Application research on high-level directional drilling technology of roof
In order to verify the gas control effect of high-level directional long boreholes in the goaf of Shanxi Sanyuan Coal Industry,a group of high-level directional long boreholes were arranged in the test working face.During the test,the composite drilling technology,fixed-point grouting reinforcement technology and full-hole section sieve tube lowering technology were used to ensure the drilling hole formation and gas drainage effect.The results show that the new technology can effectively reduce the influence of the collapse of the hole wall in the local unstable section on the drilling drainage volume,which is conducive to the stable drainage of gas in the goaf.