Method of predicting fracture azimuth based on shear wave polarization analysis

Abstract

The invention discloses a method of predicting the fracture azimuth based on shear wave polarization analysis. The method includes the steps of acquiring a converted shear wave of a seismic wave; linearly polarizing according to the propagation law of the converted shear wave in an anisotropic solid medium to obtain a shear wave polarized vector under a natural coordinate system; and orthogonally decomposing quick and slow shear vectors in the shear wave polarized vector under the natural coordinate system along R and T directions with time difference [delta]t, according to the superposition principle of the wave, obtaining a shear wave polarized vector under an observation coordinate system in a seismic record of a shear wave R-direction and T-direction polarized components received respectively along R and T directions, and in a time window of wavelength, putting the shear wave polarized vector under the observation coordinate system in a rectangular region range constituted by four tangent lines with every two lines perpendicular to each other to solve the fracture azimuth. The invention solves the problem of large amount of calculation and great influence of noise in the prior art.

Description

technical field [0001] The invention relates to the technical field of seismic exploration, in particular to a method for predicting fracture azimuth based on shear wave polarization analysis. Background technique [0002] Accurate prediction of fracture parameters is of great significance to the exploration and development of fractured reservoirs, and it is also a difficult point in the exploration and development of fractured reservoirs. Existing fracture prediction methods based on multi-wave seismic data mainly use shear wave birefringence to predict fracture parameters. The shear wave birefringence phenomenon is used to predict fractures, and the existence of shear wave splitting in anisotropic media is confirmed, and the polarization direction of fast shear waves is consistent with the direction of fractures, and the characteristics of shear wave polarization in VSP data are studied. On this basis, some studies have proposed the rotation method, and use this method to...

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Problems solved by technology

[0004] The main purpose of the present invention is to provide a method for predicting fracture azimuth based on shear wave polarization analysis, to solve the problems of large amount of calculation and large influence by noise in the prior art

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