Resource evaluation of selected tar-sand deposits in southern Oklahoma

The cooperative program between the Oklahoma Geological Survey and the U.S. Department of Energy has permitted evaluation of specific tar-sand deposits in Carter and Murray counties, Oklahoma. The Sulphur deposit was evaluated by a combination of industry and DOE-OGS boreholes. Bitumen content of the cores varied from 0 to 13 wt %, and "measured" in-place bitumen is approximately 34 million barrels. An additional 12.5 million barrels of bitumen is considered "probable" at the Sulphur deposit. This site has several open pits and was worked until 1958; cumulative production is estimated at 1.5 million tons. The bitumen occurs in an Ordovician sandstone, which is hydraulically mined, at other locations, for glass sand. The South Woodford deposit contains 8 million barrels of "measured" in-place bitumen as defined by a ninehole, 2.5-mi transect. The bitumen is concentrated in vertical 26-m (85-ft) thick sandstone of Mississippian age. There are several oil seeps in the area, and bitumen occurs at the surface and at depths as great as 80 m (270 ft). The bitumen content of the recovered cores varied from 9.5 to 14 wt %. The tar-sand deposit located at the edge of Overbrook oil field contains "probable" in-place bitumen of approximately 3 million barrels. This deposit was evaluated by a single core and field relations. Bitumen content of the Pennsylvanian age sandstone varied from 2.9 to 8.0 wt %. The Dougherty deposit was evaluated on the basis of field relations and bitumen yields from outcrop samples. The "probable" in-place bitumen is estimated to be 3.5 million barrels.