Formation of carbon dioxide hydrate at the injection of carbon dioxide into a depleted hydrocarbon field

The carbon dioxide injection into a reservoir which contains methane and water in the free state is investigated. A mathematical model for forming carbon dioxide hydrate at the phase transition front that separates the methane and carbon dioxide regions is proposed. Conditions at the interface are derived and an asymptotic solution of the problem is found. It is shown that the CO2 hydrate formation may occur at pressures and temperatures that do not lie on the dissociation curve. Critical diagrams of the process, which determinine the range of parameters at which the complete transition of the injected gas into the hydrate state takes place are obtained.