Methane hydrate formation and dissociation in porous media

摘要

Natural gas hydrate is a potential source of energy for the future. However, the understanding as to how hydrates are formed in porous media and how gas and water are produced from hydrate bearing sediment is limited. In this thesis, the formation and dissociation kinetics of methane hydrates under conditions similar to the naturally occurring hydrates are experimentally investigated. In the first part of the thesis, the effects of salts and sand sizes on methane hydrate formation and dissociation were investigated in an excess gas environment. In the second part of the thesis, a fine-tuned experimental procedure was developed to produce consistent water saturated hydrate bearing sediments, enabling the comparison of gas/water production under both thermal stimulation and depressurization approaches. In both studies, clear interdependence between gas and water production was observed. This thesis provided valuable insights on the formation and dissociation behavior of methane hydrate in porous media.