Displacement of methane from a gas hydrate reservoir in the process of carbon dioxide injection

In this paper, a numerical simulation of the process of methane displacement from a gas hydrate reservoir during the injection of carbon dioxide followed by methane substitution by carbon dioxide in the composition of the hydrate was performed. The process of gas replacement was assumed to occur in a stable field of methane hydrates and carbon dioxide with CO$_2$ in a gaseous state. The intensity of carbon dioxide hydrate formation was determined by diffusion of carbon dioxide across the hydrate layer formed between a stream of the gas mixture and the methane hydrate in the porous channels.
The general pressure of the system, the partial pressures of the carbon dioxide and methane, the saturations of hydrates of carbon dioxide and methane, and the temperature as functions of time were obtained. In the initial stage of the process, free methane was forced out, and subsequently the methane received after the gas replacement process was extracted. This resulted in a complete transition of methane hydrate into carbon dioxide hydrate and a complete extraction of methane from the porous reservoir.