USGS boosts ANWR resources estimates

• ANWR Coastal Plains Economically Recoverable [46,027 bytes]

The Clinton Administration has declined to consider leasing the area.

The USGS now estimates that the 1.5 million acre Coastal Plain contains 11.6-31.5 billion bbl of oil as in-place resources (95% and 5% probabilities).

"This means there is a 95% probability that more than 11.6 billion bbl are present, and a 5% probability that more than 31.5 billion bbl are present," said USGS. "By comparison, the USGS estimates that were made a decade ago were 4.8 and 29.4 billion bbl (95% and 5% probabilities).

"The general increase in estimated oil resources results from improved resolution of reprocessed seismic data, which allowed the identification of a larger number of potential petroleum accumulations, and new information regarding petroleum occurrences in nearby wells drilled since the previous study."

USGS said, "Technically recoverable resources are estimated to be between 4.3 billion and 11.8 billion bbl (95% and 5% probabilities). Quantities of technically recoverable oil are not expected to be uniformly distributed throughout the Arctic Refuge Coastal Plain."

The USGS study indicates about 85% of the technically recoverable oil may be concentrated in the western part of the refuge, near Prudhoe Bay and other fields in production on the North Slope.

"In contrast, a decade ago, USGS estimated that most resources may be located in the eastern part. Different rock formations are present across the refuge, and new information suggests that oil potential may be greater in those formations present in the western part of the area."

The USGS study presented results of the economic analysis as curves relating market price to the volume of oil that may be profitably recovered (see graph, p. 23). Using the mean, or expected, value of technically recoverable resources, USGS estimates that no oil is economically recoverable at a market price below about $15/bbl, about 2.4 billion bbl are economically recoverable at $18/bbl, and about 3.2 billion bbl are economically recoverable at $20/bbl.

It said, "These amounts are expected to occur in numerous accumulations, rather than in one large accumulation."

USGS says that, in the decade since it last assessed the petroleum resources of the Coastal Plain, numerous wells have been drilled and several oil fields have been discovered nearby, more geological data have become available, industry has developed methods to reprocess older seismic data, and the economics of North Slope oil development have changed.

A team of USGS scientists spent nearly 3 years analyzing the scientific data stemming from these developments and incorporating their conclusions into the new resource estimates.

USGS noted, "These estimates are of undiscovered petroleum resources and should not be confused with petroleum reserves, which are resources that have been discovered and proved recoverable."

Seismic exploration

"These numbers show once again that this area of Alaska is still the single best prospect in America to explore for oil, oil that would enable us to reduce our dependence on foreign sources.

"It certainly highlights that the 3-day 'back of the envelope' study estimates unveiled by the Interior Secretary (Bruce Babbitt) back in the summer of 1995 were, what we said then, nothing more than an attempt to support the Secretary's antidevelopment political agenda (OGJ, Aug. 28, 1995, p. 33)."

Murkowski said the new estimates are based on decades-old seismic data.

"We have the technology now to get a more accurate picture of the slope's potential. All we need is the permission to collect enough new seismic data, which then can be analyzed using the new three dimensional seismic processes. Even as huge as these estimates are, new data likely would raise them.

"USGS has good theoretical expertise, but their estimates are hamstrung by use of old data. You can now obtain detailed images of the subsurface geology with little or no impact on the environment, and we ought to do so."

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