A method and system for extracting incident angle gathers

Abstract

An embodiment of the invention discloses an incident angle gather extraction method and system. The method includes the steps of reading sub-wave data, seismic shot gather data and interval velocity model data and calculating a shot point wave field and a detection point wave field in a preset area; calculating the seismic offset imaging result of a seismic shot gather according to the shot point wave field and the detection point wave field and obtaining three-dimensional data on the basis of the seismic offset imaging result; calculating a single frequency shot point wave field on the basis of the shot point wave field and a pre-set frequency value; calculating an incident direction vector on the basis of the single frequency shot point wave field and calculating a normal vector on the basis of the three-dimensional data; calculating an incidence angle corresponding to a coordinate position in the preset area according to the incident direction vector and the normal vector and mapping an offset imaging energy value of the position to an angle domain formed by the incident angle for obtaining an incidence angle gather. The incident angle gather extraction method and system can improve the accuracy of the extracted incident angle gather.

Description

technical field [0001] The present application relates to the technical field of seismic exploration, in particular to a method and system for extracting incident angle gathers. Background technique [0002] Seismic exploration refers to a geophysical exploration method that uses the difference in elasticity and density of underground media to infer the nature and shape of underground rock formations by observing and analyzing the response of the earth to artificially excited seismic waves. The incident angle gather is very important seismic data in the seismic exploration process, and the incident angle gather may include: a coordinate position in the formation, an incident angle corresponding to the coordinate position, and a wave field energy value at the coordinate position. The incident angle gather is of great significance for lithology analysis in formation, reservoir analysis, and wave field propagation modeling. [0003] Existing methods for extracting incident ang...

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Problems solved by technology

[0005] In the process of implementing this application, the inventors found that there are at least the following problems in the prior art: the existing method for extracting incident angle gathers directly generates underground offset gathers based on the results of dislocation imaging, without considering the formation dip angle, and this method is only suitable for Applied to horizontal strata

However, in the process of seismic exploration, the terrain is generally complex, and the stratum is usually inclined. When this method is used to extract the incident angle gather in the complex terrain, because the stratum inclination is not considered, the incident angle obtained by timing has deviations, so this method produces The calculation accuracy of the incident angle gather is not high

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