Phosphoria reservoir facies exposed in the northeast Bighorn basin - an exhumed Cottonwood Creek oil field
Detailed stratigraphic correlations between well-exposed outcrops and nearby oil wells permit the delineation of porous carbonate reservoir facies within the Phosphoria Formation (Guadalupian) in the northeastern part of the Bighorn basin. The most significant petroleum reservoirs in this area occur in two depositional facies defined by faunas and vertical sequences of sedimentary and biogenic structures. Effective porosity development in the peritidal facies occurs in intraclast-pellet, dolomite packstone/grainstone, and irregularly laminated, fenestral algal-boundstone. In the restricted-marine facies, reservoir development occurred in bioturbated, dolomite mudstone-wackestone, and phylloid-algal and mollusk dolomite wackestone-packstone. Based on regional analysis, fenestral algal-boundstone pods are thought to have evolved as peninsula-island complexes paralleling reactivated northwest-southeast-trending faults on the east side of the Bighorn basin. In the northeastern Bighorn basin, peninsula-island complexes accumulated on the Bighorn and Sheep Mountain paleohighs. They defined an embayment in which restricted marine rocks were deposited. Porous peritidal rocks appear to have been concentrated along the seaward flanks of the thickest algal-boundstone pods, which grade laterally into porous restricted-marine lithologies. The geologic setting of exposed peritidal and restricted-marine reservoirs in the northeastern Bighorn basin appears to be similar to that of Cottonwood Creek field. An understanding of facies relationships may be useful in the further development of Cottonwood Creek field and for exploration for similar types of carbonate stratigraphic traps along the eastern margin of the Bighorn basin.
- Research Organization:
- RPI Colorado, Inc., Boulder
- OSTI ID:
- 7053815
- Report Number(s):
- CONF-8609129-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Vol. 70:8; ISSN AAPGB
- Country of Publication:
- United States
- Language:
- English
Similar Records
Paleotectonic controls on reservoir distribution in Phosphoria formation and related strata, Bighorn basin, Wyoming
Evaluation of Cottonwood Creek field complex, Bighorn basin, Wyoming
Related Subjects
020200* -- Petroleum-- Reserves
Geology
& Exploration
CARBONATE ROCKS
DEPOSITION
EXPLORATION
FEDERAL REGION VIII
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC STRUCTURES
GEOLOGY
MINERAL RESOURCES
NORTH AMERICA
OIL FIELDS
PETROLEUM DEPOSITS
RESERVOIR ROCK
RESOURCES
ROCKS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
STRATIGRAPHY
USA
WYOMING