P‐wave seismic anisotropy in a fractured carbonate reservoir: A case study from East Texas

Summary We present a case study where we calculated P-wave seismic anisotropy for a land, 3D seismic survey at a gas field in east Texas. We calculated the azimuthal AVO (AzAVO) and azimuthal velocity (AzNMO) anisotropy. We compared the results with interpreted faults, fractures from oriented core, image logs, present day stress, and a dipole sonic log. High- anisotropy anomalies align with faults on the flanks of the structure. Low seismic anisotropy characterizes the crest of the structure, and may be an artifact of an associated amplitude shadow. Locally, orientations predicted from seismic anisotropy agree with our subsurface fracture observations. Full quantitative fracture interpretation is restricted, however, by signal noise, local reduction in inversion quality by an amplitude artifact, and limited subsurface fracture correlation.