Study on sealing technology and pressure measurement device optimization for measuring gas pressure in water-bearing rock borehole
JIANG Kun
ZHOU Wei
Abstract：To address the challenge of measuring coal seam gas pressure in water-bearing surrounding rock under fracture water interference,this study analyzes the equilibrium relationship between gas and water pres-sure in water-bearing coal-rock layers.It reveals that for vertical boreholes,the pressure measurement tube should first drain water before venting gas,while for inclined boreholes,gas venting precedes water drainage.Based on fluid statics principles and integrated with innovative sealing technology and pressure measurement devices,the system achieves automatic gas-water separation in the pressure measurement chamber.Through field measurements,theoretical calculations,and result comparisons,the study accurately determines coal seam gas pressure.The paper proposes a "three-seal three-injection" segmented pressurized grouting sealing process combined with gas-water separation devices in pressure measurement chambers,enabling automatic gas -water separation and cyclic water drainage.Field measurements and theoretical analysis at the Sun Tuan Coal Mine's 10th coal seam roof and floor multi-layer sandstone aquifer successfully measured real coal seam gas pressure(0.32-0.46 MPa),effectively resolving measurement distortion caused by water pressure interference in traditional methods.This provides a reliable technical approach for accurate gas pressure determination in water-rich coal seams.
Keywords：water-bearing surrounding rockgas pressuregas-water separation devicethree-seal and three- injection
Publication Date：2026-02-28
Online Publishing Date：2026-03-12(First online date of this platform, not the publication date of the document)
Pages：7( 92-98 )