petroleum reserves. The Clark-Drew Model is capable of determining (1) the 

 field size distribution of total resources, (2) field size distribution of 

 deposits discoverable at different levels of cost and technology, and (3) 

 production curves over time using various socioeconomic assumptions (U.S. 

 Department of the Interior 1980a). 



The Clark-Drew Model indicates that there are over 

 reservoirs yet to be discovered in the Gulf of Mexico, 

 likely be small, each perhaps containing less than one 

 recoverable oil . 



1,000 fields and/or 

 Half of them would 

 million barrels of 



Under suitable market conditions and technological innovations, these 

 fields could be profitably brought into production. The oil and gas produced 

 would not cause any great increase in oil and gas production, but the date of 

 ultimate depletion could be extended. There are no published estimates of oil 

 and gas reserves in the eastern Gulf of Mexico. 



Resource and Reserve Estimates 



The USGS is responsible for estimating oil and gas reserves on the Outer 

 Continental Shelf. For this purpose, USGS conducts geophysical studies and 

 reviews data gathered by oil and gas companies under prelease exploratory 

 permits, or as a result of exploration and development conducted on leases 

 obtained from the government. 



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

 Their estimates are based on undiscovered recoverable oil and gas in October 

 1980, and known remaining recoverable reserves in January 1979 (Table 4). 



Table 4. Gulf of Mexico OCS oil and gas 

 (U.S. Department of the Interior 1980b). 



reserves (mean estimates) in 1979 



Gulf area 



Oil , Gas ^ 

 (billion bbl)^ (trillion ft"^) 



Mean estimates of undiscovered 

 recoverable reserves 



Western Gulf of Mexico 

 (Main pass area and west) 

 0-2,500 m water depth 



Eastern Gulf of Mexico 

 (East of Main pass area) 

 0-2,500 m water depth 



5.2 



1.3 



69.0 



2.9 



Known reserves 



2.8 



37.2 



bbl = barrel = 42 U.S. gallons 



145 



