shall be effective for all purposes of the Plan and on each
outstanding Option that involves the particular type of stock for which a change
was effected.

4.6 Rights to Subscribe. If the Company shall at any time grant to the holders
of its Stock rights to subscribe pro rata for additional shares thereof or for
any other securities of the Company or of any other corporation, there shall be
reserved with respect to the shares then under Option to any Participant of the
particular class of Stock involved the Stock or other securities which the
Participant would have been entitled to subscribe for if immediately prior to
such grant the Participant had exercised his entire Option. If, upon exercise of
any such Option, the Participant subscribes for the additional shares or other
securities, the Option Price shall be increased by the amount of the price that
is payable by the Participant for such additional shares or other securities.

4.7 General Adjustment Rules. No adjustment or substitution provided for in this
Section 4 shall require the Company to sell a fractional share of Stock under
any Option, or otherwise issue a fractional share of Stock, and the total
substitution or adjustment with respect to each Option shall be limited by
deleting any fractional share. In the case of any such substitution or
adjustment, the total Option Price for the shares of Stock then subject to the
Option shall remain unchanged but the Option Price per share under each such
Option shall be equitably adjusted by the Committee to reflect the greater or
lesser number of shares of Stock or other securities into which the Stock
subject to the Option may have been changed.

4.8 Determination by the Committee, Etc. Adjustments under this Section 4 shall
be made by the Committee, whose determinations with regard thereto shall be
final and binding upon all parties thereto.

                                    SECTION 5

                          REORGANIZATION OR LIQUIDATION

In the event that the Company is merged or consolidated with another corporation
and the Company is not the surviving corporation, or if all or substantially all
of the assets or more than 20 percent of the outstanding voting stock of the
Company is acquired by any other corporation, business entity or person, or in
case of a reorganization (other than a reorganization under the United States
Bankruptcy Code) or liquidation of the Company, and if the provisions of Section
8 hereof do not apply, the Committee, or the board of directors of any
corporation assuming the obligations of the Company, shall, as to the Plan and
outstanding Options either (i) make appropriate provision for the adoption and
continuation of the Plan by the acquiring or successor corporation and for the
protection of any such outstanding Options by the substitution on an equitable
basis of appropriate stock of the Company or of the merged, consolidated or
otherwise reorganized



                                       5
<PAGE>   9

corporation which will be issuable with respect to the Stock, provided that no
additional benefits shall be conferred upon the Participants holding such
Options as a result of such substitution, and the excess of the aggregate Fair
Market Value of the shares subject to the Options immediately after such
substitution over the Option Price thereof is not more than the excess of the
aggregate Fair Market Value of the shares subject to such Options immediately
before such substitution over the Option Price thereof, or (ii) upon written
notice to the Participants, provide that all unexercised Options shall be
exercised within a specified number of days of the date of such notice or such
Options will be terminated. In the latter event, the Committee shall accelerate
the exercise dates of outstanding Options so that all Options become fully
vested prior to any such event.

                                    SECTION 6

                                  PARTICIPATION

Participants in the Plan shall be those Eligible Employees who, in the judgment
of the Committee, are performing, or during the term of their incentive
arrangement will perform, vital services in the management, operation and
development of the Company or an Affiliated Corporation, and significantly
contribute, or are expected to significantly contribute, to the achievement of
the Company's long-term corporate economic objectives. Participants may be
granted from time to time one or more Options; provided, however, that the grant
of each such Option shall be separately approved by the Committee, and receipt
of one such Option shall not result in automatic receipt of any other Option.
Upon determination by the Committee that an Option is to be granted to a
Participant, written notice shall be given to such person, specifying the terms,
conditions, rights and duties related thereto. Each Participant shall, if
required by the Committee, enter into an agreement with the Company, in such
form as the Committee shall determine and which is consistent with the
provisions of the Plan, specifying such terms, conditions, rights and duties.
Options shall be deemed to be granted as of the date specified in the grant
resolution of the Committee, which date shall be the date of any related
agreement with the Participant. In the event of any inconsistency between the
provisions of the Plan and any such agreement entered into hereunder, the
provisions of the Plan shall govern.

                                    SECTION 7

                                  STOCK OPTIONS

7.1 Grant of Stock Options. Coincident with or following designation for
participation in the Plan, an Eligible Employee may be granted one or more
Options. Grants of Options under the Plan shall be made by the Committee. In no
event shall the exercise of one Option affect the right to exercise any other
Option or affect the number of shares of Stock for which any other Option may be
exercised, except as provided in subsection 7.2(j) hereof. During the life of
the Plan, no Eligible Employee may be granted Options



                                       6
<PAGE>   10

which in the aggregate pertain to in excess of 25 percent of the total shares of
Stock authorized under the Plan.

7.2 Stock Option Agreements. Each Option granted under the Plan shall be
evidenced by a written stock option agreement which shall be entered into by the
Company and the Participant to whom the Option is granted (the "Stock Option
Agreement"), and which shall contain the following terms and conditions, as well
as such other terms and conditions, not inconsistent therewith, as the Committee
may consider appropriate in each case.

         (a) Number of Shares. Each Stock Option Agreement shall state that it
covers a specified number of shares of Stock, as determined by the Committee.

         (b) Price. The price at which each share of Stock covered by an Option
may be purchased shall be determined in each case by the Committee and set forth
in the Stock Option Agreement, but in no event shall the price be less than the
Fair Market Value of the Stock on the date the Option is granted.

         (c) Duration of Options; Employment Required For Exercise. Each Stock
Option Agreement shall state the period of time, determined by the Committee,
within which the Option may be exercised by the Participant (the "Option
Period"). The Option Period must end, in all cases, not more than ten years from
the date an Option is granted. Except as otherwise provided in Sections 5 and 8
and subsection 7.2(d)(iv) hereof, each Option granted under the Plan shall
become exercisable in increments such that 25 percent of the Option will become
exercisable on each of the four subsequent one-year anniversaries of the date
the Option is granted, but each such additional 25-percent increment shall
become exercisable only if the Participant has been continuously employed by the
Company from the date the Option is granted through the date on which each such
additional 25-percent increment becomes exercisable.

         (d) Termination of Employment, Death, Disability, Etc. Each Stock
Option Agreement shall provide as follows with respect to the exercise of the
Option upon termination of the employment or the death of the Participant:

                  (i) If the employment of the Participant by the Company is
terminated within the Option Period for cause, as determined by the Company, the
Option shall thereafter be void for all purposes. As used in this subsection
7.2(d), "cause" shall mean a gross violation, as determined by the Company, of
the Company's established policies and procedures, provided that the effect of
this subsection 7.2(d) shall be limited to determining the consequences of a
termination and that nothing in this subsection 7.2(d) shall restrict or
otherwise interfere with the Company's discretion with respect to the
termination of any employee.



                                       7
<PAGE>   11

                  (ii) If the Participant retires from employment by the Company
on or after attaining age 65, the Option may be exercised by the Participant
within 36 months following his or her retirement (provided that such exercise
must occur within the Option Period), but not thereafter. In the event of the
Participant's death during such 36-month period, each Option may be exercised by
those entitled to do so in the manner referred to in (iv) below. In any such
case the Option may be exercised only as to the shares as to which the Option
had become exercisable on or before the date of the Participant's retirement.

                  (iii) If the Participant becomes disabled (as determined
pursuant to the Company's Long-Term Disability Plan or any successor plan),
during the Option Period while still employed, or within the three-month period
referred to in (v) below, or within the 36-month period referred to in (ii)
above, the Option may be exercised by the Participant or by his or her guardian
or legal representative, within twelve months following the Participant's
disability, or within the 36-month period referred to in (ii) if applicable and
if longer (provided that such exercise must occur within the Option Period), but
not thereafter. In the event of the Participant's death during such twelve-month
period, each Option may be exercised by those entitled to do so in the manner
referred to in (iv) below. In any such case, the Option may be exercised only as
to the shares of Stock as to which the Option had become exercisable on or
before the date of the Participant's disability.

                  (iv) In the event of the Participant's death while still
employed by the Company, each Option of the deceased Participant may be
exercised by those entitled to do so under the Participant's will or under the
laws of descent and distribution within twelve months following the
Participant's death (provided that in any event such exercise must occur within
the Option Period), but not thereafter, as to all shares of Stock which are
subject to such Option, including each 25-percent increment of the Option, if
any, which has not yet become exercisable at the time of the Participant's
death. In the event of the Participant's death within the 36-month period
referred to in (ii) above or within the twelve-month period referred to in (iii)
above, each Option of the deceased Participant that is exercisable at the time
of death may be exercised by those entitled to do so under the Participant's
will or under the laws of descent and distribution within twelve months
following the Participant's death or within the 36-month period referred to in
(ii), if applicable and if longer (provided that in any event such exercise must
occur within the Option Period). The provisions of this paragraph (iv) of
subsection 7.2(d) shall be applicable to each Stock Option Agreement as if set
forth therein word for word. Each Stock Option Agreement executed by the Company
prior to the adoption of this provision shall be deemed amended to include the
provisions of this paragraph and all Options granted pursuant to such Stock
Option Agreements shall be exercisable as provided herein.




                                       8
<PAGE>   12




                  (v) If the employment of the Participant by the Company is
terminated (which for this purpose means that the Participant is no longer
employed by the Company or by an Affiliated Corporation) within the Option
Period for any reason other than cause, the Participant's retirement on or after
attaining age 65, the Participant's disability or death, the Option may be
exercised by the Participant within three months following the date of such
termination (provided that such exercise must occur within the Option Period),
but not thereafter. In any such case, the Option may be exercised only as to the
shares as to which the Option had become exercisable on or before the date of
termination of the Participant's employment.

         (e) Transferability. Each Stock Option Agreement shall provide that the
Option granted therein is not transferable by the Participant except by will or
pursuant to the laws of descent and distribution, and that such Option is
exercisable during the Participant's lifetime only by him or her, or in the
event of the Participant's disability or incapacity, by his or her guardian or
legal representative.

         (f) Agreement to Continue in Employment. Each Stock Option Agreement
shall contain the Participant's agreement to remain in the employment of the
Company, at the pleasure of the Company, for a continuous period of at least one
year after the date of such Stock Option Agreement, at the salary rate in effect
on the date of such agreement or at such changed rate as may be fixed, from time
to time, by the Company.

         (g) Exercise, Payments, Etc.

                  (i) Each Stock Option Agreement shall provide that the method
for exercising the Option granted therein shall be by delivery to the Office of
the Secretary of the Company of written notice specifying the number of shares
of Stock with respect to which such Option is exercised and payment of the
Option Price. Such notice shall be in a form satisfactory to the Committee and
shall specify the particular Options (or portions thereof) which are being
exercised and the number of shares of Stock with respect to which the Options
are being exercised. The exercise of the Option shall be deemed effective on the
date such notice is received by the Office of the Secretary and payment is made
to the Company of the Option Price (the "Exercise Date"). If requested by the
Company, such notice shall contain the Participant's representation that he or
she is purchasing the Stock for investment purposes only and his or her
agreement not to sell any Stock so purchased in any manner that is in violation
of the Securities Act of 1933, as amended, or any applicable state law. Such
restriction, or notice thereof, shall be placed on the certificates representing
the Stock so purchased. The purchase of such Stock shall take place at the
principal offices of the Company upon delivery of such notice, at which time the
Option Price shall be paid in full by any of the methods or any combination of
the methods set forth in (ii) below. A properly executed certificate or
certificates representing the Stock shall be issued by the Company and delivered
to the Participant. If certificates representing Stock are used to pay all or
part of the Option Price, separate certificates for the same number of shares of
Stock shall be issued by the Company and 



                                       9
<PAGE>   13

delivered to the Participant representing each certificate used to pay the
Option Price, and an additional certificate shall be issued by the Company and
delivered to Participant representing the additional shares of Stock, in excess
of the Option Price, to which the Participant is entitled as a result of the
exercise of the Option.

