OCCIDENTAL PETROLEUM CORP

Occidental Petroleum was founded in Los Angeles, California, in 1920. In 1957, Armand Hammer became the company's president and CEO after acquiring a controlling stake. The 1960s marked a period of expansion as Occidental established operations in Peru, Venezuela, Bolivia, Trinidad, and the United Kingdom. [ citation needed ] In 1961, the company discovered the Lathrop Gas Field in Lathrop, California.

In 1965, Occidental won exploration rights in Libya, where it operated until 1986 when United States economic sanctions led to the suspension of activities. The company diversified in 1968 by entering the chemical business with the acquisition of Hooker Chemical Company, following the Love Canal contamination incident.

In 1971, Occidental received approval to build an oil refinery in Canvey Island in Essex, England, but construction ceased in 1975 due to the 1970s energy crisis. The site remained derelict; the tanks and the chimney were subsequently demolished. Only some concrete foundations and the river jetty remain extant.

In 1973, Occidental negotiated a phosphate-for-natural-gas deal with the Soviet Union, in which the Hammer-controlled firms Occidental Petroleum and Tower International would export to the Soviet Union phosphate, which Occidental mined in northern Florida, in return for the Soviet Union exporting from Odessa and Ventspils through Hammer's firms natural gas that would be converted into ammonia, potash, and urea. The total value of this trade was estimated at $20 billion. The construction of Soviet port facilities, designed by Hammer's firms, was partially financed by the Export-Import Bank as endorsed by Nixon.

In August 1973, Libya nationalized 51% of Occidental's assets in the country. In February 1974, the company announced a 35-year oil exploration agreement with Libya. 81% of the oil extracted by Occidental Petroleum was to go to the Libyan government, with 19% retained by Occidental Petroleum. In 1986, the company suspended operation in the country due to economic sanctions imposed by the United States. In 2005, Occidental and its partner, Liwa, won 9 out of 15 exploration spots on the EPSA-4 auction, making both companies among the first to enter the Libyan market since the United States lifted its embargo on Libya.

The company was one of the first companies to research developing oil shale. In 1983, Occidental and Ecopetrol, the Colombian state-owned oil company, discovered the giant Caño Limón oilfield in Arauca. In July 1996, the company sold its interest in 3 oilfields in the Congo to the Congolese government for $215 million. The following year, it paid $3.65 billion to acquire the Elk Hills Oil Field.

In 1984, billionaire David H. Murdock owned about 5% of the company and was a member of its board of directors, after the company acquired IBP, Inc., of which Murdock owned 19%. After disagreements between Murdock and then CEO Armand Hammer, the company paid greenmail to buy Murdock's shares at $40.09 each, while the market price was $28.75.

In 1986, the company formed a joint venture with Church & Dwight, which makes Arm & Hammer products, for a potassium carbonate plant at Muscle Shoals, Alabama. On July 6, 1988, an explosion and subsequent inferno on the company's Piper Alpha platform in the Scottish North Sea, resulted in 167 fatalities in what remains the world's most deadly offshore disaster. In 1990, Armand Hammer died and Ray R. Irani became chairman and chief executive officer of the company. In 1991, Occidental sold its stake in IBP, Inc. In 1993, the company sold its remaining coal operations.

In 2006, the government of Ecuador seized the company's interest in block 15 of the Amazon rainforest, forcing the company to take a $306 million after-tax charge. In 2016, Ecuador agreed to pay $980 million in restitution to the company, down from the original award of $1.77 billion. The agreement was based on a 2012 arbitration award from the International Center for Settlement of Investment Disputes.

In 2007, Occidental's compensation policies came under scrutiny after it was announced that Irani received $460 million in compensation in 2006. In May 2011, Irani retired as CEO after CalSTRS and Relational Investors, two major shareholders, objected to the company's compensation policies for top executives. President Stephen I. Chazen was named CEO to replace Irani and in 2013, shareholders ousted Irani as chairman. Despite his outlandish compensation, during Irani's tenure, the company grew from a collection of unrelated businesses to one that focuses on oil and gas and the market capitalization of the company went from $5.5 billion to $80 billion.

In December 2010, Occidental acquired shale oil properties in the Williston Basin in North Dakota for $1.4 billion. These assets, as well as other assets acquired by Oxy in the Williston Basin, were sold in 2015 for $600 million. The company also sold its proven and probable reserves of 393 million barrels of oil equivalent (2.40 × 10 9 GJ) in Argentina to Sinopec, a subsidiary of China Petrochemical Corporation, and acquired properties in South Texas and North Dakota for $3.2 billion.

