THERMODYNAMIC MODELING OF VAPOR-LIQUID EQUILIBRIUM FOR PETROLEUM FLUIDS

THERMODYNAMIC MODELING OF VAPOR-LIQUID EQUILIBRIUM FOR PETROLEUM FLUIDS

Barbosa Neto, Antonio Marinho; Ribeiro, Jônatas; Aznar, Martín; Bannwart, Antonio Carlos

Artigo Completo:

The phase behavior prediction is essential for the development and optimization of the hydrocarbon production in petroleum engineering applications. Well succeed projects in this field, such as management of a reservoir, multiphase flow analysis in production systems, and petroleum primary processing, depend on the correct prediction of phase behavior and the estimation of thermodynamic properties, like phase composition and compressibility factor. In this way, the present work purpose was to develop a computational tool that performs isothermal flash calculations for oil and gas multicomponent mixtures with enough precision for both project and operation. The computer program was developed in Visual Basic Application (VBA). The Peng-Robinson equation of state was used to model the vapor-liquid equilibrium. Newton-Raphson method was applied to obtain both the convergence of the Rachford-Rice equation and the cubic equation roots. The root for each phase was determined by the Gibbs energy minimization. There is a quantitative agreement between the results computed and the results provided by the commercial simulator HYSYS (AspenTech) over industrially relevant ranges of compositions, pressures and temperatures. Furthermore, the answers obtained are within precision which apply to compositional modeling for petroleum fluids. The composition and compressibility factor simulations for petroleum fluid were performed using real field conditions. The results found were investigated from the thermodynamic viewpoint and were consistent with both practice and theory.

The phase behavior prediction is essential for the development and optimization of the hydrocarbon production in petroleum engineering applications. Well succeed projects in this field, such as management of a reservoir, multiphase flow analysis in production systems, and petroleum primary processing, depend on the correct prediction of phase behavior and the estimation of thermodynamic properties, like phase composition and compressibility factor. In this way, the present work purpose was to develop a computational tool that performs isothermal flash calculations for oil and gas multicomponent mixtures with enough precision for both project and operation. The computer program was developed in Visual Basic Application (VBA). The Peng-Robinson equation of state was used to model the vapor-liquid equilibrium. Newton-Raphson method was applied to obtain both the convergence of the Rachford-Rice equation and the cubic equation roots. The root for each phase was determined by the Gibbs energy minimization. There is a quantitative agreement between the results computed and the results provided by the commercial simulator HYSYS (AspenTech) over industrially relevant ranges of compositions, pressures and temperatures. Furthermore, the answers obtained are within precision which apply to compositional modeling for petroleum fluids. The composition and compressibility factor simulations for petroleum fluid were performed using real field conditions. The results found were investigated from the thermodynamic viewpoint and were consistent with both practice and theory.

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DOI: 10.5151/mathpro-cnmai-0105

Referências bibliográficas

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Como citar:

Barbosa Neto, Antonio Marinho; Ribeiro, Jônatas; Aznar, Martín; Bannwart, Antonio Carlos; "THERMODYNAMIC MODELING OF VAPOR-LIQUID EQUILIBRIUM FOR PETROLEUM FLUIDS", p-610-619. In: Anais do Congresso Nacional de Matemática Aplicada à Indústria [= Blucher Mathematical Proceedings, v.1, n.1]. São Paulo: Blucher, 2015.
ISSN soon, DOI 10.5151/mathpro-cnmai-0105