Chester Paris¹

(1) Petrotechnical Resources of Alaska, Anchorage, AK

ABSTRACT: Basin Evolution and Petroleum Potential of the Nenana and Yukon Flats Basins, Alaska

Relatively little petroleum exploration has taken place in the Nenana and Yukon Flats basins, which lie between 40 and 100 miles of the Trans-Alaska Pipeline. Both are Tertiary in age and have a half, "steers head" morphology consisting of a relatively narrow deep rift and a superimposed broad thermal subsidence basin. Seismic stratigraphy indicates that the basin fill consists of a lacustrine/alluvial fan sequence, a fluvial sequence post-rift sequence; and a coal-bearing sequence that filled the thermal subsidence basin

Wells drilled on the margins of both basins encountered a coal-bearing sequence capable of generating gas and oil. Fluvial sandstone and conglomerates developed within all three sequences should have good reservoir characteristics. Seismic and gravity data indicate that the deepest part of the Nenana and Yukon Flats basins are over 12,000 feet and 20,000 feet deep respectively. Large inversion anticlines are located in the deepest part of the Yukon Flats basin and similar inversion features could exist in the deepest part of the Nenana basin. The potential for stratigraphic traps exist along the basin margins and intra-basinal, horst-block highs.

The large inversion structures in the Yukon Flats Basin could contain 50 to 500 million barrels of oil equivalent recoverable, and the total basin reserves could contain 350 million to over one billion barrels of oil equivalent recoverable. In the Nenana Basin, field sizes could range from 10 to 100 million barrels of oil equivalent recoverable with total basin reserves ranging from 250 million to 750 million barrels of oil equivalent recoverable.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado