Dissociation experiment of hydrate core sample using thermodynamic inhibitors

Natural gas hydrate that exists in the sediment constitutes a large natural gas reservoir and is expected to be an energy resource in the future. To make recovery of natural gas from hydrates commercially viable, hydrates must be dissociated in-situ. Dissociation behavior of an artificial hydrate core sample in inhibitor aqueous solution (methanol aqueous solution) was studied. A newly constructed experimental set-up equipped with core holder was used to investigate the dissociation behavior of hydrate core sample under similar condition under seafloor. The dissociation behavior of pure methane hydrate pellet in methanol aqueous solution was studied as a first step. The actual concentration near the MH reaction surface was lower than initial concentration because of the generated water by MH dissociation. The obtained outlet temperature changed continuously suggesting that the concentration near the MH reaction surface also changed by the generated water. The obtained gas production results of methanol solution represented exponential trend, while the results of pure water represented linear trend. The advantage to use the inhibitor was remarkable at lower temperature. This is an abstract of a paper presented at the 15th International Offshore and Polar Engineering Conference (Seoul, Korea 6/19/2005).