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FORM 10-K

ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d)

For the Year Ended December 31, 2004

ANADARKO PETROLEUM CORPORATION

Securities registered pursuant to Section 12(b) of the Act:

Common Stock, par value $0.10 per share

The above Securities are listed on the New York Stock Exchange.

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  ü      No           .

     Indicate by check mark if the 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 the 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  ü.

     Indicate by check mark whether registrant is an accelerated filer.     Yes  ü      No           .

     The aggregate market value of the Company’s common stock held by non-affiliates of the registrant on June 30, 2004 was $14.5 billion.

     The number of shares outstanding of the Company’s common stock as of January 31, 2005 is shown below:

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PART I

General

      Anadarko Petroleum Corporation is among the largest independent oil and gas exploration and production companies in the world, with 2.4 billion barrels of oil equivalent (BOE) of proved reserves as of December 31, 2004. The Company’s major areas of operations are located in the United States, primarily in Texas, Louisiana, the mid-continent region and the western states, Alaska and in the deep waters of the Gulf of Mexico, as well as in Canada and Algeria. Anadarko also has production in Venezuela and Qatar and is executing strategic exploration programs in several other countries. The Company actively markets natural gas, oil and natural gas liquids (NGLs) and owns and operates gas gathering systems in its core producing areas. In addition, the Company engages in the hard minerals business through non-operated joint ventures and royalty arrangements in several coal, trona (natural soda ash) and industrial mineral mines located on lands within and adjacent to its Land Grant holdings. The Land Grant is an 8 million acre strip running through portions of Colorado, Wyoming and Utah where the Company owns most of its fee mineral rights. Anadarko is committed to minimizing the environmental impact of exploration and production activities in its worldwide operations through programs such as carbon dioxide (CO₂) sequestration and the reduction of surface area used for production facilities.

Available Information The Company files Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, registration statements and other items with the Securities and Exchange Commission (SEC). Anadarko provides access free of charge to all of these SEC filings, as soon as reasonably practicable after filing, on its internet site located at www.anadarko.com. The Company will also make available to any stockholder, without charge, copies of its Annual Report on Form 10-K as filed with the SEC. For copies of this, or any other filings, please contact: Anadarko Petroleum Corporation, Public Affairs Department, P.O. Box 1330, Houston, Texas 77251-1330 or call (832) 636-1219.

Refocused Strategy

      Anadarko announced a refocused strategy in June 2004. Strategy execution included an asset realignment that resulted in the Company completing over $3 billion in pretax asset sales during 2004 through a series of separate unrelated transactions. Combined, the divested properties represented about 11% of Anadarko’s year-end 2003 proved reserves and about 20% of 2004 oil and gas production. The Company used proceeds from asset sales to reduce debt, repurchase Anadarko common stock and otherwise to have funds available for reinvestment in other strategic options. For additional information see Refocused Strategy under Item 7 of this Form 10-K.

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Oil and Gas Properties and Activities

Proved Reserves

      As of December 31, 2004, Anadarko had proved reserves of 7.5 trillion cubic feet (Tcf) of natural gas and 1.1 billion barrels of crude oil, condensate and NGLs. Combined, these proved reserves are equivalent to 2.4 billion barrels of oil or 14.2 Tcf of gas. During 2004, the Company’s reserves decreased 6% due to the divestiture of non-core properties in the United States and Canada in conjunction with the refocused strategy, partially offset by proved reserve additions related to successful exploration and development drilling in North America. The Company’s reserves have grown 3% over the past three years primarily due to successful exploration and development drilling in the United States and Canada, the acquisition of Howell Corporation (Howell) in 2002 and the acquisition of producing properties, partially offset by the effect of the disposition of non-core producing properties during 2004. As of December 31, 2004, Anadarko had proved developed reserves of 5.5 Tcf of natural gas and 606 million barrels (MMBbls) of crude oil, condensate and NGLs. Proved developed reserves comprise 64% of total proved reserves.

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Sales Volumes and Prices

      The following table shows the Company’s annual sales volumes. Volumes for natural gas are in billion cubic feet (Bcf) at a pressure base of 14.73 pounds per square inch. For the computation of million barrels of oil equivalent (MMBOE), six thousand cubic feet (Mcf) of gas is the energy equivalent of one barrel of oil, condensate or NGLs.

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      The following table shows the Company’s annual average sales prices and average production costs. The average sales prices include gains and losses for derivative contracts the Company utilizes to manage price risk related to the Company’s sales volumes. Production costs are costs incurred to operate and maintain the Company’s wells and related equipment and include cost of labor, well service and repair, location maintenance, power and fuel, transportation, cost of product, property taxes, production and severance taxes and production related general and administrative costs. Additional information on volumes, prices and markets is contained in Financial Results and Marketing Strategies under Item 7 of this Form 10-K. Additional detail of production costs is contained in the Supplemental Information under Item 8 of this Form 10-K. Information on major customers is contained in Note 15 of the Notes to Consolidated Financial Statements under Item 8 of this Form 10-K.