In January 2011, Occidental partnered with Abu Dhabi's state oil company in developing the Shah Field, one of the largest natural gas fields in the Middle East, through a joint venture known as Al Hosn Gas. Al Hosn Gas became operational in 2015.

In September 2014, Occidental moved its headquarters to Houston, Texas. In November, the company sold its 50% interest in BridgeTex Pipeline Company, owner of a 300,000 barrel-per-day crude oil pipeline system that extends from Colorado City, Texas to Texas City, Texas, for $1.075 billion. In December 2014, Occidental distributed 80.5% of its shares in California Resources Corporation, the largest producer of oil and natural gas on a gross-operated barrels of oil equivalent basis in California, to Occidental shareholders and distributed its remaining stake to shareholders in March 2016. In June 2017, the company sold land in the Permian Basin for $600 million and used the proceeds to acquire other assets in the area.

In October 2015, Occidental completed the first phase of a $500 million carbon dioxide flooding project in Hobbs, New Mexico. In March 2017, the company and its 50/50 joint venture partner Mexichem began operations of a 1.2-billion-pound per year capacity ethylene cracker at the OxyChem plant in Ingleside, Texas, along with pipelines and storage at Markham, Texas.

In May 2016, Vicki Hollub, who had worked at Occidental since 1981 and joined the board in 2015, became the chief executive officer of the company, the first female to serve as chief executive officer of a major U.S. oil and gas company. In January 2018, Occidental was found to be partially responsible for the Bayou Corne sinkhole, along with Texas Brine Company and Vulcan Materials Company.

In October 2020, Occidental sold its onshore operations in Colombia to the Carlyle Group for $825 million. The deal included operations and working interests in the Llanos Norte, Middle Magdalena, and Putumayo Basins. Working interest on exploration offshore in Colombia remained under ownership of Oxy in partnership with Ecopetrol, with plans to drill the first well by 2024. Anadarko Colombia, a subsidiary of Oxy, and Ecopetrol entered into a joint exploration agreement in May 2022 for offshore exploration in deep waters of the Caribbean, with plans to drill the world's deepest offshore oil well by 2024.

In August 2023, Occidental acquired Carbon Engineering, a direct air capture technology company, for $1.1 billion. In August 2024, the company acquired CrownRock, a Permian producer, for $12.4 billion. In August 2024, Anadarko Peru, a subsidiary of Oxy, completed the initial phase of a 3D marine seismic acquisition project in northern Peruvian waters. In April 2025, Oxy acquired Holocene, a carbon removal startup active in enhanced oil recovery. In August 2025, Oxy sold its natural gas gathering affiliate in the Permian Basin to Enterprise Products for $580 million.

In January 2026, Occidental sold OxyChem to Berkshire Hathaway —which owns 28% of Occidental's stock—for $9.7 billion. Occidental said it would use $6.5 billion to lower debt. It also retained all legacy environmental liabilities for OxyChem. In May 2026, Oxy acquired a 10% stake in Exxon Mobil 's deepwater exploration block offshore Trinidad and Tobago. Effective June 2026, CEO Vicki Hollub retired and was replaced by COO Richard Jackson, with Hollub remaining on the board in an advisory capacity.

Acquisitions

In 1981, Occidental acquired IBP, Inc., one of largest producers of beef and pork products in the United States. In 1988, the company acquired Cain Chemical for $2 billion.

In 2005, the company acquired Vintage Petroleum for $3.8 billion. In 2008, it acquired a 10% stake in Plains All American Pipeline. The company also acquired assets from Plains Exploration & Production for $1.3 billion. In October 2009, Occidental acquired Citigroup 's Phibro energy-trading business, for its net asset value of approximately $250 million. The unit was managed by Andrew J. Hall, who received compensation of approximately $100 million per year in 2007 and 2008. After the acquisition, the division reported its first losses since the 1990s. In 2016, Phibro was wound down and sold.

In August 2019, Occidental acquired Anadarko Petroleum for $57 billion, making the deal the world's fourth biggest oil and gas acquisition to date. Anadarko was the subject of the largest environmental settlement in American history, involved with the Deepwater Horizon BP disaster and was fined under the Clean Water Act. The deal was clinched as Berkshire Hathaway invested $10 billion in exchange for 100,000 shares of cumulative perpetual preferred stock with a value of $100,000 per share. Berkshire also received a warrant to purchase up to 80 million more shares at an exercise price of $62.50 a share.