1887

Abstract

Summary

Relationships between pressure, temperature and density are generally described by an equation of state. For CO2, the Span-Wagner equation is generally assumed to give the best fit to measured data. The high accuracy of this equation does not come without a cost. Therefore, this equation of state is mostly used as a reference for comparisons with other formulations.

In reservoir simulations, cubic equations of state such as the Peng-Robinson and the Soave-Redlich-Kwong equations are widely used. They are fairly accurate, and computation of the solution is fast. In this paper, a generalized cubic equation of state is introduced. This equation is computationally precisely as efficient as the traditional equations of state. With the generalized equation of state, improved approximations of the density of CO2 in predefined temperature-pressure domains may be obtained. The parameters of the generalized cubic equation of state are determined through comparison with the Span-Wagner equation.

We show applications of the generalized cubic equation of state for different temperature-pressure domains. When compared with the Peng-Robinson equation, the root mean square density deviation is reduced by a factor 2 for domains containing the critical point, and a facto 7 for supercritical domains. Similarly, thermal simulations with the generalized cubic equation of state show large improvements in density and improvements in saturation close to the CO2 front.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.20141848
2014-09-08
2024-04-19
Loading full text...

Full text loading...

References

  1. Aavatsmark, I.
    [1995] Mathematische Einführung in die Thermodynamik der Gemische. Akademie Verlag, Berlin.
    [Google Scholar]
  2. Abbott, M.M.
    [1973] Cubic equations of state. AIChE Journal, 19, 601–.
    [Google Scholar]
  3. Bielinski, A.
    [2006] Numerical simulation of CO2 sequestration in geological formations. Ph.D. thesis, University of Stuttgart, Germany.
    [Google Scholar]
  4. Edmister, W.C. and Lee, B.I.
    [1984] Applied Hydrocarbon Thermodynamics. I. Gulf Publishing Company, Houston.
    [Google Scholar]
  5. Fenghour, A., Wakeham, W.A. and Vesovic, V.
    [1998] The viscosity of carbon dioxide. Journal of Physical and Chemical Reference Data, 27, 44–.
    [Google Scholar]
  6. Fletcher, R.
    [1971] A modified Marquardt subroutine for non-linear least squares. Tech. Rep. AERE - R 6799, Atomic Energy Research Establishment, Harwell.
    [Google Scholar]
  7. Heimsund, B.O.
    [2005] Mathematical and numerical methods for reservoir fluid flow simulation. Ph.D. thesis, University of Bergen, Norway.
    [Google Scholar]
  8. Péneloux, A., Rauzy, E. and Frèze, R.
    [1982] A consistent correction for Redlich-Kwong-Soave volumes. Fluid Phase Equilibrium, 8, 23–.
    [Google Scholar]
  9. Peng, D.Y. and Robinson, D.B.
    [1976] A new two-constant equation of state. Industrial and Engineering Chemistry Fundamentals, 15, 64–.
    [Google Scholar]
  10. Poling, B.E., Prausnitz, J.M. and O'Connell, J.P.
    [2001] The properties of gases and liquids. McGraw-Hill, New York.
    [Google Scholar]
  11. Redlich, O. and Kwong, J.N.S.
    [1949] On the thermodynamics of solutions. V: An equation of state. Fugacities of gaseous solutions. Chemical Reviews, 44, 244–.
    [Google Scholar]
  12. Robinson, D.B. and Peng, D.Y.
    [1978] The characterization of heptanes and heavier fractions for the GPA Peng-Robinson programs. Report RR-28, Gas Processors Association, Tulsa.
    [Google Scholar]
  13. Soave, G.
    [1972] Equilibrium constants from a modified Redlich-Kwong equation of state. Chemical Engineering Science, 27, 1203–.
    [Google Scholar]
  14. Span, R. and Wagner, W.
    [1996] A new equation of state for carbon dioxide covering the fluid region from the triple-point temperature to 1100K at pressures up to 800MPa. Journal of Physical and Chemical Reference Data, 25, 1596–.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.20141848
Loading
/content/papers/10.3997/2214-4609.20141848
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error