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Petroleum Reserves            
Last Updated: February 2009
Next Update: February 2010

What are proved reserves?

Proved reserves of crude oil are the estimated quantities which geological and engineering data demonstrate with reasonable certainty can be recovered in future years from known reservoirs, assuming existing economic and operating conditions. Proved reserves make up the domestic production base and are the primary source of oil and gas used in the United States. Total proved reserves of crude oil in the United States, as of year-end 2007, are 21.3 billion barrels, a 1.6 percent increase from those of 2006. In 2007, U.S. petroleum consumption was about 21 million barrels of oil and natural gas liquids per day.

What States contain crude oil reserves?

Thirty-one States have crude oil reserves. The top five are:

  • Texas, with 5.1 billion barrels
  • Alaska, with 4.2 billion barrels
  • California, with 3.3 billion barrels
  • New Mexico, with 735 million barrels
  • Wyoming, with 690 million barrels

Also, there are substantial crude oil reserves located in Federal Offshore fields: 3.5 billion barrels in the Gulf of Mexico and 441 million barrels in the Pacific. Offshore refers to that geographic area that lies seaward of the coastline. In general, the coastline is the line of ordinary low water along with that portion of the coast that is in direct contact with the open sea or the line making the seaward limit of inland water.

Crude Oil Proved Reserves by Area, 2007

Crude Oil Proved Reserves by Area, 2007
click on image to enlarge
Source: Energy Information Administration, U.S. Crude Oil, Natural Gas, and Natural Gas Liquids Reserves 2007 Annual Report

What is not included in estimates of proved crude oil reserves?

Estimates of proved crude oil reserves do not include the following:

  • "Indicated additional reserves," a category of oil that is reported separately and may become available from known reservoirs through the application of improved recovery techniques using current technology
  • Natural gas liquids (including lease condensate)
  • Oil of doubtful recovery because of uncertainty as to geology, reservoir characteristics, or economic factors
  • Oil that may occur in undrilled prospects
  • Oil that may be produced from oil shales, coal, Gilsonite (asphalt), and other such sources

 

What about stored crude oil?

Volumes of crude oil placed in underground storage, such as those in the Strategic Petroleum Reserve, are not considered proved reserves. The Strategic Petroleum Reserve was created to diminish the impact of disruptions in petroleum supplies and to carry out obligations of the United States under the International Energy Program. In 1975, Public Law 94-163 (the Energy Policy and Conservation Act) established the Strategic Petroleum Reserve of up to one billion barrels of petroleum supplies. These petroleum stocks are to be maintained by the Federal Government for use during periods of major supply interruptions.


More information on this subject can be found in the following EIA publications:
    bullet item U.S. Crude Oil, Natural Gas, and Natural Gas Liquids Reserves
    bullet item Annual Energy Review
    bullet item Petroleum (Oil) - A Fossil Fuel