Performance verification test of directional drilling continuous coring tools for tunnel exploration

Abstract:

To address the challenges of low efficiency associated with traditional vertical boreholes and the inability of conventional directional drilling tools to achieve continuous coring in deep-buried water conveyance tunnel exploration， a novel directional drilling continuous coring tool was developed based on wireline coring and directional drilling technologies. An indoor drilling test platform was established to validate the tool''s performance in directional deflection and continuous coring. The results demonstrate that the tool operates stably， successfully achieving directional drilling and high-quality continuous coring. The actual deflection capability reached 3.50°/30 m， closely aligned with the theoretical calculation. The core recovery rate was as high as 93%~98%， with a Rock Quality Designation （RQD） value ranging from 80% to 91%. This research provides an efficient and reliable technical solution for the exploration of deep-buried long tunnels and holds significant importance for advancing the development of directional drilling continuous coring technology.