By Justin E. Birdwell, Tracey J. Mercier, Ronald C. Johnson, and Michael E. Brownfield,,,(Feb 7th 2013)
Abstract Using a geology-based assessment methodology, the U.S. Geological Survey estimated a total of 4.285 trillion barrels of oil in-place in the oil shale of the three principal basins of the Eocene Green River Formation. Using oil shale cutoffs of potentially viable (15 gallons per ton) and high grade (25 gallons per ton), it is estimated that between 353 billion and 1.146 trillion barrels of the in-place resource have a high potential for development
For additional information contact: Director, Central Energy Resources Science Center U.S. Geological Survey Box 25046, MS-939 Denver Federal Center Denver, CO 80225-0046 http://energy.usgs.gov/
Green River Shale formation has been under testing for a very long time. The petroleum cannot be produced by only drilling, even with horizontal drilling and hydraulic fracturing.
Previous attempts of this type formation involved mining, crushing the rock releasing Kerogen that was made into a syncrude suitable for an existing refinery.
Shell has been running a pilot program in the area for a long time. They have found by cooking the shale while still in the ground, what gets released is a light oil, esentially processed in place.
More info at:
http://www.shell.us/aboutshell/projects-locations/mahogany/technology.html
Just like the Canadian Oil sands don’t actually produce crude oil (it is bitumen) and it cannot be produced by drilling alone (they use steam assisted gravity drain, or mining), it really doesn’t matter. Like Bakken, Eagle Ford, etc it is more expensive to produce than traditional drilling. But after the products are produced and processed, my truck doesn’t tell the difference in the gasoline.