This section covers researching past and present oil and gas companies, resources for starting a company in the oil and gas industries, and references to top companies. Energy companies, nationally owned and privately owned, are some of the biggest companies that have every existed in the world. Many of them are well known, Exxon (U.S.), Chevron (U.S.), Saudi Aramco (Saudi Arabia), Gazprom (Russia), China National Petroleum Corporation (China), Equinor (formerly Statoil of Norway), TOTAL (France), and ENI (Italy). Additionally, companies that use oil and natural gas, like autos, electric providers, and airlines are also among the most well-known and largest companies.
The oil and gas industry is frequently divided into three segments: upstream, midstream and downstream. While each of these areas has a number of independent companies, major companies in oil and gas are often considered integrated, meaning their businesses consist of a mix of upstream, midstream and downstream activities. Companies can be private, public, or state-owned, which impacts the amount of information available.
Supermajor integrated oil and gas companies are involved in each segment of the industry and are defined as typically having market capitalization of $100 billion or more.1 They are often international oil companies (IOCs).
Major integrated companies are defined as typically having market capitalization of $10 billion to $100 billion.2
An independent company focuses on one segment of the industry and is defined as a producer who does not have more than $5 million in retail sales of oil and gas in a year or who does not refine more than an average of 75,000 barrels per day of crude oil during a given year.3
Regardless of size, there is more data available for publicly-owned companies. Private companies, including government-owned companies, are often not legally required to disclose information, making company research more difficult. More details on general company research can be found in our guide:
Upstream companies focus on exploration and production. Most crude oil production is controlled by National Oil Companies, which includes OPEC, or integrated international oil companies.4 Upstream companies benefit from high oil and gas prices and high volumes. Other metrics include rig count and capital spending.5
Midstream companies handle the transportation and storage of oil and gas. This segment is made up of many independent transportation operators.6 Oil and gas volumes are important to midstream companies, and prices as they relate to volume: If the price drops so low that upstream companies stop producing, midstream companies are not needed for transportation.7
Downstream companies manage the refining and marketing of oil and gas. There is lower market concentration than the upstream segment. Downstream companies benefit from profit margins where they are able to sell their refined products for more than the cost of acquiring the crude resources. Other metrics include the number and size of refineries.8
Because this industry often shifts with mergers and acquisitions, we've provided example companies in each segment of the industry.
| Integrated | Upstream | Midstream | Downstream |
|---|---|---|---|
| BP | Devon Energy | Enable Midstream Partners LP | Delek US Holdings |
| Chevron | Occidental | Enbridge | Marathon Petroleum |
| ExxonMobile | Kinder Morgan | Valero Energy | |
| Royal Dutch Shell | Seacor Holdings Inc. | ||
| Teekay Shipping Corp. | |||
| Western Gas Partners LP |
Since Mexico nationalized its oil production in 1938, countries have been creating private state-owned companies or purchasing significant shares in publicly traded oil companies.9 The rise of oil nationalization is seen as a response to historical exploitation by international oil companies, and as a political strategy to control access to and decisions surrounding national resources.10
| Company | Country |
|---|---|
| Saudi Aramco | Saudi Arabia |
| National Iranian Oil Company (NIOC) | Iran |
| Gazprom | Russia |
| China National Petroleum Corporation (CNPC) | China |
The subscription resources marked with a padlock 
are available to researchers on-site at the Library of Congress. If you are unable to visit the Library, you may be able to access these resources through your local public or academic library.
The following title links to fuller bibliographic information in the Library of Congress Online Catalog. Links to additional online content are included when available.
A Comparative History of National Oil Companies by A number of databases contain company profiles. The subscription resources marked with a padlock are available to researchers on-site at the Library of Congress. If you are unable to visit the Library, you may be able to access these resources through your local public or academic library. The following are useful starting points for oil and gas companies:
Most company databases have tools to make lists which can be sorted on a number of metrics. Additionally, some publications use their own methodologies to compile specific company lists from the energy industry, oil and gas industry, or specific oil and gas segments.
Additional works on companies in the oil and gas industries in the Library of Congress may be identified by searching the Library of Congress Online Catalog under appropriate Library of Congress subject headings. Choose the topics you wish to search from the following list of Library of Congress subject headings to link directly to the Catalog and automatically execute a search for the subject selected. For assistance in locating the many other subject headings which relate to this subject, please consult a reference librarian.
Browse or search using the company name as a subject heading. For example:
Information on national oil companies can be listed under the company name, or in publications affiliated with that particular country. For example:
