超高压水射流割缝+注氮驱替技术应用研究  

Research on application of ultra-high pressure water jet slotting+nitrogen injection displacement technology

作　　者：华军 韩桂奇 HUA Jun;HAN Guiqi(Shaanxi Huangling No.2 Coal Mine Co.,Ltd.,Yan'an 716000,China)

机构地区：[1]陕西黄陵二号煤矿有限公司,陕西延安716000

出　　处：《煤炭科学技术》2024年第S2期71-78,共8页Coal Science and Technology

摘　　要：针对黄陵二号井217工作面2号煤层瓦斯含量高、煤层透气性差以及钻孔有效抽采时间短等基本特点。通过理论分析超高压水射流割缝+注氮驱替的技术原理,采用COMSOLMultiphysics多物理场耦合模拟软件,模拟并建立了钻孔采取不同技术措施后瓦斯抽采效果的数学模型,在前期工业性试验研究的基础上结合现有的技术工艺特点,提出了超高压水射流+注氮驱替技术工艺并设计了注氮钻孔的二次封孔技术。结果表明:水射流割缝+注氮驱替对钻孔瓦斯抽采作用效果最明显,水力割缝促进了周围次生裂隙的发育,注氮驱替对次生裂隙瓦斯运移起到驱赶作用,促使瓦斯径向流动,提升瓦斯抽采效率,模拟结果与现场工业性试验结果基本一致。In view of the basic characteristics of high gas content,poor permeability and short effective extraction time of No.2 coal seam in 217 working face of Huangling No.2 well,the technical measures of ultra-high pressure water jet+nitrogen injection displacement coal seam gas enhanced extraction were put forward.Based on the theoretical analysis of the technical principle of ultra-high pressure water jet slotting+nitrogen injection displacement,the technology of ultra-high pressure water jet slotting+nitrogen injection displacement and the secondary sealing technology of nitrogen injection drilling were proposed.By means of COMSOL Multiphysics multi-field coupling software numerical simulation,the mathematical model of gas extraction effect after different technical measures were analyzed and summarized,which was basically consistent with the field industrial test results.The results show that the effect of water jet slotting+nitrogen injection displacement on borehole gas extraction was the most obvious.The gas extraction effect of borehole was mainly affected by the secondary cracks caused by the fracture of surrounding coal body caused by water jet slotting.Nitrogen injection displacement plays a driving role in the gas migration of secondary cracks,which promoted the radial flow of gas and improved the efficiency of gas extraction.

关 键 词：水射流割缝 注氮驱替 联合增透措施 瓦斯抽采效果 数值模拟 

分 类 号：TD712[矿业工程—矿井通风与安全]