The Péneloux-Rauzy-Fréze (PRF) method of improving volumetric predictions by introducing a third parameter into a two-parameter equation of state (EOS) is applied to the Peng-Robinson EOS (PR-EOS). The modified PR-EOS is evaluated for application to hydrocarbon fluids. A method is developed for characterizing the third parameter for the heptanes-plus fractions. The usefulness of the modified PR-EOS in improving volumetric predictions is illustrated by applying the equation to several crude-oil and gas-condensate systems from the literature.

Keywords:
upstream oil & gas, molecular weight, hydrocarbon, pseudocomponent, standard condition, heptane-plus fraction, fluid modeling, gas condensate, experiment, characterization
Subjects:
Fluid Characterization, Fluid modeling, equations of state, Phase behavior and PVT measurements
Copyright 1988, Society of Petroleum Engineers
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