Sealing Technology of Fixed-point Pressure-bearing for Drilling Through Aquifer

Aiming at the technical problems of sealing difficulty and low efficiency about gas drainage through the aquifer in 3^# coal seam of Changping Coal Mine, by the combination of theoretical analysis and field test, the technology of fixed-point pressure-bearing sealing is proposed. The minimum water injection pressure is calculated by analyzing the pressure condition of capsule sealing to achieve the fixed-point pressure-bearing. The high water absorption gel is taken as the grouting material to absorb the pressure water in the hole. The application results show that compared with traditional sealing methods, the fixed-point pressure-bearing sealing method is five times of the previous ones on the success rate, the maximum concentration of average drainage in single hole is 53.42%, 65.94 times increased, furthermore, the concentration of gas drainage decays more slowly.