The Uinta Basin is unique among sedimentary basins for the variety of petroleum resources occurring within its geographic borders in Utah and Colorado. The form, quantity, and types of surface and subsurface occurrences make this sedimentary basin of prime interest to the oil industry of the Rocky Mountain province.
The surface deposits, such as the bituminous sandstones of the Sunnyside area along the Book Cliffs, contain saturated sandstones with a crude oil recovery of 94 per cent for an estimated reserve of 1.5 billion barrels. Along Asphalt Ridge at the unconformable contact of the Cretaceous and Tertiary are sandstones with a yield of 96 per cent for an estimated recovery of 20.5 million barrels per square mile and a total reserve of 1–3 billion barrels of recoverable crude oil.
Solid and semi-fluid hydrocarbons such as the vein and fracture deposits of gilsonite, albertite, wurtzilite, and ozocerite add to the potentiality of the basin. The kerogen shales of the Green River formation, particularly the "Mahogany Marker" unit, constitute one of the world's largest oil-shale deposits. This unit produces an average of 60–70 gallons of kerogen per short ton of shale and contains an estimated 400 billion barrels of reclaimable crude oil. New economic importance can be given the kerogen shales with the recent discovery of reclaiming them with a zinc catalyst. Great advancement can be expected in reclaiming the kerogen deposits of the Green River formation of the Uinta Basin.
The subsurface of the Uinta Basin also contributes to the petroleum reserve. Shows of oil and/or gas have been encountered in 95 per cent of the wells drilled within the basin. Daily production is approximately 75,000 barrels, the greater part of which is from Rangely. Rangely field has produced in 10 years approximately 140 million barrels of oil. Gas reserves for the Uinta basin are estimated at 1,001,095,800 Mcf., and oil reserves at 468,000,000 barrels.
The general geologic features of the Uinta Basin follow closely those of other Rocky Mountain areas having intermontane basins. The synclinal structure is moderately complex, with the axis trending east-west paralleling the anticlinal axis of the Uinta Mountains and is asymmetrical with the basin trough lying near the Uinta Mountain uplift. The structural form started in late Cretaceous and continued into late Tertiary time.
Paleozoic rocks, 4,300 feet thick, represent all systems from Cambrian to Permian with the exception of Silurian. Mesozoic rocks, 10,175 feet thick, of Triassic, Jurassic and Cretaceous age, are present, with basin-filling starting at the close of Cretaceous time. Lacustrine and non-lacustrine deposition continued through the Tertiary to late Miocene time. These continental beds, 11,000 feet thick, contain a vast store of permeable sandstones and hydrocarbons, which constitute large crude-oil reserves. The oil and gas reserves, together with various forms of hydrocarbons and surface accumulation of petroleum, require only further economic development to increase the resources of our nation.
Figures & Tables
The history of oil exploration in a large basin is very much like the history of research in most fields of investigation. In the history of research into the subject of oil occurrence, however, the rate of increase of knowledge has fluctuated greatly. Sourced from the 1955 AAPG Annual Meeting, this publication contains many of the papers presented at that meeting, which discuss the habitat of most of the oil found in the world prior to 1955.