Thin coal belt detection method and system based on refracted wave periodic amplitude attenuation

Abstract

The invention discloses a thin coal belt detection method and system based on refracted wave periodic amplitude attenuation. The thin coal belt detection method comprises the steps that S1, an instrument is arranged, wherein a seismic survey line is composed of S excitation points and R receiving points; seismic data di (t) with the total number of channels being N is formed between the excitation points and the receiving points through signal acquisition and data transmission; s2, acquiring stratum data and calculating to obtain a refracted wave period: acquiring a longitudinal wave speed vr of surrounding rock and a longitudinal wave speed vc of a coal seam, measuring the thickness h of the coal seam exposed by the roadway on the lateral wall of the roadway, and calculating the refracted wave period T; s3, processing di (t) to obtain seismic data si (t) after deconvolution and in-channel equalization; the amplitude ratio of the seismic data si (t) to the reference channel s0 (t) at the np order is solved to serve as the refracted wave period amplitude coefficient ap of the point P, and the numerical value of ap reflects the thickness of the coal seam at the point P. The coal seam refracted wave used in the method is another underground seismic wave which is simultaneously generated with the slot wave, the thin coal belt boundary is more accurately explained by using the refracted wave, and the working efficiency and the resource utilization rate of coal mine recovery are improved.

Description

technical field [0001] The invention belongs to the technical field of coalfield geophysical prospecting, and relates to an underground geophysical prospecting method and system for detecting thin coal zones in a coal mining working face. The method separates the refraction wave from the seismic wave excited and received in the coal seam, and uses the attenuation degree of the periodic amplitude of the refraction wave to estimate the detection method of the boundary of the thin coal zone. Background technique [0002] The thin coal belt is the area where the thickness of the coal seam is reduced due to the thinning of the bottom of the coal seam or the influence of river erosion. The existence of thin coal belts in the coal mining face not only increases the difficulty of mining and reduces coal production, but also easily induces geological disasters such as gas outburst or water seepage. Therefore, accurate detection of the position and development of the concealed thin c...

AI Technical Summary

Problems solved by technology

The existing downhole thin coal belt detection is mainly based on the drilling method, which has low efficiency and low precision

There is a lack of methods that can accurately detect thin coal belts in downhole geophysical prospecting methods. At present, only channel wave detection technology uses the dispersion characteristics of channel waves to detect coal thickness. The detection results are not ideal

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