(286c) Prediction of Gas Hydrate Formation Conditions in Brine Systems with the Enrtl Model

As oil and gas fields and developments delve into deeper water, the harsh conditions in terms of high pressure and salinity requires reliable and accurate prediction of hydrate phase equilibrium conditions in salt aqueous solutions with concentration up to saturation over a wide range of pressures. This study develops a predictive method to estimate hydrate suppression temperature in high salinity systems. The simple but robust prediction is based on the fundamental principle of freezing point depression, which for hydrate is equivalent to the suppression temperature from the uninhibited (salt-free) systems. The water activity, highly dependent on the salt species and concentration, is the key factor for determining the hydrate inhibition strength. Therefore, in this developed predictive method, the hydrate suppression temperature with any saline systems can be accurately and directly predicted with the calculation of water activity using the electrolyte-NRTL (eNRTL) model. The presentation will show the reliability of the predictions as well as how it can be generally used for the prediction of the hydrate suppression temperature for any brine system.