井工式液态CO_(2)相变致裂煤层关键参数及应用效果研究  

Study on Key Parameters and Application Effect of Underground Liquid CO_(2)Phase-transition Fracturing Coalbed

作　　者：马小辉 李文福 刘咸富 王向阳 何伟 王岩 白晓敏 刘万成 MA Xiaohui;LI Wenfu;LIU Xianfu;WANG Xiangyang;HE Wei;WANG Yan;BAI Xiaomin;LIU Wancheng(Shaanxi Binchang Mengcun Mining Co.,Ltd.,Xianyang 713600,China;CCTEG Shenyang Research Institute Co.,Ltd.,Shenyang 110000,China;Liaoning University of Technology Xijin Mining Technology Co.,Ltd.,Fuxin 123000,China)

机构地区：[1]陕西彬长孟村矿业有限公司,陕西咸阳713600 [2]中煤科工集团沈阳研究院有限公司,沈阳110000 [3]辽宁工大西金矿业技术有限公司,辽宁阜新123000

出　　处：《煤炭技术》2025年第3期198-202,共5页Coal Technology

摘　　要：陕西彬长孟村矿业有限公司4#煤层具有瓦斯含量高、压力大、渗透性低、瓦斯预抽效率低的特点。主要在明确液态CO_(2)瞬时相变致裂煤层渗透率演化规律基础上,在孟村煤矿4#煤层专用安全辅助运输大巷开展工业试验,以SF_(6)示踪气体为测试指标,测定了液态CO_(2)相变致裂煤层有效半径,确定了煤层卸压增透过程渗透率系数及瓦斯抽采衰减系数变化,对比验证了试验前后煤层瓦斯抽采半径和抽采效果。结果表明:在瞬时相变压力大于200 MPa时,示踪气体法检测到液态CO_(2)瞬时相变致裂煤层有效半径为7.0 m,试验区域煤层渗透率提高17.49~22.76倍。液态CO_(2)致裂前后抽采钻孔瓦斯流量系数由0.7253 d^(-1)减小至0.0476 d^(-1),负压抽采半径达到3.56 m,相比钻孔瓦斯抽采浓度和流量分别增大3.16倍和1.71倍。表明井工式液态CO_(2)相变致裂煤层卸压增透和瓦斯促抽效果明显。The No.4 coal seam of Shaanxi Binchang Mengcun mining co.,ltd.,has the characteristics of high gas-content,high-pressure,low-permeability and low gas extraction efficiency.Based on clarifying the permeability evolution law of the fractured coalbed caused by the instantaneous phase-transition of liquid CO_(2),the in-situ test is carried out in the special safety auxiliary transportation roadway of No.4 coal seam in Mengcun coal mine.Taking SF_(6) tracer gas as the test index,the effective permeability of the fractured coalbed caused by the phase-transitionby liquid CO_(2)is measured,and the variations of permeability coefficient and gas extraction attenuation coefficient during the pressure relief and permeability enhancement process of the coalbed are determined.The gas extraction radius and effect of the coalbed before and after the in-situ test are compared and verified.The results show that as the instantaneous phase-transition pressure is greater than 200 MPa,the effective radius of the fractured coalbed caused by the instantaneous phase-transitionby liquid CO_(2)detected by the tracer gas method is 7.0 m,and the coalbed permeability in the test area is increased by 17.49-22.76 times.Before and after the fracturing of liquid CO_(2),the gas flow coefficient in the extraction group decreased from 0.7253 d^(-1) to 0.0476 d^(-1),and the gas drainage radius reached 3.56 m,which increased by 3.16 times and 1.71 times compared with the gas extraction concentration and flow in the borehole,respectively.The results show that the effect of instantaneouspressure-relief to enhance coalbed permeability and gas extraction in caused by phase-transition of underground liquid CO_(2)fracturing is obvious.

关 键 词：瓦斯抽采 煤层渗透性 相变致裂 有效半径 液态CO_(2) 

分 类 号：TD712[矿业工程—矿井通风与安全]