Skip to content
— CH. 1 · FOUNDING AND EARLY EXPANSION —

Occidental Petroleum

~4 min read · Ch. 1 of 5
5 sections

  • Los Angeles, 1920 marked the birth of Occidental Petroleum. Armand Hammer took control in 1957 and steered the company through a decade of rapid growth. The 1960s saw operations expand into Peru, Venezuela, Bolivia, Trinidad, and the United Kingdom. In 1961, geologists discovered the Lathrop Gas Field near Lathrop, California. This find provided early momentum for the firm's exploration efforts. By 1965, Occidental secured rights to explore oil reserves in Libya. The company operated there until economic sanctions forced a suspension in 1986. Diversification arrived in 1968 when Occidental bought Hooker Chemical Company following the Love Canal contamination incident. A refinery project on Canvey Island in Essex, England began in 1971 but halted construction by 1975 due to the energy crisis. Only concrete foundations and a river jetty remain at that site today.

  • August 1983 brought a major discovery in Colombia with Ecopetrol. They found the Caño Limón oilfield in Arauca. July 1996 saw the sale of three Congo oilfields to the Congolese government for $215 million. The following year, Occidental paid $3.65 billion to acquire the Elk Hills Oil Field. December 2010 marked an entry into shale oil properties in North Dakota's Williston Basin for $1.4 billion. These assets were sold five years later for $600 million. January 2011 initiated a partnership with Abu Dhabi's state oil company to develop the Shah Field. This joint venture known as Al Hosn Gas became operational in 2015. September 2014 moved headquarters to Houston, Texas. November 2014 involved selling a 50% interest in BridgeTex Pipeline Company for $1.075 billion. August 2019 saw the acquisition of Anadarko Petroleum for $57 billion. This deal ranked as the world's fourth largest oil and gas acquisition ever recorded. December 2023 added CrownRock, a Permian producer, for $12 billion.

  • the 6th of July 1988 witnessed the destruction of the Piper Alpha platform in the North Sea. A gas leak triggered an explosion that killed 167 workers. It remains the deadliest offshore disaster in history. The inquiry blamed inadequate maintenance and safety procedures by Occidental. No criminal charges followed the tragedy. the 11th of October 2008 brought an oleum spill at a facility in Petrolia, Pennsylvania. Over 2,000 residents evacuated due to toxic gas clouds. the 14th of June 1997 marked an explosion at the Magurchhaqra gas field in Bangladesh. The blast damaged 28 tea gardens and caused estimated damages between 90 and 140 billion BDT. the 10th of May 2007 initiated legal action by 25 Achuar Peruvians regarding drilling in Block 1-AB. They claimed dumping of toxic oil by-products caused health issues. A 2006 study found cadmium levels above safe limits in nearly all tested individuals. March 2015 concluded with a settlement funding health projects in five Achuar communities. the 13th of December 1998 involved a bombing in Santo Domingo, Colombia where 17 civilians died after misidentification by AirScan.

  • Armand Hammer maintained a long friendship with Senator Albert Gore, Sr. Gore served on the company board before becoming head of Island Creek Coal Company in September 1972. Much coal production occurred in Tennessee, the state Gore represented. The company liquidated these assets in 1993 after Hammer's death. Vice President Al Gore inherited shares upon his father's death in 1998 but sold them immediately. In 2005, Occidental contributed $250,000 to George W. Bush's second inauguration. Donations between $10,000 and $25,000 went to the Clinton Foundation. August 1984 saw billionaire David H. Murdock receive greenmail payments for his shares. The company paid $40.09 per share while market value sat at $28.75. January 2024 introduced a class action lawsuit accusing Occidental of price-fixing shale oil production. This scheme allegedly raised gasoline prices for American drivers. February 2011 involved investigations into the Libyan Investment Authority regarding bribery laws.

  • May 2016 brought Vicki Hollub as the first female CEO of a major U.S. oil and gas company. She had worked at Occidental since 1981. June 2024 established a memorandum with TAE Technologies to explore nuclear fusion for direct air capture projects. DAC removes carbon from the atmosphere using energy-intensive processes. October 2025 finalized the sale of OxyChem subsidiary to Berkshire Hathaway for $9.7 billion. Proceeds included $6.5 billion used to lower debt. The company retained all legacy environmental liabilities for OxyChem. December 2023 added CrownRock, a Permian producer, for $12 billion. March 2017 began operations of an ethylene cracker in Ingleside, Texas. This facility produces 1.2 billion pounds annually alongside pipelines and storage at Markham. August 2023 saw the acquisition of Carbon Engineering for $1.1 billion to advance direct air capture technology. July 2024 marked a partnership to use clean electricity for these decarbonization efforts.

Continue Browsing

Companies listed on the New York Stock Exchange

Common questions

When was Occidental Petroleum founded and who took control in 1957?

Los Angeles, 1920 marked the birth of Occidental Petroleum. Armand Hammer took control in 1957 and steered the company through a decade of rapid growth.

What major oil field did Occidental discover near Lathrop California in 1961?

In 1961 geologists discovered the Lathrop Gas Field near Lathrop California. This find provided early momentum for the firm's exploration efforts.

How much did Occidental pay to acquire Anadarko Petroleum in August 2019?

August 2019 saw the acquisition of Anadarko Petroleum for $57 billion. This deal ranked as the world's fourth largest oil and gas acquisition ever recorded.

Who became the first female CEO of Occidental Petroleum in May 2016?

May 2016 brought Vicki Hollub as the first female CEO of a major U.S. oil and gas company. She had worked at Occidental since 1981.

When did Occidental move its headquarters to Houston Texas?

September 2014 moved headquarters to Houston Texas. November 2014 involved selling a 50% interest in BridgeTex Pipeline Company for $1.075 billion.

