Elastic reverse-time migration without wavefield decomposition

Abstract

Elastic reverse time migration is a linear inversion of the reflectivity of the subsurface elastic interface using primarily reflected waves and primarily converted waves given a smooth migration model with accurate elastic wave kinematics. Combining this with the noncurl characteristic of P-waves and nondivergence characteristics of S-waves, we propose an innovative elastic reverse-time migration approach without wavefield decomposition applied to heterogeneous isotropic media. In this paper, pure propagators of P- and S-wave independent of each other are derived. We obtain ideal imaging results when we apply the proposed method to elastic synthetic seismic data generated by pure P- or S-wave source, demonstrating the validity of our method. Because the innovative migration method does not include wavefield decomposition which requires a large number of complex calculations, it has a great significant computational cost advantage over the migration method based on vector decomposition. Meanwhile, when compared to the Helmholtz separation migration method, it can avoid the loss of important geological information due to phase shift and amplitude distortion. Note: This paper was accepted into the Technical Program but was not presented at IMAGE 2022 in Houston, Texas.