Peng-Robinson Equation of State Predictions for Gas Condensate Before and After Lumping

Raffie Hosein, Richard A. Dawe, Mahmood Amani


Gas condensate compositional simulation studies are conducted to evaluate gas and condensate reserves and make comparisons of production methods for the economic development of a reservoir. The data needed for the evaluation are dew point pressure, gas compressibility factor, liquid volume and produced gas. Hosein and Dawe showed that compositional analysis greater than Single Carbon Number 24 (SCN24) is required for accurate prediction of these data by a tuned Equation of State (EOS). However they did not demonstrate the accuracy of their tuning technique with lumped components which are applied when performing simulation studies to reduce cost and computer time involved. 
Simple and complex schemes for lumping of the SCN groups into less than 6 Multiple Carbon Number (MCN) groups have been devised. However there are currently no criteria for selecting the best lumping scheme that will give similar accuracy to using many SCN groups except by trial and error, or by algorithms designed to test a number of schemes and to select the best one. In this paper we have used Whitson’s lumping scheme which is in the form of a simple mathematical expression in comparison to other lumping schemes from the open literature.
The tuning technique of Hosein and Dawe was applied and differences of less than ±4.0 % from tuned EOS predictions before and after lumping of the SCN groups were obtained. These results indicate that the tuning technique of Hosein and Dawe could be used to perform accurate simulation studies of lean and rich gas condensate systems using MCN groups lumped by the Whitson’s lumping scheme. Complex algorithms are not necessary to select an appropriate lumping scheme.
Key words: Gas condensate; Equation of state; Predictions; Single carbon number; Lumping


Gas condensate; Equation of state; Predictions; Single carbon number; Lumping

Full Text:



[1] Agarwal, R. K., LI, Y.-K., & Nghiem, L. (1990). A Regression Technique with Dynamic Parameter Selection for Phase Behaviour Matching. SPE Res. Eng., 5(1), 115-119.

[2] Ahmed, T. (1989). Hydrocarbon Phase Behaviour. Houston: Gulf Publishing Company.

[3] Al-Meshari, A. A., & McCain, W. Jr. (2007, 3). Validation of Splitting the Hydrocarbon Plus Fraction: First Step in Tuning Equation of State. SPE 104631-MS. Paper presented at SPE Middle East Oil and Gas Show and Conference in Bahrain (pp. 11-14).

[4] Behrens, R., & Sandler, S. (1986). The Use of Semi-Continuous Description to Model the C7+ Fraction in EOS Calculations.SPE Res. Eng., 3(3), 1041-1047. Paper presented at the SPE/DOE Fifth Symposium on Enhanced Oil Recovery of the Society of Petroleum Engineers and the Department of Energy held in Tulsa, Oklahoma. April 20-23.

[5] Coats, K. H., & Smart, G. T. (1986). Application of a Regression Based Equation of State PVT Program to Laboratory Data. SPE Res. Eng., 1(3), 277-299.

[6] Danesh, A. (1998). PVT and Phase Behaviour of Petroleum Reservoir Fluids. Amsterdam: Elsevier.

[7] Dennis Jr., J.E., Gay, D.M., & Welsch, R.E. (1981). An Adaptive Nonlinear Least-Squares Algorithm. ACM Trans. Math. Software, 7(3), 348-386.

[8] Hosein, R. (2004). Phase Behaviour of Trinidad Gas Condensates. Ph.D. Dissertation, The University of the West Indies, St Augustine, Trinidad.

[9] Hosein, R., & Dawe, R. A. (2011). A Parametric Methodology in Tuning the Peng-Robinson (PR) Equation of State for Gas Condensate Systems. Paper submitted to Journal of Petroleum Science and Technology (accepted, in press).

[10] Hosein, R., & Dawe, R. A. (2011). TBP and Chromatographic Data for Gas Condensates Characterization. J. of Petrol. Sci. and Eng., 75(3-4), 283-288.

[11] Hosein, R., & McCain, W. Jr. (2009). Extended Analysis for Gas Condensate Systems. Reservoir Evaluation and Engineering, 12(1), 159-166.

[12] Kai, L. (2001). Reduce the Number of Components for Compositional Reservoir Simulation. Paper presented at the 2001 SPE Reservoir Simulation Symposium in Houston, Texas (11-14).

[13] Katz, D. L., & Firoozabadi, A. (1978). Predicting Phase Behavior of Condensate/Crude Oil Systems Using Methane Interaction Coefficients. J. Pet. Tech., 30(11), 1649-1655.

[14] Lee, B. I., & Kesler, M. G. (1975). A Generalized Thermodynamics Correlation Based on Three-Parameter Corresponding States. AICHE J., 21(3), 510-527.

[15] McCain, W. D. (1990). The Properties of Petroleum Fluids, Second Edition. Tulsa, Oklahoma: Penn Well Publishing Co..

[16] Oellrich, L., Plocker, U., Prausnitz, J. M., & Knapp, H. (1981). Equation of State Methods for Computing Phase Equilibria and Enthalpies. Chem. Eng. Int., 21(1), 1-15.

[17] Peng, D. Y., & Robinson, D. B. (1976). A New Two-Constant Equation of State. Ind. & Eng. Chem. Fund., 15(1), 59-64.

[18] Pedersen, K. S., Fredenslund, Aa., & Thomassen, P. (1989). Properties of Oil and Natural Gases. Houston: Gulf Publishing Co..

[19] Soave, G. (1972). Equilibrium Constants from a Modified Redlich-Kwong Equation of State. Chem. Eng. Sci., 27, 1197-1203.

[20] WINPROP (2002). User’s Guide – Practical Solutions in Reservoir Modeling by CMG. Calgary, Alberta, Canada.

[21] Whitson, C. H. (1980). Characterizing Hydrocarbon Plus Fractions. Paper EUR 183 presented at the European Offshore Petroleum Conference and Exhibition in London (pp. 21-24).

[22] Whitson, C. H., & Torp, S. B. (1983). Evaluating Constant Volume Depletion Data. J. Pet. Tech., 35(3), 610-620.



  • There are currently no refbacks.

Copyright (c)

Share us to:   


  • How to do online submission to another Journal?
  • If you have already registered in Journal A, then how can you submit another article to Journal B? It takes two steps to make it happen:

1. Register yourself in Journal B as an Author

  • Find the journal you want to submit to in CATEGORIES, click on “VIEW JOURNAL”, “Online Submissions”, “GO TO LOGIN” and “Edit My Profile”. Check “Author” on the “Edit Profile” page, then “Save”.

2. Submission

  • Go to “User Home”, and click on “Author” under the name of Journal B. You may start a New Submission by clicking on “CLICK HERE”.

We only use three mailboxes as follows to deal with issues about paper acceptance, payment and submission of electronic versions of our journals to databases:;;

 Articles published in Advances in Petroleum Exploration and Development are licensed under Creative Commons Attribution 4.0 (CC-BY)


Address:1055 Rue Lucien-L'Allier, Unit #772, Montreal, QC H3G 3C4, Canada.

Telephone: 1-514-558 6138
Website: Http://

Copyright © 2010 Canadian Research & Development Centre of Sciences and Cultures