Ray equation acquisition method, Gaussian beam calculation method and pre-stack depth migration method

Abstract

The invention provides an anisotropic medium ray tracing equation acquisition method, a Gaussian beam calculation method and a pre-stack depth migration method. The acquisition method includes the steps of: deriving the first ray equations of kinematics in the anisotropic medium according to Christopher's equation; introducing the phase velocity and group velocity into the first ray equations of kinematics to obtain the second ray equations of kinematics and the The first ray equations of dynamics characterized by phase velocity; the first ray equations of dynamics are described by the wavefront orthogonal coordinate system, and the second ray equations of dynamics are obtained. The Gaussian beam calculation method includes using the kinematic second ray equation set and the dynamic second ray equation set to perform Gaussian beam synthesis. The prestack depth migration method includes the step of calculating the Gaussian beam in the anisotropic medium by using the above-mentioned Gaussian beam calculation method. The invention can significantly simplify the ray tracing process, remarkably improve the calculation efficiency of the anisotropic medium ray tracing, and facilitate the realization of codes.

Description

technical field [0001] The present invention relates to anisotropic medium seismic wave theory, more specifically, relates to a method for obtaining anisotropic medium ray tracing equation, a calculation method for anisotropic medium Gaussian beam and a pre-stack depth migration method. Background technique [0002] As an effective improvement of the Kirchhoff migration method, Gaussian ray beam (also known as Gaussian beam) prestack depth migration can not only image multiple arrivals, but also overcome the caustic problem existing in Kirchhoff migration. It also retains its advantages of high efficiency and flexibility and the ability to image steep structures, making its imaging accuracy close to that of wave equation migration, but its calculation efficiency is much higher than that of wave equation migration. The Gaussian beam method was first introduced into the field of geophysics by Cerveny (or Cerveny) and applied to seismic wave field simulation. Then Hill propose...

AI Technical Summary

Problems solved by technology

[0003] However, in anisotropic media, the kinematic ray tracing and dynamic ray tracing required to synthesize Gaussian beams become very complicated, which greatly affects the computational efficiency and implementation difficulty of Gaussian beams in anisotropic media.

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