Natural gas hydrate has currently been recognized as a potential alternative to traditional energy resources. In this study, the layered hydrate, which is a kind of grain-displacing hydrate, was synthetized in sea muds from South China Sea, and its dissociation behaviors by depressurization with different ambient temperature were investigated. The experimental results indicated that the cumulative gas production increases quickly with the pressure decrease. When the pressure reaches the setting production pressure and keeps constant, the gas production rate decreases significantly. The hydrate dissociation rate increases with the increase of the ambient temperature. There are obvious layered hollows in sea muds after hydrate dissociation. The sediment deformation cannot be ignored during the gas recovery from layered hydrate in sea muds.
Keywords hydrate, layered, sea muds, dissociation, depressurization