Multiparameter least-squares reverse time migration for acoustic—elastic coupling media based on ocean bottom cable data

Abstract

In marine seismic exploration, ocean bottom cable technology can record multicomponent seismic data for multiparameter inversion and imaging. This study proposes an elastic multiparameter lease-squares reverse time migration based on the ocean bottom cable technology. Herein, the wavefield continuation operators are mixed equations: the acoustic wave equations are used to calculate seismic wave propagation in the seawater medium, whereas in the solid media below the seabed, the wavefields are obtained by P- and S-wave separated vector elastic wave equations. At the seabed interface, acoustic-elastic coupling control equations are used to combine the two types of equations. P- and S-wave separated elastic migration operators, demigration operators, and gradient equations are derived to realize the elastic least-squares reverse time migration based on the P- and S-wave mode separation. The model tests verify that the proposed method can obtain high-quality images in both the P- and S-velocity components. In comparison with the traditional elastic least-squares reverse time migration method, the proposed method can readily suppress imaging crosstalk noise from multiparameter coupling.