APPLICATION OF SEISMIC ATTRIBUTES TO THE STUDY OF POLY-PHASE DEFORMATION ON THE CENTRAL BASIN PLATFORM OF WEST TEXAS

The Pennsylvanian-Permian age Central Basin Platform of West Texas exhibits structures related to poly-phase convergence and strike-slip deformation. Structural deformation affects seismic reflectivity in several ways, as a result of offset of discrete reflectors, syntectonic deposition, pressure compartmentalization, and differential rotation of fault blocks. Resulting seismic waveform displacements and waveform changes are imaged by seismic coherence attribute, whereas changes in reflector vector dip can be imaged by direct measures of reflector dip, azimuth, curvature, and rotation. Vector dip attributes are particularly useful for delineating subtle features, including sub seismic faults and fracture systems.

We apply all of these multi-trace attributes to study the poly-phase fault systems of a southern part of the Central Basin Platform of West Texas. Coherence volumes clearly image strike-slip faults with an east-west trend, indicate the complex nature of a major fault zone, and allow calculation of offset along strike slip faults. Displays of vector dip, curvature, rotation, and amplitude gradient attributes show previously unrecognized continuations of faults as monoclines, illuminate Reidel shears, and provide evidence for a post-Wolfcamp compressional event.