The 4th International Symposium on Mine Safety Science and Engineering (ISMSSE2018)

202 / 2018-06-30 14:23:33

Effects of liquid CO2 fracturing technique between bedding hole and perforation hole

Carbon dioxide fracturing,Expanding crack circle,Gas flow,Drilling site concentration

Gas of Coal Mine & Coal and Gas Outburst > Coal and gas outburst

Abstract: In order to use CO2 fracturing technology in low permeability, high gas and strong outburst coal seam better, a field test of outburst prevention of CO2 phase change fracturing was carried out in 11224 transport lane and 212 Rock cross-cut of Jin Jia Coal Mine. The results show that the liquid CO2 phase change cracking time is 2~2.5 hours, which requires multiple injections of liquid CO2 to crack the gas to improve the gas drainage effect. The liquid CO2 fracturing technology can reduce the gas content in coal seam by 6%-12% and the gas pressure by 9%-12% on the original basis. The effect of the layered hole is worse than that of the layered hole, but the law of the layered hole is not as stable as that of the layered hole; The cracking radius of liquid CO2 cracking technology is 6~12m. In order to improve the cracking effect, the method of superimposed cracking can be used to increase the drainage effect of the drilling group; This comparative study provides an effective basis for the application of liquid CO2 phase change cracking technology in the field of coal mine gas outburst prevention and control.