Grouting and plugging technology of in-seam borehole methane drainage

Abstract

Based on the analysis of the gas leakage mechanism and the principle of plugging in the surrounding rock of the in-seam borehole, a new grouting and plugging technology by separating the space and staggering time to cut off the air leakage channel was proposed. The separating space was embodied in dividing the sealing section of the borehole into a cavity section and a reserved section and a reserved section for grouting and plugging. The staggering time reflected in dividing the technical process into three stages: preparation, primary grouting and secondary plugging stages. In addition, an integrated special borehole sealing device and supporting equipment for grouting operations were designed. In order to verify the effect of the new grouting and plugging technology, a test study on the borehole grouting and plugging technology was carried out in a high gas mine in Shanxi Province. The research results showed that the concentration of gas drainage in boreholes immediately rebounded sharply, the life of in-seam borehole had increased from about 40 days to more than 80 days, and the effective drainage time of borehole had been extended to more than 2.1 times the original drainage time after the application of the new grouting and plugging technology.

Keywords

• in-seam borehole
• methane extraction
• surrounding rock of borehole
• air leakage
• grouting and plugging