First-order Quasi-P wave equation forward modeling and boundary conditions in VTI medium
Han Ling-he, He Bing-shou
Ministry of Education Key Lab of Submarine Geosciences and Prospecting Techniques,College of Marine Geosciences,Ocean University of China,Qingdao City,Shandong Province,266100,China
Abstract：Based on the first-order Quasi-P wave equation in VTI medium,the high-order finite difference scheme of the equation which was solved in the staggered grid was constructed in this paper,the stability condition of the equation was also given,the Perfectly Matched Layer(PML)absorbing boundary conditions which fit the equation were thoroughly studied in this paper,based on the studies above the forward modeling was realized for the first-order Quasi-P wave equation in VTI medium,high precision wavefield snapshot and synthetic record were obtained,the pre-stack reverse-time depth migration algorithm was used to conduct migration imaging for the complicated model,then good imaging results were achieved.The numerical experiments show that the Quasi-P wave equation forward modeling can overcome some of the defects of the conventional wave equation modeling,it also can facilitate the research on wave propagation mechanism in the anisotropic medium.The pre-stack reverse-time depth migration algorithm could accurately image the complex models;by comparing and analyzing the synthetic records and imaging results of the two migration algorithms for the isotropic and anisotropic Marmousi model,it can be indicated that the anisotropic parameters will have significant influence on the wave field characteristics(travel time and amplitude),which can not be ignored in the seismic data processing,inversion and interpretation.
