Interpreting seismic anisotropy and AVO for the characterization of natural fracture patterns in the Wind River Basin, Wyoming.

Summary A new generation of seismic techniques have revealed a much more detailed picture of the complex heterogeneity within these reservoirs, and the interpretation and application of this data requires a new conceptualization of both the geology and engineering of fractured reservoirs. The anisotropic nature of P and S wave velocities can be used to determine parameters such fracture intensity and fracture orientation. Initial interpretation of azimuthal AVO and velocity anisotropy data in structural reservoirs has proven difficult as it was previously not clear if trends occurring in the seismic data were caused by the natural fracture patterns or were an artifact of the processing. By examining a three-dimensional stress field created by a palinspastic reconstruction, we demonstrate the patterns of heterogeneity imaged on the seismic data are consistent with patterns of fracture heterogeneity that would be expected in these reservoirs, and that these patterns realistically portray the reservoir-process scale permeability patterns in the reservoir.