低渗煤层CO_2预裂增透高效瓦斯抽采原理及应用  

High efficient gas drainage principle and application of low permeable seam with CO_2 pre-fracturing and permeability improvement

作　　者：孙文忠 

机构地区：[1]山西高河能源有限公司,山西长治046100

出　　处：《煤炭科学技术》2017年第1期100-105,共6页Coal Science and Technology

基　　金：国家自然科学基金资助项目(51274146);山西省回国留学人员科研资助项目(2015-037)

摘　　要：为了解决低渗透煤层抽采效率低、抽采时间长等难题,提出利用CO_2高能气体预裂增透技术改造低渗透煤层,增大煤层透气性,提高瓦斯抽采量和抽采效率;通过分析低渗煤层高能气体预裂增透技术的卸压增透机理,制定了回采工作面和掘进工作面的高能气体预裂增透瓦斯抽采技术方案,并进行了现场试验和效果分析。结果表明:高能气体预裂能够在煤层形成裂隙卸压圈或裂隙卸压区,使圈(区)内煤层透气性和瓦斯解吸速度增高,掘进工作面预裂增透后的平均瓦斯抽采浓度、平均抽采纯流量和平均百米钻孔抽采纯流量分别增加了1.5、4.7、17.8倍;回采工作面预裂增透后,平均瓦斯抽采浓度、平均抽采纯流量和平均百米钻孔抽采纯流量分别增加了0.8、1.0、1.5倍。In order to solve the low gas drainage efficiency,long gas drainage time and other problems of the low permeable seam, the CO2 high energy pre-fracturing and permeability improved technology was applied to reconstruct the low permeable seam, to improve the seam gas permeability and to improve the gas drainage volume and gas drainage efficiency. With the analysis on the pressure releasing and per- meability improved mechanism of the high energy gas pro-fracturing and permeability improved technology for the low permeable seam, a gas drainage technology plan with the high energy gas pre-fracturing and permeability improvement was set up for the coal mining face and the excavated face. The site experiment and effect of the technology were analyzed. The results showed that the high energy gas pre-fractu- ring could form a crack and pressure released ring or the crack and pressure released zone in the seam and thus the seam permeability and gas desorption speed within the ring （zone） was improved. After the pre-fracturing and permeability improved of the gateway driving face, the average gas drainage concentration, average gas drainage pure flow and average gas drainage pure flow per 100 m borehole were individ- ually increased by 1.5 times,4.7 times and 17.8 times. After the pre-fracturing and permeability improved of the coal mining face, the av- erage gas drainage concentration,the average gas drainage pure flow and the average gas drainage pure flow per 100 m borehole were in- creased by 0.8 time, 1.0 time and 1.5 times individually.

关 键 词：低渗透煤层 高能CO2预裂 卸压增透 瓦斯抽采 

分 类 号：TD712[矿业工程—矿井通风与安全]