Reston, VA – North Dakota and Montana
have an estimated 3.0 to 4.3 billion barrels of undiscovered,
technically recoverable oil in an area known as the Bakken Formation.

A U.S. Geological Survey assessment, released April 10, shows a
25-fold increase in the amount of oil that can be recovered compared to
the agencys 1995 estimate of 151 million barrels of oil.

Technically recoverable oil resources are those producible using
currently available technology and industry practices. USGS is the only
provider of publicly available estimates of undiscovered technically
recoverable oil and gas resources.

New geologic models applied to the Bakken Formation, advances in
drilling and production technologies, and recent oil discoveries have
resulted in these substantially larger technically recoverable oil
volumes. About 105 million barrels of oil were produced from the Bakken
Formation by the end of 2007.

The USGS Bakken study was undertaken as part of a nationwide project
assessing domestic petroleum basins using standardized methodology and
protocol as required by the Energy Policy and Conservation Act of 2000.

The Bakken Formation estimate is larger than all other current USGS
oil assessments of the lower 48 states and is the largest "continuous"
oil accumulation ever assessed by the USGS. A "continuous" oil
accumulation means that the oil resource is dispersed throughout a
geologic formation rather than existing as discrete, localized
occurrences. The next largest "continuous" oil accumulation in the U.S.
is in the Austin Chalk of Texas and Louisiana, with an undiscovered
estimate of 1.0 billions of barrels of technically recoverable oil.

"It is clear that the Bakken formation contains a significant amount
of oil – the question is how much of that oil is recoverable using
todays technology?" said Senator Byron Dorgan, of North Dakota. "To
get an answer to this important question, I requested that the U.S.
Geological Survey complete this study, which will provide an up-to-date
estimate on the amount of technically recoverable oil resources in the
Bakken Shale formation."

The USGS estimate of 3.0 to 4.3 billion barrels of technically
recoverable oil has a mean value of 3.65 billion barrels. Scientists
conducted detailed studies in stratigraphy and structural geology and
the modeling of petroleum geochemistry. They also combined their
findings with historical exploration and production analyses to
determine the undiscovered, technically recoverable oil estimates.

USGS worked with the North Dakota Geological Survey, a number of
petroleum industry companies and independents, universities and other
experts to develop a geological understanding of the Bakken Formation.
These groups provided critical information and feedback on geological
and engineering concepts important to building the geologic and
production models used in the assessment.

Five continuous assessment units (AU) were identified and assessed
in the Bakken Formation of North Dakota and Montana – the Elm
Coulee-Billings Nose AU, the Central Basin-Poplar Dome AU, the
Nesson-Little Knife Structural AU, the Eastern Expulsion Threshold AU,
and the Northwest Expulsion Threshold AU.

At the time of the assessment, a limited number of wells have
produced oil from three of the assessments units in Central
Basin-Poplar Dome, Eastern Expulsion Threshold, and Northwest Expulsion
Threshold.
The Elm Coulee oil field in Montana, discovered in
2000, has produced about 65 million barrels of the 105 million barrels
of oil recovered from the Bakken Formation.

Results of the assessment can be found at http://energy.usgs.gov.

For a podcast interview with scientists about the Bakken Formation, listen to episode 38 of CoreCast at http://www.usgs.gov/corecast/.