Research and application of hole-forming technology of high-position directional long borehole in complex stratum

In order to solve the technical problems of the difficulty of making holes in the roof high-position directional long borehole caused by the mudstone hydration under the complex stratum conditions of Shuguang Coal Mine, field tests were carried out using directional guide holes and large diameter spiral reaming of hole-forming technology. Nine high-level directional long boreholes were successfully constructed with a depth of more than 520 m and a hole diameter of 153 mm, with a maximum drilling depth of 801m for a single hole, forming a high-level directional long boreholesdrilling technology suitable for complex stratum on the roof of Shuguang Coal Mine. The research results show that cutting the mudstone hydration zone around the borehole wall by spiral reaming can help improve the stability of the borehole wall. Also, the annulus composite row formed by the large-diameter spiral reaming process can significantly improve the drilling slag discharge energy efficiency.