Yukon Flats Cretaceous-Tertiary Extensional Basin, East-Central Alaska; Burial and Thermal History Modeling

摘要

One-dimensional burial and thermal history modeling of the Yukon Flats basin, east-central Alaska, was conducted as part of an assessment of the regions undiscovered oil and gas resources. No deep exploratory wells have been drilled in the Yukon Flats region, and the subsurface geology of the basin is inferred from seismic reflection, gravity and magnetic surveys, and studies of shallow core holes in the basin and outcrops in the surrounding region. A thick sequence of Upper Cretaceous and Cenozoic nonmarine sedimentary rocks is believed to fill the basin; coal and organic-rich mudstone and shale within this sequence represent potential hydrocarbon source rocks. The burial and thermal history models presented here represent the sole source of information on the thermal maturity of these potential source rocks at depth. We present four alternative burial history scenarios for a hypothetical well through the deepest portion of Yukon Flats basin. They differ from each other in the thicknesses of Upper Cretaceous and Cenozoic strata, the timing of initial basin subsidence, and the timing of inferred unconformities. The burial modeling results suggest a present-day depth to the oil window of approximately 6,000 feet.