When CO_2 is injecting into marine sediments, CO_2 forms solid CO_2 hydrate and it blocks voids of the sediments. So an injecting method is necessary for long term injection in order to use CO_2. We have been focused into the exothermic heat of CO_2 hydrate. The heat can warm saturated sands by about 9 degrees centigrade. This means that the layers are warmed to phase equilibrium temperature between solid CO_2 hydrate and liquid We have shown CO_2 can flow at the phase equilibrium temperature CO_2/water emulsion can generate heat at the top of flow without blocking the voids. The emulsion flows through sands at the phase equilibrium temperature.