Study On Optimization And Application Of Borehole Gas Drainage Parameters In 8410 Workine Face Of Yangquan Wu Mine

Gas disasters are the main factors that restrict the production and long-term development of coal mine.Yangquan Wu Mine increase gradually to the deep mining and mining intensity,gas emission increased gradually,through field investigation and evaluation,extraction parameters of 15#coal seam is not reasonable and causing low extraction rate is not reached purpose of outburst elimination.Thus,determining reasonable extraction parameters become a problem to be solved.Aim at the problem that extraction parameters of 15#coal seam is not reasonable,through theoretical research,numerical simulation,field experiment,the influence law of extraction parameters on the extraction effect and reasonable extraction parameters were studied systematically.The variation characteristics of the gas content and gas pressure of 15#coal seam with the depth were analyzed;The basic parameters of 8410 working face were obtained through testing directly and testing in the laboratory;Based on the basic theory of fluid flow in porous media,the mathematical model of pre-drainage coal seam gas through the hole drilled along seam is set up.Utilizing fluid dynamics software simulation analysis of the different extraction time,extraction pressure,borehole diameter and hole spacing on the extraction effect law,and obtain the appropriate extraction parameters;The reasonable pre-drainage parameters are determined by the measurement of hole arrangement in 8410 working face.According to the above study,gas content,pressure and depth of coal seam in the mining field are high in the west and low in the east.And gas content,gas pressure and coal seam buried depth obey linear positive correlation.Through numerical simulation:The influence of the extraction time,borehole aperture and hole spacing on the extraction effect is greater,and the influence of the negative pressure on the extraction quantity is greater,and the range of the extraction parameters is obtained.According to the range of the parameters on account of the simulation,the measurement of 8410 working face is obtained:the extraction from negative pressure is-25kPa,the extraction time is 120d,the borehole spacing is 5m,and the drilling diameter is 110mm,these parameters are reasonable through site validation.The results show that,the extraction scheme effectively solved the problem of low extraction rate and outburst threat in 8410 working face.