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Generation and migration of Bitumen and oil from the oil shale interval of the Eocene Green River formation, Uinta Basin, Utah

June 24, 2016

The results from the recent U.S. Geological Survey assessment of in-place oil shale resources of the Eocene Green River Formation, based primarily on the Fischer assay method, are applied herein to define areas where the oil shale interval is depleted of some of its petroleum-generating potential along the deep structural trough of the basin and to make: (1) a general estimates of the amount of this depletion, and (2) estimate the total volume of petroleum generated. Oil yields (gallons of oil per ton of rock, GPT) and in-place oil (barrels of oil per acre, BPA) decrease toward the structural trough of the basin, which represents an offshore lacustrine area that is believed to have originally contained greater petroleum-generating potential than is currently indicated by measured Fischer assay oil yields. Although this interval is considered to be largely immature for oil generation based on vitrinite reflectance measurements, the oil shale interval is a likely source for the gilsonite deposits and much of the tar sands in the basin. Early expulsion of petroleum may have occurred due to the very high organic carbon content and oil-prone nature of the Type I kerogen present in Green River oil shale. In order to examine the possible sources and migration pathways for the tar sands and gilsonite deposits, we have created paleogeographic reconstructions of several oil shale zones in the basin as part of this study.

Citation Information

Publication Year 2016
Title Generation and migration of Bitumen and oil from the oil shale interval of the Eocene Green River formation, Uinta Basin, Utah
Authors Ronald C. Johnson, Justin E. Birdwell, Tracey J. Mercier
Publication Type Book Chapter
Publication Subtype Book Chapter
Index ID 70179192
Record Source USGS Publications Warehouse
USGS Organization Central Energy Resources Science Center