An asymmetric Laramide foreland basin holding up to 32,000 ft of Paleozoic through Tertiary fill. Production comes from a self-sourced lacustrine petroleum system in the Eocene Green River Formation and from the fluvial Wasatch Formation below it. Horizontal development now targets stacked carbonate and sandstone benches in the lower Green River.
93%of Utah's crude oil comes from the Uinta Basin
65.1Mbarrels of crude oil produced in Utah in 2024
32,000 ftof sedimentary rock at the deepest point
11,500square miles of basin
Geologic summary
A self-sourced lacustrine petroleum system.
Tectonic setting and structure
The Uinta Basin formed during the Laramide orogeny (Late Cretaceous to Eocene) as the Uinta Mountain uplift was thrust south along the Uinta Basin boundary fault. The load flexed the crust into an east to west trending, strongly asymmetric syncline whose axis lies close to the northern margin.
North flank dips 10 to 15° south; south flank dips 4 to 6° north
Sediment fill of 30,000 to 32,000 ft at the trough; roughly 55% of it Tertiary
Basin area of about 11,500 mi²; north to northwest trending regional fractures
Depositional system
Paleocene to Eocene Lake Uinta occupied the basin floor. Alluvial and fluvial systems of the Wasatch (Colton) Formation fed the lake margins, while the Green River Formation records open lacustrine carbonate and organic-rich mud deposition that interfingers with marginal deltaic sandstones.
Green River Formation 2,000 to over 8,000 ft thick; top at 2,315 to 7,456 ft
Productive channel sandstones typically 10 to 30 ft; carbonate grainstones 10 to 20 ft
Most Green River wells produce from zones 3,000 to 4,000 ft below the formation top
Uteland Butte records the first major transgression of Lake Uinta, in climate-driven clay to carbonate cycles of 4 to 12 m
Source, maturity and pressure
Lacustrine mudstones of the Green River are the principal source rocks, so lower Green River reservoirs are largely self-sourced. The oil shale section higher in the formation is thermally immature except in the northern trough.
TOC of 2 to 5% in mudstones adjacent to the Uteland Butte; vitrinite reflectance (Ro) 0.7 to 1.1%
Normal to slightly overpressured on the southwest flank; overpressured toward the Altamont area
Gradients above 0.5 psi/ft from as shallow as 8,500 ft; high-volume production at 12,000 to 14,000 ft in the Flagstaff and Colton
Crude character
Uinta crude is paraffinic, with very low sulfur, acid and metals. Its high pour point means it cannot be diluted to flow like heavy crude; it moves in heated trucks and rail cars.
Black wax (Green River): about 32° API, pour point about 105 °F
Yellow wax (Altamont, Wasatch): about 42° API, pour point about 120 °F
The Uinta supplies about 93% of Utah crude; Utah produced 65.1 million bbl in 2024
Block diagram
South to north structural cross section.
Diagram 1. A block cut from the gentle south flank to the Uinta Mountain front, showing the asymmetric syncline, the boundary fault and the main producing trends. Select a unit for its lithology, thickness and reservoir data. Units in navy are TRP targets.
Illustrative. Not to scale. Vertical scale exaggerated.Depths from USGS and Utah Geological Survey
Stratigraphic column
Petroleum system chart.
Diagram 2. Tertiary and Upper Cretaceous section at the basin center, with lithology, thickness and depth data, and each unit's role as source, reservoir or seal. Brackets mark the mature oil window and the overpressured interval.
Unit heights are schematic, not to scale.Data from USGS, Utah Geological Survey, BIA and TRP Minerals
Productive reservoirs
Unit data, shallow to deep.
Unit
Age
Role
Description
Key data
Activity
Who is drilling, and where.
Altamont-Bluebell
Northern trough near the mountains. Deep, high-pressure oil from stacked Green River and Wasatch sands, mostly 12,000 to 14,000 ft. One of the basin's largest fields, with more than 300 million barrels produced.
Central basin horizontals
The new horizontal play in the lower Green River: Uteland Butte, Castle Peak and Douglas Creek. SM Energy reported three Douglas Creek laterals longer than 10,000 ft averaging 870 barrels of oil equivalent per day, 94% oil.
South and east
Monument Butte produces shallower Green River oil on the gentle south flank. To the east, Natural Buttes produces gas from Wasatch and Mesaverde sands.
