Pre-stack high-angle fast Fourier transform seismic imaging method, system and equipment

Abstract

The invention belongs to the field of geophysical exploration and seismic imaging, particularly relates to a pre-stack high-angle fast Fourier transform seismic imaging method, system and equipment, and aims to solve the problems of low imaging quality and efficiency and excessive dependence on speed model precision when an existing seismic imaging method is used for imaging a high and steep structure. The method comprises the following steps: acquiring seismic data; extracting a common shot point gather from the seismic data, converting the common shot point gather into a common offset gather, and converting the common offset gather from a time-space domain to a frequency wavenumber domain; calculating a wave propagation angle, and dividing an imaging area into a small-angle area and a large-angle area; solving constant coefficients of small-angle and large-angle areas; carrying out frequency-divided layer-by-layer wave field continuation to obtain imaging results of different depths and different frequencies; integrating an imaging result and converting the imaging result into a spatial domain to obtain a common-offset imaging profile; and carrying out superposition processing on all the common offset distance imaging sections to obtain a final imaging result. According to the invention, high-precision seismic imaging of a high steep structure is realized.

Description

technical field [0001] The invention belongs to the fields of geophysical exploration and seismic imaging, and in particular relates to a pre-stack high-angle fast Fourier transform seismic imaging method, system and equipment. Background technique [0002] With the continuous deepening of exploration, oil and gas reservoirs such as extremely complex fault block reservoirs, strike-slip fault reservoirs, and fractured buried hills have become new fields that urgently need breakthroughs in oil and gas exploration. Correspondingly, high and steep fault block structures, high and steep Strike-slip faults and fractured buried hill structures produce seismic reflections with high angles and weak amplitudes. The traditional first-order approximation split-step Fourier transform (SSF) high-efficiency seismic imaging technology based on the Born approximation is only suitable for formation imaging at gentle dip angles (<15 degrees), which cannot meet the needs of current explorati...

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Problems solved by technology

[0003] In order to solve the above-mentioned problems in the prior art, that is, in order to solve the problems of imaging quality, low efficiency and over-reliance on the accuracy of the velocity model in the existing seismic imaging methods when imaging high-steep structures (that is, high-angle strata), this paper In the first aspect of the invention, a pre-stack high-angle fast Fourier transform seismic imaging method is proposed, the method includes the following steps:

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