Irregular model aperture-based common offset Kirchhoff prestack depth migration imaging method

Abstract

The invention relates to an irregular model aperture-based common offset Kirchhoff prestack depth migration imaging method. With too small width, the conventional rectangular aperture can suppress shallow offset noise but lowers depth imaging quality; with too large width, the conventional rectangular aperture can guarantee depth imaging quality but causes stronger offset noise and lowers shallowimaging quality. Considering both offset size and maximum depth of an imaging model space, the method designs an irregular model space offset aperture with narrow shallow and wide deep, splits the irregular aperture by using grids of unequal distances and calculates a travel timetable in the irregular model aperture alone, then performs common offset Kirchhoff prestack depth migration imaging. Themethod can suppress shallow offset noise effectively and guarantees depth imaging quality; a travel timetable outside an irregular aperture is not calculated, so that calculation efficiency is improved; the range of the depth offset aperture is maximized without increasing excessive calculation amount, so that advantages like higher depth even super-depth imaging quality are increased.

Description

technical field [0001] The invention belongs to the technical field of geophysical seismic data processing, in particular to a seismic migration imaging method, in particular to a common offset Kirchhoff pre-stack depth based on an irregular model aperture for the migration aperture problem in migration imaging Offset imaging method. Background technique [0002] Due to its advantages of high computational efficiency, stable imaging quality, low sensitivity to inaccurate velocity models, and easy implementation of migration velocity analysis, the Kirchhoff pre-stack depth migration imaging method with common offset is still the main method in the field of oil and gas exploration in the petroleum industry. and mainstream seismic imaging methods. The imaging quality of the conventional common-offset Kirchhoff prestack depth migration imaging method is controlled by many factors, among which the migration aperture is a crucial one. How to design a reasonable aperture range an...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to solve the problem that a large amount of offset noise is introduced or a large amount of effective signals are lost in a wide or narrow rectangular aperture, and the shallow and deep imaging quality, imaging efficiency and offset noise suppression cannot be taken into account. Co-offset Kirchhoff Prestack Depth Migration Imaging Method

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