Comparison of hydrocarbon production trends in Middle and Upper members of Minnelusa formation
The main reservoir rocks in the upper and middle members of the Minnelusa Formation consist of wind blown dunal sands in the area surrounding the Lusk embayment. Changes in the local depositional setting, tectonic framework, and eustatic sea level controlled the distribution and reservior quality of these sandstones. The middle member exhibits two production trends. Age-equivalent Tensleep rocks deposited along the western margin of the embayment produce from sandstones accumulated in a sand sea paleoenvironment. Structure is atnececessary for trapping owing to permeability continuity. Along the eastern margin of the embayment, production comes from isolated accumulations of sandstone deposited as dunes on broad coastal sabkhas. Fields in these sandstones define a linear trend due to the coast-parallel alignment of these dunes. Production from the upper member defines four major trends. Upper member sandstones in the southern part of the basin, similar to Leo reservoirs, produce from sediments deposited as coast-parallel dunes in a northwest-southeast alignment. In the northern portion of the basin, production is from sandstones deposited in broad, flat eolian sand seas. Because of the permeability continuity of these sandstones, structural closure is necessary for trapping hydrocarbons. Upper member production has been influenced by the unconformity developed at the top of the Minnelusa. Movement along the Rosebud arch resulted in a southwest-northeast production trend apparent in each sandstone unit reflecting their northwestward erosional limits. The last, and most apparent, production trend, results from the Opeche Shale infilling of northwest-southeast-oriented stream valleys. Most production to date has been from sandstones following this alignment juxta-posed downdip of these impermeable shales.
- Research Organization:
- RPI, Boulder, CO
- OSTI ID:
- 5077342
- Report Number(s):
- CONF-8506201-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Vol. 69:5; ISSN AAPGB
- Country of Publication:
- United States
- Language:
- English
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Predictive depositional models for eolian deposits of Leo member of Minnelusa Formation, Powder River basin, eastern Wyoming
Stratigraphy and depositional environments of middle member of Minnelusa formation, central Powder River basin, Wyoming
Related Subjects
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
COMPARATIVE EVALUATIONS
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
GEOLOGIC FORMATIONS
GEOLOGIC TRAPS
NATURAL GAS
PERMEABILITY
PETROLEUM
PRODUCTION
RESERVOIR ROCK
ROCKS
SANDSTONES
SEDIMENTARY ROCKS