Properties and Activities — United States

Overview Anadarko’s active areas in the United States include the Lower 48 states, Alaska and the Gulf of Mexico. Reserves in the United States comprised 69% of Anadarko’s total proved reserves at year-end 2004. During 2004, the Company’s drilling efforts in the United States resulted in 548 gas wells, 193 oil wells and 17 dry holes. During 2004, the Company sold its interests in certain non-core properties located in the United States representing an estimated 226 MMBOE of proved reserves on the date of sale. The majority of these properties were located in the shallow waters of the Gulf of Mexico and the mid-continent region. The accompanying maps illustrate by state Anadarko’s net undeveloped and developed lease and fee mineral acreage, number of net producing wells and other data relevant to its domestic onshore and offshore oil and gas operations.

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      The following table presents selected 2004 U.S. operating data by area.

(1)	Gross number of wells in which Anadarko has an interest.
(2)	Includes 714 gross development wells with a 99% success rate and 44 gross exploration wells with a 77% success rate.
(3)	The results of these wells are held confidential for competitive reasons.

Onshore — Lower 48 States At the end of 2004, about 57% of the Company’s proved reserves were located onshore in the Lower 48 states. During 2004, the Company sold certain properties from this area representing about 119 MMBOE of proved reserves on the date of sale. At the end of 2004, net production from the retained properties in the Lower 48 states averaged 1,149 million cubic feet per day (MMcf/d) of gas and 71 thousand barrels per day (MBbls/d) of oil, condensate and NGLs. The Company’s 2005 capital budget for this area ranges from $1.1 billion to $1.3 billion and provides for drilling an expected 940 development and 60 exploration wells.

North Louisiana During 2004, an additional gas treating plant was built at the Vernon field in order to facilitate the increase in production resulting from the Company’s successful drilling and to provide greater marketing flexibility. Anadarko’s tight gas drilling program in the Vernon field remains focused on extending the boundaries and developing the field areas with the highest production rates, recoverable reserves and economic returns.

East Texas The Dowdy Ranch, Dew/ Mimms Creek, Bald Prairie and Marquez fields continue to be the primary focus in the east Texas tight gas Bossier play. Anadarko also continues to be active in its Cotton Valley infill drilling program in the Carthage area.

Central Texas Anadarko’s horizontal drilling program continues to be the focus in central Texas where the objective is to exploit the multiple pay zones in the Austin Chalk formation of the Giddings and Brookeland fields. In addition, a successful reentry program is in place. In 2005, Anadarko expects to continue its horizontal drilling and reentry programs, focusing on building inventory while sustaining production volumes.

West Texas Operations in west Texas are primarily concentrated on tight gas, conventional exploration and production and waterflood projects in the Permian basin.

Mid-Continent In 2004, the Company sold its producing interests in the deep Hugoton area and retained properties producing from the shallow formations. At the end of 2004, net production from the retained properties averaged 60 MMcf/d of gas and 6 MBbls/d of oil, condensate and NGLs. During 2005, the Company’s focus will be on production operations, gathering and facility maintenance.

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*	Drilling activities were conducted in these areas in 2004.

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Western States The majority of the activity in the western states area is associated with conventional drilling in the Wamsutter area, coalbed methane (CBM) and enhanced oil recovery (EOR) projects. The western states area includes the Company’s oil and gas properties in the Land Grant area of Wyoming, Colorado and Utah. Anadarko’s operations on the Land Grant are concentrated in the greater Green River basin.

Alaska Anadarko’s activity in Alaska is concentrated primarily on the North Slope. About 4% of the Company’s proved reserves at year-end 2004 were in Alaska. The Company’s capital budget is expected to range from $70 million to $90 million for Alaska in 2005, which includes drilling about 14 development wells and three exploration wells.

Gulf of Mexico In 2004, the Company sold all of its interests in properties located on the continental shelf of the Gulf of Mexico. The properties sold included about 107 MMBOE of proved reserves on the date of sale. At the end of 2004, net production from the retained deepwater properties averaged 25 MMcf/d of gas and 23 MBbls/d of oil, condensate and NGLs. At year-end 2004, about 8% of the Company’s proved reserves were located offshore in the deepwater of the Gulf of Mexico where Anadarko owns an average 73% interest in 190 blocks. Anadarko has budgeted about $700 million for capital spending in the deepwater Gulf of Mexico for 2005, which includes drilling about 19 wells.

