Methane hydrate is being considered as a potential future energy source but may at the same time constitute a considerable geo-hazard. In the present study, methane hydrate bearing sand sediment was created by pressurizing methane gas into previously moistened, then chilled, packed sand specimen (excess gas method). The excess gas was then replaced by water at high pressure. Afterward, a heating/cooling cycle was applied under undrained conditions, in order to completely dissociate gas hydrates and then recreate them inside the specimen. Finally, the pore pressure was reduced to the atmospheric pressure to dissociate gas hydrates. The whole process was performed in a magnetic resonance imaging (MRI) system, allowing the determination of water and/or gas and hydrate quantity (and spatial distribution) at various times. The MRI signal was finally analyzed to interpret various processes in sand sediment: initial hydrate formation, heating-induced hydrate dissociation, cooling-induced hydrate re-formation, and depressurizing-induced hydrate dissociation.

甲烷水合物被认为是潜在的未来能源，但同时可能构成巨大的地质灾害。在本研究中，通过将甲烷气体加压到预先润湿，然后冷却，填充的砂样中（过量气体法）来产生含甲烷水合物的砂沉积物。然后将过量的气体用高压水代替。此后，在不排水的条件下进行加热/冷却循环，以完全分解气体水合物，然后在样品中重新生成它们。最后，将孔隙压力降低至大气压以分解气体水合物。整个过程在磁共振成像（MRI）系统中执行，从而可以确定不同时间的水和/或气体和水合物含量（和空间分布）。