--> ABSTRACT: Structural Geology and Petroleum Potential of Long Valley, White Pine County, Nevada, by Alfred H. Pekarek; #91040 (2010)

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Structural Geology and Petroleum Potential of Long Valley, White Pine County, Nevada

Alfred H. Pekarek

Although at least three orogenic events affected the Long Valley area, the degree of tectonic disturbance appears to be significantly less than in other parts of Nevada, such as Railroad Valley. Consequently, in Long Valley, hydrocarbon traps should be larger than in areas with a greater degree of tectonic disturbance.

Long Valley is flanked by a synclinorium on the east and an anticlinorium on the west. This basic structural framework probably dates from the Jurassic and was enhanced by the Tertiary Basin and Range orogeny. In general, oil generated in the synclinorium to the east should have migrated into structural traps of the anticlinorium.

All five wells drilled in Long Valley had shows of live oil. Geochemical analyses show that source rocks of Cambrian through Mississippian age are capable of generating hydrocarbons and have been buried to sufficient depths for generation since Permian. Traps and migration paths have been rearranged by at least two tectonic events in the Mesozoic and Tertiary. Hydrocarbons generated after each tectonic event were available to fill the new traps.

Log data show good sandstone reservoirs in the Chainman Shale and very porous reservoirs in the carbonates of Pennsylvanian, Devonian, and Ordovician age. Flow rates commonly exceed 1,000 bbl per day from porous zones that may be more than 50 ft thick.

The Long Valley area has good source rocks in combination with thick, prolific reservoirs in relatively large traps strongly suggesting the possibility of large hydrocarbon accumulations. The only missing ingredient is a sufficient density of wells to permit a discovery.

AAPG Search and Discovery Article #91040©1987 AAPG Rocky Mountain Section Meeting, Boise, Idaho, September 13-16, 1987.