                  (ii) the Option Price shall be paid by any of the following
methods or any combination of the following methods:

                           (A) in cash;

                           (B) by personal, certified or cashier's check payable
to the order of the Company;

                           (C) by delivery to the Company of certificates
representing a number of shares of Stock then owned by the Participant, the Fair
Market Value of which equals the Option Price of the Stock purchased pursuant to
the Option, properly endorsed for transfer to the Company; provided however,
that shares of Stock used for this purpose must have been held by the
Participant for such minimum period of time as may be established from time to
time by the Committee; for purposes of this Plan, the Fair Market Value of any
shares of Stock delivered in payment of the Option Price upon exercise of the
Option shall be the Fair Market Value as of the Exercise Date; the Exercise Date
shall be the day of delivery of the certificates for the Stock used as payment
of the Option Price; or

                           (D) by delivery to the Company of a properly executed
notice of exercise together with irrevocable instructions to a broker to deliver
to the Company promptly the amount of the proceeds of the sale of all or a
portion of the Stock or of a loan from the broker to the Participant necessary
to pay the Option Price.

                  (h) Date of Grant. An Option shall be considered as having
been granted on the date specified in the grant resolution of the Committee.

                  (i) Tax Withholding. Each Stock Option Agreement shall provide
that, upon exercise of the Option, the Participant shall make appropriate
arrangements with the Company to provide for the amount of additional tax
withholding required by Sections 3102 and 3402 or any successor section(s) of
the Internal Revenue Code and applicable state income tax laws, including
payment of such taxes through delivery of shares of Stock or by withholding
Stock to be issued under the Option, as provided in Section 13 hereof.

                  (j) Adjustment of Options. Subject to the provisions of
Sections 4, 5, 7, 8 and 12 hereof, the Committee may make any adjustment in the
number of shares of Stock covered by, or the terms of an outstanding Option and
a subsequent granting of an Option, by amendment or by substitution for an
outstanding Option; however, except as 



                                       10
<PAGE>   14

provided in Sections 4, 5, 8 and 12 hereof, the Committee may not adjust the
Option Price of any outstanding Option. Such amendment or substitution may
result in terms and conditions (including the number of shares of Stock covered,
vesting schedule or Option Period) that differ from the terms and conditions of
the original Option. The Committee may not, however, adversely affect the rights
of any Participant to previously granted Options without the consent of such
Participant. If such action is effected by amendment, the effective date of
grant of such amendment will be the date of grant of the original Option.

7.3 Stockholder Privileges. No Participant shall have any rights as a
stockholder with respect to any shares of Stock covered by an Option until the
Participant becomes the holder of record of such Stock. Except as provided in
Section 4 hereof, no adjustments shall be made for dividends or other
distributions or other rights as to which there is a record date preceding the
date on which such Participant becomes the holder of record of such Stock.

                                    SECTION 8

                                CHANGE IN CONTROL

8.1 In General. In the event of a change in control of the Company as defined in
Section 8.3 hereof, then the Committee may, in its sole discretion, without
obtaining stockholder approval, to the extent permitted in Section 12 hereof,
take any or all of the following actions: (a) accelerate the dates on which any
outstanding Options become exercisable or make all such Options fully vested and
exercisable; (b) grant a cash bonus award to any Participant in an amount
necessary to pay the Option Price of all or any portion of the Options then held
by such Participant; (c) pay cash to any or all Participants in exchange for the
cancellation of their outstanding Options in an amount equal to the difference
between the Option Price of such Options and the greater of the tender offer
price for the underlying Stock or the Fair Market Value of the Stock on the date
of the cancellation of the Options; and (d) make any other adjustments or
amendments to the outstanding Options.

8.2 Limitation on Payments. If the provisions of this Section 8 would result in
the receipt by any Participant of a payment within the meaning of Section 280G
or any successor section(s) of the Internal Revenue Code, and the regulations
promulgated thereunder, and if the receipt of such payment by any Participant
would, in the opinion of independent tax counsel of recognized standing selected
by the Company, result in the payment by such Participant of any excise tax
provided for in Sections 280G and 4999 or any successor section(s) of the
Internal Revenue Code, then the amount of such payment shall be reduced to the
extent required, in the opinion of independent tax counsel, to prevent the
imposition of such excise tax; provided, however, that the Committee, in its
sole discretion, may authorize the payment of all or any portion of the amount
of such reduction to the Participant.


                                       11
<PAGE>   15

8.3 Definition. For purposes of the Plan, a "change in control" shall mean any
of the events specified in the Company's Income Continuance Plan or any
successor plan which constitute a change in control within the meaning of such
plan.

                                    SECTION 9

                        RIGHTS OF EMPLOYEES, PARTICIPANTS

9.1. Employment. Nothing contained in the Plan or in any Option granted under
the Plan shall confer upon any Participant any right with respect to the
continuation of his or her employment by the Company or any Affiliated
Corporation, or interfere in any way with the right of the Company or any
Affiliated Corporation, subject to the terms of any separate employment
agreement to the contrary, at any time to terminate such employment or to
increase or decrease the level of the Participant's compensation from the level
in existence at the time of the grant of an Option. Whether an authorized leave
of absence, or absence in military or government service, shall constitute a
termination of employment shall be determined by the Committee at the time.

9.2 Nontransferability. No right or interest of any Participant in an Option
granted pursuant to the Plan shall be assignable or transferable during the
lifetime of the Participant, either voluntarily or involuntarily, or subjected
to any lien, directly or indirectly, by operation of law, or otherwise,
including execution, levy, garnishment, attachment, pledge or bankruptcy. In the
event of a Participant's death, a Participant's rights and interests in Options
shall, to the extent provided in Section 7 hereof, be transferable by
testamentary will or the laws of descent and distribution, and payment of any
amounts due under the Plan shall be made to, and exercise of any Options may be
made by, the Participant's legal representatives, heirs or legatees. If in the
opinion of the Committee a person entitled to payments or to exercise rights
with respect to the Plan is disabled from caring for his or her affairs because
of mental condition, physical condition or age, payment due such person may be
made to, and such rights shall be exercised by, such person's guardian,
conservator or other legal personal representative upon furnishing the Committee
with evidence satisfactory to the Committee of such status.

                                   SECTION 10

                              GENERAL RESTRICTIONS

10.1 Investment Representations. The Company may require a Participant, as a
condition of exercising an Option, to give written assurances in substance and
form satisfactory to the Company and its counsel to the effect that such person
is acquiring the Stock subject to the Option for his own account for investment
and not with any present intention of selling or otherwise distributing the
same, and to such other effects as the



                                       12
<PAGE>   16

Company deems necessary or appropriate in order to comply with federal and
applicable state securities laws.

10.2 Compliance with Securities Laws. Each Option shall be subject to the
requirement that, if at any time counsel to the Company shall determine that the
listing, registration or qualification of the shares of Stock subject to such
Option upon any securities exchange or under any state or federal law, or the
consent or approval of any governmental or regulatory body, is necessary as a
condition of, or in connection with, the issuance or purchase of shares of Stock
thereunder, such Option may not be accepted or exercised in whole or in part
unless such listing, registration, qualification, consent or approval shall have
been effected or obtained on conditions acceptable to the Committee. Nothing
herein shall be deemed to require the Company to apply for or to obtain such
listing, registration, qualification, consent or approval.

                                   SECTION 11

                             OTHER EMPLOYEE BENEFITS

The amount of any compensation deemed to be received by a Participant as a
result of the exercise of an Option shall not constitute "earnings" with respect
to which any other employee benefits of such Participant are determined,
including without limitation benefits under any pension, profit sharing, life
insurance or salary continuation plan.

                                   SECTION 12

                  PLAN AMENDMENT, MODIFICATION AND TERMINATION

The Board may at any time terminate, and from time to time may amend or modify
the Plan provided, however, that no amendment or modification may become
effective without approval of the amendment or modification by the Company's
stockholders if stockholder approval is required to enable the Plan to satisfy
any applicable statutory or regulatory requirements, or if the Company, on the
advice of counsel, determines that stockholder approval is otherwise necessary
or desirable.

No amendment, modification or termination of the Plan shall in any manner
adversely affect any Option theretofore granted under the Plan, without the
consent of the Participant holding such Option.



                                       13
<PAGE>   17





                                   SECTION 13

                                   WITHHOLDING

13.1 Withholding Requirement. The Company's obligations to deliver shares of
Stock upon the exercise of an Option shall be subject to the Participant's
satisfaction of all applicable federal, state and local income and other tax
withholding requirements.

13.2 Withholding With Stock. At the time the Committee grants an Option, it may,
in its sole discretion, grant the Participant an election to pay all such
amounts of tax withholding, or any part thereof, by the transfer to the Company,
or to have the Company withhold from shares of Stock otherwise issuable to the
Participant upon the exercise of an Option, shares of Stock having a value equal
to the amount required to be withheld or such lesser amount as may be elected by
the Participant. All such elections shall be subject to the approval or
disapproval of the Committee. The value of shares of Stock to be withheld shall
be based on the Fair Market Value of the Stock on the Exercise Date. Any such
elections by Participants to have shares of Stock withheld for this purpose will
be subject to the following restrictions:

                  (a) All elections shall be made on or prior to the Exercise
Date.

                  (b) All elections shall be irrevocable.

                  (c) If the Participant is an officer or director of the
Company within the meaning of Section 16 or any successor section(s) of the 1934
Act ("Section 16"), the Participant must satisfy the requirements of such
Section 16 and any applicable rules and regulations thereunder with respect to
the use of Stock to satisfy such tax withholding obligation.

                                   SECTION 14

                               REQUIREMENTS OF LAW

14.1 Requirements of Law. The issuance of Stock and the payment of cash pursuant
to the Plan shall be subject to all applicable laws, rules and regulations.

14.2 Federal Securities Laws Requirements. If a Participant is an officer or
director of the Company within the meaning of Section 16, Options granted
hereunder shall be subject to all conditions required under Rule 16b-3, or any
successor rule(s) promulgated under the 1934 Act, to qualify the Option for any
exception from the provisions of Section 16 available under such Rule. Such
conditions are hereby incorporated herein by reference and shall be set forth in
the agreement with the Participant which describes the Option.



                                       14
<PAGE>   18

14.3 Governing Law. The Plan and all Stock Option Agreements hereunder shall be
construed in accordance with and governed by the laws of the State of Texas.

                                   SECTION 15

                              DURATION OF THE PLAN

The Plan shall terminate at such time as may be determined by the Board, and no
Option shall be granted after such termination. If not sooner terminated under
the preceding sentence, the Plan shall fully cease and expire at midnight on May
4, 2000. Options outstanding at the time of the Plan termination shall continue
to be exercisable in accordance with the Stock Option Agreement pertaining to
such Option.

