Research On Gas Pressure Measurement Method Based On Gas Dissolved In Water

When the determination of gas pressure in water bearing coal seam is going on, water will enter the air chamber test, affecting the accuracy of the coal bed gas pressure determination. In order to solve this problem, this paper puts forward a method to measure the gas pressure in the coal measure strata based on the gas dissolved in water. In this paper, the theoretical calculation method of gas solubility in water is analyzed, and the effect of gas pressure, temperature, salinity and organic matter on the gas solubility is studied. The gas pressure measuring process of water cut coal measure strata based on water gas dissolved in water was designed, and the field test method and test equipment were processed. We take the gas pressure test In Taoyuan Coal Mineof Huaibei Mining Group, and the gas pressure determined II 4 10 coal mining area is successful.Based on the oretical calculation, the solubility of gas in water under different conditions was calculated, and the influence factors of gas solubility were analyzed. The solubility of gas in water increased with the development of pressure, the solubility of gas in water decreased first and then increased with the development of temperature, the solubility of gas in water decreased with the development of salinity.The analysis law of gas dissolved in water and its influencing factors are studied by experiments. Through the experiment we found that dissolution equilibrium quantity of gas with gas pressure increase and increase, showed a linear correlation; gas pressure of dissolution equilibrium time had no effect, after 100 h dissolved gas in different gas pressures are close to or reach dissolution equilibrium state; temperature rise will lead to gas dissolving equilibrium time shorter, while reducing the amount of dissolved gas balance; salinity rise will result in the decrease of of gas solubility in water, and organic matter produced by the impact is on the contrary.The gas pressure measuring process of water cut coal measure strata based on water gas dissolved in water was designed.The field testing equipment and laboratory testing equipment were processed. Pressure flow two steps: in situ testing and laboratory testing.The testing device can complete downhole drilling and water drainage, gas analysis and measurement, water gas sample collection work. The laboratory test device can perform well under different pressure water sample analysis of gas volume and solubility measurements. The relationship between the water solubility of gas balance and gas pressure canbe found, finally get the gas pressure of the measuring point.We take the gas pressure test In Huaibei mining group Taoyuan Coal Mine 4 mining area 10 coal seam. According to the field and laboratory testing process get the original coal gas pressure 0.40 MPa, and according to the gas pressure gradient formula suggested by the gas pressure(0.38mpa) comparison, the relative error is less than 10%. The measurement of this gas pressure provides a successful example for the future application.This paperanalyzes the influence factors of gas solubility through theoretical computation; Through the experiment studied pressure, temperature, salinity, organic matter content of gas in the influence of dissolved gas analysis, compiled based on the amount of gas dissolved in water.Water coal bearing strata gas pressure determination of design flow and processing the field testing equipment and laboratory test device; In Taoyuan Coal Mine of Huaibei mining group, we take the gas pressure test, and the successful determination of the II area 4 10 coal seam gas pressure. The research results are of great significance to the safety production of the mine.