Impact research of CH4 replacement with CO2 in hydrous coal under high pressure injection

Purpose. Based on high-pressure gas injection technology that enhances coal seam drainage, the effect of CH4 replacement with CO2 in aquiferous has been studied. Methods. Using laboratory experimental method and self-built device, is injected into different moisture contents to replace under adsorption equilibrium pressures. Findings. With an increase content, capacity for gradually weakens, always greater than CH4, rate ratio decrease. It concluded are negatively correlated water content coal. pre-adsorption pressure (0.5, 0.75, 1.0, 1.3 2.0 MPa), first sharply then slowly increase. The transition point MPa (pre-adsorption CH4). Originality. characteristics injection, influence analyzed, mechanism Practical implications. results have important guiding significance selecting reasonable source drive its underground seam.