Dated: December 17, 1998

                                           APACHE CORPORATION

ATTEST:

/s/ CHERI L. PEPER                         By:  /s/ DANIEL L. SCHAEFFER
- ---------------------------------               --------------------------------
Cheri L. Peper                                  Daniel L. Schaeffer
Corporate Secretary                             Vice President





                                       15


<PAGE>   1
                                                                   EXHIBIT 10.23














                               APACHE CORPORATION

                             1998 STOCK OPTION PLAN

                            (AS AMENDED AND RESTATED
                               DECEMBER 17, 1998)


<PAGE>   2


                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                     PAGE
                                                                                                     ----
<S>               <C>                                                                                <C>
Section 1 - Introduction.................................................................................1

         1.1      Establishment..........................................................................1
         1.2      Purposes...............................................................................1
         1.3      Effective Date.........................................................................1

Section 2 - Definitions..................................................................................1

         2.1      Definitions............................................................................1
         2.2      Headings; Gender and Number............................................................3

Section 3 - Plan Administration..........................................................................3

Section 4 - Stock Subject to the Plan....................................................................4

         4.1      Number of Shares.......................................................................4
         4.2      Other Shares of Stock..................................................................4
         4.3      Adjustments for Stock Split, Stock Dividend, Etc.......................................4
         4.4      Dividend Payable in Stock of Another Corporation, Etc..................................4
         4.5      Other Changes in Stock.................................................................5
         4.6      Rights to Subscribe....................................................................5
         4.7      General Adjustment Rules...............................................................5
         4.8      Determination by the Committee, Etc....................................................5

Section 5 - Reorganization or Liquidation................................................................6

Section 6 - Participation................................................................................6

Section 7 - Stock Options................................................................................7

         7.1      Grant of Stock Options.................................................................7
         7.2      Stock Option Agreements................................................................7
         7.3      Stockholder Privileges................................................................11

Section 8 - Change in Control...........................................................................12

         8.1      In General............................................................................12
         8.2      Limitation on Payments................................................................12
         8.3      Definition............................................................................12
</TABLE>


                                        i

<PAGE>   3

<TABLE>
<CAPTION>
<S>               <C>                                                                                <C>
Section 9 - Rights of Employees, Participants...........................................................12

         9.1      Employment............................................................................12
         9.2      Nontransferability....................................................................13

Section 10 - General Restrictions.......................................................................13

         10.1     Investment Representations............................................................13
         10.2     Compliance with Securities Laws.......................................................13

Section 11 - Other Employee Benefits....................................................................14

Section 12 - Plan Amendment, Modification and Termination...............................................14

Section 13 - Withholding................................................................................14

         13.1     Withholding Requirement...............................................................14
         13.2     Withholding With Stock................................................................15

Section 14 - Requirements of Law........................................................................15

         14.1     Requirements of Law...................................................................15
         14.2     Federal Securities Laws Requirements..................................................15
         14.3     Governing Law.........................................................................15

Section 15 - Duration of the Plan.......................................................................16
</TABLE>




                                       ii

<PAGE>   4

 


                               APACHE CORPORATION

                             1998 STOCK OPTION PLAN


                                    SECTION 1

                                  INTRODUCTION

1.1 Establishment. Apache Corporation, a Delaware corporation (hereinafter
referred to, together with its Affiliated Corporations (as defined in Section
2.1 hereof) as the "Company" except where the context otherwise requires),
hereby establishes the Apache Corporation 1998 Stock Option Plan (the "Plan")
for Eligible Employees (as defined in Section 2.1 hereof). The Plan permits the
grant of stock options to Eligible Employees selected by the Committee (as
defined in Section 2.1 hereof).

1.2 Purposes. The purposes of the Plan are to provide the Eligible Employees
designated by the Committee for participation in the Plan with added incentives
to continue in the long-term service of the Company and to create in such
employees a more direct interest in the future success of the operations of the
Company by relating incentive compensation to increases in stockholder value, so
that the income of those employees is more closely aligned with the interests of
the Company's stockholders. The Plan is also designed to attract outstanding
individuals and to retain and motivate Eligible Employees by providing an
opportunity for investment in the Company.

1.3 Effective Date. The Effective Date of the Plan (the "Effective Date") shall
be February 6, 1998. This Plan and each option granted hereunder is conditioned
on and shall be of no force or effect until approval of the Plan by the holders
of the shares of voting stock of the Company unless the Company, on the advice
of counsel, determines that stockholder approval is not necessary. The Committee
may grant options the exercise of which shall be expressly subject to the
condition that the Plan shall have been approved by the stockholders of the
Company.

                                    SECTION 2

                                   DEFINITIONS

2.1 Definitions. The following terms shall have the meanings set forth below:

         (a) "Affiliated Corporation" means any corporation or other entity
(including but not limited to a partnership) which is affiliated with Apache
Corporation through 


                                       1

<PAGE>   5

stock ownership or otherwise and is treated as a common employer under the
provisions of Sections 414(b) and (c) or any successor section(s) of the
Internal Revenue Code.

         (b) "Board" means the Board of Directors of the Company.

         (c) "Committee" means the Stock Option Plan Committee of the Board,
which is empowered hereunder to take actions in the administration of the Plan.
The Committee shall be constituted at all times as to permit the Plan to comply
with: (i) Rule 16b-3 or any successor rule(s) promulgated under the Securities
Exchange Act of 1934, as amended (the "1934 Act"), and (ii) Section 162(m) or
any successor section(s) of the Internal Revenue Code and the regulations
promulgated thereunder.

         (d) "Eligible Employees" means full-time employees (including, without
limitation, officers and directors who are also employees) of the Company or any
division thereof.

         (e) "Fair Market Value" means the closing price of the Stock as
reported on the New York Stock Exchange, Inc. Composite Transactions Reporting
System for a particular date. If there are no Stock transactions on such date,
the Fair Market Value shall be determined as of the immediately preceding date
on which there were Stock transactions.

         (f) "Internal Revenue Code" means the Internal Revenue Code of 1986, as
it may be amended from time to time.

         (g) "Option" means a right to purchase Stock at a stated price for a
specified period of time. All Options granted under the Plan shall be Options
which are not "incentive stock options" as described in Section 422 or any
successor section(s) of the Internal Revenue Code.

         (h) "Option Price" means the price at which shares of Stock subject to
an Option may be purchased, determined in accordance with subsection 7.2(b)
hereof.

         (i) "Participant" means an Eligible Employee designated by the
Committee from time to time during the term of the Plan to receive one or more
Options under the Plan.

         (j) "Stock" means the $1.25 par value Common Stock of the Company.



                                       2

<PAGE>   6



2.2 Headings; Gender and Number. The headings contained in the Plan are for
reference purposes only and shall not affect in any way the meaning or
interpretation of the Plan. Except when otherwise indicated by the context, the
masculine gender shall also include the feminine gender, and the definition of
any term herein in the singular shall also include the plural.

                                    SECTION 3

                               PLAN ADMINISTRATION

The Plan shall be administered by the Committee. In accordance with the
provisions of the Plan, the Committee shall, in its sole discretion, select the
Participants from among the Eligible Employees, determine the Options to be
granted pursuant to the Plan, the number of shares of Stock to be issued
thereunder, the time at which such Options are to be granted, fix the Option
Price, and establish such other terms and requirements as the Committee may deem
necessary or desirable and consistent with the terms of the Plan. The Committee
shall determine the form or forms of the agreements with Participants which
shall evidence the particular provisions, terms, conditions, rights and duties
of the Company and the Participants with respect to Options granted pursuant to
the Plan, which provisions need not be identical except as may be provided
herein. The Committee may from time to time adopt such rules and regulations for
carrying out the purposes of the Plan as it may deem proper and in the best
interests of the Company. The Committee may correct any defect, supply any
omission or reconcile any inconsistency in the Plan, or in any agreement entered
into hereunder, in the manner and to the extent it shall deem expedient and it
shall be the sole and final judge of such expediency. No member of the Committee
shall be liable for any action or determination made in good faith. The
determination, interpretations and other actions of the Committee pursuant to
the provisions of the Plan shall be binding and conclusive for all purposes and
on all persons.

The Plan is intended to comply with the requirements of Section 162(m) or any
successor section(s) of the Internal Revenue Code ("Section 162(m)") as to any
"covered employee" as defined in Section 162(m), and shall be administered,
interpreted and construed consistently therewith. In accordance with this
intent, the amount of compensation a Participant may receive from Options
granted under the Plan shall be based solely on an increase in the value of the
Stock after the date of the grant of the Option, or such other bases as may be
permitted by applicable law. The Committee is authorized to take such additional
action, if any, that may be required to ensure that the Plan satisfies the
requirements of Section 162(m) and the regulations promulgated or revenue
rulings published thereunder.




                                       3

<PAGE>   7

                                    SECTION 4

                            STOCK SUBJECT TO THE PLAN

4.1 Number of Shares. Subject to Section 7.1 and to adjustment pursuant to
Section 4.3 hereof, two million five hundred thousand (2,500,000) shares of
Stock are authorized for issuance under the Plan in accordance with the
provisions of the Plan and subject to such restrictions or other provisions as
the Committee may from time to time deem necessary. This authorization may be
increased from time to time by approval of the Board and the stockholders of the
Company if, in the opinion of counsel for the Company, such stockholder approval
is required. Shares of Stock which may be issued upon exercise of Options shall
be applied to reduce the maximum number of shares of Stock remaining available
for use under the Plan. The Company shall at all times during the term of the
Plan and while any Options are outstanding retain as authorized and unissued
Stock, or as Stock in the Company's treasury, at least the number of shares from
time to time required under the provisions of the Plan, or otherwise assure
itself of its ability to perform its obligations hereunder.

4.2 Other Shares of Stock. Any shares of Stock that are subject to an Option
which expires, is forfeited, is cancelled, or for any reason is terminated
unexercised, and any shares of Stock that for any other reason are not issued to
a Participant or are forfeited shall automatically become available for use
under the Plan.

4.3 Adjustments for Stock Split, Stock Dividend, Etc. If the Company shall at
any time increase or decrease the number of its outstanding shares of Stock or
change in any way the rights and privileges of such shares by means of the
payment of a Stock dividend or any other distribution upon such shares payable
in Stock, or through a Stock split, subdivision, consolidation, combination,
reclassification or recapitalization involving the Stock, then in relation to
the Stock that is affected by one or more of the above events, the numbers,
rights and privileges of the following shall be increased, decreased or changed
in like manner as if they had been issued and outstanding, fully paid and
nonassessable at the time of such occurrence: (i) the shares of Stock as to
which Options may be granted under the Plan; and (ii) the shares of the Stock
then included in each outstanding Option granted hereunder.

4.4 Dividend Payable in Stock of Another Corporation, Etc. If the Company shall
at any time pay or make any dividend or other distribution upon the Stock
payable in securities or other property (except money or Stock), a proportionate
part of such securities or other property shall be set aside and delivered to
any Participant then holding an Option for the particular type of Stock for
which the dividend or other distribution was made, upon exercise thereof. Prior
to the time that any such securities or other property are delivered to a
Participant in accordance with the foregoing, the 



                                       4

<PAGE>   8

Company shall be the owner of such securities or other property and shall have
the right to vote the securities, receive any dividends payable on such
securities, and in all other respects shall be treated as the owner. If
securities or other property which have been set aside by the Company in
accordance with this Section are not delivered to a Participant because an
Option is not exercised, then such securities or other property shall remain the
property of the Company and shall be dealt with by the Company as it shall
determine in its sole discretion.

4.5 Other Changes in Stock. In the event there shall be any change, other than
as specified in Sections 4.3 and 4.4 hereof, in the number or kind of
outstanding shares of Stock or of any stock or other securities into which the
Stock shall be changed or for which it shall have been exchanged, and if the
Committee shall in its discretion determine that such change equitably requires
an adjustment in the number or kind of shares subject to outstanding Options or
which have been reserved for issuance pursuant to the Plan but are not then
subject to an Option, then such adjustments shall be made by the Committee and
shall be effective for all purposes of the Plan and on each outstanding Option
that involves the particular type of stock for which a change was effected.

4.6 Rights to Subscribe. If the Company shall at any time grant to the holders
of its Stock rights to subscribe pro rata for additional shares thereof or for
any other securities of the Company or of any other corporation, there shall be
reserved with respect to the shares then under Option to any Participant of the
particular class of Stock involved the Stock or other securities which the
Participant would have been entitled to subscribe for if immediately prior to
such grant the Participant had exercised his entire Option. If, upon exercise of
any such Option, the Participant subscribes for the additional shares or other
securities, the Option Price shall be increased by the amount of the price that
is payable by the Participant for such additional shares or other securities.