See all questions about Occidental Petroleum →

All sources

120 references cited across the entry

  1. 1webOccidental Petroleum Corporation 2025 Form 10-K Annual ReportU.S. Securities and Exchange Commission — February 18, 2026
  2. 2webFortune: Occidental Petroleum
  3. 3webForbes: Occidental Petroleum
  4. 4webOccidental Petroleum Corporation American company Britannica
  5. 5bookSpies, Wiretaps, and Secret Operations; An Encyclopedia of American Espionage: Hammer, ArmandABC-CLIO — 2011
  6. 6newsDeal-maker Armand Hammer Moscow's capitalist comradeLynde McCormick — July 3, 1980
  7. 7newsOIL OFFICIALS ARE SAID TO LEAVE LIBYAJUDITH MILLER — January 30, 1986
  8. 8newsOut-of-Court Settlement Reached Over Love CanalMATTHEW L. WALD — June 22, 1994
  9. 9webStock Photo - The remains of the Occidental Petroleum Jetty on Canvey Island in Essex
  10. 10newsSoviet and Occidental Oil In Multibillion-Dollar DealHedrick Smith — 1973-04-13
  11. 11newsTHE RIDDLE OF ARMAND HAMMER1981-11-29
  12. 12newsOCCIDENTAL SIGNS DEAL WITH SOVIETHedrick Smith — 1974-06-29
  13. 13newsOccidental-Libya Exploration Pact Set8 February 1974
  14. 14webMubadala awarded exploration licenses in Libya2005-01-02
  15. 15bookA Preliminary Assessment of the Environmental Impacts from Oil Shale DevelopmentsUnited States Environmental Protection Agency — 1977
  16. 16newsOccidental to invest $80M in ColombiaJuly 16, 2003
  17. 17newsOccidental Petroleum Announces LayoffsFebruary 14, 1996
  18. 18newsOccidental's $3.7-Billion Bid Buys Elk Hills FieldCHRIS KRAUL — October 7, 1997
  19. 19newsArmand Hammer to Own Pinch of Arm &September 23, 1986
  20. 20newsRemembering Piper Alpha disasterSteven Duff — June 6, 2008
  21. 21newsArmand Hammer Dies at 92; Industrialist and Philanthropist Forged Soviet LinksERIC PACE — December 12, 1990
  22. 22newsRay Irani Officially Named Oxy ChairmanDecember 14, 1990
  23. 23newsOCCIDENTAL PETROLEUM SHEDS ITS LAST COAL COMPANYApril 16, 1993
  24. 24newsEcuador Cancels an Oil Deal With Occidental PetroleumMay 17, 2006
  25. 25newsOccidental Petroleum takes $306M charge on Ecuador operationsJuly 5, 2006
  26. 26newsEcuador to pay $980 million to Occidental for asset seizureAlexandra Valenci — January 13, 2016
  27. 27newsOccidental CEO's 2006 paycheck: $460 millionElizabeth Douglas — April 7, 2007
  28. 28newsOccidental's Irani to retire as CEO in 2011: reportAnna Driver — August 31, 2010
  29. 29newsOccidental Petroleum Chairman Ray Irani ousted at annual meetingShan Li et al. — May 4, 2013
  30. 30newsIs Occidental's Irani Worth His Big Pay Check?Michael Corkery — August 3, 2010
  31. 31newsOccidental stockholders want say on pay every yearNichola Groom — May 6, 2011
  32. 32newsOccidental buys land for $1.4 billionNick Smith — December 13, 2010
  33. 33newsExclusive: Oxy to exit North Dakota's oil fields in sale to private equity fundErnest Scheyder et al. — October 15, 2015
  34. 34newsOccidental Adds to Its U.S. Oil PropertiesTHOMAS KAPLAN et al. — December 10, 2010
  35. 35newsChina's Sinopec buys Occidental's Argentina assetsJim Bai et al. — December 10, 2010
  36. 36newsOccidental wins Abu Dhabi Shah gas project: sourcesJanuary 19, 2011
  37. 37newsUAE's Shah gas project now seen online early 2015-ADNOCJanuary 20, 2014
  38. 38newsOccidental Petroleum splintering and moving its headquarters to HoustonJordan Blum — February 14, 2014
  39. 39newsOccidental Petroleum to move headquarters to Houston, spin off California assetsShan Li — February 14, 2014
  40. 40press releasePlains All American Pipeline, L.P. Enters into Agreement to Acquire 50% Interest in BridgeTex Pipeline Company from Occidental Petroleum CorporationBusiness Wire — November 6, 2014
  41. 41newsOccidental Petroleum to sell BridgeTex interest to Plains for $1BOlivia Pulsinelli — November 6, 2014
  42. 42newsOccidental Petroleum completes California spin-offNora Olabi — December 1, 2014
  43. 43press releaseOccidental Petroleum Announces Regular Quarterly DividendBusiness Wire — February 18, 2016
