Full Wavefield Inversion of Time-Lapse Data for Improved Imaging and Reservoir Characterization

Abstract

We apply full wavefield inversion (FWI) to determine from time-lapse data the changes in the subsurface due to production. It is well recognized that a significant velocity change between the baseline and monitor survey introduces a time shift in the seismic data. Current practices are to apply time-shift analysis or to perform time-shift inversion to interpret such changes. These changes can be large enough that the background velocity model needs to be updated between the base and the monitor survey. Ideally if the velocity models can be estimated for both the base and monitor surveys, then these large changes can be interpreted. The FWI framework is ideally suited to accomplish this task. The objective of this paper is to demonstrate this concept and its impact on imaging time-lapse data. A synthetic 2D example is used to demonstrate the solution to this problem.