Time-Lapse Seismic Difference-and-Joint Prestack AVA Inversion

Abstract

Time-lapse (4-D) seismic exploration is one of the essential means for accurately reconstructing the underground geological model, enhancing oil/gas recovery (EOR), and predicting remaining oil distribution. Under the assumption that the rock skeleton is almost unchanged in the process of development, inversion of time-lapse seismic difference data can be used to characterize the dynamic reservoir parameter. However, the inaccuracy of the forward operator, lack of constraints, and inappropriate regularization weight may lead to ill-posedness. Thus, the ill-posedness is still a key factor affecting the accuracy and stability of time-lapse seismic inversion. In this article, an improved difference-and-joint inversion strategy is proposed using the modified linear approximation as the forward operator. First, based on the modified approximation as the forward operator, time-lapse seismic difference inversion is exploited to obtain the variations of elastic parameter reflectance caused by the production-induced model perturbation. Then, we innovatively proposed to take the production-induced model perturbation as constraints, thereby achieving more accurate geological models for multiperiod seismic data joint inversion. Moreover, the L-curve method is exploited in this article to acquire the optimal regularization weight adaptively in each iteration step. Finally, the difference inversion results are used as constraints to precisely invert the geological model by combining multiperiod seismic data.