Micro-CT analysis of structural characteristics of natural gas hydrate in porous media during decomposition

Natural gas hydrate in porous medium is a widespread form of hydrate in the natural world. In this study, porous media composed of sand at three particle sizes (0.85-1.18, 1.18-2.85, and 2.85-4.8 mm) were used to form natural gas hydrate by the Hydrate Synthetic Test System. The temperature and pressure during the formation process were described. The micro structural characteristics of the backbone, porosity, and the synthetic natural gas hydrate in porous media were studied by the High-precision Micro-CT Test System during decomposition. The results indicate that the hydrate is uniformly distributed and almost completely fill the pores of the porous media. The micro structural characteristics of the natural gas hydrate in porous media of three particle sizes and the backbones are also studied during the decomposition process. The relationship between the sand particle size and the maximum deformation of the backbone in the final stage of hydrate decomposition is determined.