PS-Wave Azimuthal Anisotropy in a North American Carbonate Basin

In an onshore example from a US carbonate basin, an embedded multicomponent test exhibits good PS-wave signal quality at the depth of interest, and all the expected characteristics of converted waves in azimuthally anisotropic media. In particular, there are clear azimuthal polarity reversals on the transverse receiver component, separated by null amplitudes defining the symmetry planes of the natural coordinate system; azimuthal velocity variations on the radial component then distinguish the specific symmetry plane aligned with maximum horizontal stress. The cumulative anisotropy is in good agreement with regional horizontal stress from borehole breakouts.