关键词: 高抽巷, 下向钻孔, 初采期, 瓦斯抽采, 卸压圈

Abstract: ased on the difficulty of gas drainage at the initial stage of mining in the first mining face, the deformation and pressure relief of the roadway and surrounding rock formations after the construction of the borehole are analyzed, and the model of the double pressure relief ring of the borehole and the roadway is established to calculate the gas pressure at any point between the borehole and the roadway. According to the gas stress, the gas flow quality equation at this point is obtained, so as to propose the gas extraction plan of the downhole drilling in the high suction tunnel, and put forward corresponding countermeasures for the drilling problem of the downhole drilling, and finally the first mining work in 1301 is carried out. Engineering tests are carried out. The research results show that the gas extraction time is 10m ahead of the initial pressure step; there is no gas over-limit or power outage during the mining of the working face. Therefore, the downward drilling gas drainage scheme in the high-drainage roadway solves the gas over-limit problem in the initial mining face, which proves that the drilling-roadway double pressure relief ring model is reasonable and feasible. The gas management of the surface is of guiding significance.