Constant gradient ray tracing algorithm and its application on VSP-CDP mapping
Cai Lu-lu1, Sun Zan-dong1,2,4, Bai Hai-jun1, Hao Hui-min3
1. Laboratory for Integration of Geology and Geophysics, China University of Petroleum(Beijing), Beijing, 102249, China;
2. State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum(Beijing), Beijing, 102249, China;
3. BGP Inc.,CNPC, Zhuozhou, Hebei, 072751, China
Abstract:Among different ray tracing methods,the constant gradient algorithm proposed by Langan R.T et al.(1985) is considered to be both accurate and highly efficient,where the model is discretized into rectangular cells characterized with a constant velocity gradient.For a certain grid,ray exit position,orientation and traveltime are computed based on the position and orientation of the ray at entry point.This method can not only trace rays through medium with arbitrary velocity distribution,but also ensure higher accuracy and efficiency.Reflected wave ray tracing using this algorithm is discussed in this paper,where the two-point problem is solved by combination of step-search method and linear interpolation.Then VSP-CDP mapping based on this method is implemented for both numerical modeled and field VSP data.
蔡露露, 孙赞东, 白海军, 郝会民. 常梯度射线追踪法及在VSP-CDP成像中的应用[J]. 石油地球物理勘探, 2011, 46(增刊1): 34-39.
Cai Lu-lu, Sun Zan-dong, Bai Hai-jun, Hao Hui-min. Constant gradient ray tracing algorithm and its application on VSP-CDP mapping. OGP, 2011, 46(增刊1): 34-39.