The Minerals Management Service estimates U.S. Outer Continental Shelf conventionally recoverable resources amount to 45.6 billion bbl of oil and 268 tcf of gas as of Jan. 1, 1995.
MMS disclosed the figures, prepared with the U.S. Geological Survey, after the National Academy of Sciences criticized the methods used in a similar 1991 report.
Compared with a 1987 study, MMS said Alaska and Pacific OCS reserves are up sharply, but the Gulf of Mexico registered slight drops.
Since the 1987 assessment, nearly 2.5 billion bbl of oil and 30 tcf have been produced in the gulf, only 1 billion bbl and 13 tcf of which were not replaced by resources in the undiscovered categories or from unproved reserves.
Similarly, 1 billion bbl and 4.7 tcf currently considered unproved reserves were most likely assessed as undiscovered resources in the previous report.
Assuming $2.11/Mcf natural gas, undiscovered economically recoverable resources on the OCS are 72.5 tcf, broken out as 1.1 tcf off Alaska, 5.2 tcf in the Atlantic, 57.9 tcf in the Gulf of Mexico, and 8.3 tcf in the Pacific.
Assuming $18/bbl oil, the OCS holds 14.4 million bbl: 3.8 million bbl off Alaska, 400,000 bbl in the Atlantic, 4.9 million bbl in the Gulf of Mexico, and 5.3 million bbl in the Pacific.
MMS used recent technological advances in seismic surveys, offshore drilling, and development operations in its assumptions. But it made no attempt to determine a relationship between future technological advances and estimated resources.
MMS said, "It is believed, however, any technological advances in the future will significantly affect the portion of the undiscovered conventionally recoverable resources, which will then be viewed as the economically recoverable resources. The estimates of undiscovered economically recoverable resources may be higher if finding costs are reduced."
The agency pointed out that conclusions drawn from direct comparisons in the assessment with previous assessments may be misleading because of changes in methodology and models used.
It said previous assessments generally focused on estimating economically recoverable resources.
In addition, "MMS incorporated numerous changes into this (latest) assessment to better reflect the full extent of recoverable oil and natural gas resources yet to be discovered on the OCS, resulting in generally higher estimates (as expected) for most areas."
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