My guess at what the USGS will report as the recoverable oil in the Bakken formation tomorrow.
Stackfrac horizontal drilling that is available today could recover up to 15% of the oil in parts of the formation. 75% of the formation is in the USA. 25% is in Canada. Not all parts of the formation would have 15% recovery, some might have 0-10%. Even though future technology could improve this number, that is not what will be projected. The high price of oil means that quick wells that produce for as little as 6-12 months could be profitably drilled.
I will say for the US portion 380 billion barrels of oil in place and 42 billion barrels of recoverable oil with todays technology. My guess is whole formation has 510 billion barrels of oil in place. 15 Billion barrels of recoverable oil in Canada.
The Cost of Energy summarizes some of the data and reports and agrees there is a lot of oil in place but wants the USGS and other sources to pin down whether recoverable oil is 3% or 50% and then will not say how fast it will be developed
USGS 1995 study and current decline rates