New Technology of Precision Measuring Gas Pressure in Upstream Drilling with Water

For the current situation of difficult gas pressure measurement under the complex geological conditions like coal moisture, water seepage, easily broken roof and so on, we analyze the influence of measurement results under different water seepage condition of up-pressure-drilling, and find that some drill holes have excessive water or collapsed, the revised pressure will have deviation by deleting water pressure. And thus We design the pressure measurement system that the core is the "high-low double piezometer tubes" and the supporting corresponding rapid grouting hole sealing device. After the analysis and test in Zhenxing No.2 Mine in Zhengzhou Coal Mine Group, the results shows that the pressure measurement system can effectively remove the accuracy of the gas pressure measurement influenced by the phenomena of borehole moisture, borehole collapse, and provide a complete set of technical methods of the accurate coal seam gas pressure measurement under the complicated geological conditions.