水力冲孔钻孔周围煤层透气性变化规律  

Change regulation of coal seam permeability around hydraulic flushing borehole

作　　者：王凯[1] 李波[1,2] 魏建平[2] 李鹏[1] 

机构地区：[1]中国矿业大学(北京)资源与安全工程学院,北京100083 [2]河南理工大学河南省瓦斯地质与瓦斯治理重点实验室--省部共建国家重点实验室培育基地,河南焦作454000

出　　处：《采矿与安全工程学报》2013年第5期778-784,共7页Journal of Mining & Safety Engineering

基　　金：国家重点基础研究发展计划(973)项目(2012CB723103);国家高技术研究发展计划(863)重点项目(2009AA063201);国家自然科学基金项目(51074067;51174212);教育部新世纪优秀人才支持计划项目(NCET-10-0724);高等学校博士学科点专项科研基金项目(20120023110006);河南省瓦斯地质与瓦斯治理重点实验室--省部共建国家重点实验室培育基地开放课题项目(WS2012A01);河南省重大公益性科研项目(HNZB[2010]N91)

摘　　要：为了研究水力冲孔钻孔周围煤层透气性变化及分布规律，基于煤层实际赋存条件，采用压力法和含量法对水力冲孔卸压范围进行了现场试验考察。采用RFPA^2D-Flow软件模拟分析了水力冲孔钻孔周围煤体应力及透气性变化规律。结果表明：受水力冲孔的影响，孔洞周围形成了半径为5．0～6．0m的卸压范围，卸压范围内应力在0．038～6．545MPa之间，在距被考察孔6．8m处，出现应力集中现象，最大主应力为15．85MPa，与现场考察结果基本一致。孔洞周围煤层透气性的分布规律与主应力变化趋势相一致。距卸压区域距离不同，煤体最大主应力不同，越靠近孔洞的区域，应力和瓦斯压力下降幅度越大，煤层透气性系数也就越大。To research the change and distribution rules of coal seam permeability around hydraulic flushing boreholes, based on the actual occurrence conditions of coal seam, the pressure relief range of hydraulic flushing was investigated by using gas pressure and gas content methods in this paper. Additionally, the stress and permeability changes of coal mass around hydraulic flushing boreholes were simulated by RFPA2D-Flow Software. The results show that under the influence of hydraulic flushing, the pressure relief range with the radius of 5.0-6.0 m are formed around the borehole, and the stress within this area changes from 0.038 MPa to 6.545 MPa. Meanwhile, in the place about 6.8 m away from the reviewed borehole, stress concentration phenomenon is observed. The maximum principal stress is 15.85 MPa, which is basically consistent with the field investigation results. Furthermore, the distribution regulation of coal seam permeability around borehole is similar to the change trend of principal stress. While the distance away from the pressure relief range is different, the principal stress of coal mass is also various. The nearer to the borehole, the larger the decrease amplitudes of stress and gas pressure, and the larger the permeability coefficient of coal seam.

关 键 词：水力冲孔 透气性 卸压增透 数值模拟 卸压范围 

分 类 号：TD713[矿业工程—矿井通风与安全]