Gas Comprehensive Control Technology of Shallow Hole Drainage in Working Face of Unusual Gas District

The NO.12 mining area of Chensilou Coal Mine was the unusual gas emission area, and safe mining in this area had been a problem to be solved. The change laws of coal seam permeability in front of the working face and the influence factors of drillings arrangement for gas drainage effect were studied, and the new comprehensive technology of shallow hole drainage in working face of unusual gas district was put forward. It took shallow hole drainage as core content, combined with the working face ventilation management method of "U type ventilation+ upper and lower corner plugging measures". This technology was applied in 21207 working face, the gas concentration in upper corner reduced from 0.5% (top 0.7%) to the value between 0.1% and 0.2%, the gas emission reduced to less than 2.5 m³/min, and the gas concentration reduced effectively during working face mining.