Bakken Reassessment Provides Reasurrance

Red line defines the Williston Basin boundary; the blue line defines the Bakken TPS; the peach area is the Three Forks Conventional AU; and purple shows Three Forks continous oil AU. Graphic courtesy of U.S. Geological Survey
Red line defines the Williston Basin boundary; the blue line defines the Bakken TPS; the peach area is the Three Forks Conventional AU; and purple shows Three Forks continous oil AU. Graphic courtesy of U.S. Geological Survey

The much-anticipated updated numbers that all thought would reveal even more about an already prolific area are in – and the numbers are giving operators yet another reason to smile.

The bottom line: When you combine the mean oil resource of the Bakken Formation in North Dakota and Montana with the underlying Three Forks, you get a total estimated mean of 7.4 Bbo of undiscovered technically recoverable oil.

This is the number just released by the U.S. Geological Survey resulting from its new reassessment of the Bakken shale play in the Williston Basin in North Dakota and Montana (April EXPLORER) .

This area has produced about 450 million barrels of oil since 2008.

The initial USGS assessment of the Bakken in 2008 estimated a mean of 3.65 Bbo for unconventional oil resources (June 2008 EXPLORER). While that number remains steadfast, the reassessment allocates an estimated mean resource of 3.73 Bbo to the Three Forks, bringing the total to 7.3 Bbo, with a range of 4.42 (95 percent chance) to 11.43 Bbo (5 percent chance).

The Three Forks resource was not included in the 2008 program, as the play did not demonstrate significant momentum until early in 2012. Until then, the operators’ principle focus had been on the overlying Bakken.

The Bakken has sometimes been tagged the “Saudi Arabia of the United States.” The reassessment release essentially coincided with an international oil dignitary’s statement reported in the mainstream media that the United States is naïve to contemplate the possibility of energy independence.

What the future might hold is a whole other story.

Oil AND Gas

Commenting that such a quick reassessment is rare, the USGS emphasized the Bakken is an unusual reservoir. The agency noted that what is technically recoverable has changed during a short period of time.

More than 4,000 wells have been drilled in the Williston Basin since the 2008 assessment. These have provided a trove of additional data, including an enhanced understanding of the Three Forks and its resource potential.

Oil is not the only game in play here.

The Bakken and Three Forks reportedly are estimated by the USGS to contain a mean of 6.7 Tcf of undiscovered, technically recoverable natural gas and 0.53 billion barrels of undiscovered, technically recoverable natural gas liquids.

Gas estimates range from 3.43 (95 percent chance) to 11.25 (5 percent chance) Tcf and 0.23 (95 percent chance) to 0.95 (5 percent chance) billion barrels of natural gas liquids.

The agency reported this estimate is a nearly threefold increase in mean natural gas from the 2008 assessment and an almost threefold increase in mean natural gas liquids resources. These increases are attributed for the most part to the inclusion of the Three Forks formation.

The USGS effort is receiving kudos from some of the experts – including AAPG past president and Honorary member Steve Sonnenberg, professor and Boettcher Chair in petroleum geology in the Department of Geology and Geological Engineering at Colorado School of Mines, Denver – and head of the school’s Bakken Research Consortium.

“I think the new assessment by the USGS is very good,” Sonnenberg said, “and agrees with successes seen by the operators.”

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Emphasis: Offshore Developments