摘要
为了解决现代化高产高效矿井因回采速度大幅度提高而引起的采煤工作面上隅角瓦斯超限问题,突破传统的煤矿井下抽采瓦斯措施存在的在时间、空间上对治理采煤工作面的瓦斯方法单一的局限,依托国家科技重大专项示范工程,模拟研究了山西重点煤矿区晋城、阳泉等矿区采煤工作面回采引起采动区地面井不同距离时煤岩层裂隙在超前支承压力转移、采动覆岩反复扰动、采动覆岩基本稳定3个阶段的形成机理,据此确定并验证了采动区卸压瓦斯的运移通道及富集区。研究结果表明:山西重点煤矿区采动区地面直井井位应布置在回采工作面回风巷侧地表沉降拐点连线和采场中线之间为重点研究区域;采动区L型水平井层位应优先布置在裂隙带中部且厚度及强度均较大的岩层中。由采动区地面井变形破坏模拟发现,岩层移动的剪切滑移位移量、离层拉伸位移量是对地面井井身结构产生影响的关键参量。因此,采用增大采动区地面直井的井径、改进固井技术提高地面井的有效通径以增强其抗拉剪能力。通过生产实践研发了采动区地面直井应穿越煤层并将生产套管(筛管)布置在采动裂隙带上边缘至冒落带的最优“三开”井身结构。在岳城矿、塔山矿、新景矿等矿区进行了100多口的采掘扰动区地面“仅钻井、不压裂”的钻井与抽采工程示范,大部分井取得了较好的瓦斯抽采效果,单井平均总产气量约200万m3,最高达3000万m3以上。采动区地面井同时对采煤工作面上隅角瓦斯治理也起到了非常重要的作用,工作面上隅角瓦斯体积分数降幅平均达50%左右,在煤层气抽采及工作面涌出瓦斯治理两方面效果显著,具有良好的推广应用价值。
In order to solve the problem of gas overrun in the upper corner of the coal mining working face caused by the substantial increase of the mining speed in the modern high-yield and high-efficiency coal mine,and break through the limitation of the single gas control method in time and space existing in the traditional underground gas drainage measures,relying on the National Science and Technology Major Special Demonstration Project,the mining activities of coal mining face in key mining areas of Jincheng,Yangquan and other mines in Shanxi key coal mines areas are simulated and observed on the formation mechanism of coal seam fissures in the three stages of advanced abutment pressure transfer,repeated disturbance of mining overburden and basic stability of mining overburden when the mining face is different from the surface well in the mining area.Based on this,the migration channel and enrichment area of pressure relief gas in the mining areaswere determined and verified.Research and engineering demonstrations have determined that the ground vertical well in the mining area of Shanxi key coal mine should be located in the area between the connection of the ground subsidence inflection point and the center line of the stope.The layer of L-type horizontal wells in the mining area should be preferentially arranged in the middle of the fissure zone and the rock stratum with large thickness and strength.According to the simulation of the deformation and failure of the surface wells in the mining area,it is found that the shear slip displacement and the tensile displacement of the strata are the key parameters that affect the structure of the surface wells.Therefore,the diameter of the surface vertical well in the mining area is increased and and the effective diameter of the surface well is improved by improving the cementing technology to enhance its tensile and shear resistance.Through the production practice,the optimal triple-shaft structure of the vertical well is developed so that the surface vertical well in the mining area should pass through the coal seam and the production casing should be arranged from the upper edge of the mining fracture zone to the caving zone.In the mining areas of Yuecheng Mine,Tashan Mine,Xinjing Mine,more than 100 drilling and drainage engineering demonstrations"drilling only,not fracturing"in the disturbance zone were performed.Most of the wells have achieved good gas drainage effect and the average total gas production of a single surface well is about 2 million m3,up to more than 30 million m3.The surface well in the mining area also played a very important role in the gas control in the upper corner of the coal mine working face.The gas concentration in the upper corner of the working face decreased by about 50%on average,which has significant effects in both coalbed methane drainage and gas emission control at working faces,and has good promotion and application value.
作者
李国富
付军辉
李超
李日富
LI Guofu;FU Junhui;LI Chao;LI Rifu(State Key Laboratory of Coal and CBM Co-mining,Jincheng 048012,China;Jincheng Anthracite Mining Group,Jincheng 048006,China;Chongqing Research Institute Ltd.,China Coal Technology and Engineering Group,Chongqing 400037,China;Shandong University of Science and Technology,Qingdao 266590,China)
出处
《煤炭科学技术》
CAS
CSCD
北大核心
2019年第12期83-89,共7页
Coal Science and Technology
基金
国家科技重大专项资助项目(2016ZX05067)
山西科技重大专项资助项目(MQ2015-02)
关键词
煤矿采动区
煤层气
地面抽采
L型水平井
coal mining area
coalbed methane
surface drainage
L-type horizontal well