Prediction of the conditions for sour gas hydrate formation in the presence of methanol inhibitor

ABSTRACT

In this work a new thermodynamic model for accurate prediction of H₂S and CO₂ containing sour gas hydrate equilibrium dissociation temperatures in the presence of a gas hydrate thermodynamic inhibitor (methanol) is presented. The average absolute deviation between the predicted and measured sour gas hydrates dissociation temperatures (AADT%) considering pure and mixed acid gases in the presence of methanol inhibitor is about 0.274% which is much lower than those obtained by the other available thermodynamic models. The proposed approach is quite reliable over wide ranges of methanol and acid gases concentrations and can be used for performance evaluation of other gas hydrate inhibitors regarding the design of sour natural gas flow assurance systems in oil and gas industries.

KEYWORDS:

• gas hydrate
• acid gas
• natural gas
• inhibitor
• flow assurance

Nomenclature

Ti,pred	=	predicted hydrate equilibrium dissociation temperature in Eq. (11(11) )
Ti,exp	=	measured hydrate equilibrium dissociation temperature in Eq. (11(11) )
N	=	number of data points in Eq. (11(11) )