CCTEG Xi'an Research Institute: Shoring Up Coal Mine Safety Defense with Long - Distance Directional Drilling Technology

Recently, relying on its advanced long-distance directional drilling technology and innovative processes, CCTEG Xi'an Research Institute successfully addressed the threat posed by accumulated water in the goaf of the upper coal seam of a coal mine in Ordos City, during cross-heading excavation. This highlights the significant value of technology in empowering the safe production of coal mines.

For a long time, this coal mine has faced complex problems, including a small spacing between coal seams, long-distance directional boreholes for water drainage, and difficulty draining water from old goafs. These issues have limited the mine's tunneling efficiency and endangered miners' lives. Relying on its technological accumulation, CCTEG Xi'an Research Institute actively carried out collaborative research, providing a systematic solution to break through the bottleneck of coal mine water hazard prevention and control with precise directional drilling technology.

During the project implementation, the ZDY15000LD crawler-type directional drilling rig and the BLY-500 crawler-type mud pump truck, both independently developed by CCTEG Xi'an Research Institute, were selected to ensure that the drilling depth met the engineering requirements. The directional drilling tool, combined with high-toughness triangular spiral wire-passing drill pipes, was used to efficiently remove slag and prevent accidents such as pump blockage and hole collapse caused by rock fragmentation. For boreholes with a relatively rapid decline in water inflow after hole formation, the innovative reverse-drilling lateral-branching process was adopted to precisely control the borehole trajectory and ensure effective water drainage. Up to now, more than 200,000 m³ of accumulated water in the upper old goaf has been drained, and the water head of the old goaf has dropped by more than 10m.

Through efficient construction and precise borehole targeting, the team completed 12 main holes and 3 branch holes in 117 days. The effective footage reached 6,100 meters, with the maximum daily footage reaching 300 meters. This significantly reduced pressure on water hazards during the rapid excavation of the cross-heading, successfully protected the cross-heading excavation, and remarkably improved mine safety and excavation efficiency. It also provided a replicable technical solution for similar subsequent projects.