Non-repeatability effects on time-lapse 4D seismic full-waveform inversion

Full waveform inversion (FWI) can be applied to time-lapse (4D) seismic data for subsurface reservoir monitoring. However, non-repeatability (NR) can contaminate the data preventing reliable estimates of 4D changes. Using realistic reservoir models and NR measurements, we show the effects of sourcereceiver position errors and seawater changes on the 4D seismic data, and test 4D FWI against these effects. We find that ignoring these NR effects in the inversion can cause strong artifacts in velocity models, and thus should be addressed before or during inversion. By averaging forward and reverse bootstrap estimates, the central-difference 4D FWI method is more robust to these NR errors than the parallel and bootstrap 4D FWI methods.