Azimuthal-dependent VTI Anisotropy Estimated from P-wave Arrival Times

This study searches for the evidence of fine layering anisotropy using two pairs of borehole seismic data sets collected from three boreholes. Finely layered sedimentary media may have different velocity values in the vertical and horizontal directions, and particularly the horizontal component is greater than the vertical one for vertical transverse isotropy (VTI) media. This VTI-type anisotropic property in the vertical space is also azimuthal dependent in the horizontal plane, affected by the orientation of fractures within the crust. This azimuthal anisotropy may reflect the fracture orientation due to large-scale tectonic movements, and is very important in the production of oil reservoirs, as the seismically fast directions can indicate preferred directions of fluid flow.