Study of Mechanical Cavity-forming Technology for Underground Gas Drainage Hole Drilling
ZHAO Jizhan
Abstract：In order to solve the problem of difficult gas drainage from the coal seam with low permeability, study was carried out on the main ways for improving gas drainage efficiency by theoretical analysis and numerical simulation,coal-bed methane well completion technology was used for reference, a cavity-forming tool with a retractable arm was developed, which took the drill feed and rotation as the power and was suitable to drill gas drainage holes, with this cavity-forming tool, Φ600 mm cavity-forming technology can be achieved at a fixed position in underground gas drainage holes. The cavity-forming drilling test in Luling Coal Mine showed that the mechanical cavity-forming technology for coal gas drainage drilling can significantly improve the efficiency of gas drainage, and compared with the conventional gas drainage drilling, the gas concentration of a single hole with the cavity-forming drilling technology increased by 2. 31 to 4. 00 times and the pure gas flow increased by 2. 63 ~ 5. 11 times.
Keywords：coal seam with low permeabilitygas drainagemechanical cavity-formingnumerical simulation
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 66-68,72 )