ESTIMATION BY EXPERIMENTS AND ITS ANALYSIS FOR THERMAL STIMULATION OF METHANE HYDRATE USING EXOTHERMIC REACTION OF CO₂ HYDRATE FORMATION

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 proposed. Here we focused on the exothermic reaction of CO₂ hydrate formation for thermal stimulation of the layers. The possibility for raising temperature of the sedimentary layers by the exothermic heat of CO₂ hydrate is considered by following items. 1) A laboratory experiment to measure temperature through CO₂ hydrate formation in a pressure cell. 2) Proposing a numerical temperature-raising model by CO₂ hydrate formation. 3) An estimation of the temperature raising model using unsteady heat diffusion analysis by simulating the results of the laboratory experiment. 3) An analysis considering the boundary condition of sedimentary layers and the estimated model. As a result, the temperature of the layers can be raised by about 9°C using CO₂ hydrate formation. Then this shows a possibility to use CO₂ as a warming material for oceanic sedimentary layers to exploit MH.