Predicting the dew point pressure for gas condensate reservoirs by Esmaeilzadeh-Roshanfekr equation of state

This paper presents a new equation of state (ER-EOS) to estimate dew point pressure (DPP) for gas condensate reservoirs. Three gas condensate fluid samples taken from three wells in a real field in Iran, here referred to as SA1, SA4 and SA8 as well as five samples from literature have been used to check the validity of the ER EOS in calculating the dew point pressure of gas condensate mixtures. The accuracy of the ER EOS has been compared to Peng-Robinson (PR) EOS. In order to have an unbiased comparison between the ER and PR EOS, van der Waals mixing rules are used without using any adjustable parameters(kij=0). Also, no pure component parameters are adjusted. In this work Kesler-Lee, Pedersen et al. and Riazi-Daubert methods are used to estimate critical properties and acentric factors of plus fraction components. The results of dew point pressure calculations show that dew point pressure is sensitive to the methods of calculating critical properties and acenteric factors of plus-fractions. However, the results of the ER EOS are closer to the experimental data than the PR EOS.

Keywords:

Dew point pressure , Critical properties , Equation of state , Gas condensate , Mixture