Theory and method of coal seam gas enrichment area based on radio wave perspective detection

In order to accurately predict the coal gas enrichment area of coal seam mining face, based on the theory of mine radio wave perspective, this paper investigated the relationship between the coal gas pressure and the radio wave perspective curves.According to the actual situation of coal mining face, the variation characteristics of the radio wave curve in the coal seam gas enrichment area were simulated, and the feasibility of detecting coal seam gas was discussed.Also, some experiments were conducted in underground coal mine.This study concluded that the gas pressure of coal seam and the radio wave attenuation curve showed a consistent change, the coal seam gas existences could cause the abnormal region of radio wave penetration.Compared to the received value of normal coal seam receiver,the abnormal curve of coal seam gas showed a whole smaller received value,and the attenuation was larger in middle area of model,the relative attenuation was smaller on both sides of model.The pattern formation was a "bat" shape.Through the experimental verification in the coal mine,the radio wave perspective results combined with geological data analysis could be used to accurately divide the coal gas outburst dangerous area.