瓦斯抽采钻孔漏气规律检测与煤层卸压影响分析  

Gas leakage detection of gas extraction drilling and influence of coal seam pressure relief

作　　者：魏东 WEI Dong(No.1 Coal Mine,Shaanxi Shanmei Huangling Mining Co.,Ltd.,Yan’an 727300,China)

机构地区：[1]陕西陕煤黄陵矿业有限公司一号煤矿,陕西延安727300

出　　处：《陕西煤炭》2024年第10期77-81,90,共6页Shaanxi Coal

摘　　要：瓦斯抽采钻孔的变形破坏与裂隙网络发育会导致煤层瓦斯在抽采过程中发生逸散,从而降低瓦斯抽采效果。为探究瓦斯抽采钻孔的变形破坏特征与漏气特性,以黄陵一矿820工作面的本煤层瓦斯抽采工程为例,分析了抽采钻孔的随钻孔深度变化的应力分区特征与裂隙发育状态,采用钻孔漏气检测装置测定了回风顺槽的钻孔瓦斯浓度变化规律,对比研究了进风顺槽与回风顺槽的瓦斯浓度与纯量的演化规律。结果表明,抽采钻孔的裂隙发育程度随钻孔深度的不同应力分区逐渐变化;回风顺槽钻孔由于煤层卸压导致钻孔漏气性较高,存在3种瓦斯浓度变化趋势,分别为平缓型、16~19 m漏气型、19~23 m漏气型;进风顺槽的瓦斯浓度与纯量表现为负指数形式的衰减规律,由于煤层未卸压,煤层内裂隙网络发育程度较低,钻孔密封性良好,相较之下,回风顺槽的瓦斯浓度表现为线性衰减规律,且由煤层卸压导致瓦斯抽采钻孔的漏气程度较高。The deformation and failure of the gas extraction drilling and the development of fracture network will lead to the gas escape in the coal seam during the extraction process,thus reducing the gas extraction effect.In order to explore the deformation,failure and leakage characteristics of the gas extraction drilling,taking the gas extraction project of the coal seam on the 820 working face of Huangling No.1 Mine as an example,the stress zoning characteristics and fracture development state of the drilling as the change of drilling depth were analyzed.The gas concentration variation rule of the drilling along the return air channel was analyzed by using the drilling leak detection device.The evolution law of gas concentration and pure quantity in inlet channel and return channel is compared,and the gas leakage characteristics of drilling are explored.The results show that the fracture development degree of extraction drilling changes gradually with different stress zones of drilling depth.Due to the pressure relief of coal seam,the gas leakage in the drilling is high,and there are three gas concentration variation trends,i.e.,gentle type,16~19 m gas leakage type,and 19~23 m gas leakage type.The gas concentration and pure quantity of the inlet channel show a decay law in the form of negative exponential.Because the coal seam has not relieved pressure,the fracture network in the coal seam is relatively developed,and the drilling is well sealed.In contrast,the gas concentration of the return air channel shows a linear decay law,and the gas leakage degree of the gas extraction drilling is higher due to the coal seam pressure relief.

关 键 词：瓦斯抽采 钻孔变形 漏气检测 抽采浓度 煤层卸压 

分 类 号：TD712[矿业工程—矿井通风与安全]