Facies Architecture of Submarine Channel-Levee and Lobe Sandstones: Permian Bell Canyon Formation, Delaware Mountains, West Texas

The Bureau of Economic Geology at The University of Texas at Austin recently conducted an outcrop characterization study of Bell Canyon exposures as part of a reservoir characterization project funded by the U.S. Department of Energy (DOE). The project focused on slope and basin elastic reservoirs of the Delaware Mountain Group of West Texas and Southeast New Mexico reservoirs because of the significant resources they contain and the complex internal architecture and distribution of petrophysical properties they display. The outcrops were examined to provide unambiguous and high-resolution information on sandstone body and seal architecture. In addition to the outcrop study, the project involved field studies of two Delaware Mountain Group reservoirs (Geraldine Ford and Ford West), a 3-D seismic survey, a petrophysical study of the Ramsey Sandstone within the Geraldine Ford field, and a reservoir simulation within a portion of the Geraldine Ford field.

On this trip, we will visit exposures of the Bell Canyon Formation that were deposited in the deepwater Delaware Basin during the late Permian. The origin of these sandstones has been a source of controversy, with depositional interpretations ranging from contourites, turbidity current deposits, and saline density currents deposits. Our outcrop study focuses on a stratigraphic unit in the Bell Canyon Formation that is analogous to the highly productive Ramsey Sandstone. This unit shows complex stacking patterns and facies changes that are related to the progradation and retrogradation of a system of channel levees and attached lobes. The guidebook provides most of the geological background necessary for this trip as well as data (maps, photographs, logs, and cross-sections) and discussions relevant to each field trip stop. Issues to be addressed will include the recognition and correlation of key surfaces, the distribution of facies, and processes responsible for how the sandstones were deposited.