Study on Gas Drainage with Large Diameter High Level Borehole to Replace High Level Gas Drainage Gateway

According to the high engineering and high investment problems in a construction of high level gas drainage gateway,an experiment of large diameter high level borehole to replace a high level gas drainage gateway was conducted in No.24207 fully mechanized coal mining face in Shaqu Mine and a comparison and analysis on the gas drainage effects of the two methods was conducted.The gas drainage effect with high level borehole was reached the gas drainage effect with high level gateway.The high level boreholes with a layout of fan could expand the gas drainage scope,could extend the gas drainage service time and could improve the gas drainage rate.The gas volume fraction of the air returning gateway in the coal mining face could be controlled around 0.33%.The application results showed that the large diameter high level borehole was feasible to replace the high level gas drainage gateway for gas drainage.