Environmentally Friendly CO_2Storage in Hydrate Reservoirs Benefits From Associated Spontaneous Methane Production

摘要

Magnetic Resonance Images (MRI) of core plug experiments shows that CO_2 storage in gas hydrates in porous rock results in spontaneous production of methane, with no associated water production. Exposing methane hydrate to liquid CO_2 causes methane production from the hydrate that indicates an exchange of methane molecules with CO_2 molecules within the hydrate; without addition of heat. Thermodynamic simulations based on Phase Field theory support this assumption and predict similar methane production rates observed in several reproduced experiments 3D-visualizations of the formation of hydrates in the porous rock and the methane production improve the interpretation of the experiments. Sequestering a greenhouse gas while simultaneously producing the freed natural gas may offer access to the significant amount of energy bound in hydrates and may offer an attractive potential for CO_2 storage Relative to the potential danger of catastrophic dissociation of hydrate structures, and corresponding collapse of geological formations, the increased thermodynamic stability of the CO_2 hydrate relative to the natural gas hydrate is also a positive issue related to the combined CO_2 storage and gas exploitation strategy.