[thackney]

Bakken’s oil in place has not grown significantly. It has been the technically recoverable amount that has greatly grown.

[tatown]

Dow issued a paper back in 1974 that estimated total reserves to be 10 billion bbls. Since that time the estimates have continued to be revised up (almost exponentially). The estimates for recoverable oil have grown at a similar, if not greater, rate.

http://www.energyandcapital.com/resources/bakken-oil-field