The R&D on gas hydrate production focuses on optimizing field applications of depressurization techniques in the Ulleung Basin in the East Sea. Depressurization-based production technology was applied to a 3D m-scale gas hydrate production system and to a core-scale X-ray CT system. In addition to these experiments, we developed a numerical THM code for gas hydrate production. From our experiments and simulations, we could confirm that the propagation of gas hydrate dissociation was delayed at high hydrate saturation rates. It was also found that the impact of salinity appeared to have a significant effect on the propagation of gas hydrate dissociation (Fig. 1).
In a study of well-bore stability during the GH production process, various experiments were performed to investigate the interaction between the well bore and GH-bearing sediment and to predict sand production behavior. As a result, we presented models of shear and normal coupling stiffness with confining stress and applied the models to a numerical analysis of well-bore stability (Fig. 2). We also developed a model of the behavior of physical properties according to the fine migration of GH-bearing sediment and proposed a major constitutive model of fine migration behavior.
