Major tar sand deposits of Utah, United States: Recent field investigations

The results of field investigations at three major Utah tar sand deposits are presented along with representative core sections. A resource evaluation of the PR Spring deposit in the southeastern Uinta Basin includes stratigraphic cross sections and isopleth maps of significant reservoir engineering properties for the bitumen-bearing units. Resource and site selection criteria are presented. Areas of greatest potential for in situ combustion processing are identified. Adverse and favorable geologic resource characteristics which affected in situ combustion processing and steamflooding at the Northwest Asphalt Ridge deposit, northeastern Uinta Basin, are described. This study led to a better understanding of the structural and lithologic influences on in situ thermal processing. Stratigraphic correlations and a fence diagram constructed from core data from the Tar Sand Triangle, deposit, southeastern Utah, are illustrated. The total resource estimate is calculated to be 6.3 billion barrels of oil in place, making the Tar Sand Triangle apparently the single largest tar sand deposit in the United States.