Oil is a global industry that shows no signs of slowing down. Ripe for investment, the U.S. oil and natural gas industry is booming, supporting some 9.8 million U.S. jobs. Three of the top 10 oil companies in the world are in the United States: Exxon, Chevron and ConocoPhillips. This trio of oil giants, along with other American oil companies, pump billions of dollars annually into the U.S. economy while supplying the energy needs of American businesses and homeowners. Collectively, these companies find, develop and commercialize oil and natural gas.

Petroleum Industry Overview

The petroleum industry is divided into three main sectors where operations are concentrated by oil companies: upstream, midstream and downstream industries. Many of the top American oil companies are involved in all three sectors of the industry. Other oil companies specialize in specific aspects of one or more sectors or provide support services.

Exxon Mobil Corporation

Exxon and Mobil merged in 1999 to become the Exxon Mobil Corporation. Based in Irving, Texas, it is the largest non-state-run American oil company and the second largest energy company in the world after PetroChina. Its multinational operations span the globe including the United States, Canada, Belgium and Norway. Exxon Mobil operates in all three sectors of the petroleum industry producing gasoline, kerosene, lubricants, asphalt and adhesives that are sold under the brand names of Exxon, Mobil and Esso.

From its early days as part of John D. Rockefeller's Standard Oil empire, Exxon Mobil has become the largest American oil company with a 2017 market value of $341.61 billion.

Chevron Corporation

Chevron Corporation is a multinational American oil company based in San Ramon, California. Descended from Pacific Coast Oil Company, which was formed after the discovery of oil in California in 1879, the company has undergone several mergers, most recently with Gulf Oil to become Chevron. Chevron operates across all sectors of the petroleum industry engaging in natural gas exploration and refining, oil-based chemical manufacturing, and geothermal energy production. Its global refining system includes working refineries in California, Virginia and Mississippi in the United States, and one each in Ireland, South Korea, Singapore and Thailand.

With major operations in some of the world’s most important oil and gas regions, Chevron focuses on the Gulf of Mexico, offshore Western Australia, West Africa, and shale and other tight formations in the U.S. and Canada, among other regions. Fuels and other products are marketed under the Chevron, Texaco and Caltex brands. It ranks second of the top three American oil companies with a 2017 market value of $197.03 billion.

ConocoPhillips Co.

Conoco Inc. and Phillips Petroleum Company merged in 2002 to form ConocoPhillips Co., an American multinational energy corporation with headquarters in Houston, Texas. Based on its proven reserves and production of natural gas and natural gas liquids (NGLs), which are ethane, propane and butane, ConocoPhillips is the world’s largest independent exploration and production (E&P) company. In addition, it transports and markets its products, which include crude oil, asphalt, natural gas, plastics, solvents, automobile and aviation fuels, NGLs and liquefied petroleum gas worldwide. As of the end of 2016, the company had operations in Alaska and the lower 48 states in the United States, Canada, Europe, North Africa, Asia Pacific and the Middle East.

From its beginning in 1875 in Utah as the Continental Oil and Transportation Company, which distributed oil, coal and gas throughout the western United States, the company has grown to rank third in the top three American oil companies with a market value of $53.28 billion.

Occidental Petroleum Company

Occidental Petroleum Corporation is based in Houston, Texas. It has operations in the United States, Middle East and Latin America across all three sectors of the petroleum industry. In addition to E&P, Occidental’s midstream and downstream segments gather, process, transport, store, purchase and market oil, gas, NGLs and other commodities. Occidental owns OxyChem, a leading North American chemical manufacturer.

Founded in 1920, Occidental has approximately 33,000 employees and contractors worldwide as of 2016. One of the top 10 largest American oil companies, Occidental’s market value is $44.81 billion.

