Regimes of methane recovery from gas hydrate on injection of “warm” carbon dioxide into a porous medium

Resumo

Specificities of an injection of “warm” liquid carbon dioxide into a porous medium saturated with methane and its gas hydrate are studied using a mathematical model presented in this work. The release of methane from gas hydrate during injection can proceed in two different regimes. In the first regime, the injection is accompanied by the replacement of methane with carbon dioxide in methane hydrate without the release of free water. In the second one, the injection is accompanied by the decomposition of methane hydrate into methane and water and by the formation of carbon dioxide gas hydrate. For each regime, selfsimilar solutions are constructed and critical conditions separating these regimes are found.