Application of high pressure DSC to the kinetics of formation of methane hydrate in water-in-oil emulsion

A micro DSC analyzer fitted with special high-pressure vessels was used to investigate the kinetics of methane hydrate formation in the water phase dispersed as a stable emulsion in deep offshore drilling fluids. At high sub-cooling conditions, the peak of hydrate formation is perfectly visible and regular-shaped, and could be fitted by a Gaussian law. The average time for hydrate crystallization of the water droplets' population was represented as a logarithmic function of the inverse of absolute temperature. At low sub-cooling conditions, the formation appears confused with the baseline; the amount of hydrate formed was thus measured from its enthalpy of dissociation, after periods of formation of variable duration.