基于多瓦斯钻孔耦合的钻孔分布形态对瓦斯浓度影响分析  

Influence of Borehole Distribution on Gas Concentration Based on Multi Gas Borehole Coupling

作　　者：许文韬 卢平[1] 余陶[1] XU Wentao;LU Ping;YU Tao(School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,China)

机构地区：[1]安徽建筑大学土木学院,安徽合肥230601

出　　处：《兰州工业学院学报》2022年第2期1-6,共6页Journal of Lanzhou Institute of Technology

基　　金：国家自然科学基金(51974006);安徽省重点研究和开发计划(1804a0802208);安徽省自然科学基金(1808085QE150);安徽省教育厅重点项目资助(KJ2018A0502)。

摘　　要：基于COMSOL数值模拟、达西定律和相对压力法相结合的测定方法研究钻孔分布对瓦斯卸压速度的影响,结合工作面现场实践及采样数据,得到煤层中瓦斯压力变化情况。通过对比瓦斯压力、瓦斯卸压速度与时间的关系,来获得效率最佳的瓦斯钻孔分布形态。结果表明:当抽采60 d、钻孔孔径0.094 m、钻孔间距0.55 m、抽采负压0.04 MPa、钻孔以正三边形态分布时,各个测压点瓦斯压力降幅最大,其最大降幅超过56%;其他情况下因内部流场扰动,在单位面积钻孔更多的情况下并未获得更明显的卸压效果,经模拟及实践发现该结论在扩大钻孔间距后仍然有效,因此出于实际经济因素及卸压效率的综合考虑,正三边形形态更具优势。the influence of borehole distribution on gas pressure relief speed is mainly studied in this paper,and the change of gas pressure in coal seam is obtained by using the measurement method based on COMSOL numerical simulation,Darcy's law and relative pressure method,combined with the field practice and sampling data of working area.By comparing the relationship between gas pressure,gas pressure relief speed and time,the gas borehole distribution with the best efficiency is obtained.The simulation results show that when the extraction is 60 days,the borehole diameter is 0.094 m,the borehole spacing is 0.55 m,and the extraction negative pressure is 0.04 MPa,the gas pressure drops at each pressure measuring point is the largest in the form of positive trilateral distribution,and the maximum drop is more than 56%.In other cases,due to the disturbance of internal flow field,more boreholes per unit area do not achieve more obvious pressure relief effect.Through simulation and practice,it is found that this conclusion is still effective after expanding the borehole spacing.Therefore,for the comprehensive consideration of practical economic factors and pressure relief efficiency,the positive trilateral shape has more advantages.

关 键 词：COMSOL 瓦斯钻孔 瓦斯浓度 多钻孔耦合 达西定律 

分 类 号：X932[环境科学与工程—安全科学]