Double-layer pipe hole sealing method for directional long drill hole in thick coal seam mining pressure relief zone

The invention discloses a thick coal seam mining pressure relief zone directional long drill hole double-layer pipe hole sealing method which comprises the following steps: analyzing and researching a pressure relief zone range around a stope face goaf by adopting comprehensive analysis methods such as theoretical analysis, numerical simulation and engineering practice and combining directional long drill hole extraction drill hole design parameters and construction process parameters; the influence degree and range of the pressure relief zone on directional long drill hole construction, hole sealing and gas extraction are determined; according to the extracted gas mixing amount, the main body extraction drill hole diameter and the directional long drill hole length which are analyzed and designed, the normal extraction negative pressure of the directional long drill hole fissure zone extracted gas and the extraction negative pressure under the difficult condition are obtained, and a thick coal seam mining pr