Raytracing in TTI media using wavefront construction
Bai Hai-jun1,2, Sun Zan-dong1,4, Wang Xue-jun3
1. Lab for Integration of Geology and Geophysics, China University of Petroleum(Beijing), Beijing, 102249, China;
2. Research Institute of CNOOC Shenzhen Ltd.,Guangzhou, Guangdong, 510240, China;
3. Geophysical Research Institute,BGP Inc.Zhuozhou, Hebei, 072751, China
Abstract：The direction of ray(group velocity) and that of traveltime gradient(phase velocity) are not the same,making raytracing in TTI media rather difficult.The traditional raytracing system formulated in terms of elastic parameters in the anisotropiy is more complicated than that in the isotropic case.Furthermore,an eigenvalue problem for polarization vectors has to be solved at every ray step.As a result,raytracing in TTI media is always time consuming.Considering all the difficulties mentioned above,a kind of raytracing system formulated in terms of phase velocity and group velocity,which is similar to the expressions for isotropic media,is introduced in this paper and raytracing in TTI media is largely simplified consequently.After a comprehensive consideration for many traveltime calculation algorithms,the wavefront construction method is chosen to trace rays and propagate wavefront.By combination of simplified raytracing system and the merits of wavefront construction method,a simple and efficient method for raytracing in TTI media is realized and several numerical models are used to demonstrate its feasibility.
白海军, 孙赞东, 王学军. 基于波前构建法的TTI介质射线追踪[J]. 石油地球物理勘探, 2011, 46(增刊1): 1-6.
Bai Hai-jun, Sun Zan-dong, Wang Xue-jun. Raytracing in TTI media using wavefront construction. OGP, 2011, 46(增刊1): 1-6.
