Petrophysical Evaluation of the Tensleep Sandstone Formation Using Well Logs and Limited Core Data at Teapot Dome, Powder River Basin, Wyoming, USA

Abstract

This study presents a petrophysical analysis carried out to evaluate the rock properties of the Tensleep Sandstone Formation (TSF) at Teapot Dome, Powder River Basin, Wyoming. The TSF is dominated by porous and permeable eolian cross-bedded sandstones of dune and interdune origin, but also contains marine carbonate/dolomite beds. A-sandstone, B-dolomite, and B-sandstone units of TSF were identified by the stratigraphic well log correlations and further evaluated for hydrocarbon potentiality. Shale volume, lithofacies, porosity, and fluid saturation were identified from the well logs. Permeability was empirically driven from available core data from one well. The computed effective porosity range in TSF subunits is 4–8, 5–14, and 5–20% for A-sandstone, B-dolomite, and B-sandstone, respectively. Permeability was deduced to be 0.001–3.9, 0.01–14, and 0.1–234 mD, respectively. B-sandstone was identified as the most hydrocarbon-bearing potential zone in the TSF with its hydrocarbon saturation ranging up to 72%.