The Three Forks formation in North Dakota, South Dakota and Montana could hold more undiscovered, technically recoverable oil than the Bakken Shale that lies above it, according to the United States Geological Survey’s (USGS) latest assessment.
The mean of the estimate for the two formations’ combined undiscovered, technically recoverable oil is 7.38 billion barrels, effectively doubling the 2008 estimate for the Bakken shale alone. The mean estimate for Bakken oil, at 3.65 bn bbls – the same as in 2008 – is just shy of the Three Forks’ 3.73 bn bbl estimate.
At the time of the 2008 assessment, the Three Forks was considered unproductive, but subsequent drilling and production results showed that it warranted a closer look, said the Department of the Interior (DOI). The Three Forks and Bakken have produced a combined 450 million bbls of oil since the USGS’ 2008 Bakken assessment.
Folding the Three Forks into the Bakken assessment has also dramatically boosted mean estimates for undiscovered, technically recoverable gas and natural gas liquids. Where the 2008 assessment put mean estimates for the Bakken at 1,850 bn cubic feet (bcf) of gas and 148 million bbls of NGLs, the more recent assessment’s mean gas estimate is 6,726 bcf, and its mean NGL estimate is 527 mm bbls. “This estimate represents a nearly threefold increase in mean natural gas and a nearly threefold increase in mean natural gas liquids resources from the 2008 assessment, due primarily to the inclusion of the Three Forks Formation,” said the DOI.
Bakken production growth has been integral to the recent increase in US oil production, which climbed above 6.5 mm bbls/d in 2012 from just 5 mm bbls/d in 2008, and exceeded 7 mm bbls/d in January and February of this year, according to Energy Information Adminstration (EIA) data.
North Dakota Department of Mineral Resources data show that the state produced almost 738,000 bbls per day of oil in January of this year, and nearly 779,000 bbls/d in February. By comparison OPEC member Ecuador produced just shy of 505,000 bbls/d in 2012, according to the EIA.