Department of Geophysical Imaging

Seismic anisotropy and S-wave splitting

Perforation shots locations in a vertical cross section aligned with borehole trajectory. True locations of all 16 perforations including 3 hydroperforations are marked with yellow diamonds. 13 perforation shots locations in Backus averaged model are marked with stage-coloured stars. Perforation shots locations in best obtained model are marked with stage-colored circles.

In order to obtain proper microseismic event locations an accurate velocity model is necessary. Due to internal structure of shales and fractures seismic velocities depend on the incidence angle, and hence anisotropy needs to be taken into account when inverting for the velocity model. Following figure shows how accurate can we calibrate the velocity model when accounting for anisotropy.