Experimental research on wire-line coring drilling technology for near-horizontal boreholes in complex stratum in underground coal mine

Abstract:

For conventional single-tube coring in coal mine underground drilling, there are several disadvantages such as low core recovery, low efficiency and high labor intensity, and difficulty in drilling holes in the near-horizontal coal seam floor with clean water as the drilling medium. Field tests were carried out by selecting and using professional near-horizontal wire-line core drilling rigs and wire-line core drilling tools. Three boreholes were drilled, and two of them were completed at the depth of 151.5m and 194.5m with the average core recovery of 77% and 89% respectively, more than 24% higher than that with the single tube. Average daily footage was 22.7m/d and 36.6m/d, more than 10% higher than that with the single tube. The wire-line coring drilling equipment and technologies for near-horizontal boreholes with clear water as the drilling medium in complex coal mine tunnels was optimized through the above field experiments.