Study: Only 1% of Bakken recoverable

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 state study says.

The study released April 28 said current technology could lead to the recovery of about 2.1 billion barrels in North Dakota’s “middle Bakken” formation, where oil-producing rock is sandwiched between layers of shale about 10,000 feet under the ground.

“The future potential is enormous — it means we will be able to exploit this for the rest of the century,” said Lynn Helms, director of the North Dakota Department of Mineral Resources, which conducted the study.

Helms released the study April 28 at an annual state oil conference in Minot, N.D., where the Bakken was a big topic on the three-day agenda. The conference, limited to 1,300 participants, sold out.

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. “The Bakken rock is full of oil and companies drilling out there know that, and they know it is extremely difficult and extremely expensive.”

Costs $5 million per well

To capture oil from the middle Bakken in North Dakota, most companies “fracture stimulate” horizontal wells by forcing pressurized fluid and sand to break pores in the rock and prop them open to recover oil.

The middle Bakken, which ranges from a few feet thick to 80 feet, is between layers of loose shale. Its rock consists of sandstone and siltstone, with microscopic pores that contain the oil. The formation is 365 million years old, said Ed Murphy, the state geologist and director of the North Dakota Geological Survey.

Part of the conference will focus on sharing information on drilling technology for the Bakken, Ness said.

The state study mirrors the independent findings of a federal study released on April 10.

The U.S. Geological Survey estimated that up to 4.3 billion barrels of oil could be recovered from the Bakken shale formation in North Dakota and Montana, using current technology.

That report was done independently of the state study, Murphy said.

“Their numbers also include Montana, ours only includes North Dakota,” he said.

The federal report found up to 2.6 billion barrels could be recovered in North Dakota, compared with the state’s estimate of 2.1 billion barrels, Murphy said.

“We were quite surprised the numbers were so close,” he said.

Helms said the federal study focused on the performance of wells currently working in the Bakken, while the state “went back and looked at the rock.”

He said the state study partially validates a study done by Leigh Price, a USGS geologist who died in 2000 before his study was published. Price estimated the Bakken held between 200 billion and 500 billion barrels of oil.

The most recent federal study does not estimate how much oil may be in the formation — only what the agency believes can be recovered using current technology.

The state study gives an estimate of what the Bakken may hold in North Dakota, in what is known as an “in-place oil resource.”

— James MacPherson

The Associated Press