  44. 44newsOxy makes two $600M deals to sell, buy Permian assetsJoshua Mann — June 19, 2017
  45. 45news$500 million oil recovery project wraps up first phase in HobbsSal Christ — October 21, 2015
  46. 46newsOxyChem, Mexichem commission Texas ethylene complexRobert Brelsford — March 1, 2017
  47. 47newsOccidental Names Hollub First Woman CEO of Big U.S. Oil FirmApril 29, 2016
  48. 48inlineJudge: Fault for Bayou Corne sinkhole lies with Texas Brine, OxyChem, Vulcan; companies had decades of warnings The Advocate
  49. 49webThe Carlyle Group to acquire Occidental's onshore operations in Colombia The Carlyle Group
  50. 50webOccidental Petroleum and Ecopetrol to Drill World's Deepest Offshore Oil Well OilPrice.com
  51. 51newsOccidental Will Sell Its Stake in Iowa Beef UnitMICHAEL PARRISH — September 5, 1991
  52. 52newsOCCIDENTAL TO ACQUIRE IOWA BEEFJune 2, 1981
  53. 53newsOxy Buys Cain Chemical; Deal Valued at $2 BillionDONALD WOUTAT — April 15, 1988
  54. 54newsWorkers Cheer Cain's Sale, And the $100,000 WindfallsTHOMAS C. HAYES — April 18, 1988
  55. 55press releaseOccidental Agrees to Acquire Vintage PetroleumBusiness Wire — October 13, 2005
  56. 56newsOxy Agrees to Acquire Vintage PetroleumElizabeth Douglass — October 14, 2005
  57. 57newsOccidental Petroleum to invest in Plains All AmericanJuly 2, 2008
  58. 58newsPlains Passes Assets To OccidentalMelinda Peer — September 25, 2008
  59. 59press releaseOccidental Petroleum Announces Acquisition of PhibroBusiness Wire — October 9, 2009
  60. 60newsOccidental buys Phibro from CitigroupOctober 9, 2009
  61. 61newsExclusive: Oil legend Andy Hall suffers first loss since 1990sBarani Krishnan et al. — February 9, 2012
  62. 62newsFormer Wall Street banker buys Phibro from Occidental Petroleum: FTManish Parashar — January 26, 2016
  63. 63newsThe biggest ever mergers and acquisitions in the oil and gas industryVasanthi Vara — June 19, 2019
  64. 64webOccidental to Acquire DAC Firm Carbon Engineering for $1.1B
  65. 65webOccidental Completes Acquisition of CrownRock
  66. 66webWarren Buffett's Berkshire Hathaway set to make its biggest deal in three years CNN BusinessJordan Valinsky — 2025-10-02
  67. 67webBerkshire Hathaway to pay $9.7 billion for OxyChem, potentially Warren Buffett's last big deal2025-10-02
  68. 68newsOccidental Petroleum CEO Vicki Hollub to retire, COO Jackson to succeedMarch 26, 2026
  69. 69newsOccidental to continue funding growth opportunities in OmanApril 21, 2014
  70. 70newsOxy to 'stay very diligent' in Qatar and MideastPratap John — January 24, 2016
  71. 71webdetail
  72. 72webOccidental subsidiary completes seismic acquisition offshore Peru Oil & Gas JournalAugust 19, 2024
  73. 73webOxy Eyes Nuclear Fusion as Possible DAC Power Source2024-06-11
  74. 74newsOccidental Petroleum wins major oil deal with LibyaSteve Gelsi — November 26, 2007
  75. 75magazineGaddafi's Corporate QuislingsMassimo Calabresi — June 14, 2011
  76. 76newsOil Companies That Gave 'Bonuses' to Libya Also Lobbied Against Disclosure RulesMarian Wang — March 24, 2011
  77. 77webInternal Report Shows Even Before War, Libya's SWF Was in ChaosBenjamin Ruffel — July 1, 2011
  78. 78newsUK Prosecutors Team Up With SEC to Investigate Bribery Among SWFsPaula Vasan — June 29, 2011
  79. 79newsOccidental not planning to divest assets in Oman, Abu Dhabi and Qatar: Occidental chiefJanuary 23, 2016
  80. 80webOMV Expands in Libya With Purchase Of Oxy Zueitina Stake2017-02-10
  81. 81newsJust 100 companies responsible for 71% of global emissions, study saysTess Riley — July 10, 2017
  82. 82newsOccidental Petroleum Wants to Be 'Part of the Solution' on Climate ChangeSusie Gharib — June 12, 2017
  83. 83newsOnce barren Copper Basin reaches major milestone in restoration effort photosDavid Cobb — May 10, 2016
  84. 84press releaseDepartment of Justice and EPA Announce $50 Million Settlement to Clean Up Contamination at Eastern Tennessee Superfund SiteUnited States Department of Justice — April 22, 2016
