Experimental research on displacing coal bed methane with supercritical CO2

摘要

The high gas and low permeability are the common problems of coal mine in China, which restrain the mining of coal seam gas resources safely and efficiently. To solve the problem of low permeability of coal seam, an experimental system was set up and the effect of the displacement of methane by injecting supercritical CO2 into coal samples was studied by the use of the experimental system. The experimental results indicated that due to the extraction effect of supercritical CO2 the coal porosity was changed and the seepage channel for methane was broadened. Thus, the methane could be desorbed effectively from the coal matrix, and flow through more cracks at higher speed.