When CO2 is injecting into marine sediments, CO2 forms solid CO2 hydrate and it blocks voids of the sediments. So an injecting method is necessary for long term injection in order to use CO2 for methan hydrate recovery. We have been focused into the exothermic heat of CO2 hydrate. The heat can warm saturated Toyoura sands by about 9 degrees centigrade. This means that the layers are warmed to phase equilibrium. We have shown CO2 can flow at the phase equilibrium temperature. CO2/water emulsion can generate heat at the top of flow without blocking the voids. The emulsion flows through sands at the phase equilibrium temperature. This function of CO2 emulsion shows a possibity for enhanced recovery of methane hydrate using CO2.
