Paleogeothermal gradients and timing of oil generation in the Belden Formation, Eagle Basin, northwestern Colorado

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Mountain Geologist; (USA)

OSTI ID:6992225

Nuccio, V F; Johnson, S Y; Schenk, C J ^[1]

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1. Geological Survey, Denver, CO (USA)

Paleogeothermal gradients and timing of oil generation for the Lower and Middle Pennsylvanian Belden Formation have been estimated for four locations in the Eagle Basin of northwestern Colorado, by comparing measured vitrinite reflectance with maturity modeling. Two thermal models were made for each location: one assumes a constant paleogeothermal gradient through time while the other is a two-stage model with changing paleogeothermal gradients. The two-stage paleogeothermal gradient scenario is considered more geologically realistic and is used to estimate the timing of oil generation throughout the Eagle basin. Thermal-history modeling illustrates that the Belden Formation entered and exited the oil window at different time in different parts of the Eagle basin. In the Gilman area, paleogeothermal gradients place the oil window for the Belden Formation between 284 and 263 Ma. At the Sweetwater locality, gradients located the oil window between 283-80 Ma, a much longer time interval than at Gilman. At Glenwood Springs, gradients the oil window for the Belden Formation between 250 and 75 Ma. For the Buford area, gradients place the oil window between 140 and 73 Ma. The inferred variability in the late Paleozoic geothermal gradients probably resulted from different heat flow and rock conductivity, and the effects of intrabasinal block faulting. From these data and interpretations, one would expect Belden oil to be found in either upper Paleozoic or Mesozoic reservoir rocks.

• OSTI ID: 6992225
• Journal Information: Mountain Geologist; (USA), Journal Name: Mountain Geologist; (USA) Vol. 26:1; ISSN MOGEA; ISSN 0027-254X
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
AGE ESTIMATION
COLORADO
COMPARATIVE EVALUATIONS
ENERGY SOURCES
EXPLORATION
FEDERAL REGION VIII
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GEOTHERMAL GRADIENTS
HEAT FLOW
MACERALS
MATURATION
MESOZOIC ERA
MINERAL RESOURCES
NORTH AMERICA
OPTICAL PROPERTIES
PALEOTEMPERATURE
PALEOZOIC ERA
PENNSYLVANIAN PERIOD
PETROLEUM
PETROLEUM DEPOSITS
PHYSICAL PROPERTIES
RECOMMENDATIONS
REFLECTIVITY
RESERVOIR ROCK
RESOURCES
SURFACE PROPERTIES
TEMPERATURE GRADIENTS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
USA
VARIATIONS
VITRINITE