Method for acquiring seismic wave path through wave equation

Abstract

The invention relates to a method for acquiring a seismic wave path through a wave equation. The method comprises the following steps that firstly, an initial parameter is given; secondly, a complex and non-uniform underground medium model to be explored is divided into mesh-shaped grid points; thirdly, a seismic source is placed in the seismic source point S of the model, and seismic wave fields in certain frequencies in the frequency band to be solved in the whole space are calculated point by point; fourthly, the seismic source is arranged at the receiving point R of the model, and the seismic wave fields in certain frequencies in the frequency band to be solved in the whole space are calculated point by point; fifthly, in the frequency domain, the calculated seismic wave fields at the seismic source point S and the receiving point R under the same frequency are multiplied and added to the multiplying result obtained under the previous frequency; sixthly, frequency circulation is carried out in the frequency band to be solved, and the seismic wave path is stored if the frequency circulation is finished. According to the method, the high-frequency approximation and multi-path problems of a traditional method are avoided, and the method can be widely applied to seismic simulation, seismic lighting and seismic offset technology in a complex geologic structure of oil exploration.

Description

technical field

[0001] The invention relates to a method for acquiring a seismic wave path in the field of petroleum exploration, in particular to a method for acquiring a seismic wave path by using a wave equation. Background technique

[0002] At present, the path of seismic waves is usually calculated by Kirchhoff (Kirchhoff) theory, which performs high-frequency approximation, that is, it is considered that the energy of seismic waves is concentrated on a certain line (called "ray") between two points in the underground medium. However, seismic waves are actually signals of a limited frequency band. According to the Fermat principle, the seismic wave propagates along the path with the smallest travel time, that is, the path with the shortest time for the seismic wave to propagate from the source point S to the receiving point R. The ray method draws on the shortest path algorithm to find the shortest travel time between the source and the receiver. In practice, because...

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