Institute of Petroleum Engineering

Centre for Gas Hydrate Research Publications

Abstract 021
Gas Solubility and Hydrate Formation
Tohidi, B., Danesh, A., and Todd, A. C
First MASTER Workshop, Gent, Belgium, 18-20 September (1996).
The mechanism of gas hydrate formation in sub-sea sediments is subject of some debate. Some researchers suggest that the presence of free gas phase is necessary and gas hydrates form in gas-water interface. Other believe that at least a local supersaturation of gas with respect to gas-water equilibria is required. Some propose that this supersaturation will result in evolution of microbubbles. Finally, there are some researchers who suggest that equilibrium concentration will vary with temperature and pressure, and it can be below saturation levels with respect to the free gas phase. In this presentation, and in-house numerical model, is used to predict methane concentration (in water-rich phase) in methane-water, methane-hydrate-water, and hydrate-water equilibria in the presence of distilled or formation water. The results show that the concentration of methane in the water-rich phase in equilibrium with hydrates is far less than that with the gas phase. Therefore, as far as hydrate formation in ocean sediments is concerned, hydrate can be potentially present with water which is undersaturated (so called) with methane.