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USGS estimates U.S. reserves growth Thinks 32 billion barrels of oil reserves could potentially be added to conventional fields across the entire United States Alan Bailey Petroleum News
The U.S. Geological Survey has published a new assessment of the extent to which the oil and gas reserves associated with known oil fields in the United States might increase in the future. The reserves additions would be achieved through a process known as “reserves growth,” in which field development tends over time to reveal and enable the possibility of producing more oil than originally thought. Oil “reserves” refer to oil known to exist through exploration and development drilling, and capable of production, as distinct from oil thought to exist but unproven, or known oil that cannot be produced.
Following the new assessment, USGS thinks that there could be a total U.S. reserves growth of 32 billion barrels of oil; 291 trillion cubic feet of natural gas recovered in association with oil production; 241 trillion cubic feet of natural gas from gas fields; and 10 billion cubic feet of natural gas liquids.
USGS has aggregated data for Alaska reserves growth with that from the Pacific Coast, including California. The result indicates that this composite region, with possible growth of 20.2 billion barrels, has by far the largest potential growth of any region in the U.S. The Gulf Coast has the biggest potential for natural gas reserves growth, with a potential growth of 135 trillion cubic feet. It is important, however, to stress that these growth figures relate to existing fields and bear no relationship to growth potential from new exploration and the resulting development of new fields.
Growth trends Traditionally, reserves growth assessments of this type are done using statistical growth trends determined from aggregated historic oilfield data. These trends enable the prediction of potential future reserves growth of known, producing oil accumulations.
In this new assessment, USGS applied this traditional technique to smaller oil fields. But, recognizing that a relatively small number of larger fields tend to make a disproportionately large contribution to the aggregate growth figures, the agency used a new technique for assessing 68 oil accumulations in 55 large oil fields. The new technique involved taking each field individually and using statistical techniques to determine likely reserve growth for that field, based on the characteristics of that particular field. The estimates for the individual large fields were then aggregated, before being aggregated with the growth estimates for the smaller fields.
Two gas fields were assessed using the new method, with all other gas fields assessed using the traditional growth trend approach.
It turned out that the 68 oil accumulations in the larger fields accounted for 70 percent of the total potential oil reserve growth for the United States, with smaller oil accumulations accounting for the remaining 30 percent, USGS said.
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