Thermophysical Properties, Hydrate and Phase Behaviour Modelling in Acid Gas-Rich Systems

Abstract : In this communication we present experimental techniques, equipment and thermodynamic modelling for investigating systems with high acid gas concentrations and discuss experimental results on the phase behaviour and thermo-physical properties of acid gas-rich systems. The effect of high CO2 concentration on density and viscosity were experimentally and theoretically investigated over a wide range of temperature and pressures. A corresponding-state model was developed to predict the viscosity of the stream and a volume corrected equation of state approach was used to calculate densities. The phase envelope and the hydrate stability (in water saturated and under-saturated conditions to assess dehydration requirements) of some acid gas-rich fluids were also experimentally determined to test a generalized model, which was developed to predict the phase behaviour, hydrate dissociation pressures and the dehydration requirements of acid gas rich gases.