USGS: Wolfcamp shale holds 20 billion undiscovered barrels of oil

Drillers have wrung oil out of West Texas for a century, but there’s still plenty left in untapped shale rocks.

In its first assessment of the Wolfcamp shale, the U.S. Geological Survey estimated the formation holds 20 billion undiscovered, technically recoverable barrels of oil, three times as much as the Bakken Shale in North Dakota. That’s enough gasoline to drive your car nearly two light years.

“Even in areas that have produced billions of barrels of oil, there is still the potential to find billions more,” said Walter Guidroz, program coordinator for the agency’s energy resource program, in a written statement.

The USGS makes estimates of undiscovered, technically recoverable resources, or oil that could be extracted with modern technology. That’s different than the proven reserves that oil companies actually book on their balance sheets after they drill wells and study reservoir data.

Because of recent technological breakthroughs in drilling, the agency has begun to reassess the size of several hotbeds of shale drilling, like the Eagle Ford Shale in South Texas. The last time it studied the Permian Basin, the region that encompasses the Midland Basin’s Wolfcamp shale, was in 2007.

The agency said the Wolfcamp was its largest assessment of shale oil in the U.S. so far. In addition to the 20 billion barrels of oil, the region also holds 16 trillion cubic feet of associated natural gas and 1.6 billion barrels of natural gas liquids, the USGS said in the study released Tuesday.

The oil industry seems to be aware of the vast resources buried in the region. U.S. drillers have paid billions in recent months for acreage in the Permian even though crude prices still languish below $50 a barrel.