Laboratory experiments of methane displacement with carbon dioxide in the process of CO2 geological sequestration in mature gas reservoirs

Measurements of MeH displacement with CO2, in permeable rocks were performed for 2 rock cores with different permeability sampled from wells located in south-west part of Poland. Pressure and temp. conditions during the measurements represented gaseous, liq. and supercrit. conditions of CO2. The results were compared with approx anal. models, which allowed for inference on the character of the displacement process and its efficiency under various conditions. Displacement of MeH with CO2 was most effective for CO2 in a supercritical or liq. state. The MeH depletion index varied in the range of 60-72% and 58-74% under supercritical and liq. CO2 injection conditions, resp.