Converted SH wave wash zone detection method based on shock wave excitation source

Abstract

The invention discloses a converted SH wave wash zone detection method based on a shock wave excitation source. Drilling holes are constructed in an inlet, the middle and an open-off cut of an intakeairway of a stope face respectively, shock wave excitation is carried out for multiple times in each drill hole to generate three common shot point gathers, a coordinate system is established, seismicrecords with converted SH wave signals are extracted from each common shot gather for analysis, SH waves are converted from Love type groove waves, so that the energy of the converted SH waves is notweak before encountering a wash zone, the energy of the converted SH wave becomes stronger after a large amount of the Love type groove waves are converted and developed after encountering the wash zone, imaging is carried out by utilizing the energy difference of the converted SH wave in different time periods, and a position image of the wash zone is obtained after superposition. Thus, technical guidance is provided for subsequent safety production.

Description

technical field [0001] The invention relates to a method for detecting a scour zone in a working face, in particular to a method for detecting a scour zone based on a converted SH wave that excites a seismic source with a shock wave. Background technique [0002] Due to the influence of geological conditions, the scour zone affects the occurrence and distribution of coal seams to a certain extent. Under the background of intelligent, efficient and precise mining, the existence of the scour zone seriously hinders the mining of the working face. Therefore, , fine detection of scour zone is an urgent need for coal mine production. [0003] At present, for the detection of scour zones in coal seam working faces, the main methods include geological law method, coal-rock mechanical parameter method and ground three-dimensional seismic exploration, among which the geological law method and coal-rock mechanical parameter method are limited by the workload of drilling and roadway exp...

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Problems solved by technology

[0003] At present, for the detection of the scour zone in the coal seam working face, the main methods include the geological law method, the coal-rock mechanical parameter method, and the ground three-dimensional seismic exploration, etc., among which the geological law method and the coal-rock mechanical parameter method are limited by the workload of drilling and roadway investigation , due to the high cost of drilling and tunneling, the long construction period, and the limited detection range of "one hole diameter", the accuracy of detecting the scour zone is low

However, 3D seismic exploration on the ground is affected by complex terrain and shallow mined-out areas. Since the ground is far away from the target body, when encountering these overlying geological anomalies, most of the seismic wave energy is reflected back to the ground, and only a small part of the seismic wave energy Downward transmission leads to weaker effective signal energy reflected back to the ground in the later stage, which eventually makes it difficult to identify the effective wave. At the same time, there are other interference waves, which increases the difficulty of post-processing, resulting in the current method for the exploration of the scour zone in the working face. Accuracy is limited, and innovations in scour zone detection methods are urgently needed

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