Phase Behavior of a United Arab Emirates Stock-Tank Oil and Carbon Dioxide at Reservoir Conditions: Experiments and Thermodynamic Modeling

DOI: 10.4236/ojogas.2016.11001   PDF   HTML     2,001 Downloads   2,844 Views   Citations


Injection of a soluble gas like CO2 into an oil reservoir reduces the interfacial tension and oil viscosity and contributes to oil swelling, which together, in turn, enhance the oil mobility and relative permeability. In this work an experimental phase equilibrium setup for the recombination of live oil (stock-tank oil and first-stage separator gas) and measurement of the corresponding phase behaviors of CO2/live oil mixtures is described. In the recombination process, the vapor-to-oil molar ratio was adjusted until the composition of the original reservoir fluid was obtained. The average of the absolute error (AAE) in composition was about 0.77% and 1.09% for the two reservoir fluids under test (named here wells A#22 and A#33, respectively). The optimum vapor-to-oil molar ratio for zero deviation in the methane composition in the live oil (recombined) was about 0.42 for both wells. In addition, the PVTi simulator was used to reproduce the live oil (by combining the first-stage separator gas and the stock-tank oil) and also to predict the recombined oil characteristics at the reservoirs’ saturation pressure and bottom hole temperature. On the other hand, the PVTpro simulator was used to investigate the oil swelling rate and establish the relationship between saturation pressure and the injected CO2 mass fraction. The average of the absolute relative error (AARE) between experimental and predicted saturation pressures was 7.78% for well A#22 and 5.38% for well A#33.

Share and Cite:

Abu-Eishah, S. and Mohammad, R. (2016) Phase Behavior of a United Arab Emirates Stock-Tank Oil and Carbon Dioxide at Reservoir Conditions: Experiments and Thermodynamic Modeling. Open Journal of Yangtze Oil and Gas, 1, 1-22. doi: 10.4236/ojogas.2016.11001.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Patil, S., Dandekar, A. and Khataniar, S. (2008) Phase Behavior, Solid Organic Precipitation, and Mobility Characterization Studies in Support of Enhanced Heavy Oil Recovery on the Alaska North Slope. DOE Award No.: DE-FC26- 01NT41248. Prepared for US Department of Energy, National Energy Technology Laboratory, Submitted by Petroleum Development Laboratory Institute of Northern Engineering, University of Alaska Fairbanks.
[2] Moortgat, J., Firoozabadi, A., Li, Z. and Espósito, R. (2013) CO2 Injection in vertical and horizontal cores: Measurements and numerical simulation. SPE Journal, 18, 1-14.
[3] Danesh, A. (1998) PVT and Phase Behaviour of Petroleum Reservoir Fluids, Developments in Petroleum Science. Elsevier Science, 47.
[4] Mathiassen, O.M. (2003) CO2 as Injection Gas for Enhanced Oil Recovery and Estimation of the Potential on the Norwegian Continental Shelf. M.Sc. Thesis, Norwegian University of Science & Technology (NTNU), Trondheim/ Stavanger, Part I of II.
[5] Yuan, S., Ye, J. and Sun, Z. (2003) Theory and Practice in Gas-Condensate Reservoir Development. China Petroleum Industry Press, Beijing.
[6] Wang, S., Chen, S. and Li, Z. (2016) Characterization of Produced and Residual Oils in the CO2 Flooding Process. Energy Fuels, 30, 54-62.
[7] Pedersen, K.S., Fredenslund, A. and Thomassen, P. (1989) Properties of Oils and Natural Gases. Gulf Publ. Co., Houston.
[8] Araujo, C.B.K., Capitelli, F.O., Rajagopal, K., Corazza, M.L. and Ndiaye, P.M. (2012) Phase Behavior of Brazilian Stock-Tank Oil and Carbon Dioxide at Reservoir Conditions: Experiments and Thermodynamic Modeling. IX Iberoamerican Conference on Phase Equilibria and Fluid Properties for Process Design (EquiFase 2012), Puerto Varas, 8-12 October 2012.
[9] Al-Jarba, M. and Al-Anazi, B.D. (2009) A Comparison Study of the of the CO2-Oil Physical Properties Literature Correlations Accuracy Using Visual Basic Modelling Technique. NAFTA, 60, 287-291.
[10] Emera, M.K. and Sarma, H.K. (2006) Genetic Algorithm (GA)-Based Correlations Offer More Reliable Prediction of CO2-Oil Physical Properties. Canadian International Petroleum Conference, Calgary, 13-15 June 2006.
[11] Feizabadi, S.A., Abedi, J. and Chen, Z. (2012) Importance of a Second Liquid Phase Formation in CO2 Injection into Bitumen Reservoirs and Its Effect on Production. SPE Improved Oil Recovery Symposium, Tulsa, 14-18 April 2012.
[12] CSLF Task Force (2013) Technical Challenges in the Conversion of CO2-EOR Projects to CO2 Storage Projects. Final Report, Carbon Sequestration Leadership Forum, September.
[13] Mohammad, R.S. (2012) PVT Study of Selected UAE Reservoir Fluids. M.Sc. Thesis, UAE University, Al Ain.
[14] Brill, J.P. and Beggs, H.D. (1974) Two-Phase Flow in Pipes. University of Tulsa, INTERCOMP Course, The Hague.
[15] Rojey, A., Jaffrey, C., Cornot-Gandolphe, S., Durand, B., Jullian, S. and Vallais, M. (1997) Natural Gas. Production, Processing, Transport, éditions Technip, Paris, 429 p.
[16] Angus, S., Armstrong, B., de Reuck, K.M., Altunin, V.V., Gadetskii, O.G., Chapela, G.A. and Rowlinson, J.S. (1976) International Union of Pure and Applied Chemistry (IUPAC). Carbon Dioxide: International Thermodynamic Tables of the Fluid State, Vol. 3, Pergamon Press, Oxford, 1522-2640.
[17] Kokal, S.L. and Sayegh, S.G. (1990) Gas-Saturated Bitumen Density Predictions Using the Volume-Translated Peng-Robinson Equation of State. Journal of Canadian Petroleum Technology, 29, 77-82.
[18] Lielmezs, J., Howell, S.K. and Campbell, H.D. (1983) Modified Red-lich-Kwong Equation of State for Saturated Vapor-Liquid Equilibrium. Chemical Engineering Science, 38, 1293-1301.
[19] Peng, D.Y. and Robinson, D.B. (1976) A New Two Constant Equation of State. Industrial and Engineering Chemistry, Fundamentals, 15, 59-64.
[20] Peneloux, A., Rauzy, E. and Freze, R. (1982) A Consistent Correction for Redlich-Kwong-Soave Volumes. Fluid Phase Equilibria, 8, 7-23.
[21] Katz, D.L. and Firoozabadi, A. (1978) Predicting Phase Behavior of Condensate/Crude Oil Systems Using Methane Interaction Coefficients. Journal of Petroleum Technology, 30, 1649-1655.
[22] Chueh, P.L. and Prausnitz, J.M. (1968) Calculation of High-Pressure Vapor-Liquid Equilibria. Industrial & Engineering Chemistry, 60, 34-52.

comments powered by Disqus

Copyright © 2020 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.