The Simulation Of Coal Reservoir Soluble Gas And Research On Hydrogeologic Gas Controlling In Fukang Mining Area

In order to estimate the content of soluble gas in coal reservoirs in Fukang Mining Area.The change law of CBM solubility under the condition of different temperature, pressure, salinity, CBM components, and reservoir water ion type were studied. Based on the dissolved mechanism of gas in the electrolyte solution, the calculation method of the gas solubility was contrast. The CO2 solubility calculation model under the condition of 0 to 3 MPa, the CH4 solubility calculation model under the condition of 0 to 3 MPa, the N2 solubility calculation model under the condition of 0 to 3MPa and the CH4 solubility calculation model under the condition of 3~30 MPa were established respectively. On this basis, the solubility calculation model of CBM was established under the condition of the different temperature, pressure, salinity and gas composition. The relative error of CBM solubility is less than 4% between the calculation method and measured method. The coal samples porosity from Fukang Mining Area under the different confining pressure was physical simulated. On the basis of physical simulation, the relationship between coal reservoir porosity and effective stress of Fukang Mining Area was discussed. The calculation model of relationship between the coal reservoir porosity and effective stress is established. The numerical simulation method was proposed by using reservoir porosity measured in ordinary pressure to deduce the porosity in situ coal reservoir. On the basis of numerical simulation of the coal reservoir porosity and the CBM solubility, the calculate method of soluble gas content in coal reservoir was established. The calculated soluble gas content of No. 45 coal seam in Fukang Mining Area of Badaowan Formation ranges from 0.043 to 0.063 m3/t.The relation between hydrogeololgy and the depth of coal seam oxidation zone, gas content and secondary biogenic gas was explored.