700 



500 



300 



200 



1975 



1980 



1985 



1990 



1995 



2000 



Figure 6. Projected oil and gas production for the Gulf of Mexico from 1975 

 to 2000 (U.S. Department of the Interior 1980a, 1980b). 



The Clark-Drew Model indicates that there are over 1,000 oil fields or 

 reservoirs yet to be discovered in the Gulf of Mexico. Half of them would 

 likely be small, perhaps each containing less than one million barrels of re- 

 coverable oil. Under suitable market conditions and technological innova- 

 tions, these fields could be profitably brought into production. Oil and gas 

 produced from these fields would not greatly increase, but the date of ulti- 

 mate depletion would be extended. There are no published estimates of oil and 

 gas reserves in the eastern Gulf of Mexico. 



RESOURCE AND RESERVE ESTIMATES 



To determine OCS oil and gas reserves, the USGS conducts geophysical 

 studies, reviews data gathered by oil and gas companies under pre-lease ex- 

 ploratory permits, and examines the exploration and development of existing 

 OCS oil and gas exploratory and production activities. 



The most recent estimates of oil and gas reserves were made by USGS. 

 These estimates are based on undiscovered recoverable oil and gas in 1980 and 

 known remaining recoverable reserves in January 1979 (Table 6). 



Recoverable reserves is the amount of oil and gas in a given field before 

 exploration, development, and production. The original recoverable reserves 

 in the Gulf of Mexico were estimated by USGS to have been 7.52 billion barrels 

 of oil and 76.2 trillion ft^ of gas. More than three decades of production 

 yielded 4.76 billion bbl of oil and 39 trillion ft^ of gas (U.S. Department of 

 the -Interior 1980b). The most recent undiscovered recoverable reserve esti- 

 mates for the Gulf of Mexico are 6.5 billion bbl of oil and 71.9 trillion 

 ft^ of gas. 



144 



