TY - JOUR

T1 - Implementation of the methodology for calculation of the three-phase equilibrium of hydrocarbons and the aqueous phase

AU - Aksenov, Oleg

AU - Kozlov, Mikhail

AU - Usov, Eduard

AU - Taylakov, Dmitry

AU - Kayurov, Nikita

AU - Cheremisin, Alexander

N1 - The work has been financially supported by Ministry of science and higher education of the Russian Federation (project FSUS-2024–0025).

PY - 2025/3

Y1 - 2025/3

N2 - The paper discusses the development and implementation of the algorithm for calculation of the three-phase equilibrium in the hydrocarbon/aqueous system. The work is done as a part of PVT module improvement for the “d-Flow” hydraulic simulator which is under development at Novosibirsk R&D Center LLC. The numerical methods used in the presented three-phase algorithm are simple and available in the literature, however these methods are often need to be improved and tuned before an actual application. In order to increase phase composition calculation stability, a modification for stationary point selection algorithm is proposed. Moreover, unexpected behavior of the algorithm may be revealed during implementation, which is not described in the original articles. This work attempts to present the three-phase equilibrium calculation algorithm ready for direct use in the designed hydraulic simulator and provide the detailed description for different aspects and difficulties of the implementation. The numerical schemes for the phase stability test and the calculation of equilibrium compositions are described, and the general equilibrium search algorithm is given. To test the algorithm, simulations of different mixtures are done and phase diagrams are presented for several mixtures. The solubility of hydrocarbons in water for binary mixtures is also calculated and compared with experimental data from the literature.

AB - The paper discusses the development and implementation of the algorithm for calculation of the three-phase equilibrium in the hydrocarbon/aqueous system. The work is done as a part of PVT module improvement for the “d-Flow” hydraulic simulator which is under development at Novosibirsk R&D Center LLC. The numerical methods used in the presented three-phase algorithm are simple and available in the literature, however these methods are often need to be improved and tuned before an actual application. In order to increase phase composition calculation stability, a modification for stationary point selection algorithm is proposed. Moreover, unexpected behavior of the algorithm may be revealed during implementation, which is not described in the original articles. This work attempts to present the three-phase equilibrium calculation algorithm ready for direct use in the designed hydraulic simulator and provide the detailed description for different aspects and difficulties of the implementation. The numerical schemes for the phase stability test and the calculation of equilibrium compositions are described, and the general equilibrium search algorithm is given. To test the algorithm, simulations of different mixtures are done and phase diagrams are presented for several mixtures. The solubility of hydrocarbons in water for binary mixtures is also calculated and compared with experimental data from the literature.

KW - Hydrocarbons/water mutual solubility

KW - Multicomponent mixtures

KW - Numerical methods

KW - Peng-Robinson equation of state

KW - Phase equilibrium

UR - https://www.mendeley.com/catalogue/0032a31c-e3a1-354e-9cb4-9d0e0839cea9/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85215580028&origin=inward&txGid=465a6db75671d91845f47217cc3c0925

U2 - 10.1016/j.ijft.2025.101093

DO - 10.1016/j.ijft.2025.101093

M3 - Article

VL - 26

JO - International Journal of Thermofluids

JF - International Journal of Thermofluids

SN - 2666-2027

M1 - 101093

ER -