Method for separating seismic diffraction waves by median resistance filtering

Abstract

The invention discloses a method for separating seismic diffraction waves by median resistance filtering, which comprises the following steps: 1) reading single-shot seismic data containing m channelseach with n sampling points into a two-dimensional array R1; 2) correcting the normal time difference of the array R1 to obtain an array R2; 3) extracting the seismic data of a row of diffraction waves in the array R2 to obtain a low-cut wave number, and determining a channel window parameter of the median resistance filtering; 4) carrying out one-dimensional median resistance filtering on the data of the array R2 to obtain an array R3; 5) implementing a median resistance filtering to extract diffraction waves, and subtracting median filter array R3 from the array R2; 6) repeating steps 4 and5), performing median resistance filtering processing on each row of data in the array R2 to obtain a two-dimensional array R4, performing inverse-normal time difference correction on the extracted diffraction waves to obtain an array R5, and performing the median resistance filtering to separate the diffraction waves; 7) repeating steps 1) to 6), processing seismic line data, performing seismicmigration imaging processing on the diffraction waves to obtain a diffraction wave imaging profile. The method effectively improves the prediction accuracy of coal mine collapse columns.

Description

technical field [0001] The invention belongs to the technical field of seismic data processing, in particular to a method for separating seismic diffracted waves by median-resistance filtering. Background technique [0002] Coal mine subsidence column is an isolated geological body, which has the characteristics of poor development regularity, irregular spatial shape, large scale disparity, and strong concealment, which makes detection difficult. There are generally obvious geological differences between the top, interior and surrounding rock of the collapsed column, which will cause changes in the seismic response characteristics, which are often expressed in the form of diffracted waves. The existence of diffraction waves, on the one hand, has brought great challenges to the accurate imaging of reflected waves; on the other hand, diffraction waves are seismic responses caused by subsurface uneven geological bodies, and they carry high If the rich information carried by di...

AI Technical Summary

Problems solved by technology

The existence of diffraction waves, on the one hand, has brought great challenges to the accurate imaging of reflected waves; on the other hand, diffraction waves are seismic responses caused by subsurface uneven geological bodies, and they carry high If the rich information carried by the diffracted wave can be effectively utilized, the prediction accuracy of the coal mine collapse column will be further improved.

However, compared with the reflected wave, the energy of the diffracted wave is weak, especially the diffracted wave generated by the small-scale collapsed column is often submerged in the background of the strong energy reflected wave, so how to separate the diffraction wave caused by the collapsed column The key to effective use of diffracted waves to detect collapsing pillars is to radiate waves and accurately image them

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