Replacement of Ch4 with Co2 in a Hydrate Reservoir at the Injection of Liquid Carbon Dioxide

On the basis of the equations of multiphase media mechanics the mathematical model is proposed for the replacement of methane with carbon dioxide in a porous reservoir of finite length, initially saturated with methane and its hydrate, at the injection of liquid carbon dioxide. Solutions of the axisymmetric problem describing pressure and temperature distributions in the reservoir are constructed. It has been found that at low injection pressure the reservoir pressure in a portion of the region, saturated with carbon dioxide and its hydrate, may fall below the boiling point of CO2. This corresponds to the appearance of an additional phase transitions surface on which the carbon dioxide boils.