4.7 General Adjustment Rules. No adjustment or substitution provided for in this
Section 4 shall require the Company to sell a fractional share of Stock under
any Option, or otherwise issue a fractional share of Stock, and the total
substitution or adjustment with respect to each Option shall be limited by
deleting any fractional share. In the case of any such substitution or
adjustment, the total Option Price for the shares of Stock then subject to the
Option shall remain unchanged but the Option Price per share under each such
Option shall be equitably adjusted by the Committee to reflect the greater or
lesser number of shares of Stock or other securities into which the Stock
subject to the Option may have been changed.

4.8 Determination by the Committee, Etc. Adjustments under this Section 4 shall
be made by the Committee, whose determinations with regard thereto shall be
final and binding upon all parties thereto.



                                       5

<PAGE>   9

                                    SECTION 5

                          REORGANIZATION OR LIQUIDATION

In the event that the Company is merged or consolidated with another corporation
and the Company is not the surviving corporation, or if all or substantially all
of the assets or more than 20 percent of the outstanding voting stock of the
Company is acquired by any other corporation, business entity or person, or in
case of a reorganization (other than a reorganization under the United States
Bankruptcy Code) or liquidation of the Company, and if the provisions of Section
8 hereof do not apply, the Committee, or the board of directors of any
corporation assuming the obligations of the Company, shall, as to the Plan and
outstanding Options either (i) make appropriate provision for the adoption and
continuation of the Plan by the acquiring or successor corporation and for the
protection of any such outstanding Options by the substitution on an equitable
basis of appropriate stock of the Company or of the merged, consolidated or
otherwise reorganized corporation which will be issuable with respect to the
Stock, provided that no additional benefits shall be conferred upon the
Participants holding such Options as a result of such substitution, and the
excess of the aggregate Fair Market Value of the shares subject to the Options
immediately after such substitution over the Option Price thereof is not more
than the excess of the aggregate Fair Market Value of the shares subject to such
Options immediately before such substitution over the Option Price thereof, or
(ii) upon written notice to the Participants, provide that all unexercised
Options shall be exercised within a specified number of days of the date of such
notice or such Options will be terminated. In the latter event, the Committee
shall accelerate the exercise dates of outstanding Options so that all Options
become fully vested prior to any such event.


                                    SECTION 6

                                  PARTICIPATION

Participants in the Plan shall be those Eligible Employees who, in the judgment
of the Committee, are performing, or during the term of their incentive
arrangement will perform, vital services in the management, operation and
development of the Company or an Affiliated Corporation, and significantly
contribute, or are expected to significantly contribute, to the achievement of
the Company's long-term corporate economic objectives. Participants may be
granted from time to time one or more Options; provided, however, that the grant
of each such Option shall be separately approved by the Committee, and receipt
of one such Option shall not result in automatic receipt of any other Option.
Upon determination by the Committee that an Option is to be granted to a
Participant, written notice shall be given to such person, specifying the terms,
conditions, rights and duties related thereto. Each Participant shall, if
required by the Committee, enter into an agreement with the Company, in such
form as the Committee shall



                                       6

<PAGE>   10

determine and which is consistent with the provisions of the Plan, specifying
such terms, conditions, rights and duties. Options shall be deemed to be granted
as of the date specified in the grant resolution of the Committee, which date
shall be the date of any related agreement with the Participant. In the event of
any inconsistency between the provisions of the Plan and any such agreement
entered into hereunder, the provisions of the Plan shall govern.


                                    SECTION 7

                                  STOCK OPTIONS

7.1 Grant of Stock Options. Coincident with or following designation for
participation in the Plan, an Eligible Employee may be granted one or more
Options. Grants of Options under the Plan shall be made by the Committee. In no
event shall the exercise of one Option affect the right to exercise any other
Option or affect the number of shares of Stock for which any other Option may be
exercised, except as provided in subsection 7.2(j) hereof. During the life of
the Plan, no Eligible Employee may be granted Options which in the aggregate
pertain to in excess of 25 percent of the total shares of Stock authorized under
the Plan.

7.2 Stock Option Agreements. Each Option granted under the Plan shall be
evidenced by a written stock option agreement which shall be entered into by the
Company and the Participant to whom the Option is granted (the "Stock Option
Agreement"), and which shall contain the following terms and conditions, as well
as such other terms and conditions, not inconsistent therewith, as the Committee
may consider appropriate in each case.

         (a) Number of Shares. Each Stock Option Agreement shall state that it
covers a specified number of shares of Stock, as determined by the Committee.

         (b) Price. The price at which each share of Stock covered by an Option
may be purchased shall be determined in each case by the Committee and set forth
in the Stock Option Agreement, but in no event shall the price be less than the
Fair Market Value of the Stock on the date the Option is granted.

         (c) Duration of Options; Employment Required For Exercise. Each Stock
Option Agreement shall state the period of time, determined by the Committee,
within which the Option may be exercised by the Participant (the "Option
Period"). The Option Period must end, in all cases, not more than ten years from
the date an Option is granted. Except as otherwise provided in Sections 5 and 8
and subsection 7.2(d)(iv) hereof, each Option granted under the Plan shall
become exercisable in increments such that 25 percent of the Option will become
exercisable on each of the four subsequent one-year 


                                       7

<PAGE>   11

anniversaries of the date the Option is granted, but each such additional
25-percent increment shall become exercisable only if the Participant has been
continuously employed by the Company from the date the Option is granted through
the date on which each such additional 25-percent increment becomes exercisable.

         (d) Termination of Employment, Death, Disability, Etc. Each Stock
Option Agreement shall provide as follows with respect to the exercise of the
Option upon termination of the employment or the death of the Participant:

                  (i) If the employment of the Participant by the Company is
terminated within the Option Period for cause, as determined by the Company, the
Option shall thereafter be void for all purposes. As used in this subsection
7.2(d), "cause" shall mean a gross violation, as determined by the Company, of
the Company's established policies and procedures, provided that the effect of
this subsection 7.2(d) shall be limited to determining the consequences of a
termination and that nothing in this subsection 7.2(d) shall restrict or
otherwise interfere with the Company's discretion with respect to the
termination of any employee.

                  (ii) If the Participant retires from employment by the Company
on or after attaining age 65, the Option may be exercised by the Participant
within 36 months following his or her retirement (provided that such exercise
must occur within the Option Period), but not thereafter. In the event of the
Participant's death during such 36-month period, each Option may be exercised by
those entitled to do so in the manner referred to in (iv) below. In any such
case the Option may be exercised only as to the shares as to which the Option
had become exercisable on or before the date of the Participant's retirement.

                  (iii) If the Participant becomes disabled (as determined
pursuant to the Company's Long-Term Disability Plan or any successor plan),
during the Option Period while still employed, or within the three-month period
referred to in (v) below, or within the 36-month period referred to in (ii)
above, the Option may be exercised by the Participant or by his or her guardian
or legal representative, within twelve months following the Participant's
disability, or within the 36-month period referred to in (ii) above if
applicable and if longer (provided that such exercise must occur within the
Option Period), but not thereafter. In the event of the Participant's death
during such twelve-month period, each Option may be exercised by those entitled
to do so in the manner referred to in (iv) below. In any such case, the Option
may be exercised only as to the shares of Stock as to which the Option had
become exercisable on or before the date of the Participant's disability.

                  (iv) In the event of the Participant's death while still
employed by the Company, each Option of the deceased Participant may be
exercised by those entitled to 



                                       8

<PAGE>   12

do so under the Participant's will or under the laws of descent and distribution
within twelve months following the Participant's death (provided that in any
event such exercise must occur within the Option Period), but not thereafter, as
to all shares of Stock which are subject to such Option, including each
25-percent increment of the Option, if any, which has not yet become exercisable
at the time of the Participant's death. In the event of the Participant's death
within the 36-month period referred to in (ii) above or within the twelve-month
period referred to in (iii) above, each Option of the deceased Participant that
is exercisable at the time of death may be exercised by those entitled to do so
under the Participant's will or under the laws of descent and distribution
within twelve months following the Participant's death or within the 36-month
period referred to in (ii) above, if applicable and if longer (provided that in
any event such exercise must occur within the Option Period). The provisions of
this paragraph (iv) of subsection 7.2(d) shall be applicable to each Stock
Option Agreement as if set forth therein word for word. Each Stock Option
Agreement executed by the Company prior to the adoption of this provision shall
be deemed amended to include the provisions of this paragraph and all Options
granted pursuant to such Stock Option Agreements shall be exercisable as
provided herein.

                  (v) If the employment of the Participant by the Company is
terminated (which for this purpose means that the Participant is no longer
employed by the Company or by an Affiliated Corporation) within the Option
Period for any reason other than cause, the Participant's retirement on or after
attaining age 65, the Participant's disability or death, the Option may be
exercised by the Participant within three months following the date of such
termination (provided that such exercise must occur within the Option Period),
but not thereafter. In any such case, the Option may be exercised only as to the
shares as to which the Option had become exercisable on or before the date of
termination of the Participant's employment.

         (e) Transferability. Each Stock Option Agreement shall provide that the
Option granted therein is not transferable by the Participant except by will or
pursuant to the laws of descent and distribution, and that such Option is
exercisable during the Participant's lifetime only by him or her, or in the
event of the Participant's disability or incapacity, by his or her guardian or
legal representative.

         (f) Agreement to Continue in Employment. Each Stock Option Agreement
shall contain the Participant's agreement to remain in the employment of the
Company, at the pleasure of the Company, for a continuous period of at least one
year after the date of such Stock Option Agreement, at the salary rate in effect
on the date of such agreement or at such changed rate as may be fixed, from time
to time, by the Company.



                                       9

<PAGE>   13

         (g) Exercise, Payments, Etc.

                  (i) Each Stock Option Agreement shall provide that the method
for exercising the Option granted therein shall be by delivery to the Office of
the Secretary of the Company of written notice specifying the number of shares
of Stock with respect to which such Option is exercised and payment of the
Option Price. Such notice shall be in a form satisfactory to the Committee and
shall specify the particular Options (or portions thereof) which are being
exercised and the number of shares of Stock with respect to which the Options
are being exercised. The exercise of the Option shall be deemed effective on the
date such notice is received by the Office of the Secretary and payment is made
to the Company of the Option Price (the "Exercise Date"). If requested by the
Company, such notice shall contain the Participant's representation that he or
she is purchasing the Stock for investment purposes only and his or her
agreement not to sell any Stock so purchased in any manner that is in violation
of the Securities Act of 1933, as amended, or any applicable state law. Such
restriction, or notice thereof, shall be placed on the certificates representing
the Stock so purchased. The purchase of such Stock shall take place at the
principal offices of the Company upon delivery of such notice, at which time the
Option Price shall be paid in full by any of the methods or any combination of
the methods set forth in (ii) below. A properly executed certificate or
certificates representing the Stock shall be issued by the Company and delivered
to the Participant. If certificates representing Stock are used to pay all or
part of the Option Price, separate certificates for the same number of shares of
Stock shall be issued by the Company and delivered to the Participant
representing each certificate used to pay the Option Price, and an additional
certificate shall be issued by the Company and delivered to Participant
representing the additional shares of Stock, in excess of the Option Price, to
which the Participant is entitled as a result of the exercise of the Option.

