| Alaska Arctic Slope Basin is partly located in land of Alaska and partly in seas. It is shown that the basin has experienced four stages of tectonic evolutions, which are the pre-middle Devonian Ellesmere orogeny, the late Devonian to Triassic passive margin, the Jurassic to early Cretaceous rifting and the middle-late Cretaceous to Quaternary foreland, respectively. A good source-reservoir-cap assemblage develops in offshore area. The Triassic Shublik source rock is the major source rock. The lower Cretaceous Kuparuk neritic and deltaic sandstone is the main target reservoir and the upper Cretaceous Torok deltaic sandstone is the secondary target reservoir. The lower Cretaceous mudstone with good seal condition is regarded as the regional cap rock. A large number of traps formed during the tectonic evolutions, predominantly including large-scaled low-rising anticlinal traps and structural/stratigraphic combined traps, and developing several plays. Based on comprehensive analysis, it is shown that there are excellent geological conditions for hydrocarbon accumulation and enormous undiscovered hydrocarbon resources in the offshore area. The compressional structural belt in the foreland, Chukchi coast and Barrow Arch should be the favorable area of exploration. |
