Instability of dissociation process of methane hydrate bearing soil

Abstract

Methane hydrates which exist in both the permafrost sediments and the deep seabed ground are viewed as a new energy resource. It is, however, well known that dissociation process of gas hydrate such as methane hydrate may lead to instability such as large deformation, uncontrollable gas production etc. In the present study, a linear instability analysis was performed in order to investigate which variable has a significant effect on the onset of the instability of methane hydrate bearing geo-materials subjected to methane hydrate dissociation. Stability analysis shows that the onset of the growing instability of the material system mainly depends on the hydrate dissociation rate and the strain hardening-softening parameters. In addition, the stability depends on the wave number of the fluctuation. For larger value of the wave number of the fluctuation, the magnitude of viscoplastic parameter affects the instability, as well as the hardening-softening parameter.