Experimental Modeling of Methane Hydrate Formation and Decomposition in Wet Heavy Clays in Arctic Regions

Experimental studies on clay sample saturation by methane hydrates proved that clay particles play an important role in the hydrate accumulation and decomposition processes in sediments. Depending on water content, the same clay mineral can serve as inhibitor, neutral component and promoter of hydrate formation. Wet clay is a good mineral surface for hydrate formation, but clays represent the worst media for hydrate accumulation and existence. Nevertheless, there are many observations of hydrate presence in clay-containing sediments, especially offshore. Experimental modelling of metastable hydrate decomposition in sediment samples recovered from permafrost in Yamal crater in the Russian Arctic has shown that metastable hydrates located in frozen, salted clays can generate huge volumes of gas, even with a negligible (tenth and hundredth of a degree) temperature rise.