                  (ii) the Option Price shall be paid by any of the following
methods or any combination of the following methods:

                           (A) in cash;

                           (B) by personal, certified or cashier's check payable
to the order of the Company;

                           (C) by delivery to the Company of certificates
representing a number of shares of Stock then owned by the Participant, the Fair
Market Value of which equals the Option Price of the Stock purchased pursuant to
the Option, properly endorsed for transfer to the Company; provided however,
that shares of Stock used for this purpose must have been held by the
Participant for such minimum period of time as may be established from time to
time by the Committee; for purposes of this Plan, the Fair Market Value of any
shares of Stock delivered in payment of the Option Price upon 


                                       10

<PAGE>   14

exercise of the Option shall be the Fair Market Value as of the Exercise Date;
the Exercise Date shall be the day of delivery of the certificates for the Stock
used as payment of the Option Price; or

                           (D) by delivery to the Company of a properly executed
notice of exercise together with irrevocable instructions to a broker to deliver
to the Company promptly the amount of the proceeds of the sale of all or a
portion of the Stock or of a loan from the broker to the Participant necessary
to pay the Option Price.

         (h) Date of Grant. An Option shall be considered as having been granted
on the date specified in the grant resolution of the Committee.

         (i) Tax Withholding. Each Stock Option Agreement shall provide that,
upon exercise of the Option, the Participant shall make appropriate arrangements
with the Company to provide for the amount of additional tax withholding
required by Sections 3102 and 3402 or any successor section(s) of the Internal
Revenue Code and applicable state income tax laws, including payment of such
taxes through delivery of shares of Stock or by withholding Stock to be issued
under the Option, as provided in Section 13 hereof.

         (j) Adjustment of Options. Subject to the provisions of Sections 4, 5,
7, 8 and 12 hereof, the Committee may make any adjustment in the number of
shares of Stock covered by, or the terms of an outstanding Option and a
subsequent granting of an Option, by amendment or by substitution for an
outstanding Option; however, except as provided in Sections 4, 5, 8 and 12
hereof, the Committee may not adjust the Option Price of any outstanding Option.
Such amendment or substitution may result in terms and conditions (including the
number of shares of Stock covered, vesting schedule or Option Period) that
differ from the terms and conditions of the original Option. The Committee may
not, however, adversely affect the rights of any Participant to previously
granted Options without the consent of such Participant. If such action is
effected by amendment, the effective date of grant of such amendment will be the
date of grant of the original Option.

7.3 Stockholder Privileges. No Participant shall have any rights as a
stockholder with respect to any shares of Stock covered by an Option until the
Participant becomes the holder of record of such Stock. Except as provided in
Section 4 hereof, no adjustments shall be made for dividends or other
distributions or other rights as to which there is a record date preceding the
date on which such Participant becomes the holder of record of such Stock.



                                       11

<PAGE>   15

                                    SECTION 8

                                CHANGE IN CONTROL

8.1 In General. In the event of a change in control of the Company as defined in
Section 8.3 hereof, then the Committee may, in its sole discretion, without
obtaining stockholder approval, to the extent permitted in Section 12 hereof,
take any or all of the following actions: (a) accelerate the dates on which any
outstanding Options become exercisable or make all such Options fully vested and
exercisable; (b) grant a cash bonus award to any Participant in an amount
necessary to pay the Option Price of all or any portion of the Options then held
by such Participant; (c) pay cash to any or all Participants in exchange for the
cancellation of their outstanding Options in an amount equal to the difference
between the Option Price of such Options and the greater of the tender offer
price for the underlying Stock or the Fair Market Value of the Stock on the date
of the cancellation of the Options; and (d) make any other adjustments or
amendments to the outstanding Options.

8.2 Limitation on Payments. If the provisions of this Section 8 would result in
the receipt by any Participant of a payment within the meaning of Section 280G
or any successor section(s) of the Internal Revenue Code, and the regulations
promulgated thereunder, and if the receipt of such payment by any Participant
would, in the opinion of independent tax counsel of recognized standing selected
by the Company, result in the payment by such Participant of any excise tax
provided for in Sections 280G and 4999 or any successor section(s) of the
Internal Revenue Code, then the amount of such payment shall be reduced to the
extent required, in the opinion of independent tax counsel, to prevent the
imposition of such excise tax; provided, however, that the Committee, in its
sole discretion, may authorize the payment of all or any portion of the amount
of such reduction to the Participant.

8.3 Definition. For purposes of the Plan, a "change in control" shall mean any
of the events specified in the Company's Income Continuance Plan or any
successor plan which constitute a change in control within the meaning of such
plan.

                                    SECTION 9

                        RIGHTS OF EMPLOYEES, PARTICIPANTS

9.1 Employment. Nothing contained in the Plan or in any Option granted under the
Plan shall confer upon any Participant any right with respect to the
continuation of his or her employment by the Company or any Affiliated
Corporation, or interfere in any way with the right of the Company or any
Affiliated Corporation, subject to the terms of any separate employment
agreement to the contrary, at any time to terminate such 



                                       12

<PAGE>   16

employment or to increase or decrease the level of the Participant's
compensation from the level in existence at the time of the grant of an Option.
Whether an authorized leave of absence, or absence in military or government
service, shall constitute a termination of employment shall be determined by the
Committee at the time.

9.2 Nontransferability. No right or interest of any Participant in an Option
granted pursuant to the Plan shall be assignable or transferable during the
lifetime of the Participant, either voluntarily or involuntarily, or subjected
to any lien, directly or indirectly, by operation of law, or otherwise,
including execution, levy, garnishment, attachment, pledge or bankruptcy. In the
event of a Participant's death, a Participant's rights and interests in Options
shall, to the extent provided in Section 7 hereof, be transferable by
testamentary will or the laws of descent and distribution, and payment of any
amounts due under the Plan shall be made to, and exercise of any Options may be
made by, the Participant's legal representatives, heirs or legatees. If in the
opinion of the Committee a person entitled to payments or to exercise rights
with respect to the Plan is disabled from caring for his or her affairs because
of mental condition, physical condition or age, payment due such person may be
made to, and such rights shall be exercised by, such person's guardian,
conservator or other legal personal representative upon furnishing the Committee
with evidence satisfactory to the Committee of such status.

                                   SECTION 10

                              GENERAL RESTRICTIONS

10.1 Investment Representations. The Company may require a Participant, as a
condition of exercising an Option, to give written assurances in substance and
form satisfactory to the Company and its counsel to the effect that such person
is acquiring the Stock subject to the Option for his own account for investment
and not with any present intention of selling or otherwise distributing the
same, and to such other effects as the Company deems necessary or appropriate in
order to comply with federal and applicable state securities laws.

10.2 Compliance with Securities Laws. Each Option shall be subject to the
requirement that, if at any time counsel to the Company shall determine that the
listing, registration or qualification of the shares of Stock subject to such
Option upon any securities exchange or under any state or federal law, or the
consent or approval of any governmental or regulatory body, is necessary as a
condition of, or in connection with, the issuance or purchase of shares of Stock
thereunder, such Option may not be accepted or exercised in whole or in part
unless such listing, registration, qualification, consent or approval shall have
been effected or obtained on conditions acceptable to the Committee. Nothing
herein shall be deemed to require the Company to apply for or to obtain such
listing, registration, qualification, consent or approval.





                                       13

<PAGE>   17

                                   SECTION 11

                             OTHER EMPLOYEE BENEFITS

The amount of any compensation deemed to be received by a Participant as a
result of the exercise of an Option shall not constitute "earnings" with respect
to which any other employee benefits of such Participant are determined,
including without limitation benefits under any pension, profit sharing, life
insurance or salary continuation plan.

                                   SECTION 12

                  PLAN AMENDMENT, MODIFICATION AND TERMINATION

The Board may at any time terminate, and from time to time may amend or modify
the Plan provided, however, that no amendment or modification may become
effective without approval of the amendment or modification by the Company's
stockholders if stockholder approval is required to enable the Plan to satisfy
any applicable statutory or regulatory requirements, or if the Company, on the
advice of counsel, determines that stockholder approval is otherwise necessary
or desirable.

No amendment, modification or termination of the Plan shall in any manner
adversely affect any Option theretofore granted under the Plan, without the
consent of the Participant holding such Option.

                                   SECTION 13

                                   WITHHOLDING

13.1 Withholding Requirement. The Company's obligations to deliver shares of
Stock upon the exercise of an Option shall be subject to the Participant's
satisfaction of all applicable federal, state and local income and other tax
withholding requirements.



                                       14

<PAGE>   18



13.2 Withholding With Stock. At the time the Committee grants an Option, it may,
in its sole discretion, grant the Participant an election to pay all such
amounts of tax withholding, or any part thereof, by the transfer to the Company,
or to have the Company withhold from shares of Stock otherwise issuable to the
Participant upon the exercise of an Option, shares of Stock having a value equal
to the amount required to be withheld or such lesser amount as may be elected by
the Participant. All such elections shall be subject to the approval or
disapproval of the Committee. The value of shares of Stock to be withheld shall
be based on the Fair Market Value of the Stock on the Exercise Date. Any such
elections by Participants to have shares of Stock withheld for this purpose will
be subject to the following restrictions:

         (a) All elections shall be made on or prior to the Exercise Date.

         (b) All elections shall be irrevocable.

         (c) If the Participant is an officer or director of the Company within
the meaning of Section 16 or any successor section(s) of the 1934 Act ("Section
16"), the Participant must satisfy the requirements of such Section 16 and any
applicable rules and regulations thereunder with respect to the use of Stock to
satisfy such tax withholding obligation.

                                   SECTION 14

                               REQUIREMENTS OF LAW

14.1 Requirements of Law. The issuance of Stock and the payment of cash pursuant
to the Plan shall be subject to all applicable laws, rules and regulations.

14.2 Federal Securities Laws Requirements. If a Participant is an officer or
director of the Company within the meaning of Section 16, Options granted
hereunder shall be subject to all conditions required under Rule 16b-3, or any
successor rule(s) promulgated under the 1934 Act, to qualify the Option for any
exception from the provisions of Section 16 available under such Rule. Such
conditions are hereby incorporated herein by reference and shall be set forth in
the agreement with the Participant which describes the Option.

14.3 Governing Law. The Plan and all Stock Option Agreements hereunder shall be
construed in accordance with and governed by the laws of the State of Texas.



                                       15

<PAGE>   19




                                   SECTION 15

                              DURATION OF THE PLAN

The Plan shall terminate at such time as may be determined by the Board, and no
Option shall be granted after such termination. If not sooner terminated under
the preceding sentence, the Plan shall fully cease and expire at midnight on
February 6, 2003. Options outstanding at the time of the Plan termination shall
continue to be exercisable in accordance with the Stock Option Agreement
pertaining to such Option.

Dated: December 17, 1998

                                          APACHE CORPORATION

ATTEST:

/s/ Cheri L. Peper                        By: /s/ Daniel L. Schaeffer
- --------------------------------              --------------------------------
Cheri L. Peper                                Daniel L. Schaeffer
Corporate Secretary                           Vice President




                                       16




<PAGE>   1



                                                                   EXHIBIT 10.26



                               APACHE CORPORATION

                    NON-EMPLOYEE DIRECTORS' COMPENSATION PLAN

                    As Amended and Restated December 17, 1998


                                     PURPOSE

         The purpose of the Non-Employee Directors' Compensation Plan (the
"PLAN") is to set forth certain of the compensation arrangements for members of
the board of directors (the "BOARD") of Apache Corporation ("APACHE") who are
not also employees of Apache ("NON-EMPLOYEE DIRECTORS"). The Plan supersedes the
Directors' Deferred Compensation Plan; however, all elections previously made
thereunder, until terminated or modified, shall remain in effect in respect of
the Plan. The Plan does not supersede or amend in any way any other arrangements
relating to Non-Employee Directors including specifically, without limitation,
the Equity Compensation Plan for Non-Employee Directors, the Outside Directors'
Retirement Plan, indemnification provisions of Apache's charter or bylaws, or
policies with respect to reimbursement of expenses.


