Petrologic-Petrophysical-Engineering Relationships, Selected Wells near the Arctic National Wildlife Refuge, Alaska

Abstract

In the context of the reservoir management and resource assessment programs of the U.S. Bureau of Land Management in Alaska, selected stratigraphic horizons were studied in a number of wells adjacent to the Arctic National Wildlife Refuge (ANWR), northeast Alaska. Petrographic analyses were integrated with petrophysical and engineering data, in order to provide a substantive knowledge base from which to infer reservoir potentials elsewhere in the region, using geological and geophysical methods. Of particular interest in the latter regard is the ANWR area. Horizons of concern with regard to reservoir characteristics include Franklinian through Brookian strata. Of particular interest are clastic Ellesmerian 'Break-up/Rift Sequence' sediments such as the Lower Cretaceous Thomson sand, and deeper-water marine clastics, as exemplified by the Brookian Colville Group 'turbidites.' Also of concern are pre-Ellesmerian 'basement' rocks, some of which are hosts to hydrocarbon accumulations in the Point Thomson field. Petrologic-mineralogic characteristics have been keyed to various wireline log responses and related to available engineering data, as feasible, for the wells considered. Synthesis of this information in terms of the regional geological framework, tied in with geophysical data, will facilitate more refined, effective resource assessment and management.