Reservoir Quality Studies, Arctic National Wildlife Refuge, Alaska

MOWATT, THOMAS C., and A. BANET, U.S. Bureau of Land Management, Anchorage, AK

Reservoir quality studies are part of the reservoir management and resource assessment programs of the U.S. Bureau of Land Management in Alaska.

Petrographic analyses have been carried out of samples collected from surface exposures in the Arctic National Wildlife Refuge (ANWR), Alaska, to evaluate surface materials as to their potential reservoir rock qualities in the subsurface. This entails characterization of relevant petrologic-petrophysical properties, integration with regional geological-geophysical relationships, and synthesis in terms of likely diagenetic, structural, and stratigraphic conditions in the subsurface. There is a paucity of relevant data in this region. Inferences must be predicated largely on general principles and known relationships elsewhere.

A spectrum of lithologies were studied, representing a substantial portion of the regional stratigraphic column. In a number of cases, particularly among the pre-Brookian samples, the rocks appear to have low reservoir potential, based on their present high degree of diagenetic maturity. There is always the possibility--deemed somewhat unlikely here--of subsurface equivalents with more favorable characteristics, due to different original compositions, textures, and/or geologic histories. Brookian sandstones and conglomerates feature

samples with fair-good reservoir characteristics, with prospects of being equally good or better in the subsurface.

The samples studied suggest the likelihood of horizons with viable reservoir qualities in the subsurface within the ANWR region.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)