Research Of Sealing Process Along Cross Hole In Bottom Pumping Alley Of Chaohua Coal Mine

Gas is the main disaster source of coal mines,and it is also an unconventional natural gas clean energy with abundant reserves.Gas drainage is a prerequisite for gas management and utilization.Gas drainage drilling and sealing is the key to guarantee the drainage effect.At present,Chaohua Coal Mine mainly relies on drilling through the bottom of the tunnel to carry out gas pre-drainage.This thesis focuses on the problems of serious borehole gas leakage and excessively rapid attenuation of gas drainage concentration during gas drainage in Chaohua Coal Mine.Based on the study of the sealing mechanism of the "two plugs and one injection" technology,the reasons for the excessive attenuation of the concentration of gas drainage boreholes were pointed out,and a reasonable plugging depth was determined,a second plugging technology was used,and a plug with good performance was selected.Leakage materials and grouting equipment are effective measures to improve the gas drainage effect of drilling;developed a new plugging integrated hole sealer,developed a supporting leaking grouting material;determined the theoretical analysis and COMSOL software simulation The range of the pressure relief zone of the surrounding rock of the mine roadway is 0 ～ 7 meters.According to the actual situation of Chaohua Mine,the sealing depth is determined to be 1m below the interface of coal and rock.In combination with the actual situation of Chaohua Mine,a new three-capsule seal is adopted.Perforator for field experiments.The results of engineering experiments show that within 3 months,the average concentration of the test holes drilled by the People’s Bank of China in the No.3 drill field reached 24.56%(the average concentration of the mine’s comparative hole was12.72%),and the average concentration of the test holes in the No.1 Transverse No.1field reached 16.89%.(The average concentration of the comparison hole in the mine side is 10.42%).The average concentration of the test hole in the 1st and 2nd drilling site has reached 17.62%(the average concentration of the comparison hole in the mining side is 10.99%).(The average concentration of the contrast holes in the mine side is 6.97%);It shows that the "blocking integration" sealing technology is an effective method to improve the sealing effect of drilling through the bottom of the tunnel in Chaohua Mine.