Gas condensate characterization from chromatogram areas and retention times

In a routine thermodynamic modeling performance test, mean values for pseudocomponents’ critical temperatures and pressures up to C40 are re-estimated for Brazilian gas condensate fields based on Gas Chromatography (GC) areas and retention times. Once the fractionʹs n-paraffin is located by its retention time in the chromatogram, the areas of all other peaks after the previous n-paraffin are computed to make up a fake non-paraffinic compound of the fraction, whose mean boiling temperature is related to its area-weighted retention time. Using a traditional three-parameter relationship among density, molecular weight and boiling temperature, these parameters, together with the molecular weight and density of the non-paraffinic compound, are estimated for each fraction up to C40, and used for the other samples to provide local Single Carbon Number (SCN) tables. The performance of such tables is compared with the original one proposed in the literature in predicting experimental PVT data using Peng-Robinson EOS in commercial simulators. Results were not improved as expected, suggesting that gas condensate thermodynamic properties are very sensitive to heavy ends mole fraction provided by GC. Rather than introducing new concepts on gas condensate thermodynamic modeling, this paper intends to provide new experimental data (and also some simple treatment on them), checking some day-by-day tools to confirm that EOS tuning strategies for gas condensate fluids remain unavoidable.