Offshore Oil and Gas Resources:

Differences in Estimates by Interior and Industry for Offshore California

RCED-86-179BR: Published: Jul 10, 1986. Publicly Released: Jul 21, 1986.

Additional Materials:


Office of Public Affairs
(202) 512-4800

Pursuant to a congressional request, GAO examined the procedures and assumptions the Department of the Interior and the petroleum industry used to develop estimates of offshore oil and gas resources in federal lands off California.

GAO found that: (1) the department's Minerals Management Service (MMS) uses a computer model to estimate the potential volume and value of offshore energy resources in a given area; (2) the model's outputs are considered conditional estimates of the quantities of offshore resources in a given area; (3) the oil industry's methods for estimating offshore resources are essentially the same as those MMS uses; (4) many industry sources consider their resource estimation methods proprietary; (5) the accuracy of any offshore resource estimate depends on the amount, type, and quality of available geophysical and other data; (6) MMS estimated in 1984 that the unleased federal lands off California contain the equivalent of 2.47 billion barrels of oil; and (7) an oil industry source estimated in 1985 that the same lands contain the equivalent of 5 billion barrels of oil.

Mar 20, 2018

Mar 14, 2018

Feb 28, 2018

Feb 16, 2018

Feb 6, 2018

Jan 30, 2018

Dec 7, 2017

Nov 14, 2017

Nov 1, 2017

Oct 26, 2017

Looking for more? Browse all our products here