Skip Links

USGS - science for a changing world

Fact Sheet 2015–3005

In-Place Oil Shale Resources of the Mahogany Zone, Green River Formation, Sorted by Grade, Overburden Thickness, and Stripping Ratio, Piceance Basin, Colorado, and Uinta Basin, Utah

By Justin E. Birdwell, Tracey J. Mercier, Ronald C. Johnson, and Michael E. Brownfield

Thumbnail of and link to report PDF (1.4 MB)Abstract

A range of geological parameters relevant to mining oil shale have been examined for the Mahogany zone of the Green River Formation in the Piceance Basin, Colorado, and Uinta Basin, Utah, using information available in the U.S. Geological Survey Oil Shale Assessment database. Basinwide discrete and cumulative distributions of resource in-place as a function of (1) oil shale grade, (2) Mahogany zone thickness, (3) overburden thickness, and (4) stripping ratio (overburden divided by zone thickness) were determined for both basins on a per-acre basis, and a resource map showing the areal distribution of these properties was generated. Estimates of how much of the Mahogany zone resource meets various combinations of these parameters were also determined. Of the 191.7 billion barrels of Mahogany zone oil in-place in the Piceance Basin, 32.3 percent (61.8 billion barrels) is associated with oil shale yielding at least 25 gallons of oil per ton (GPT) of rock processed, is covered by overburden 1,000 feet thick or less, and has a stripping ratio of less than 10. In the Uinta Basin, 14.0 percent (29.9 billion barrels) of the 214.5 billion barrels of Mahogany zone oil in-place meets the same overburden and stripping ratio criteria but only for the lower grade cutoff of 15 GPT.

First posted February 25, 2015

For additional information, contact:
Director, Central Energy Resources Science Center
U.S. Geological Survey
Box 25046, MS-939
Denver, CO 80225–0046

Part or all of this report is presented in Portable Document Format (PDF). For best results viewing and printing PDF documents, it is recommended that you download the documents to your computer and open them with Adobe Reader. PDF documents opened from your browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge. More information about viewing, downloading, and printing report files can be found here.

Suggested citation:

Birdwell, J.E., Mercier, T.J., Johnson, R.C., and Brownfield, M.E., 2015, In-place oil shale resources of the Mahogany zone, Green River Formation, sorted by grade, overburden thickness, and stripping ratio, Piceance Basin, Colorado, and Uinta Basin, Utah: U.S. Geological Survey Fact Sheet 2015–3005, 6 p.,

ISSN 2327–6932 (print)

ISSN 2327–6916 (online)

Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contact USGS
Page Last Modified: Tuesday, November 29, 2016, 06:34:28 PM