  85. 85webSuperfund Site: LOVE CANAL, NIAGARA FALLS, NYUnited States Environmental Protection Agency
  86. 86press releaseOccidental to pay $129 Million in Love Canal SettlementUnited States Department of Justice — December 21, 1995
  87. 87newsChemical cloud brings tense hoursDON HOPEY — October 13, 2008
  88. 88press releaseCSB Issues Final Report on Oleum Release from INDSPEC Chemical Corp. that Forced Thousands to Evacuate in October 2008; Report Cites Use of Pump Power Supply that Lacked SafeguardsU.S. Chemical Safety and Hazard Investigation Board — October 5, 2009
  89. 89web26th anniv of Magurchhara gas field disaster todayMintu Deshwara — 2024-06-14
  90. 90webOccidental's gasfield at Magurchhara abandonedIqbal Siddiquee — 1998-01-20
  91. 91webNo compensation even after 22 years of Magurchhara tragedy2019-06-14
  92. 92newsOil Giant vs. Mother Earth: Bets Are OnRobert W. Benson — June 20, 1997
  93. 93newsActivists Urge Occidental Petroleum Shareholders to Sell Their StockNANCY RIVERA BROOKS — April 29, 2000
  94. 94newsOccidental Petroleum Abandons Oil Development on U'wa LandMay 3, 2002
  95. 95press releaseOccidental Petroleum to Leave U'wa Land! Company Announces Plans to Leave Controversial Colombia Oil ProjectAmazon Watch — May 3, 2002
  96. 96press releaseOccidental Petroleum Faces Lawsuit for Its Role in Massacre in Colombia Plaintiff Questions CEO at the Company's Annual MeetingAmazon Watch — April 25, 2003
  97. 97newsOccidental Averts Suit for Colombia MassacreMATT REYNOLDS — November 13, 2014
  98. 98courthttp://cdn.ca9.uscourts.gov/datastore/opinions/2009/05/11/05-56056o.pdf2009
  99. 99newsIndigenous Peruvians win Amazon pollution payout from US oil giantDan Collyns — March 5, 2015
  100. 100newsPeruvian Indigenous Communities Pleased with Settlement of Pollution Lawsuit Against Occidental PetroleumMarch 5, 2015
  101. 101newsIndigenous Achuar Face Off Against Occidental Petroleum in Amazon Pollution CaseMarch 8, 2010
  102. 102webMaynas Carijano v. Occidental PetroleumUnited States Court of Appeals for the Ninth Circuit — December 6, 2010
  103. 103newsUS reaches $5.15 billion environmental settlementEric Tucker — April 3, 2014
  104. 104newsExclusive: BP Bills Anadarko $272 Million In Gulf Spill ResponseRachel Slajda — June 30, 2010
  105. 105newsU.S. Supreme Court rejects BP, Anadarko over Deepwater Horizon spill penaltiesLawrence Hurley — Reuters — June 29, 2015
  106. 106webBuffett's Berkshire Hathaway to invest $10 billion in Occidental Petroleum for Anadarko takeoverCNBC — April 30, 2019
  107. 107webOccidental Petroleum: Political Contributions and Lobbying
  108. 108newsDonors get good seats, great access this weekJim Drinkard — January 17, 2005
  109. 109newsFinancing the inaugurationUSA Today — January 16, 2005
  110. 110newsSome question inaugural's multi-million price tagUSA Today — January 14, 2005
  111. 111newsBig Oil and Pro-Keystone Groups Gave Millions to Clinton FoundationClare Foran — February 18, 2015
  112. 112newsGore Getting $20,000 a Year for Mineral Rights on FarmCharles R. Babcock — August 15, 1992
  113. 113newsGore's Oil MoneyKen Silverstein — May 22, 2000
  114. 114newsTHE 2000 CAMPAIGN: THE VICE PRESIDENT; Gore Family's Ties to Oil Company Magnate Reap Big Rewards, and a Few ProblemsDouglas Frantz — March 19, 2000
  115. 115newsCampaigner's finances Where the presidential hopefuls have invested their fortunes may reveal something about the character of eachDolores Kong — July 30, 2000
  116. 116webSale of the Elk Hills Naval Petroleum ReserveUnited States Department of Energy
  117. 117magazineGore's Big Oil Connection: An 'Occident' of Birth?Karon Tony — September 25, 2000
  118. 118newsOxyChem Profits from PartnershipSteve Minter — February 1, 1999
  119. 119newsOccidental Buys Back 5% StakeROBERT J. COLE — July 20, 1984
  120. 120webDrivers sue US shale oil producers over alleged price-fixing schemeMike Scarcella — 2024-01-16