Most outburst mines in China adopt the measures of pre drainage by drilling along the seam for gas control in the mining area, that is, drilling along the seam from the air roadway of the mining machine to the mining ...Most outburst mines in China adopt the measures of pre drainage by drilling along the seam for gas control in the mining area, that is, drilling along the seam from the air roadway of the mining machine to the mining area. The drainage effect of drilling along the seam is directly related to the gas control effect of the mining area. For many years, we have carried out the measures according to the provisions of the detailed rules for the prevention and control of coal and gas outburst. The sealing length of the bedding hole is consistently kept at 8m, and the depth of the sealing section is kept at about 10m, and the extraction concentration and pure amount have been maintained at a low level, resulting in relatively large gas emission during mining. We break the Convention and calculate the sealing depth of the hole according to the pre drainage equivalent width of the coal roadway. At the same time, the extended version of high-pressure grouting is used for two plugs and one injection seal, so that the hole sealing depth of the borehole is within the equivalent width of the roadway pre drainage gas, and the length of the hole sealing section is longer. At the same time, combined with the whole process casing running technology of bedding drilling, the contact area between the screen pipe and the coal wall is likely to be increased, and good results have been achieved in preventing the impact of hole collapse and other phenomena on the drainage effect. The concentration of single hole drainage and the net amount of main pipe drainage have been greatly improved, and the gas content and gas pressure of coal have decreased significantly.展开更多
文摘Most outburst mines in China adopt the measures of pre drainage by drilling along the seam for gas control in the mining area, that is, drilling along the seam from the air roadway of the mining machine to the mining area. The drainage effect of drilling along the seam is directly related to the gas control effect of the mining area. For many years, we have carried out the measures according to the provisions of the detailed rules for the prevention and control of coal and gas outburst. The sealing length of the bedding hole is consistently kept at 8m, and the depth of the sealing section is kept at about 10m, and the extraction concentration and pure amount have been maintained at a low level, resulting in relatively large gas emission during mining. We break the Convention and calculate the sealing depth of the hole according to the pre drainage equivalent width of the coal roadway. At the same time, the extended version of high-pressure grouting is used for two plugs and one injection seal, so that the hole sealing depth of the borehole is within the equivalent width of the roadway pre drainage gas, and the length of the hole sealing section is longer. At the same time, combined with the whole process casing running technology of bedding drilling, the contact area between the screen pipe and the coal wall is likely to be increased, and good results have been achieved in preventing the impact of hole collapse and other phenomena on the drainage effect. The concentration of single hole drainage and the net amount of main pipe drainage have been greatly improved, and the gas content and gas pressure of coal have decreased significantly.
