Source‐receiver reverse‐time imaging of vector‐acoustic seismic data

Abstract

Recent advances in seismic acquisition technology allow for the recording of vector-acoustic (VA) data: pressure fields and its multicomponent gradient in acoustic media. Here I present a wave-equation, reverse-time imaging method that takes full advantage of acoustic dual-field observations. The method’s formulation is based on source-receiver scattering reciprocity relations that are particularly useful in designing the presented method because they account for the proper use of VA fields both in the wavefield extrapolation and imaging condition steps in a self-consistent manner. I present a VA imaging formulation that is fully nonlinear in the subsurface parameters, but focus mostly on a linearized version which is an extension of conventional reverse-time migration (RTM). The new VARTM method is capable of naturally focussing all ghost arrivals and free-surface multiples without the need for any pre-processing for wavefield separation or multiple attenuation. Additionally, VARTM handles image amplitudes better than conventional RTM because it does not require far-field radiation assumptions, properly handling directivity information directly from the acquired VA data. This is demonstrated by the use of synthetic examples.