Preliminary Map of Oil and Gas Occurrences in Central Alaska

By

R.G. Stanley and S.M. Troutman (U.S. Geological Survey)

In conjunction with a USGS assessment of undiscovered petroleum resources, we are using published and unpublished sources to prepare a map of reported occurrences of oil and gas in wells and natural seeps in central Alaska. The map area is bounded on the north by the Brooks Range, on the south by the Alaska Range, on the east by the Canadian border, and on the west by the Bering Sea coastline. No petroleum production has been obtained from this region, and only a dozen exploratory wells have been drilled. Nevertheless, indications of petroleum in this area include (1) oil shale and numerous occurrences of bitumen in Precambrian, Paleozoic, and Mesozoic rocks in the Kandik region; (2) oil shale and possible oil seeps in Paleozoic and Mesozoic rocks in the uplands near Yukon Flats; (3) gas in Miocene coal-bearing strata in a core hole at Fort Yukon; (4) shows of gas in Tertiary coal-bearing strata in two wells in the Nenana basin; (5) gas in Quaternary deposits in wells in the Kotzebue and Northway basins; and (6) reported gas seeps and a weak show of gas in a well in the Bethel basin. Little is known about the organic geochemistry of these oil and gas occurrences or the source rocks from which they originated. The scattered distribution of petroleum shows and seeps implies that active petroleum systems are present in certain parts of central Alaska, but much remains to be learned about the geology and petroleum resource potential of these systems.

AAPG Search and Discovery Article #90008©2002 AAPG Pacific Section/SPE Western Region Joint Conference of Geoscientists and Petroleum Engineers, Anchorage, Alaska, May 18–23, 2002.