Method for generating spreading angle domain common image point gathers

Abstract

The invention relates to a method for generating spreading angle domain common image point gathers. The method comprises the following steps that: 1) longitudinally partitioning a complex inhomogeneous medium to be prospected into different depth layers from the earth surface utilized as the beginning point; 2) arousing seismic waves in a successive blasting manner at the earth surface, spreading the seismic waves aroused each time downwards in a mode of spherical waves, when the seismic waves reach the different depth layers, respectively calculating an ordinary seismic offset wave field and a seismic offset wave field with spreading angle correction on each depth layer by using a wave equation; 3) generating angle information of the wave field at an imaging point on each depth layer; 4) obtaining ware field angle information on each imaging point in the depth layers to be prospected, selecting an angle adoption interval and an angle scope so as to perform data overlapping on an offset imaging result falling in one sampling interval until the offset data overlapping within all the angle scopes is completed, and transforming common-source imaging point gathers are into common angle domain imaging point gathers. The method can be used in the generation process of the angle domain common imaging point gathers in petroleum seismic prospecting widely.

Description

technical field [0001] The invention relates to a method for generating common imaging point gathers, in particular to a method for generating common imaging point gathers in the propagation angle domain applicable to complex structures in oil exploration. Background technique [0002] Prestack depth migration technology has become a powerful tool to solve complex structural exploration problems, but its practical application is limited due to its dependence on the layer velocity model. Aiming at the problems of uncertain depth migration results and unreliable velocity models in seismic imaging, existing technologies usually use full waveform inversion method, tomographic inversion method and residual curvature method to deal with them. Among them, the full waveform inversion method A relatively reliable velocity model can be obtained, but the amount of calculation is very large, so this method is mainly applicable in the range of low frequencies (usually ≤10Hz); a relativel...

AI Technical Summary

Problems solved by technology

The existing common imaging point gather technology in the angle domain is usually completed by the common imaging point gather in the offset domain through the standard Radon mathematical transformation, but the amount of calculation and data storage are very large. Gather, this type of method needs to store five-dimensional data volume, which is subject to certain restrictions in practical applications

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