Applications of Molecular Simulation in Oil and Gas Production and Processing

Microscopic Monte Carlo simulations of liquid sheets of copper and tin have been performed in order to study the dependence of the surface tension on the thickness of the sheet. It results that the surface tension is constant with the thickness as long as the sheet remains in one piece. When the sheet is getting thinner, holes start to appear, and the calculated surface tension rapidly decreases with thickness until the sheet becomes totally unstable and forms a cylinder. We assume here that this decrease is not due to a confinement effect as proposed by Werth et al. [Physica A 392, 2359[Physica A 392, (2013] on Lennard-Jones systems, but to the appearance of holes that reduces the energy cost of the surface modification. We also show in this work that a link can be established between the stability of the sheet and the local fluctuations of the surface position, which directly depends on the value of the surface tension. Finally, we complete this study by investigating systems interacting through different forms of Lennard-Jones potentials to check if similar conclusions can be drawn.

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“…34 Code developments needed in this work have been done by the CEA under a collaboration with the Gibbs code owners.…”

Section: Acknowledgmentsmentioning

confidence: 99%

Communication: Slab thickness dependence of the surface tension: Toward a criterion of liquid sheets stability

Filippini

Bourasseau

Ghoufi

et al. 2014

The Journal of Chemical Physics

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“…We ran the MC simulations with the GIBBS code [21] and the MD simulations with the STAMP code [22]. The MC simulations used samples of limited sizes (up to 5.000 atoms) of bulk graphite and diamond with 3D periodic conditions.…”

Section: Numerical Setupmentioning

confidence: 99%

Theoretical study of the porosity effects on the shock response of graphitic materials

Pineau

Bourasseau

Maillet

et al. 2015

EPJ Web of Conferences

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Abstract. In this paper we present a theoretical study of the shock compression of porous graphite by means of combined Monte Carlo and molecular dynamics simulations using the LCBOPII potential. The results show that the Hugoniostat methods can be used with "pole" properties calculated from porous models to reproduce the experimental Hugoniot of pure graphite and diamond with good accuracy. The computed shock temperatures show a sharp increase for weak shocks which we analyze as the heating associated with the closure of the initial porosity. After this initial phase, the temperature increases with shock intensity at a rate comparable to monocrystalline graphite and diamond. These simulations data can be exploited in view to build a full equation of state for use in hydrodynamic simulations.

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“…The choice of the combining rules is a crucial point when dealing with the thermodynamic behaviour of mixtures 1,[8][9][10] , but less is known concerning their influence on the dynamic properties of mixtures. In this work, two types of combining rules are used, the usual Lorentz-Berthelot ones:…”

Section: Combining Rulesmentioning

confidence: 99%

Molecular Dynamics Simulation of Acid Gas Mixtures: A Comparison between Several Approximations

Galliéro

Nieto‐Draghi

Boned

et al. 2007

Ind. Eng. Chem. Res.

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Molecular dynamics simulations of CH4, CO2, H2S, and their mixtures, chosen as representative of acid gas mixtures, have been performed. Static properties (pressure or density) and dynamic properties (shear viscosity) have been computed. A comparison has been performed between results from three different models: a simple Lennard-Jones (LJ) model, an isotropic multipolar (IMP) one, and the usual LJ plus point charge (LJP). For pure fluids, a reasonable agreement is found between all three models and experiments except for CO2, for which the LJ model suffers from its lack of electrostatic contributions. Concerning CH4−H2S mixtures, results obtained using the three molecular models are consistent with each other for static and dynamic properties. In addition, no significant differences between the results obtained using both Lorentz−Berthelot and Kong combining rules were noticed. For the CH4−H2S−CO2 mixture, the situation is different: a strong dependence of the pressure on the molecular models as well as on the combining rules, in the case of the LJP model, has been noted. Shear viscosity was found to be less dependent on the choice of models and combining rules. Thanks to simulations on H2S−CO2 mixtures, it has been found that the way cross interactions are treated between these two compounds explains the discrepancies for CH4−H2S−CO2 mixtures. For the systems studied, the IMP approximation seems to be the best option for engineering calculations of physical properties because it is quick to compute, ensures accuracy, and is weakly dependent on the combining rules employed. In addition, it is shown that a van der Waals one fluid model combined with an accurate LJ equation of state together with a correlation on viscosity is able to provide results consistent with simulations (on both LJ and IMP models). Such a result makes this correlative scheme a good alternative for industrial applications.

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Applications of Molecular Simulation in Oil and Gas Production and Processing

Cited by 113 publications

References 38 publications

Communication: Slab thickness dependence of the surface tension: Toward a criterion of liquid sheets stability

Communication: Slab thickness dependence of the surface tension: Toward a criterion of liquid sheets stability

Theoretical study of the porosity effects on the shock response of graphitic materials

Molecular Dynamics Simulation of Acid Gas Mixtures: A Comparison between Several Approximations

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