By Patrick Rucker and Valerie Volcovici
WASHINGTON, April 30 An oil-rich region of the
north-central United States holds more than twice the
recoverable crude supplies estimated just five years ago,
according to a government study that highlights the nation's
march toward energy self-sufficiency.
The Bakken Formation and Three Forks Formation, which spans
parts of Montana, North Dakota and South Dakota together hold an
estimated 7.4 billion barrels of undiscovered, technically
recoverable oil, the U.S. Geological Survey study said, although
energy experts said those estimates likely understate the
region's full potential.
That total is more than double the previous estimate, from
2008, and officials said it is a building block towards energy
"These world-class formations contain even more energy
resource potential than previously understood, which is
important information as we continue to reduce our nation's
dependence on foreign sources of oil," Interior Secretary Sally
Jewell said in prepared remarks.
Besides the crude reserves, the two formations hold a mean
estimate of 6.7 trillion cubic feet of as-yet undiscovered
natural gas and 530 million barrels of natural gas liquids that
are within reach. In both cases those represent a nearly
three-fold increase from the previous tally.
Officials said the overall jump in reserves was chiefly due
to production now thought to be accessible in the Three Forks
Formation, in the southern edge of North Dakota, which had not
been tallied in the last study.
"Three Forks is up and coming," said Brenda Pierce,
coordinator for the Energy Resources Program at the U.S.
Geological Survey (USGS).
Rapid development in the Three Forks region means that
recoverable reserves are higher than the USGS estimate, energy
"We agree with the range of numbers and think the high
estimate of 11 billion barrels is a reasonable target as
technology and exploration of the Three Forks continues," said
Lynn Helms, director of the North Dakota Department of Mineral
Resources, referring to the upper end of the USGS estimate.
Dr. Don Van Nieuwenhuise, head of the geosciences program at
University of Houston, said the USGS numbers are conservative as
they are based on looking at "sweet spots" within the formation.
"There are chances there are sweet spots they don't know
about. The prospects of finding additional sweet spots in an
area this size is relatively high," he said. "I'm pretty sure
every drop they say you're going to find, you'll find."
New drilling technologies like hydraulic fracturing, or
fracking, have turned the Bakken Formation and Three Forks into
one of the nation's most important sources of domestic crude.
4,000 WELLS IN THE BASIN
Since the 2008 USGS assessment more than 4,000 wells have
been drilled in the Williston Basin, the area that contains the
Seven companies now producing oil in the region provided
data to the USGS about the latest technologies and recovery
rates in the region, including Marathon Oil and Sinclair Oil
The USGS considers the Bakken and Three Forks to be the
largest continuous oil formation in the continental United
The expanded estimates came hours after Saudi Arabia's
energy minister gave a speech in Washington in which he said oil
supplies are "coming from everywhere." Saudi Arabia thus "has no
plans" to dramatically boost oil production capacity, said the
kingdom's Ali al-Naimi.
During a conference call with reporters, Jewell said that
the Interior Department's Bureau of Land Management would soon
present long-anticipated draft rules to govern fracking on
"Certainly in a matter of weeks, not months," Jewell said,
noting that Interior received over 100,000 comment letters when
an unfinished draft of the rules was presented.
"There has been sufficient change to warrant another public
comment period," said Jewell, just weeks into her job as the
nation's chief steward for public lands.
The oil and gas industry, which already has extensive
drilling on federal land, worries that new fracking rules could
curtail development. Environmentalists warn that existing
fracking rules are not stringent enough to curb pollution.