                                 PLAN PROVISIONS

         1.       BOARD RETAINER. Each Non-Employee Director shall be paid, as
soon as practicable following accrual, the Board retainer fees set forth below:

                  (a) $5,000.00 shall be paid to each Non-Employee Director at
         the end of each calendar quarter during which such Non-Employee
         Director served as a member of Apache's Board ("CASH RETAINER Fee");

                  (b) $2,500.00 in value of Apache common stock, par value $1.25
         per share ("STOCK"), shall be paid from Apache's treasury shares to
         each Non-Employee Director at the end of each calendar quarter during
         which such Non-Employee Director served as a member of Apache's Board
         ("STOCK RETAINER FEE"). The number of shares of Stock shall be
         determined by dividing $2,500.00 by the per share closing price of the
         Stock as reported on The New York Stock Exchange, Inc. Composite
         Transactions Reporting System (the "Composite Tape") as of the trading
         day prior to the last trading day of the relevant calendar quarter,
         with any fractional shares to be paid to the director in cash; and

                  (c) In the event that a Non-Employee Director serves as a
         member of Apache's Board for less than an entire calendar quarter, the
         fees payable pursuant to Sections 1 (a) and (b) hereof shall be
         prorated on the basis of the number of weeks served during such
         calendar quarter.


                                      -1-

<PAGE>   2
         2.       COMMITTEE RETAINERS. Each Non-Employee Director serving on any
committee of Apache's Board shall be paid, as soon as practicable, the committee
retainer fee ("COMMITTEE RETAINER FEE") set forth below:

                  (a) $500.00 shall be paid to each Non-Employee Director at the
         end of each calendar quarter in respect of each committee on which such
         Non-Employee Director served during such quarter;

                  (b) $1,000.00 shall be paid to each Non-Employee Director at
         the end of each calendar quarter in respect of each committee on which
         such Non-Employee Director served as chairperson during such quarter;
         and

                  (c) In the event that a Non-Employee Director serves on any
         committee of Apache's Board and/or as chairperson of any committee of
         Apache's board for less than an entire calendar quarter, the fees
         payable pursuant to Sections 2 (a) and (b) hereof shall be prorated on
         the basis of number of weeks served during such calendar quarter.

         3.       ATTENDANCE FEES. Each Non-Employee Director shall receive an
attendance fee ("ATTENDANCE FEE") of $1,000.00 for each meeting of the Board and
of any committee thereof attended, such fee to be paid at each such meeting or
as soon thereafter as practicable.

         4.       OPTIONAL DEFERRAL OF FEES.

                  (a) DEFERRABLE FEES. A Non-Employee Director may defer all or
         any portion of any unpaid Cash Retainer Fee, Stock Retainer Fee,
         Committee Retainer Fee, and Attendance Fee, all of which are paid to
         Non-Employee Directors with respect to their services performed as a
         director on the Board ("DEFERRABLE FEES"). No other payments to
         Non-Employee Directors may be deferred including, without limitation,
         any expense reimbursement, any award under Apache's Equity Compensation
         Plan for Non-Employee Directors or benefits payable under Outside
         Directors' Retirement Plan.

                  (b) FORM OF DEFERRAL. Any Cash Retainer Fees and Committee
         Retainer Fees may be deferred in the form of cash or in the form of
         Stock. Any Stock Retainer Fees may be deferred only in the form of
         Stock. Any Attendance Fees may be deferred only in the form of cash,
         except as set forth in Section 4(e) hereof. Any Cash Retainer Fees,
         Stock Retainer Fees and/or Committee Retainer Fees which are deferred
         in the form of Stock by a Non-Employee Director shall not be issued
         until such deferral is terminated; however, Apache shall at all times
         have reserved from its treasury shares for issuance pursuant hereto to
         deferring Non-Employee Directors a number of shares at least equal to
         the number of shares of Stock issuable pursuant to the terms of the
         Plan.

                  (c) NUMBER OF SHARES. For any Cash Retainer Fees, Stock
         Retainer Fees and/or Committee Retainer Fees deferred in the form of
         Stock, the number of shares of Stock shall be determined by dividing
         the amount of such fees by the per share closing price of the Stock as
         reported on the Composite Tape as of the trading day prior to the last
         trading day of the relevant calendar quarter, with any fractional
         shares to be deferred in the form of cash.


                                       -2-
<PAGE>   3


                  (d)      ELECTION TO DEFER. A Non-Employee Director's election
         to defer ("ELECTION") all or any portion of Deferrable Fees shall be
         effected by execution of a Directors' Deferred Compensation Agreement
         between the participating director and Apache ("AGREEMENT"), a copy of
         the form of which is attached hereto as Exhibit A. An Agreement must be
         executed by the deferring Non-Employee Director and provided to
         Apache's Corporate Secretary on or before December 31 of the year prior
         to the year for which deferral is elected. Once executed, an Agreement
         shall be irrevocable with respect to the year made, the form of
         deferral, and the Deferrable Fees designated for deferral (the
         "DEFERRED Compensation"), and shall remain in effect with respect to
         all subsequent years until the Agreement is terminated or amended. All
         elections to defer Deferrable Fees previously made in respect of the
         Directors' Deferred Compensation Plan shall constitute valid Elections
         in respect of the Plan. Upon full or partial termination of deferral by
         a Non-Employee Director, the cash and/or Stock shall be paid and/or
         issued to such Non-Employee Director pursuant to the terms of such
         Non-Employee Director's Agreement.

                  (e)      ELECTION TO SWITCH FORM OF DEFERRED COMPENSATION.

                           (i) With respect to the year-end balance of Deferred
         Compensation in the form of cash ("Year-End Cash Balance") in his or
         her Memorandum Account (as defined below), a Non-Employee Director may
         make an annual election to switch all or any portion of his or her
         Year-End Cash Balance to the form of Stock, effective as of the first
         business day of the following year. Such election shall be made by
         executing a new Agreement and providing it to Apache's Corporate
         Secretary on or before December 31 of the year prior to the year for
         which the election is to be effective. Once executed, an Agreement
         shall be irrevocable with respect to the portion of the Non-Employee
         Director's Year-End Cash Balance to be switched. Such election shall
         pertain only to the Year-End Cash Balance for the year stated in the
         new Agreement. To make such an election for any subsequent Year-End
         Cash Balance, the Non-Employee Director shall execute another new
         Agreement as set forth above.

                           (ii) The number of shares of Stock shall be
         determined by dividing the portion of the Non-Employee Director's
         Year-End Cash Balance to be switched by the per share closing price of
         the Stock as reported on the Composite Tape for the first trading day
         of the year for which the election is effective, with any fractional
         shares remaining in the form of cash. Such shares of Stock shall be
         maintained in the Non-Employee Director's Memorandum account and shall
         accrue dividends pursuant to Section 4(g) hereof.

                           (iii) Non-Employee Directors may not switch Deferred
         Compensation in the form of Stock to the form of cash.

                  (f)      TERMINATION OR MODIFICATION OF ELECTION. Any 
         termination of an Election shall be made in writing and provided to
         Apache's Corporate Secretary on or before December 31 of the year prior
         to the year for which the termination is to be effective. Any
         modification or amendment of an Election shall be made by executing a
         new Agreement which shall supersede any previous Agreement. Such new
         Agreement must be executed by the deferring Non-Employee Director and
         provided to Apache's Corporate Secretary on or before December 31 of
         the year prior to the year for which the amended Election is to be
         effective. Upon termination or modification of an Election, all
         Deferred Compensation payable to the Non-Employee


                                      -3-
<PAGE>   4


         Director terminating or modifying the Election shall be paid in 
         accordance with the provisions of such Non-Employee Director's then 
         effective Agreement, as modified or amended.

                  (g) DIVIDENDS AND INTEREST; NO VOTING. All Deferrable Fees
         deferred by a Non-Employee Director in the form of and payable in
         Stock, and any portion of a Non-Employee Director's Year-End Cash
         Balance switched to the form of Stock, shall accrue dividends
         denominated in the cash value thereof as if such Stock were issued and
         outstanding as and when dividends are payable in respect of such Stock.
         All Deferrable Fees deferred by a Non-Employee Director in the form of
         and payable in cash, plus all previously accrued dividends and
         interest, shall accrue interest at the end of each calendar quarter or
         as of and through the date of payment of Deferred Compensation, as
         appropriate. The rate of interest per annum shall equal (i) the annual
         rate of interest earned by Apache's short-term marketable securities
         portfolio, or (ii) an equivalent index or market rate for similar
         investments in short-term marketable securities, divided by the number
         of days elapsed in the relevant period. Non-Employee Directors shall
         have no right to vote any Stock which constitutes Deferred Compensation
         prior to the date on which share certificates representing such Stock
         are issued.

                  (h) MEMORANDUM ACCOUNT. Apache will maintain a separate
         Deferred Compensation memorandum account ("MEMORANDUM ACCOUNT") for
         each deferring Non-Employee Director. All Deferred Compensation and
         accrued dividends and interest accumulated in each Memorandum Account
         will be classified in the same category as other unsecured creditors
         and accounts payable of Apache, and neither the deferring Non-Employee
         Director nor his or her beneficiary or estate shall have any property
         interest whatsoever in any specific assets of Apache. All distributions
         from a Memorandum Account of Deferred Compensation deferred in the form
         of cash, and of accrued interest and dividends, shall be paid in cash.
         All distributions from a Memorandum Account of Deferred Compensation
         deferred in the form of Stock, and any portion of a Non-Employee
         Director's Year-End Cash Balance switched to the form of Stock, shall
         be made by issuance of shares of Stock.

                  (i) TERMINATION OF DIRECTORSHIP. Upon retirement or other
         termination of a Non-Employee Director's directorship with Apache, or
         on a date specifically designated in a Non-Employee Director's
         Agreement, any balance in such Non-Employee Director's Memorandum
         Account shall be paid in cash and/or Stock, as applicable, (a) in a
         lump sum, or (b) in annual installments over a ten-year period (or over
         such shorter period as designated in the deferring Non-Employee
         Director's Agreement) beginning with the first business day of the
         calendar year immediately following retirement or other termination of
         such Non-Employee Director's directorship.

                  (j) ASSIGNMENT AND TRANSFER. The right of the deferring
         Non-Employee Director or any other person to receive payments under the
         Plan shall not be assigned, transferred, pledged or encumbered, except
         by will or by the laws of descent and distribution. Upon the death of a
         deferring Non-Employee Director, any balance remaining in such
         Non-Employee Director's Memorandum Account at the time of death shall
         be paid in cash and/or Stock, as applicable, in a lump sum to his or
         her designated beneficiary or, if there is no designated beneficiary,
         to his or her estate as soon as practicable after such Non-Employee
         Director's death.


                                      -4-
<PAGE>   5


                  (k) ADJUSTMENTS IN STOCK. In the event of any merger,
         consolidation, liquidation, dissolution, recapitalization or
         reorganization of Apache, split, subdivision or consolidation of shares
         of Stock, the payment of a stock dividend, or any other material change
         in Apache's capital structure, the number of shares of Stock shown in
         each deferring Non-Employee Director's Memorandum Account shall be
         adjusted to reflect that number of shares of Stock or such cash,
         securities or other property to which such Non-Employee Director would
         have been entitled if, immediately prior thereto, such Non-Employee
         Director had been the holder of record of the number of shares of Stock
         shown in the Memorandum Account. Notwithstanding the foregoing, the
         issuance by Apache of Stock, rights, options or warrants to acquire
         Stock, or securities convertible or exchangeable into Stock in
         consideration of cash, property, labor or services, whether or not for
         fair value, shall not result in an adjustment pursuant to this
         paragraph.

         5.    AMENDMENT OF PLAN. The Plan may be amended from time to time or
terminated by vote of the Board. Upon such amendment or termination,
Non-Employee Directors shall not be entitled to receive pursuant to the Plan any
compensation or other rights or benefits not accrued hereunder prior to the time
of amendment or termination hereof; provided, however, that no such Plan
amendment or termination shall impair any rights of Non-Employee Directors to
amounts previously accrued pursuant to the Plan or accumulated in such
Non-Employee Director's Memorandum Account.

