Natural gas hydrate has been regarded as an alternative energy resource and has attracted much attention in recent years. According to laboratory investigations and field test researches, pore-scale distribution habit of gas hydrate in the hydrate bearing sediments plays a critical role in gas hydrate exploration and exploitation. In this work, the micro X-ray computed tomography was applied to investigate the pore-scale hydrate distribution habit during hydrate formation and dissociation. The gas hydrate was formed and dissociated in-situ and a nondestructive detection was performed to observe the internal characteristics of the hydrate sediment. The experimental results indicate that the hydrate distribution habit evolves from grain-coating to pore-filling during hydrate formation. During hydrate dissociation, thermal stimulation can promote homogeneous hydrate redistribution, and uniform distribution of glass beads is promoted by the depressurization.
Keywords Gas hydrate, micro X-ray CT, distribution habits, formation, dissociation