Development of 4D Seismic Monitoring Tool Considering Anisotropic Media based on Pseudo-acoustic Wave Equation

Abstract

Seismic anisotropy can be an obstacle when we interpret the seismic data from the seismic survey and monitoring in the sedimentary basins. In this study, we discuss the inaccuracy of the conventional isotropic monitoring algorithm in strong VTI media in causing reflectivity point differences because it offsets differences without considering anisotropic media. To mitigate its shortcomings, we propose a reverse-time migration algorithm for the 4D seismic data regarding vertically transverse isotropic (VTI) media and confirm that this proposed anisotropic monitoring algorithm based on elliptical anisotropy can properly correct the monitoring results. Finally, we improve the accuracy of reflectivity point depth by adapting the anisotropic equation in the pseudo-acoustic wave equation and controlling the offset distance. We compare the efficiency between elliptical anisotropy and VTI of the proposed monitoring algorithm using the synthetic monitoring data from a complex 3D geological model.