Estimating Anisotropic Parameters Using Joint Tomographic Inversion - a Case Study from Offshore West Africa

Anisotropic parameter estimation is very challenging for new exploration areas where there are no wells. In an offshore survey of over 3000 km2 in the west of Africa, we used surface seismic data in a non-linear tomographic inversion to simultaneously estimate migration velocity and anellipticity. Although a blank model of anisotropic parameters was used as input model, the joint tomography created an anellipticity model which followed the geological structures. It was one of the first projects where the non-linear tomography achieved to build an anisotropic model which was geologically consistent and minimized residual moveout.