作　　者： (张敏）; (李振春）; (刘强）; (张凯）; (韩文功）; (徐文才）;

机构地区： 中国石油大学华东地球科学与技术学院,青岛266580

出　　处： 《地球物理学进展》 2017年第4期1721-1727,共7页

摘　　要： 射线追踪是一种高频近似前提下快速有效的波场近似计算方法,传统的基于弹性参数的各向异性介质运动学和动力学射线追踪方程,求解过程中需要处理Christoffel方程的特征值问题,因而计算效率比较低.为了解决这一问题,本文通过引入相速度和群速度,对运动学和动力学追踪方程进行修改和简化,有效地提高了各向异性介质射线追踪算法的计算效率.另外,我们将该算法应用到各向异性偏移中,实现了共炮域TI介质高斯束叠前深度偏移方法.VTI介质Hess模型和TTI介质洼陷模型的试算结果说明了该方法的正确性和有效性. The Ray tracing is an efficient technique of calculating the wave-field under the condition of high frequency approximation.The traditional kinematic and dynamic ray tracing equations in anisotropic media are formulated in terms of elastic parameters,which require solving the eigenvalue problem of Christoffel equation.Alkhalifah（1995） put forward a post-stack Gaussian beam migration method in anisotropic media based on the classical kinematic and dynamic ray tracing equations.However,it also brings approximately 40% additional computational cost in comparison with the isotropic Gaussian beam migration.Therefore,the classical anisotropic ray tracing method is actually not suitable for Gaussian beam migration due to its low efficiency. To overcome these issue,Zhu et al（2005）reformulated the ray tracing systems in terms of phase velocity.In this paper,we modified and simplified the kinematic and dynamic ray tracing equations on the basis of phase velocity and group velocity,which could enhance the computational efficiency of the anisotropic ray tracing algorithm.Furthermore,our proposed method has also been utilized in prestack Gaussian beam depth migration in common-shot domain for anisotropic TI media.Finally,the numerical experiments on Hess model in VTI media and the simple subsag model in TTI media have demonstrated the higher computational accuracy and efficiency of the proposed method compared to the traditional algorithm.

关 键 词： 各向异性射线追踪 运动学 动力学 相速度 群速度 高斯束