Valero Industries

Valero Industries is among the top 10 American oil companies. It was named for the mission San Antonio de Valero, the original name of the Alamo, and is based in San Antonio, Texas. It was incorporated in 1980 as Valero Energy Corporation, the successor of LoVaca Gathering Company, a subsidiary of the Coastal States Gas Corporation. Originally, its operations were in natural gas transportation. It later diversified into oil refining.

Valero refines about 3.1 million barrels of oil a day, making it the world’s largest independent refiner, and it is the leading ethanol producer with 11 ethanol plants throughout the midcontinent region of the United States yielding 1.4 billion gallons annually. Ranking No. 32 on the Fortune 500 list, its market value is $28.26 billion.

Other Top 10 Oil Companies

Other American oil companies among the top 10 are EOG Resources, Phillips 66, Pioneer Natural Resources, Marathon Petroleum and Anadarko Petroleum.

Upstream: Exploration and Production

The upstream industry, known as the E&P sector, finds, extracts, develops and produces crude oil or natural gas. Exploring for oil and gas starts with aerial surveys and ground surface observation by geologists and geophysicists. They scout out certain kinds of rock formations that may contain petroleum. Next, seismic surveys are performed or survey data is acquired from other companies to develop a clearer picture of the underground rock formations. Exploratory wells are drilled and – when resources are discovered – more wells are drilled to recover and extract the crude oil or raw natural gas and bring it to the surface.

Several American oil companies concentrate their operations in exploration and production. Among them are, Abraxas Petroleum Corporation, founded in 1977 and based in San Antonio, Texas. Its focus is on the development of conventional and unconventional resources in the Rocky Mountains, South Texas, Powder River Basin and Permian Basin in the United States.

American Shoreline, headquartered in Corpus Christi, Texas, also specializes in exploring for and developing oil and natural gas reserves. Concentrating its exploration primarily in South Texas, one of the most prolific natural gas producing areas in the United States, it has discovered numerous oil and gas fields and field extensions along the Texas Gulf Coast.

Midstream: Pipelines, Process, Storage, Transportation 

An integral part of the oil and gas value chain, the midstream industry consists of pipelines and other companies that process, store and transport crude oil, natural gas, sulphur and NGLs. This sector provides the vital link between wide-ranging petroleum-producing areas and the end consumer center.

Burrow Global is a mid-sized company with nine locations throughout Texas, Louisiana and Oklahoma. It provides services in the midstream sector of the oil industry. Its storage and transportation facilities include loading and unloading terminals and storage in atmospheric tanks. Other facilities separate, treat, gather and process oil. Burrow Global also has pipeline facilities that include compressors, pump stations and metering stations.

Among the many other American companies in this segment of the oil business are Dimension Energy Services, Western Gas Resources and Kinder Morgan.

Downstream: Refineries and Distributors

The downstream industry includes oil refineries, petrochemical plants, petroleum products distributors, retail outlets and natural gas distribution companies. For example, the 17 million barrels of crude oil unearthed in one day in the U.S. require teams of scientists, engineers and safety professionals employed by refineries to unleash its potential, transforming crude into natural gas, ethane, propane and butane, liquefied petroleum gas, gasoline, kerosene, jet fuel, lubricants, waxes, agricultural chemicals, pesticides, asphalt, heating oil, synthetic rubber, plastics, pharmaceuticals and hundreds of other petrochemicals.

OxyChem, a wholly owned subsidiary of Occidental Petroleum Company, manufactures polyvinyl chloride (PVC) resins and chlorine and caustic soda, which are essential ingredients in products such as plastics, water-treatment chemicals and pharmaceuticals. It is among the top three producers of these products in the United States, the top producer and marketer of caustic soda, and the world’s largest producer of caustic potash and calcium chloride. Based in Dallas, Texas, OxyChem has manufacturing facilities in the United States, Canada and Latin America.

Among the many familiar brands in the United States in the downstream segment of the oil industry are Exxon, Esso, Exxon Mobil, Texaco, Castrol, Amoco and many more.