The Bakken shale formation in North Dakota holds up to 167 billion barrels of oil but only about 1 percent of it can be recovered using current technology, a new study says.

The study released Monday said current technology could lead to the recovery of about 2.1 billion barrels in North Dakota's portion of the formation, where oil-producing rock is sandwiched between layers of shale about 10,000 feet under the ground. The estimate of recoverable oil included in the study by the state Department of Mineral Resources was similar to that of a federal study released earlier this month.


"The future potential is enormous -- it means we will be able to exploit this for the rest of the century," said Lynn Helms, the department's director, at the annual state oil conference Monday.

Ron Ness, president of the North Dakota Petroleum Council, cautioned against over-hyping the Bakken play.

"This study gives a number that by no means guarantees those are the amount of barrels we can count on," Ness said.