Reservoir Quality and Potential, National Petroleum Reserve in Alaska

MOWATT, THOMAS C., A. SEIDLITZ, C. GIBSON, R. BASCLE, and J. DYGAS, U.S. Bureau of Land Management, Anchorage, AK

As part of the reservoir management, resource assessment, and planning programs of the U.S. Bureau of Land Management in Alaska, the oil and gas resource potential of the National Petroleum Reserve in Alaska (NPRA) is undergoing review in light of new technical information, as well as changing national and international socioeconomic conditions. Emphasis is on integration of geological, petrophysical, geophysical, and engineering information to provide a refined, more technically substantive knowledge base for resource assessment and management.

Brookian clastic rocks--in particular the Nanushuk Group and underlying Torok/Topagoruk intervals--have been the principal horizons of concern. Petrologic-mineralogic characteristics have been reinvestigated, related to petrophysical parameters and wireline log responses, and integrated with available engineering data, for key wells within and peripheral to the NPRA. Particular attention has been directed to diagenetic relationships, effects on reservoir quality, and implications for untested portions of this sizable basin. Similar efforts have been directed to pre-Brookian strata as well.

Only some 127 exploratory wells (all but one under government aegis) have been drilled within or adjacent to NPRA (a geographic area on the order of 37,000 sq mi--about the size of the state of Indiana), many only to shallow depths.

In almost every well drilled to any appreciable depth in the area, there have been manifestations of the presence of hydrocarbons. The results to date are actually rather promising from a qualitative geologic-geochemical perspective, in terms of potential for significant resources to be present.

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