         6.    SUCCESSORS AND ASSIGNS. The Plan is binding upon Apache and its
successors and assigns. The Plan shall continue in effect from year to year
unless and until revoked by the Board. Any such revocation shall operate only
prospectively and shall not affect the rights and obligations under elections
previously made.

         7.    DEFINED TERMS. Except when otherwise indicated by the context,
the definition of any term herein in the singular shall also include the plural,
and the masculine gender shall also include the feminine gender.

         8.    GOVERNING LAW. The Plan and all Agreements hereunder shall be
construed in accordance with and governed by the laws of the State of Texas.

December 17, 1998

ATTEST:                                     APACHE CORPORATION


/s/ Cheri L. Peper                          /s/ Daniel L. Schaeffer
- -----------------------------               ----------------------------------
Cheri L. Peper                              Daniel L. Schaeffer
Corporate Secretary                         Vice President, Human Resources


                                      -5-


<PAGE>   1
                                                                   EXHIBIT 10.33

                               APACHE CORPORATION


                        CONDITIONAL STOCK GRANT AGREEMENT

         THIS AGREEMENT is made as of December 17, 1998 between APACHE 
CORPORATION, a Delaware corporation (the "Company"), and G. Steven Farris 
("Grantee")

         1. GRANT. Subject to the terms of this Agreement, the Company hereby
grants to Grantee a conditional stock award of up to 100,000 shares (the
"Award") of the Company's common stock, par value $1.25 per share (the "Common
Stock").

         2. RESTRICTIONS. The Award granted hereunder is subject to the
following terms, conditions, restrictions and risks of forfeiture:

                  (a) Shares of Common Stock to be issued pursuant to this Award
may not be sold, assigned, transferred, pledged, hypothecated or otherwise
disposed of by Grantee until vested and paid in accordance with paragraph 2(b)
and not otherwise forfeited in accordance with the terms hereof.

                  (b) Subject to the other provisions of this Agreement, the
Award shall be payable to Grantee in periodic installments ( each an
"Installment"), on the fifth anniversary of each commencement date (each a
"Commencement Date") as set out below for each applicable Installment (each a
"Vesting Date"):


<TABLE>
<CAPTION>
        INSTALLMENT                  COMMENCEMENT DATE            VESTING DATE
        -----------                  -----------------            ------------
(in shares of Common Stock)
<S>                                   <C>                        <C>    
            6,667                     January 1, 1999            January 1, 2004
          13,333                      January 1, 2000            January 1, 2005
          20,000                      January, 1, 2001           January 1, 2006
          26,667                      January 1, 2002            January 1, 2007
          33,333                      January 1, 2003            January 1, 2008
</TABLE>


Each Installment shall be paid to Grantee within five (5) business days of the
applicable Vesting Date for such Installment as follows: 60% of the value of the
Installment shall be in the form of shares of Common Stock and 40% of the value
of the Installment (inclusive of withholding of any required income tax
withholding) shall be in the form of cash. The value of each applicable
Installment shall be the product of (i) the number of shares for such
Installment as set out in the above table, and (ii) the closing price of the
shares of Common Stock on The New York Stock Exchange, Inc. Composite
Transactions Reporting System ("NYSE") on the Vesting Date or, if the Vesting
Date is not a day on which the NYSE is open for trading, the last business day
preceding the 


                                       1
<PAGE>   2

Vesting Date when the NYSE is open for trading. Except as otherwise provided in
subparagraph (d) through (e) below, Grantee shall not be entitled to any payment
with respect to any Installment unless Grantee is employed by the Company on the
applicable Vesting Date.

                  (c) If, prior to any Vesting Date, Grantee elects to
discontinue his employment with the Company, or his employment with the Company
is terminated for cause, as defined in that certain Employment Agreement between
Grantee and the Company dated June 6, 1988, then Grantee shall forfeit all
Installments of the Award for which a Vesting Date has not occurred as of the
date of termination as provided above.

                  (d) If, prior to any Vesting Date, the Company elects to
terminate Grantee's employment with the Company other than for cause as defined
in subparagraph (c) above, or Grantee dies or becomes totally disabled, then
Grantee (or his beneficiary, as stated below in the case of death) shall be
entitled to receive payment, as provided in this subparagraph (d), for the value
of all Installments for which a Commencement Date has occurred on or prior to
the date of termination, death or total disability, as applicable. The payment
for the value of such Installment(s) shall be made to Grantee within thirty (30)
days of the date of termination, death or disability, as applicable, shall be
solely in cash, with the value of such Installment(s) being the product of (i)
the number of shares for such Installment or Installments as set out in the
above table, and (ii) the closing price of the shares of Common Stock on the
NYSE on the date of termination, death or disability, as applicable, or, if such
date is not a day on which the NYSE is open for trading, the last business day
preceding such date when the NYSE is open for trading. Grantee may name a
beneficiary or beneficiaries to receive any payment which he would otherwise be
entitled to hereunder in the event of his death while in the employ of the
Company. Such designation shall be made on a form to be provided by and filed
with the Corporate Secretary of the Company. If Grantee fails to designate a
beneficiary or no designated beneficiary survives Grantee, such payment shall be
made to the legal representative of Grantee's estate. Grantee shall not be
entitled to receive payment under this subparagraph (d) for any Installment for
which a Commencement Date has not occurred as of the date of termination, death
or disability, as applicable.

                  (e) If, prior to any Vesting Date, an individual other than
Grantee or the current Chief Executive Officer of the Company, becomes the Chief
Executive Officer of the Company (which, for purposes of this subparagraph,
shall include any entity which comes to control the Company), then Grantee, upon
written request to the Company, is entitled to receive payment, as provided in
this subparagraph (e), for the value of all Installments for which a
Commencement Date has occurred on or prior to the date of the written request
The payment for such Installment(s) shall be made to Grantee within thirty (30)
days of receipt of Grantee's notice, shall be solely in cash, with the value of
such Installment(s) being the product of (i) the number of shares for such
Installment or Installments as set out in the above table, and (ii) the closing
price of the shares of Common Stock on the NYSE on the date of such written
request or if such date is not a day on which the NYSE is open for trading, the
last business day preceding such date when the NYSE is open for trading.



                                       2
<PAGE>   3

                  (f) The shares of Common Stock issuable in accordance with
this Agreement have not be registered under the Securities Act of 1933, as
amended (the "Act"), and are subject to the restrictions contained in paragraph
8 of this Agreement.

         3.       ENFORCEMENT OF RESTRICTIONS.

                  (a) Each stock certificate issued in the name of Grantee
pursuant to this Agreement shall bear the following restrictive legend:

                  THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO THE
                  RESTRICTIONS CONTAINED IN A CONDITIONAL STOCK GRANT AGREEMENT
                  DATED AS OF DECEMBER 17, 1998, BY AND BETWEEN APACHE
                  CORPORATION AND G. STEVEN FARRIS, A COPY OF WHICH IS ON FILE
                  AT THE OFFICE OF THE CORPORATE SECRETARY OF THE COMPANY.

                  (b) Grantee shall not be entitled to delivery of the stock
certificate for the share portion of any Installment of the Award until such
Installment has vested in Grantee and been paid by the Company in accordance
with paragraph 2(a). Prior to the Vesting Date for any Installment, all stock
certificates shall be held by the Corporate Secretary and Grantee hereby agrees
to execute a blank stock power with respect to the stock certificate
representing the share portion of any Installment.

         4. PRIVILEGES OF A STOCKHOLDER. Upon the occurrence of a Commencement
Date and subject to the restrictions of paragraph 2, Grantee shall have all
voting, dividend and liquidation rights of a stockholder of the Company with
respect to the shares of Common Stock subject to the applicable Installment,
notwithstanding that such Installment is unvested.

         5. ADMINISTRATION. This Agreement shall be administered by the Board of
Directors of Apache Corporation (the "Board of Directors") or any committee
thereof as may be empowered by the Board of Directors. Any action taken or
decision made by the Company, the Board of Directors, or its delegates arising
out of or in connection with the construction, interpretation or effect of this
Agreement shall lie within its sole and absolute discretion, and shall be final,
conclusive and binding on Grantee and all persons claiming under or through
Grantee. By accepting this Agreement, Grantee and all persons claiming under or
through Grantee shall be conclusively deemed to have indicated acceptance and
ratification of, and consent to, any action taken under this Agreement by the
Company, the Board of Directors, or its delegates.



                                       3
<PAGE>   4

         6.       ADJUSTMENTS.

                  (a) If the Company shall at any time increase or decrease the
number of its outstanding shares of Common Stock or change in any way the rights
and privileges of such shares by means of a stock dividend or any other
distribution upon such shares payable in shares of Common Stock, or through a
stock split, subdivision, consolidation, combination, reclassification or
recapitalization involving the outstanding shares of Common Stock (hereinafter a
"capital restructuring"), then upon the occurrence of a capital restructuring,
the number of shares of Common Stock of each unvested Installment shall be
appropriately increased, decreased or changed in like manner as if the number of
shares of Common Stock of each unvested Installment had been issued,
outstanding, fully paid and non-assessable at the record date for the capital
restructuring.

                  (b) In the event that the Company is merged or consolidated
with another corporation and the Company is not the surviving corporation, or if
all or substantially all of the assets or more than 50 percent of the
outstanding shares of Common Stock of the Company is acquired by any other
corporation, business entity or person, or in case of a reorganization (other
than a reorganization under the United States Bankruptcy Code) or liquidation of
the Company, and if the provisions of subparagraph (c) hereof do not apply, the
Board of Directors, or the board of directors of any corporation assuming the
obligations of the Company, shall either (i) make appropriate provision for the
adoption and continuation of this Agreement by the acquiring or successor
corporation and for the protection of Grantee by the substitution on an
equitable basis of appropriate stock of the Company or of the merged,
consolidated or otherwise reorganized corporation which will be issuable with
respect to any outstanding Installment, provided that no additional benefits
shall be conferred upon Grantee as a result of such substitution, or (ii) upon
written notice to Grantee, the Board of Directors, in its sole discretion, if it
so elects, may accelerate the vesting of any unvested Installment so that all
unvested Installments are fully vested and payable prior to any such event.

                  (c) In the event of a change in control of the Company as
defined below, then the Board of Directors may, in its sole discretion, if it so
elects, take any of the following actions: (i) accelerate the vesting of the
unvested Installments so that the unvested Installments become fully vested and
payable, which acceleration may be conditional upon the occurrence of subsequent
events including, without limitation, a change in control, and may be made
irrevocable, either conditionally or unconditionally; and (ii) make any other
adjustments or amendments to the unvested Installments as the Board of Directors
deems appropriate.

                  (d) For purposes of this Agreement, a "change in control"
shall mean any of the events specified in the Company's Income Continuance Plan
or any successor plan which constitute a change in control within the meaning of
such plan.



                                       4
<PAGE>   5

                  (e) Any adjustments under this paragraph shall be made by the
Board of Directors whose determination with regard thereto shall be final and
binding on all parties.

         7. WITHHOLDING OF TAX. The Grantee hereby agrees that the Company is
entitled to make any required income tax withholding from any payments made
under paragraph 2.

         8. INVESTMENT REPRESENTATION. Grantee hereby acknowledges that any
shares of Common Stock issued pursuant to this Agreement are acquired for
investment without a view to distribution, within the meaning of the Act, and
shall not be sold, transferred, assigned, pledged or hypothecated in the absence
of an effective registration statement under the Act or an applicable exemption
from the registration requirements of the Act and any applicable state
securities laws and the following legend shall be imprinted on any stock
certificate.

