基于抽采瓦斯量测定地面钻孔有效半径研究

Study on Effective Drainage Radius of Surface Borehole Based on Gas Drainage Quantity

为了准确考察保护层开采条件下被保护层地面钻孔有效抽采半径,从而为合理布置地面钻孔提供依据,对现有测定地面钻孔有效半径存在的问题进行了分析。基于瓦斯流动理论和煤层瓦斯抽采量、抽采率等在防治煤与瓦斯突出等瓦斯灾害以及煤层气开发和利用的要求,在保证煤层瓦斯预抽率大于等于30%和煤层瓦斯含量小于等于8 m3/t条件下,提出了基于考察地面钻孔抽采瓦斯量测定地面钻孔有效半径的新方法,接下来应用该方法对地面钻孔有效抽采半径进行了计算。研究结果表明:基于钻孔瓦斯抽采量测试新集一矿北中央采区131105工作面地面1#、2#、3#和4#钻孔有效抽采半径分别为85 m、55 m、75 m和115 m,并验证了示踪技术法测定的地面钻孔有效抽采范围内抽采指标不达标。

In order to accurately investigate the effective drainage radius of surface boreholes in the protected coal seam under the condition of protective layer mining and provide a basis for rational arrangement of surface boreholes, the existing problem of effective radius measurement of surface borehole was analyzed. Based on gas flow theory and requirements of coal and gas outburst and other gas disasters prevention and combed gas exploita- tion and utilization, such as drainage quantity, drainage rate, a new method is proposed to measure the effective radius of surface borehole, under the conditions of assurance of coal gas pre - drainage rate of more than 30% and coal seam gas content less than or equal to 8 m^3/t. The effective drainage radius of the surface borehole was calculated by using the method. The results showed that the effective drainage radius of 1#, 2#, 3# and 4# sur- face boreholes in No. 131105 working face in the Northern Central District of Xiji No. 1 Coal Mine based on the test of gas quantity drained from surface boreholes respectively is 85 m, 55 m, 75 m and 115 m. It was verified that the drainage parameters of the surface boreholes in the effective drainage range measured by tracing tech- nique method are not up to the standard.