关键词: 抽采半径, 瓦斯储量法, 瓦斯预抽钻孔, 预抽时间

Abstract: In order to solve the problem of extremely uneven gas pre-drainage time in various areas of high gas long distance mining face. Based on investigation of drainage radius, the optimum design plan for gas pre-drainage boreholes in coal mining face was put forward. The effective drainage radius of gas pre-drainage boreholes in coal mining face was investigated by gas reserve method. The effective drainage radius of gas pre-drainage borehole for different pre-drainage time in coal mining face was obtained. The high gas long advancing distance mining face was divided into several blocks according to the length of gas pre-drainage time. Each block of gas pre-drainage borehole was designed according to its effective drainage radius. The longer the pre-drainage time was, the larger the distance between the pre-drainage boreholes. The shorter the pre-drainage time was, the smaller the distance between the pre-drainage boreholes. Achieve the standard of gas drainage at the coal face mining and minimize drilling works at the same time. The results of field application showed that, the optimized design of gas pre-drainage borehole was adopted in the 2311 mining face, the amount of drilling engineering was reduced by about 70 thousand M, and the gas pre-drainage time of coal face mining was about 15d, and during the mining period, gas drainage standard and safe mining were achieved. The optimal design of gas pre-drainage borehole in the mining face based on investigation of drainage radius was adopted in the high gas long advancing distance mining face, and good technical and economic benefits had been obtained.