摘要
Full waveform inversion of time-lapse seismic data can be used as a means of estimating the reservoir changes due to the production.Since the repeated computa-tions for the monitor surveys lead to a large computational cost,time-lapse full wave-form inversion is still considered to be a challenging task.To address this problem,we present an efficient target-oriented inversion scheme for time-lapse seismic data using an integral equation formulation with Gaussian beam based Green’s function approach.The proposed time-lapse approach allows one to perform a local inversion within a small region of interest(e.g.a reservoir under production)for the monitor survey.We have verified that the T-matrix approach is indeed naturally target-oriented,which was mentioned by Jakobsen and Ursin[24]and allows one to reduce the compu-tational cost of time-lapse inversion by focusing the inversion on the target-area only.This method is based on a new version of the distorted Born iterative T-matrix inverse scattering method.The Gaussian beam and T-matrix are used in this approach to perform the wavefield computation for the time-lapse inversion in the baseline model from the survey surface to the target region.We have provided target-oriented inversion results of the synthetic time-lapse waveform data,which shows that the proposed scheme reduces the computational cost significantly.
