Two-point Ray Tracing Algorithm for Isotropic/Anisotropic Media with Complicately Shaped High-contrast Interfaces

Two-point ray tracing algorithm in anisotropic media and in isotropic media with complicated interfaces is presented and discussed. The main peculiarity of this approach is the use of finite difference solutions of Eikonal equation. The traditional ways of two point ray tracing are shooting and bending . In comparison to these well-known approaches the proposed algorithm is more stable and computationally cheaper. This approach is extremely effective as two point ray tracing method for specific acquisition geometries widely used for 3D Offset and Walk-away VSP. Really, for this statements a moderate number of receivers (a few tens usually) are used, so one should apply nonlinear eikonal solver for a few ten times as well. Another important advantage is the fact that time of computations does not depend on the complexity of a model. We present numerical results for anisotropic Gullfaks model and well known Sigsbee2a. The experiments demonstrate the approach provides stable two point ray tracing algorithm for a medium with complex geology in a presence of anisotropy layers and salt intrusions. Numerical experiments prove that the method finds a ray for any source/receiver pair in a presence of anisotropy and salt intrusions.