scholarly journals Thermodynamic Models for the Prediction of Petroleum-Fluid Phase Behaviour

10.5772/35025 ◽  
2012 ◽  
Author(s):  
Romain Privat ◽  
Jean-Nol Jaubert
Keyword(s):  
Fluid Phase ◽  
Phase Behaviour ◽  
Thermodynamic Models ◽  
Petroleum Fluid

Solid-Fluid Phase Equilibria Measurement for Mixtures of Methane, Carbon-Dioxide and N-Hexadecane

2021 ◽  
Author(s):  
Oluwakemi Victoria Eniolorunda ◽  
Antonin Chapoy ◽  
Rod Burgass
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Equation Of State ◽  
Phase Equilibria ◽  
Activity Coefficients ◽  
Fluid Phase ◽  
Ternary Mixtures ◽  
Binary Interaction ◽  
Thermodynamic Models ◽  
Methane Carbon

Abstract In this study, new experimental data using a reliable approach are reported for solid-fluid phase equilibrium of ternary mixtures of Methane-Carbon-dioxide- n-Hexadecane for 30-73 mol% CO2 and pressures up to 24 MPa. The effect of varying CO2 composition on the overall phase transition of the systems were investigated. Three thermodynamic models were used to predict the liquid phase fugacity, this includes the Peng Robison equation of state (PR-EoS), Soave Redlich-Kwong equation of state (SRK-EoS) and the Cubic plus Association (CPA) equation of state with the classical mixing rule and a group contribution approach for calculating binary interaction parameters in all cases. To describe the wax (solid) phase, three activity coefficient models based on the solid solution theory were investigated: the predictive universal quasichemical activity coefficients (UNIQUAC), Universal quasi-chemical Functional Group activity coefficients (UNIFAC) and the predictive Wilson approach. The solid-fluid equilibria experimental data gathered in this experimental work including those from saturated and under-saturated conditions were used to check the reliability of the various phase equilibria thermodynamic models.

Non-classical interfacial tension and fluid phase behaviour

1996 ◽  
Vol 117 (1-2) ◽  
pp. 312-319 ◽  
Author(s):  
P.M.W. Cornelisse ◽  
C.J. Peters ◽  
J. de Swaan Arons
Keyword(s):  
Interfacial Tension ◽  
Fluid Phase ◽  
Phase Behaviour

Fluid-Phase Behaviour for a Miscible-Gas-Injection EOR Project in a Giant Offshore Oil Field With Large Compositional Variations

2008 ◽  
Author(s):  
Niels Lindeloff ◽  
Kristian Mogensen ◽  
Paul Peter van Lingen ◽  
Son Huu Do ◽  
Soren Frank ◽  
...  
Keyword(s):  
Gas Injection ◽  
Fluid Phase ◽  
Oil Field ◽  
Phase Behaviour ◽  
Miscible Gas Injection ◽  
Compositional Variations ◽  
Offshore Oil

scholarly journals Bulk fluid phase behaviour of colloidal platelet–sphere and platelet–polymer mixtures

2013 ◽  
Vol 371 (1988) ◽  
pp. 20120259 ◽  
Author(s):  
Daniel de las Heras ◽  
Matthias Schmidt
Keyword(s):  
Phase Diagrams ◽  
Nematic Phase ◽  
Density Functional ◽  
Hard Spheres ◽  
Hard Core ◽  
Fluid Phase ◽  
Phase Behaviour ◽  
Size Ratio ◽  
Polymer Mixtures ◽  
Bulk Fluid

Using a geometry-based fundamental measure density functional theory, we calculate bulk fluid phase diagrams of colloidal mixtures of vanishingly thin hard circular platelets and hard spheres. We find isotropic–nematic phase separation, with strong broadening of the biphasic region, upon increasing the pressure. In mixtures with large size ratio of platelet and sphere diameters, there is also demixing between two nematic phases with differing platelet concentrations. We formulate a fundamental measure density functional for mixtures of colloidal platelets and freely overlapping spheres, which represent ideal polymers, and use it to obtain phase diagrams. We find that, for low platelet–polymer size ratio, in addition to isotropic–nematic and nematic–nematic phase coexistence, platelet–polymer mixtures also display isotropic–isotropic demixing. By contrast, we do not find isotropic–isotropic demixing in hard-core platelet–sphere mixtures for the size ratios considered.

scholarly journals GAFF/IPolQ-Mod+LJ-Fit: Optimized force field parameters for solvation free energy predictions

ADMET & DMPK ◽  
2020 ◽  
Author(s):  
Andreas Mecklenfeld ◽  
Gabriele Raabe
Keyword(s):  
Free Energy ◽  
Force Field ◽  
Fluid Phase ◽  
Solvation Free Energy ◽  
Rational Drug Design ◽  
Phase Behaviour ◽  
Liquid Density ◽  
Free Energies ◽  
Implicit Representation ◽  
Amber Force Field

<p class="ADMETabstracttext">Rational drug design featuring explicit solubility considerations can greatly benefit from molecular dynamics simulations, as they allow for the prediction of the Gibbs free energy of solvation and thus relative solubilities. In our previous work (A. Mecklenfeld, G. Raabe. J. Chem. Theory Comput. <strong>13 </strong>no. 12 (2017) 6266–6274), we have compared solvation free energy results obtained with the General Amber Force Field (GAFF) and its default restrained electrostatic potential (RESP) partial charges to those obtained by modified implicitly polarized charges (IPolQ-Mod) for an implicit representation of impactful polarization effects. In this work, we have adapted Lennard-Jones parameters for GAFF atom types in combination with IPolQ-Mod to further improve the accuracies of solvation free energy and liquid density predictions. We thereby focus on prominent atom types in common drugs. For the refitting, 357 respectively 384 systems were considered for free energies and densities and validation was performed for 142 free energies and 100 densities of binary mixtures. By the in-depth comparison of simulation results for default GAFF, GAFF with IPolQ-Mod and our new set of parameters, which we label GAFF/IPolQ-Mod+LJ-Fit, we can clearly highlight the improvements of our new model for the description of both relative solubilities and fluid phase behaviour.</p>

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