A dual formulation of wavefield reconstruction inversion for large-scale seismic inversion

Abstract

Many currently proposed seismic inversion techniques that focus on robustness with respect to the background model choice are not appropriate for large-scale 3D applications, and the methods that are computationally feasible for industrial problems, such as full-waveform inversion, are notoriously limited by convergence stagnation and require adequate starting models. We have developed a novel solution that is scalable and less sensitive to starting models or inaccurate parameters (such as anisotropy) that are typically kept fixed during inversion. It is based on a dual reformulation of the classic wavefield reconstruction inversion, whose empirical robustness with respect to these issues is well documented in the literature. Although the classic version is not suited to three dimensions because it leverages expensive frequency-domain solvers for the wave equation, our proposal allows the deployment of state-of-the-art time-domain finite-difference methods, and it is potentially sufficiently mature for industrial-scale problems.