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Gas Processing The Company processes gas at various third-party plants under agreements generally structured to provide for the extraction and sale of NGLs in cost efficient plants with flexible volume commitments. The Company has agreements with four plants in the western states area, 13 plants in the mid-continent area and one plant in the gulf coast area. Anadarko also processes gas and has interests in two Company-operated plants in the western states. Anadarko’s strategy to aggregate gas through Company-owned and third-party gathering systems allows Anadarko to secure processing arrangements in each of the regions where the Company has significant production.

Properties and Activities — Canada

Overview In late 2004, the Company sold Canadian properties, primarily in the Western Canadian Sedimentary basin, representing an estimated 64 MMBOE of proved reserves on the date of sale. At the end of 2004, about 11% of the Company’s proved reserves were located in Canada with average net production of 265 MMcf/d of gas and 9 MBbls/d of oil, condensate and NGLs. The Company’s 2005 capital budget for Canada ranges from $350 million to $400 million and provides for drilling an expected 192 development and 50 exploration wells. The accompanying map illustrates the Company’s net developed and undeveloped lease and fee mineral acreage, number of net producing wells and other data relevant to its Canadian properties.

      The following table presents selected 2004 Canadian operating data by area.

(1)	Gross number of wells in which Anadarko has an interest.
(2)	Includes 221 gross development wells with a 96% success rate and 55 gross exploration wells with a 75% success rate.

Fort St. John During 2004, the Company completed a complex natural gas transportation project beneath the Buckinghorse River in northeastern British Columbia. The Company believes that this technical success, combined with its broad land base, provides extensive opportunity in the region. The Company is pursuing multi-zone, deep natural gas targets in the area that are expected to add growth to the foundation asset base.

Medicine Hat In southern Alberta, Anadarko initiated its first CO₂ project in Canada and expects increased oil production and recovery from the Nisku Enchant field as a result. The Company expects the shallow gas program in southwest Saskatchewan to continue to provide steady production and exploitation opportunities with cost effective programs that can be brought on stream quickly.

Grande Prairie In 2004, Anadarko entered into a multi-year joint venture agreement to explore several high potential plays in the Western Canadian Sedimentary basin. Anadarko participated in three exploration wells with a 100% success rate. In 2005, the Company anticipates participating in drilling several additional wells and acquiring additional lease acreage and seismic data in the area.

Edson A third facility expansion in 2004 and successful drilling activity continue to make the Wild River area the most active development area for the Company in Canada. An additional plant expansion is expected to be complete in early 2005 that should increase capacity to 130 MMcf/d of gas.

Other During the 2004 winter drilling season, a Burnt Lake exploratory prospect was drilled in the Mackenzie Delta. An appraisal well will begin drilling in 2005 and the Company expects to participate in a testing program in the area throughout the year.

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Properties and Activities — Algeria

Overview Anadarko is engaged in exploration, development and production activities in Algeria’s Sahara Desert. At the end of 2004, seven fields discovered by the Company were on production. At the end of 2004, about 15% of the Company’s proved reserves were located in Algeria. In 2004, net sales volumes from the Company’s properties in Algeria totaled 22 MMBbls of crude oil, or 11% of the Company’s total sales volumes. In 2004, Anadarko participated in 17 wells with a success rate of 82%. In addition, the Company participated in 11 injection or service wells during the year. The Company’s 2005 capital budget for Algeria ranges from $80 million to $90 million and provides for drilling an expected 27 development and service wells and six exploration wells.

Contracts and Partners Anadarko’s interest in the Production Sharing Agreement (PSA) for Blocks 404, 208 and 211 is 50% before participation at the exploitation stage by Sonatrach, the national oil and gas enterprise of Algeria. The Company has two partners, each with a 25% interest, also prior to participation by Sonatrach. Under the terms of the PSA, oil reserves that are discovered, developed and produced are shared by Sonatrach, Anadarko and its two partners. Sonatrach is responsible for 51% of development and production costs. Anadarko and its partners also have an exploration program underway on Blocks 404, 208 and 211 and have exploration licenses, under separate PSAs, for Block 406b (60% interest) and Block 403c/e (67% interest). Anadarko and its joint venture partners fund Sonatrach’s share of exploration costs and are entitled to recover these exploration costs out of production in the exploitation phase. Sonatrach has owned shares of the Company’s common stock since 1986 and at year-end 2004 was the registered owner of 5.1% of Anadarko’s outstanding common stock.

