Geology and Engineering Characteristics of Selected Low-Permeability Gas Sandstones: A National Survey

Thirty-one low-permeability gas-bearing sandstones in 15 sedimentary basins were surveyed to delineate the major depositional systems and associated facies of each stratigraphic unit. The depositional system of each unit provides a basis of comparison between formations of different ages in different structural and sedimentary settings. Information as compiled on general attributes, economic factors, geologic parameters of the basin or trend, geologic and engineering parameters of the stratigraphic unit, and operating conditions at each formation or member. Results of this survey can be applied elsewhere to exploration of tight gas sandstone trends in other stratigraphic units with similar depositional systems. Tight gas sandstones reviewed here have blanket geometries and produce or could produce from strata having in situ permeabilities of 0.1 md or less, although gas may also be contained in more permeable horizons of the sandstones. Reservoirs vary from extensively developed gas plays (Clinton-Medina sandstone, Appalachian Basin) to active gas plays (Corcoran and Cozzette Sandstones, Piceance Creek Basin) to sparsely drilled units (Blair Formation, Eastern Greater Green River Basin).