Research On Anti-Reflection Technology Of Hydraulic Fracturing Of Low-Permeability Coal Seam In Nalinhe No.2 Coal Mine

As an associated resource in coal production process,gas itself is a kind of clean energy.If it can be efficiently extracted and cleanly used,it can not only promote gas treatment in high-gas mines,but also turn waste into treasure,which can not only reduce environmental pollution but also bring economic benefits to mines.The efficient comprehensive utilization of gas is in line with the safe,efficient and green development direction of modern energy and coal industry in China,and is also the Gospel of the comprehensive utilization of gas in high-gas mines.However,many high-gas mines in China have the characteristics of high gas content,high pressure and low permeability in coal seam,resulting in low gas extraction efficiency in this part of coal seam,which brings great threat to gas control and safe production in coal mine.Na Lin no.2 coal mine,the author of this paper # 3 low gas permeability of coal seam gas extraction problem of aquifer under the condition of coal gas adsorption-desorption effect expensive are studied,based on the analysis of na Lin no.2 coal mine geological conditions and the implementation of hydraulic fracturing test to determine suitable for na Lin no.2 coal seam hydraulic fracturing parameters: na Lin no.2 coal mine 3 # coal seam hydraulic fracturing hole sealing length is 16 m;The fracture pressure is 9MPa,the fracture extension pressure is 8MPa,the water injection rate of coal seam is 7.5m3,and the water injection rate is 200L/min.Hydraulic fracturing in belt lane 36 mining area industrial test,through the test before and after the hydraulic fracturing of aperture and aperture of gas monitoring data analysis,the hydraulic fracturing of coal body after construction,the aperture of mixed gas concentration,flow and scalar a test hole in a certain increase,1 hole of the fracturing effect is most obvious,the indicators increase is larger,the gas concentration,mixed flow and scalar respectively 0.866,4.94,and 4.69 times of the test hole;The concentration of gas was 0.375 times that of the test hole,the mixing flow was 3.26 times that of the test hole,and the purity was 1.24 times that of the test hole.Through hydraulic fracturing to increase the permeability of coal seam,effectively improve the mixture and pure amount of gas extraction in borehole,so as to improve the gas extraction effect and treatment effect,reduce the outburst risk,and achieve the mine safety production.