Production and Development On Block 404, production from the HBNS field averaged 126 MBbls/d of oil (gross) and production from four of the satellite fields averaged 29 MBbls/d of oil (gross) in 2004. Production from the HBN field, which extends from Block 404 into Block 403 and is unitized with other companies, averaged 71 MBbls/d of oil (gross) in 2004. Anadarko is also actively involved in the unitized Ourhoud field which is located in the southern portion of Block 404 and extends into Block 406a and Block 405. Production from the Ourhoud field averaged 224 MBbls/d of oil (gross) in 2004. Anadarko has several fields farther south on Block 208. Development of the EMK field on Block 208 is progressing and is expected to be operational in late 2007 with about 100 MBbls/d of production capacity.

Exploration During 2004, the Company participated in four exploration wells on Blocks 404, 208 and 211, one of which was successful. The first exploration well on Block 406b was also drilled and found natural gas and condensate. During 2005, the Company plans to continue exploratory drilling on Blocks 404, 208 and 211, evaluate the prospect on Block 406b for commerciality and drill its first exploration well on Block 403c/e.

      Anadarko continually monitors the political situation in Algeria and has taken steps to help ensure the safety of employees and the security of its facilities in the remote regions of the Sahara Desert. Anadarko is unable to predict with certainty any effect the current situation may have on activity planned for 2005 and beyond. However, the situation has had no material effect to date on the Company’s operations in Algeria, where the Company has had activities since 1989. For additional information on certain factors and risks associated with the Company’s foreign operations see Regulatory Matters and Additional Factors Affecting Business — Foreign Operations Risk under Item 7 of this Form 10-K.

Properties and Activities — Other International

Overview The Company’s other international oil and gas production and development operations are located primarily in Venezuela and Qatar. The Company currently has exploration acreage in Qatar, Tunisia, West Africa, Indonesia, off the coast of Georgia in the Black Sea and other selected areas. About 5% of the Company’s total proved reserves were located in other international locations at year-end 2004. During 2004, net sales volumes from the Company’s other international properties averaged 22 MBbls/d of crude oil, condensate and NGLs, or 4% of the Company’s total volumes. In 2005, the Company’s capital budget is expected to range from $160 million to $180 million in other international projects and provides for drilling an expected 21 development and nine exploration wells.

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Venezuela The Company’s Venezuelan operation consists of the Oritupano-Leona contract area, a risk service contract in which the Company has a non-operated 45% participating interest. The Company’s net oil sales volumes from this 395,000 acre area averaged 12 MBbls/d during 2004. The development program in 2004 included drilling 18 wells with a 100% success rate, converting 29 idle wells to producing wells and workover activity. During 2005, the Company expects to continue with the development of the Oritupano-Leona contract area, focusing on additional drilling and workover activity. The Venezuelan government has issued several statements recently indicating its intention to reevaluate the contractual terms of existing contracts with foreign oil companies. Anadarko is unable to predict with certainty any effect the current situation may have on activity planned for 2005 and beyond. However, the situation is not expected to have a material adverse effect on the consolidated results of operations or financial position of the Company.

Qatar The Company had interests in 1,458,000 undeveloped lease acres and 14,000 developed acres in Qatar at year-end 2004. Anadarko is the operator and has a 92.5% interest in the Al Rayyan field, which is part of an Exploration and Production Sharing Agreement covering Blocks 12 and 13. Production from the Al Rayyan field, located on Block 12, averaged 8 MBbls/d of oil (net) in 2004. During 2004, the Company recorded a ceiling test impairment of $62 million for Qatar as a result of lower production estimates and unsuccessful exploration activity. On Block 4 (100% interest), the Company was awarded a five-year exploration work program under which it plans to acquire seismic data in 2005. Anadarko also has an Exploration and Production Sharing Agreement covering offshore Block 11 (49% interest). The Company expects to drill an exploration well in this area in 2005.

Other The Company operates two blocks (55% interest) in the Ghadames basin of Tunisia, which cover 1,220,000 acres. In 2005, the Company’s focus in the area will be delineation and testing to determine commerciality of a previous natural gas and condensate discovery.

Drilling Programs

      The Company’s 2004 drilling program focused on known oil and gas provinces in the United States (Lower 48, Alaska and Gulf of Mexico), Canada and Algeria. Exploration activity consisted of 104 wells, including 34 wells in the Lower 48, three wells in Alaska, seven wells offshore in the Gulf of Mexico, 55 wells in Canada and five wells in Algeria. Development activity consisted of 965 wells, which included 690 wells in the Lower 48, eight wells in Alaska, 16 wells offshore in the Gulf of Mexico, 221 wells in Canada, 12 wells in Algeria and 18 wells in other international locations.

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Drilling Statistics

      The following table shows the results of the oil and gas wells drilled and tested: