Joint PP-PS inversion without prior data registration

Standard joint AVO inversion of PP and PS seismic data rely on a registration process beforehand to align PP and PS data in a common time domain. This is a difficult step prone to error that may deteriorate the inversion results. We present a new method to jointly invert PP and PS data without prior registration by integrating the travel times as well as the amplitudes in a model-based inversion. Including the travel times brings extra constraints on the VP/VS ratio and therefore helps the inversion converge. This new method is demonstrated on a shale gas data example and shows better results than PP inversion and standard joint inversion.