The United States Geological Survey (USGS) released an updated oil and gas resource assessment for the Bakken Formation and a new assessment for the Three Forks Formation in North Dakota, South Dakota and Montana. The assessments found that the formations contain an estimated mean of 7.4 billion barrels (BBO) of undiscovered, technically recoverable oil. The updated assessment for the Bakken and Three Forks represents a twofold increase over what has previously been thought.
The USGS assessment found that the Bakken Formation has an estimated mean oil resource of 3.65 BBO and the Three Forks Formation has an estimated mean resource of 3.73 BBO, for a total of 7.38 BBO, with a range of 4.42 (95 percent chance) to 11.43 BBO (5 percent chance). This assessment of both formations represents a significant increase over the estimated mean resource of 3.65 billion barrels of undiscovered oil in the Bakken Formation that was estimated in the 2008 assessment.