| Description |
The largest single deposit of bituminous sandstones in the United States is found in the Uinta Basin. This deposit along with two other well known occurrences of bituminous sandstones in the northeastern portion of the basin have proved reserves exceeding 1% billion barrels of oil. The reserve calculations are based only on sands which contain in excess of 9 percent bitumen by weight. The three principal deposits are favorably situated for strip mining and retorting operations or for "in situ" thermal recovery techniques. Numerous smaller deposits, some of questionable commercial value, also occur in the basin and will be discussed in this paper. The largest and perhaps best known deposit is located in the Sunnyside area on the south flank of the Uinta Basin a few miles north of the coal mining community of Sunnyside, Utah (1 on fig. 1). The U. S. Geological Survey has estimated reserves of oil in this deposit to be in excess of 728 million bbl. of 10-12° A.P.I. gravity oil. The second largest deposit is the bituminous sandstone beds of the Asphalt Ridge area four miles west of Vernal, Utah (2 on fig. 1); its proved reserves are 250 million bbl. oi oil. The third deposit which has commercial significance is the asphaltic sandstones of the Whiterocks area (3 on fig. 1); its proved reserves exceed 125 million bbl. Other deposits, whose reserves are unknown but which may have commercial possibilities, are the deposits at the P. R. Springs along the Roan Cliffs, Robert E. "Bud" Covington is a partner in the firm of Caldwell & Covington headquartered in Vernal, Utah. He received his academic training at the University of Colorado, graduating with a B.A. in geology in 1947. The following year he continued his study of geology at the Colorado School of Mines, but left after one year to join Carter Oil Company as a geologist. He joined the firm of Johnson & Bunn in 1950 and remained here until the formation of the partnership of Caldwell & Covington in 1954. The writer has published several earlier papers dealing primarily with the Uinta Basin and its economic resources as well as another paper in this guidebook. These papers have appeared in symposiums and guidebooks of the Intermountain Association of Petroleum Geologists and the Rocky Mountain Association of Geologists, as well as the recently published Bulletin 54 of the Utah Geological and Mineralogical Survey. The author is affiliated with the American Association of Petroleum Geologists, American Association for the Advancement of Science (fellow), Intermountain Association of Petroleum Geologists, Utah Geological Society, and Sigma Gamma Epsilon. at Chapita Wells, and at Dragon-Asphalt Wash. Other deposits that probably are not commercial for the foreseeable future are in the Deep Creek area, the John Starr Flat area, an area south of Whiterocks, an area northeast of Tabiona, the Lake Fork-Yellowstone area, on Leland and Pariette Benches south of Myton, in the Argyle Creek area, and on Raven Ridge. Exploitation of these deposits, probably beginning with the largest, will be dependent on the costs of mining and of extracting the bitumen from the recks. This paper evaluates some of the economic factors to be considered in developing the deposits and describes in some detail the Shell Oil Company's plan for developing asphalt sand properties in Alberta, Canada. The Uinta Basin lies in northeastern Utah and northwestern Colorado and is bounded on the north by the east-west trending Uinta Mountains, on the west by the north-south trending Wasatch Mountains, on the south by the Roan and Book Cliffs, the topographic expression of the San Rafael Swell and the Uncompahgre uplift, and on the east by the Douglas Creek arch. The basin is both a topographic and structural basin, resembling an elongated sauce dish. The more steeply dipping north flank of the basin has sedimentary beds with dips ranging from 6 to 60 degrees, while the more gentle south flank has dips which average 4 to 6 degrees. The east-west axis extends from the Utah-Colorado line to the Strawberry Reservoir area, a distance of approximately 160 mi. The north-south dimension of the basin ranges from 40 to more than 120 mi. The climate of the area is semiarid, except at higher elevations along the mountain front. The topography is extremely varied, ranging from 4,400 ft. along the Green River south of Ouray in the central part of the basin to more than 10,000 ft. en the south flank of the basin near Sunnyside. The area is drained by the Green River, which flows from northeast to southwest across the eastern one-third of the basin. The White River, a tributary to the Green, flows from east to west and joins the Green at Ouray just below the confluence of the Green with the Duchesne River, a river which drains the area north and west of Ouray. U. S. Highway 40 crosses the north part of the basin in an east-west direction; it is a major transcontinental highway that connects the Uinta Basin with Salt Lake City, Utah, and Denver, Colorado. The bituminous sandstones near Sunnyside are only about seven miles from a spur of the Denver and Rio Grande Western Railroad Company, but the nearest convenient railheads to the Asphalt Ridge and Whiterocks bituminous sandstone properties are located at Craig, Colorado, 120 mi. to the east on U. S. 40 and at Heber City, Utah 120 mi. to the west. Rocks in the basin range in age from Precambrian to Quaternary. Most of the bituminous sandstones are in the Wasatch, Green River, Uinta, and Duchesne River Formations of Eocene to Oligocene age, but the principal deposits at Asphalt Ridge occur in Cretaceous rock with minor, noncommercial tar sands in the Eocene rocks, and the deposits at Whiterocks are in the Navajo Sandstone of Triassic (?) -Jurassic age. For the purpose of this paper the term "material" refers to any asphaltic or bituminous sandstone which is of commercial significance and the term "overburden" refers to noncommercial tar sands or to barren rock. Also, the terms "asphaltic sandstone," "oil sand," "bituminous sandstone" are used interchangeably. For commercial and legal purposes the definition of any deposit of bituminous sandstone should include its location by township, range, and section and its stratigraphic position, such as "lying above the top of the Mancos Shale and below the lowest Cretaceous shales and lignites which lie en top of the Rim Rock Sandstone Member of the Mesaverde." |
