水力压裂-深孔预裂爆破复合增透技术研究  

Study on hydraulic fracturing-deep hole pre-splitting blasting composite permeability enhancement technology

作　　者：高鑫浩 王明玉[4,5] GAO Xinhao;WANG Mingyu(China Coal Research Institute,Beijing 100013,China;Shenyang Research Institute,China Coal Technology&Engineering Group,Shenyang 110016,China;Key Laboratory of Mine Thermal Power Disaster and Prevention,Ministry of Education,Fushun 113112,China;College of Safety Science and Engineering,Liaoning Technical University,Fuxin 123000,China;Key Laboratory of Mine Power Disaster and Prevention of Ministry of Education,Huludao 125105,China)

机构地区：[1]煤炭科学研究总院,北京100013 [2]煤科集团沈阳研究院有限公司,辽宁沈阳110016 [3]煤矿安全技术国家重点实验室,辽宁抚顺113122 [4]辽宁工程技术大学安全科学与工程学院,辽宁阜新123000 [5]矿山热动力灾害与防治教育部重点实验室,辽宁葫芦岛125105

出　　处：《煤炭科学技术》2020年第7期318-324,共7页Coal Science and Technology

基　　金：国家重点研发计划资助项目(2107YFC0805200)。

摘　　要：为了增加低渗透高瓦斯煤层的透气性,提高瓦斯的利用率和抽采效率,提出了水力压裂-深孔预裂爆破复合增透技术,分析了水力压裂-深孔预裂爆破复合增透的爆破致裂机理,建立了在爆轰气体作用下的裂纹应力强度因子方程和裂纹二次扩展半径方程。运用RFPA^2D-Flow模拟软件对水力压裂后孔壁周围煤岩体裂隙的产生过程与裂隙扩展规律进行模拟。利用ANSYS/LS-DYNA有限元分析模拟软件对不同长度预裂缝影响深孔预裂爆破后瓦斯抽采增透效果的程度进行模拟。同时在阳泉五矿8410工作面开展了现场工业性试验,以此验证煤矿井下进行水力压裂-深孔预裂爆破复合增透技术后的瓦斯抽采增透效果。结果表明:使用水力压裂-深孔预裂爆破复合增透技术后煤层的透气性与常规的深孔预裂爆破相比有显著提高,致裂孔的初始瓦斯涌出量是普通爆破孔的3.18倍,瓦斯含量的衰减强度降低了77.3%。深孔预裂爆破的有效影响半径随着爆破孔内预裂缝长度的增加而提高,而且二者呈线性关系。该研究中采用复合爆破后的有效影响半径可达到6.98 m,与数值模拟结果得到的有效影响半径6.763 m相近。同时数值模拟与现场工业性试验的结果均证明:提出的水力压裂-深孔预裂爆破复合增透技术,能够有效增加煤岩层的透气性,提高瓦斯的抽采效率,为其他低渗透高瓦斯煤层的瓦斯抽采增透技术提供了参考。In order to increase the permeability of low-permeability and high-gas coal seams and improve gas utilization rate and extraction efficiency,a hydraulic fracturing-deep hole presplitting blasting composite permeability enhancement technology was proposed.The mechanism of blasting cracking in hydraulic fracturing-deep-hole pre-split blasting was analyzed,and the crack stress intensity factor equation and the crack secondary radius equation under the action of detonation gas were established.The RFPA^2D Flow simulation software was used to simulate the formation process and crack propagation law of coal and rock mass cracks around the hole wall after hydraulic fracturing.ANSYS/LS-DYNA finite element analysis simulation software was used to simulate the extent to which gas pre-cracks with different lengths affect the effect of gas drainage and permeability enhancement after deep-hole pre-crack blasting.At the same time,the on-site industrial test was carried out on No.8410 working face of Yangquan No.5 mine to verify the gas drainage and permeability enhancementeffect of the hydraulic fracturing-deep hole pre-cracking blasting composite permeability enhancement technology under the coal mine.The results show that the permeability of coal seam was significantly improved compared with the conventional deep-hole pre-splitting blasting after the hydraulic fracturing-deep-hole pre-split blasting composite technology.The initial gas emission of the cracked holes was 3.18 times of the ordinary blasting hole,the attenuation intensity of gas content was reduced by 77.3%.The effective influence radius of deephole pre-splitting blasting increases with the length of the pre-splitting in the blasting hole,and there was a linear relationship between the two.In this study,the effective radius of cracking after composite blasting could reach 6.98 m,which was consistent with the effective cracking radius of 6.763 m obtained from the numerical simulation results..At the same time,the results of numerical simulation and onsite industr

关 键 词：水力压裂 复合增透 预裂爆破 瓦斯抽采 瓦斯治理 

分 类 号：TD712[矿业工程—矿井通风与安全]