USGS: Alaska's untapped oil reserves estimate lowered by about 90 percent

The U.S. Geological Survey says a revised estimate for the amount of conventional, undiscovered oil in the National Petroleum Reserve in Alaska is a fraction of a previous estimate. The group estimates about 896 million barrels of such oil are in the reserve, about 90 percent less than a 2002 estimate of 10.6 billion barrels.

The new estimate is mainly due to the incorporation of new data from recent exploration drilling revealing gas occurrence rather than oil in much of the area, the geological survey said. "These new findings underscore the challenge of predicting whether oil or gas will be found in frontier areas," USGS Director Dr. Marcia McNutt said in a statement. "It is important to re-evaluate the petroleum potential of an area as new data becomes available."

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