Abstract
Methane hydrate (MH) is expected as a new resource of natural gases. However MH is solid and it doesn't flow, thus dissociation methods of MH into water and CH4 gas in oceanic sedimentary layers are necessary by depressurization. Offshore production test is planed in 2012 and 2014 by Japan national project by using the depressurization.
On the other hand, enhanced oil recovery using CO2 has been commercialized since 1970's in the US. CO2 should be used for recovery of methane hydrate to achieve both high productivity and mitigating CO2 release to the atmosphere in the same manner. We had proposed an enhanced methane hydrate recovery method using exothermic heat of CO2 hydrate formation to raise the temperature of sedimentary layers. However, it is said that CO2 can't inject into layers, because CO2 hydrate blocks the pore of sediments. So we have validated the CO2 injection principle considering the temperature of sedimentary layers by laboratry experiments. These results show a possibility of long-term CO2 injection into layers.
