Key Technical Parameters and Application of Corner Gas Control in Soft Coal Seam with Hydraulic Slitting and Flexible Sealing Gas Wall
In order to ensure the safe mining of soft coal seam,this paper takes Tianchi Coal Mine as the background,and controls the gas overrun of this coal seam through pre-extraction and high-efficiency sealing of the upper corner.The refinement of gas control parameters can effectively improve the problems of poor permeability enhancement effect and low corner sealing efficiency in soft coal seam.In view of this,through field test and numerical simulation,the parameters such as gas drainage amount and coal output under different slotting time and water pressure are analyzed,and the technological indexes suitable for gas prevention and control technology in soft coal seam are obtained.Results show that the increase of total coal output at different slotting water pressures shows a downward trend,and with the increase of slotting water pressure,the increase of total coal output decreases and tends to be stable.The average gas extraction concentration of hydraulic slotted holes is 5.94～9.4 times that of conventional holes,and the initial extraction concentration of pre-extraction holes is more than 30％.Combined with the material performance and the field practice,the rapid plugging gas wall is designed and practised in the field.After plugging,the maximum gas concentration in the upper corner is decreased by 32.93％.
soft coal seamhydraulic slittingpre-extraction before miningupper cornergas overrun
万方数据
维普
