Experimental Study on Increasing Coal Seam Permeability and Pre-drainage Gas by Liquid CO2 Phase-transforming Fracture
HAN Ying
SHI Xiaohui
LEI Yun
SUN Liang
GUO Shan
Abstract：In order to increase coal seam permeability,enhance the gas drainage efficiency,on the basis of the rock fracturing mechanism,mathematical model of crack extension by liquid CO2 blasting was established.Using COMSOL numerical software,transient model of liquid CO2 phase fracturing was established and by analyzing the laws of fractures development around drilling under the action of blasting air pressure;it is concluded that there are three zones of crushing zone,fissure zone and vibrating zone around the drillings.The basic theory,related equipment and construction technology were introduced and the industrial test experiment on liquid CO2 pre-splitting blasting was carried out in 152 belt conveyor diphead in Mabu Mine.The experiment result showed that:the average daily extraction concentration of single pore gas is 1.37 times the size of before blasting,the average daily extraction of single pore gas is 2.95 times the size of before blasting.The attenuation coefficient of gas flow decreased by 82.8％.
Keywords：liquid CO2phase transition fracturingpermeability improvementgas drainagetunnel excavationlow permeability seam
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 17-20 )