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

TL;DR

This paper introduces a scalable dual formulation of wavefield reconstruction inversion that enhances robustness and computational efficiency for large-scale 3D seismic inversion, leveraging time-domain methods over frequency-domain solvers.

Contribution

It presents a novel dual (Lagrangian) reformulation of wavefield reconstruction inversion suitable for large-scale 3D seismic problems, improving robustness and computational feasibility.

Findings

Robustness to local minima is improved compared to classical methods.

The reformulation enables use of time-domain finite-difference methods.

The approach is suitable for industrial-scale seismic inversion.

Abstract

Most of the seismic inversion techniques currently proposed focus on robustness with respect to the background model choice or inaccurate physical modeling assumptions, but are not apt to large-scale 3D applications. On the other hand, methods that are computationally feasible for industrial problems, such as full waveform inversion, are notoriously bogged down by local minima and require adequate starting models. We propose a novel solution that is both scalable and less sensitive to starting model or inaccurate physics when compared to full waveform inversion. The method is based on a dual (Lagrangian) reformulation of the classical wavefield reconstruction inversion, whose robustness with respect to local minima is well documented in the literature. However, it is not suited to 3D, as it leverages expensive frequency-domain solvers for the wave equation. The proposed reformulation allows the deployment of state-of-the-art time-domain finite-difference methods, and is computationally mature for industrial scale problems.