穿层钻孔有效抽采半径的测定

钻孔的有效抽采半径是在矿井瓦斯抽采设计中的一个关键性参数。准确测定钻孔的有效抽采半径,有利于合理布置瓦斯的抽采钻孔,实现最佳设计、最小工程量和最优抽采效果。根据实际煤层的存在条件,首先采用压降法对矿井试验区内穿层抽采钻孔有效抽采半径和水力冲孔抽采钻孔有效抽采半径进行实测。然后通过Comsol Multiphysics数值模拟软件建立穿层钻孔瓦斯抽采的数值计算模型,所得模拟结果与现场实测数据基本一致。这证明了现场实测结果的正确性和方法的可靠性。该钻孔的有效抽采半径的测定结果可为金牛建业煤矿技改井二1煤层预抽煤层瓦斯的钻孔设计提供参考。

Measurement of Effective Extraction Radius of Perforation Borehole

The effective extraction radius of borehole is a key parameter in the design of gas extraction.The accurate determination of the effective extraction radius of the borehole can reasonably arrange the gas extraction borehole,which is conducive to the realization of the optimal design,the minimum engineering amount and the optimal extraction effect.Based on the actual conditions of coal seam occurrence,firstly,the effective extraction radius of the perforating borehole and the effective extraction radius of the hydraulic punching borehole are measured by the pressure drop method.Then,the numerical calculation model of gas extraction in cross-layer drilling is established through Comsol Multiphysics,and the simulation results are basically consistent with the field measured data,which proves the correctness of the field measured results and the reliability of the method.The measurement results of the effective extraction radius of the borehole can provide some references for the borehole design of pre-extraction of gas from coal seam in No.1 coal seam of Jinniu Jianye coal mine technical reform.