doi:10.16186/j.cnki.1673-9787.2020090055

Received:2020/09/12

Revised:2021/04/25

Published:2022/05/15

High grouting pressure secondary sealing method for coal seam gas drainage and its application

YANG Dong1, SUN Yuning1, CHENG Wei2, WANG Zhiming1, ZHANG Junxiang1

1.School of Energy Science and Engineering， Henan Polytechnic University， Jiaozuo 454000 ， Henan， China， Jincheng  048012 ， Shanxi， China;2.Shanxi Jincheng Anthracite Coal Mining Group， Jincheng  048012， Shanxi， China

Abstract:For the deficiencies of common “two sealing and one grouting” technology in the “ three soft” coal seam of Zhengzhou coal area， high pressure injection molding of the second hole sealing technology was proposed to hole sealing to get better results. “ One time” was to grout with low grouting pressure to backfill drilling with excellent expansibility of GPM material and blocked the channels which relieved the gas leakage in the shallow surrounding rock. “Secondary” was to gout with high grouting pressure to grouting the micro cracks around the borehole with good injection of JEM material to improve the bearing capacity of the surrounding rock. The results of numerical simulation showed that the sealing technology ensured the radius of grouting dif- fusion , it was proved that the process was feasible. The commercial scale test was conducted along cross hole in bottom pumping alley of Chaohua coal mine. The resuls of practical experimentation indicated that compared with“ two blocking and one injection”sealing drilling in Chaohua Mine,the application of this sealing technology greatly improved the gas drainage effect, effectively improved the gas utilization rate, and effectively controled the attenuation of gas concentration in the borehole,which proved the superiority of the technology.

Key words:hole sealing;second injection;gas extraction;high pressure

瓦斯抽采高保压二次注浆封孔工艺及工程应用_杨栋.pdf