Using one-way propagators to build a full wavefield inversion process

Abstract

Nowadays, there is a strong emphasis on explaining the full seismic wavefield for obtaining detailed subsurface information, which is indeed the way forward to improve the final resolution of images and – after that – reservoir properties. Within the full waveform inversion (FWI) community there is a strong bias towards one type of modelling, which is the finite-difference based solutions of the wave equation. However, one issue associated with FWI is that it does not yet provide a full strategy towards a broadband elastic reservoir inversion process. Traditionally, FWI is used for estimating the velocity model that is used as input for standard migration-inversion approaches, thereby losing the advantages of the full waveform approach, such as including the effect of multiples. As an alternative, the Joint Migration Inversion process, with an operator-based modelling engine, provides an open framework that can include many physical features (such as anisotropy, elastic angle-dependent reflectivity), without having to re-implement a certain wave equation. By using one-way propagators in combination with reflectivity operators, a full two-way response can be built. It provides consistent full wavefield outputs that can lead to accurate elastic parameters in the reservoir, while fully removing the overburden imprint.