Physical Simulation And Numerical Simulation Of Adsorbed State, Solubel State And Free State Gas Volume In Low Rank Coal Reservoir

As the gas content testing of soluble methane, absorbed methane and free-state methane in low-rank coal seams was inaccurate by present technologies, three states gas content was studied in this thesis. From isothermal adsorption experiment under different temperature and pressure, we discussed the effects of adsorption in low rank coal, and found the specific relation of coal components, moisture and adsorption in low rank coal reservoir, which was differed from middle/high rank coal; based on the first physical simulation of soluble methane in coal seam water, we revealed the relations of temperature, pressure, salinity, free-state CO2 content and solubility and discussed preliminary study of soluble methane mechanism in coal seam water; from the testing data of apparent relative density, true relative density, mercury injection and triaxial compression rock mechanics experiment, we simulated the deformation of low rank coal under stress and discussed mechanical properties of samples; this thesis firstly established the coupling relation of free-state methane, adsorbed methane and soluble methane in low rank coal reservoir, and set up the prediction theory and method of methane volume in low rank coal seam. Case in lignite seam of Hailar Basin, we predicted three states gas volume in coal seams above 2000m depth. This thesis enriched coal bed methane geological theory and established foundation of CBM resource exploration in low rank coal.