                  THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
                  REGISTERED UNDER THE FEDERAL SECURITIES ACT OF 1933, AS
                  AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THESE SECURITIES
                  HAVE BEEN ACQUIRED FOR INVESTMENT AND NOT WITH A VIEW TO
                  DISTRIBUTION OR RESALE AND MAY NOT BE SOLD, TRANSFERRED,
                  ASSIGNED, PLEDGED, OFFERRED, OR OTHERWISE DISPOSED OF IN THE
                  ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT UNDER
                  APPLICABLE SECURITIES LAWS OR AN OPINION FROM COUNSEL
                  ACCEPTABLE TO THE COMPANY STATING THAT SUCH REGISTRATION IS
                  NOT REQUIRED.

         9. LISTING AND REGISTRATION OF COMMON STOCK. This Agreement shall be
subject to the requirement that, if at any time counsel to the Company shall
determine that the listing, registration or qualification of the shares of
Common Stock issued pursuant to this Agreement upon any securities exchange or
under any state or federal law, or the consent or approval of any governmental
or regulatory body, is necessary as a condition of, or in connection with, the
issuance of the shares hereunder, this Agreement may not be accepted in whole or
in part unless such listing, registration, qualification, consent or approval
shall have been effected or obtained on conditions acceptable to the Board of
Directors. Nothing herein shall be deemed to require the Company to apply for or
to obtain such listing, registration or qualification.

         10. NO RIGHT TO CONTINUE AS DIRECTOR OR EMPLOYEE. Nothing contained in
this Agreement shall interfere with or limit in any way the right of the
stockholders of the Company to remove Grantee from the Board of Directors
pursuant to the Bylaws or the 


                                       5
<PAGE>   6

Restated Certificate of Incorporation of the Company, nor confer upon Grantee
any right to continue in the employment of the Company.

         11. NOTICES. Any notice hereunder to the Company shall be addressed to:
Apache Corporation, One Post Oak Central, 2000 Post Oak Boulevard, Suite 100,
Houston, Texas 77056-4400, Attention: Corporate Secretary, and any notice to
Grantee shall be addressed to Grantee at Grantee's last address on the records
of the Company, subject to the right of either party to designate at any time
hereafter in writing some other address. Any notice shall be deemed to have been
duly given when delivered personally or enclosed in a properly sealed envelope,
addressed as set forth above, and deposited (with first class postage prepaid)
with the United States Postal Service.

         12. BINDING EFFECT. This Agreement shall be binding upon and inure to
the benefit of any successors to the Company and all persons lawfully claiming
under or through Grantee.

         13. GOVERNING LAW. The validity, construction, interpretation,
administration and effect of this Agreement, shall be governed by the
substantive laws, but not the choice of law rules, of the State of Texas.

         IN WITNESS WHEREOF, the Company and Grantee have executed this
Agreement as of the date first written above.

                                      APACHE CORPORATION



                                      /s/ Daniel L. Schaeffer            
                                      ------------------------------------------
                                      By:      Daniel L. Schaeffer             
                                         ---------------------------------------
                                      Its:     Vice President                  
                                          --------------------------------------


                                      GRANTEE



                                      /s/ G. Steven Farris                     
                                      ------------------------------------------

                                      G. Steven Farris                   
                                      ------------------------------------------
                                      Printed Name

                                      [Social Security Number]           
                                      ------------------------------------------
                                      Social Security Number



                                       6


<PAGE>   1
                                                                    EXHIBIT 21.1
                                                                     PAGE 1 OF 2

                  APACHE CORPORATION - LISTING OF SUBSIDIARIES
                             AS OF FEBRUARY 28, 1999

<TABLE>
<CAPTION>

EXACT NAME OF SUBSIDIARY AND NAME                          JURISDICTION OF
UNDER WHICH SUBSIDIARY DOES BUSINESS                       INCORPORATION OR ORGANIZATION      
- -------------------------------------------------          -------------------------------------
<S>                                                        <C>
Apache Corporation (New Jersey)                            New Jersey
Apache Foundation                                          Minnesota
Apache Gathering Company                                   Delaware
Apache Holdings, Inc.                                      Delaware
Apache International, Inc.                                 Delaware
         Apache Cote d'Ivoire, Inc.                        Delaware
         Apache Qarun Corporation LDC                      Cayman Islands
Apache Overseas, Inc.                                      Delaware
         Apache Abu Gharadig Corporation LDC               Cayman Islands
         Apache Asyout Corporation LDC                     Cayman Islands
         Apache Bohai Corporation LDC                      Cayman Islands
         Apache China Corporation LDC                      Cayman Islands
         Apache Cote d'Ivoire Petroleum LDC                Cayman Islands
         Apache Darag Corporation LDC                      Cayman Islands
         Apache East Bahariya Corporation LDC              Cayman Islands
         Apache Faiyum Corporation LDC                     Cayman Islands
         Apache Matruh Corporation LDC                     Cayman Islands
         Apache Mediterranean Corporation LDC              Cayman Islands
         Apache Poland Holding Company                     Delaware
                  Apache Eastern Europe B.V.               Netherlands
                           Apache Poland Sp. z o.o.        Poland
Nagasco, Inc.                                              Delaware
         Apache Marketing, Inc.                            Delaware
         Apache Transmission Corporation - Texas           Texas
         Apache Crude Oil Marketing, Inc.                  Delaware
         Nagasco Marketing, Inc.                           Delaware
Apache Oil Corporation                                     Texas
Burns Manufacturing Company                                Minnesota
Apache Energy Limited                                      Western Australia
         Apache Northwest Pty Ltd.                         Western Australia
         Apache Carnarvon Pty Ltd.                         Western Australia
         Apache Dampier Pty Ltd.                           Western Australia
         Apache East Spar Pty Limited                      Western Australia
         Apache Finance Pty Ltd                            Australian Capital Territory
         Apache Harriet Pty Limited                        Victoria, Australia
         Apache Oil Australia Pty Limited                  New South Wales, Australia
                  Apache Airlie Pty Limited                New South Wales, Australia
         Apache Varanus Pty Limited                        Queensland, Australia
         Apache Pipeline Pty Ltd                           Western Australia
Apache West Australia Holdings Limited                     Island of Guernsey
         Apache UK Limited                                 England and Wales
                  Apache Lowendal Pty Limited              Victoria, Australia
</TABLE>


<PAGE>   2

                                                                    EXHIBIT 21.1
                                                                     PAGE 2 OF 2

                  APACHE CORPORATION - LISTING OF SUBSIDIARIES
                             AS OF FEBRUARY 28, 1999

<TABLE>
<CAPTION>

EXACT NAME OF SUBSIDIARY AND NAME                          JURISDICTION OF
UNDER WHICH SUBSIDIARY DOES BUSINESS                       INCORPORATION OR ORGANIZATION      
- -------------------------------------------------          -------------------------------------
<S>                                                        <C>
DEK Energy Company                                         Delaware
         DEK Energy Texas, Inc.                            Delaware
         DEK Exploration Inc.                              Delaware
         DEK Petroleum Corporation                         Illinois
                  Apache Canada Ltd.                       Alberta, Canada
         DEPCO, Inc.                                       Texas
         Heinold Holdings, Inc.                            Delaware
Phoenix Exploration Resources, Ltd.                        Delaware
         TEI Arctic Petroleum (1984) Ltd.                  Alberta, Canada
         Texas International Company                       Delaware
Apache Khalda Corporation LDC                              Cayman Islands
         Apache Khalda, Inc.                               Delaware
Apache Qarun Exploration Company LDC                       Cayman Islands
         Phoenix Resources Company of Qarun                Delaware
Apache North America, Inc.                                 Delaware
</TABLE>

<PAGE>   1
                                                                    EXHIBIT 23.1


                    CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS


As independent public accountants, we hereby consent to the incorporation by
reference of our report included in this Form 10-K into Apache Corporation's
previously filed Registration Statements on Form S-3 (Nos. 33-53129, 333-39973,
333-44731 and 333-57785), Form S-4 (No. 33-61669), and Form S-8 (Nos. 33-31407,
33-37402, 33-53442, 33-59721, 33-59723, 33-63817, 333-04059, 333-25201,
333-26255, 333-32557, 333-36131 and 333-53961).





                                                       /s/  Arthur Andersen LLP

                                                           ARTHUR ANDERSEN LLP

Houston, Texas
March 22, 1999

<PAGE>   1
                                                                    EXHIBIT 23.2


                       [Letterhead of Ryder Scott Company]


As independent petroleum engineers, we hereby consent to the incorporation by
reference in this Form 10-K of Apache Corporation to our Firm's name and our
Firm's review of the proved oil and gas reserve quantities of Apache Corporation
as of January 1, 1999, and to the incorporation by reference of our Firm's name
and review into Apache Corporation's previously filed Registration Statements on
Form S-3 (Nos. 33-53129, 333-39973, 333-44731 and 333-57785), on Form S-4 (No.
33-61669), and on Form S-8 (Nos. 33-31407, 33-37402, 33-53442, 33-59721,
33-59723, 33-63817, 333-04059, 333-25201, 333-26255, 333-32557, 333-36131 and
333-53961).



                                                       /s/  Ryder Scott Company
                                                       /s/  Petroleum Engineers

                                                            Ryder Scott Company
                                                            Petroleum Engineers

Houston, Texas
March 15, 1999

<PAGE>   1
                                                                    EXHIBIT 23.3


              [Letterhead of Netherland, Sewell & Associates, Inc.]

            CONSENT OF INDEPENDENT PETROLEUM ENGINEERS AND GEOLOGISTS

As independent petroleum engineers, we hereby consent to the reference in this
Form 10-K of Apache Corporation to our Firm's name and our Firm's review of the
proved oil and gas reserve quantities as of January 1, 1997 for certain of
Apache Corporation's interests located in The Arab Republic of Egypt, and to the
incorporation by reference of our Firm's name and review into Apache
Corporation's previously filed Registration Statements on Form S-3 (Nos.
33-53129, 333-39973, 333-44731 and 333-57785), on Form S-4 (No. 33-61669), and
on Form S-8 (Nos. 33-31407, 33-37402, 33-53442, 33-59721, 33-59723, 33-63817,
333-04059, 333-25201, 333-26255, 333-32557, 333-36131 and 333-53961).



                                           NETHERLAND, SEWELL & ASSOCIATES, INC.

                                           By: /s/ Clarence M. Netherland
                                               Clarence M. Netherland
                                               Chairman

Houston, Texas
March 15, 1999

<TABLE> <S> <C>

<ARTICLE> 5
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   12-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-END>                               DEC-31-1998
<CASH>                                          14,537
<SECURITIES>                                         0
<RECEIVABLES>                                  159,806
<ALLOWANCES>                                         0
<INVENTORY>                                     40,948
<CURRENT-ASSETS>                               226,970
<PP&E>                                       6,982,645
<DEPRECIATION>                               3,255,104
<TOTAL-ASSETS>                               3,996,062
<CURRENT-LIABILITIES>                          305,774
<BONDS>                                      1,343,258
                                0
                                     98,387
<COMMON>                                       124,738
<OTHER-SE>                                   1,578,708
<TOTAL-LIABILITY-AND-EQUITY>                 3,996,062
<SALES>                                        876,443
<TOTAL-REVENUES>                               875,715
<CGS>                                          952,010
<TOTAL-COSTS>                                  952,010
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              70,537
<INCOME-PRETAX>                              (187,563)
<INCOME-TAX>                                  (58,176)
<INCOME-CONTINUING>                          (129,387)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                 (129,387)
<EPS-PRIMARY>                                   (1.34)
<EPS-DILUTED>                                   (1.34)
        

</TABLE>


© 2022 IncJournal is not affiliated with or endorsed by the U.S. Securities and Exchange Commission