Wide-azimuth, long-offset seismic data allow azimuthal anisotropy and direction resulting from the presence of natural fractures and anisotropic in situ stress to be estimated. This can be done by measuring how seismic velocities and amplitudes vary as a function of the acquisition azimuth. Rock intrinsic properties like anisotropy, azimuth of fast and slow directions, fracture density, and total porosity, as well as the in-situ principal stress components, can be inferred and used to help with well design, placement, and completion strategies.

Recent advances in seismic azimuthal analysis of media having orthotropic symmetry (an orthotropic medium has three orthogonal planes...