Adjoint-state Reverse-time Migration for 4C Seismic Data - Application to Marine Seismic Imaging

Advances in marine seismic acquisition allow for the recording of four-component (4C) data from dual-source configurations, i.e., using monopole and dipole sources. Here, we describe a novel method for multicomponent reverse-time migration that is based on an adjoint-state formulation using the full vector-acoustic wave equations for pressure and displacement fields. This method takes advantage of the directional dynamic information contained in 4C acoustic fields by using source and receiver weights operators incorporated into the adjoint-state scheme. With this method, we show that the source and receiver radiation properties of the vector-acoustic(VA) depth image can be custom-designed by choosing specific weighting operators. In the examples presented, weights are chosen so that both the source- and receiver-side ghosts are jointly migrated with primary energy. Because the dipole field components (e.g., particle acceleration) are proportional to the spatial gradient components of pressure, our method is a formulation of reverse-time map migration because it images pressure fields while jointly using directional information from its recorded 3C gradient. Thus, our reverse-time 4C map migration yields less aperture- and sampling-related artifacts than migration of pressure-only or 2C seismic data. Finally, our method sets a framework for full-waveform inversion using dual-source 4C seismic data.