Use of seismic stratigraphy for Minnelusa exploration, northeastern Wyoming

Conference · Mon Aug 01 04:00:00 EDT 1983 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6433198

Daw, T B

The Powder River basin in northeastern Wyoming has long been a productive oil province. Abrupt lithology changes of the Upper Pennsylvanian-Permian Minnelusa Formation have provided a variety of hydrocarbon traps. However, these same abrupt changes have also yielded many surprises to the hopeful explorationist. Sonic logs used to construct a geologic cross section showed a significant difference in the sonic response of porous upper Minnelusa sand versus no sand. Synthetic seismograms were then produced from these wells and, when organized in cross-section form, they again showed an obvious difference in reponse from sand to no sand conditions. A pilot seismic line tying these wells was acquired. From this data, a good correlation between synthetic and actual seismic data was achieved. The updip termination of the productive Minnelusa sand was clearly identifiable on the seismic data. Two major problems were soon discovered: 1) the seismic response from a thick, relatively low velocity Opeche shale is very difficult to distinguish from an upper Minnelusa sand; and 2) thin, porous Minnelusa sands are difficult to identify seismically, thus updip trap limits are not easily defined. A variety of seismic trace attributes were examined in hopes that subtle amplitude and frequency differences would help distinguish thick Opeche shale from Minnelusa sand. This aproach produced very limited success. Better results were achieved on the second problem, that of thin bed resolution. Accentuating the upper portion of the seismic frequency spectrum (40 to 80 Hz) did allow better mapping of thin Minnelusa sands.

• Research Organization: ARCO Exploration, Denver, CO
• OSTI ID: 6433198
• Report Number(s): CONF-8309274-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 67:8
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
EXPLORATION
FEDERAL REGION VIII
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGIC TRAPS
GEOLOGY
GEOPHYSICAL SURVEYS
MINERAL RESOURCES
NORTH AMERICA
PETROLEUM DEPOSITS
RESOURCES
SEDIMENTARY BASINS
SEISMIC SURVEYS
STRATIGRAPHY
SURVEYS
USA
WYOMING