顺层钻孔瓦斯抽采影响半径分析

Influence Radius Analysis of Gas Drainage by Strata Boreholes

摘要: 本文采用理论分析对杉木树矿S3012工作面，建立轴对称径向流场，得出径向流场瓦斯渗流的连续性方程和钻孔周围瓦斯流动的非稳定径向渗流的动力学控制方程，通过设定边界条件，利用拉普拉斯变换法对半无限煤层瓦斯径向流场的定解式求解析解，得出钻孔周围瓦斯压力分布规律表达式。依据S3012工作面煤层瓦斯赋存基本参数，计算出顺层预抽钻孔周围瓦斯压力p与影响半径r之间的关系，以及钻孔间距与抽采时间关系。利用钻孔瓦斯流量法测定直径120 mm超前钻孔有效抽放半径为0.5 m。

Abstract: The article theoretically analysis the working face of ShanMuShu mine, establishing the axisymmetric radial flow field, coming up with the radial flow field of gas seepage continuity equation and dynamic governing equations of the unsteady radial gas flowing around the boreholes. With the set of boundary conditions and the determining solution of gas radial flow field in semi-infinite coal seam solved with the Laplace transform method, we finally obtained the expression of gas pressure distribution around the borehole. Based on the basic parameters of coal seam gas accumulation in S3012 working face, we finally calculated the relationship between the gas pressure p and the influence radius, and the relationship between drilling distance and extraction time was gained at the same time. The measurement effective drainage radius was 0.5 m with the method of borehole gas flow to measure the 120 mm advanced bore.