Analysis of various approaches to accurately prediction of phase equilibrium of binary helium systems based on the Peng-Robinson equation of state

2020 ◽  
pp. 117-126
Author(s):  
V.L. Malyshev ◽  
◽  
E.F. Moiseeva ◽  
Keyword(s):  
Phase Equilibrium ◽  
Equation Of State ◽  
Phase Behavior ◽  
Binary Interaction ◽  
Binary Interaction Parameter ◽  
Multicomponent Systems ◽  
Interaction Coefficients ◽  
Acentric Factor ◽  
Robinson Equation

The paper presents a detailed algorithm for calculating the vapor-liquid phase equilibrium for multicomponent systems based on the Peng-Robinson equation of state. Various approaches are considered that make it possible to improve the quality of predicting phase equilibrium by the example of eight binary helium systems containing nitrogen, argon, carbon dioxide, methane, ethane, propane, isobutane, and n-butane. The influence of the acentric factor and the binary interaction parameter on the accuracy of the helium systems phase behavior predicting is analyzed. The optimal interaction coefficients for the presented systems are found under the assumption that this parameter does not depend on temperature. The temperature range of applicability of various approaches is determined, which makes it possible to maximize the description of the phase behavior of helium systems.

scholarly journals Application of Peng-Robinson Equation of State for Calculating Solid-Vapor and Solid-Liquid Equilibrium of CH4-CO2 System

2015 ◽  
Vol 9 (7) ◽  
pp. 177 ◽  
Author(s):  
Gede Wibawa ◽  
Muhammad F. A. Nafi ◽  
Asti Permatasari ◽  
Asalil Mustain
Keyword(s):  
Equation Of State ◽  
Binary Interaction ◽  
Binary Interaction Parameter ◽  
Average Absolute Deviation ◽  
Liquid Equilibrium ◽  
Absolute Deviation ◽  
Vapor Equilibrium ◽  
Solid Liquid ◽  
Parameter Values ◽  
Robinson Equation

In this study, the performances of Peng-Robinson Equation of State combined with the classical mixing ruleswere evaluated to calculate solid-vapor equilibrium (SVE) and solid-liquid equilibrium (SLE) of CH4-CO2system. The evaluation was performed by comparing the calculated values with the literature data. In thecalculation of SVE, the new binary interaction parameter values (kij) of CH4-CO2 mixtures were proposed in thiswork based on the experimental data. The proposed kij obtained in this work might increase the accuracy ofPeng-Robinson Equation of State by reducing average absolute deviation in the temperatures between calculatedvalues and literature data from (2.18% to 0.26%), (0.88% to 0.70%) and (0.61% to 0.44%) at CO2 compositionof 1%, 1.91% and 2.93%, respectively. Significant improvement was found at CO2 composition of 1%. In thecalculation of SLE, new parameters were not proposed since the calculation using the existing (literature) kijgives good results with an average absolute deviation of 0.5%.

scholarly journals Revisiting Kelvin equation and Peng–Robinson equation of state for accurate modeling of hydrocarbon phase behavior in nano capillaries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ilyas Al-Kindi ◽  
Tayfun Babadagli
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Equation Of State ◽  
Phase Behavior ◽  
Pore Radius ◽  
Microfluidic Chips ◽  
Tight Sandstone ◽  
Kelvin Equation ◽  
Rock Samples ◽  
Robinson Equation

AbstractThe thermodynamics of fluids in confined (capillary) media is different from the bulk conditions due to the effects of the surface tension, wettability, and pore radius as described by the classical Kelvin equation. This study provides experimental data showing the deviation of propane vapour pressures in capillary media from the bulk conditions. Comparisons were also made with the vapour pressures calculated by the Peng–Robinson equation-of-state (PR-EOS). While the propane vapour pressures measured using synthetic capillary medium models (Hele–Shaw cells and microfluidic chips) were comparable with those measured at bulk conditions, the measured vapour pressures in the rock samples (sandstone, limestone, tight sandstone, and shale) were 15% (on average) less than those modelled by PR-EOS.

scholarly journals Pore-Scale Simulation of Confined Phase Behavior with Pore Size Distribution and Its Effects on Shale Oil Production

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1315
Author(s):  
Jingwei Huang ◽  
Hongsheng Wang
Keyword(s):  
Phase Equilibrium ◽  
Equation Of State ◽  
Pore Size Distribution ◽  
Phase Behavior ◽  
Pore Size ◽  
Size Distribution ◽  
Critical Role ◽  
Shale Oil ◽  
Pore Scale ◽  
Modified Equation

Confined phase behavior plays a critical role in predicting production from shale reservoirs. In this work, a pseudo-potential lattice Boltzmann method is applied to directly model the phase equilibrium of fluids in nanopores. First, vapor-liquid equilibrium is simulated by capturing the sudden jump on simulated adsorption isotherms in a capillary tube. In addition, effect of pore size distribution on phase equilibrium is evaluated by using a bundle of capillary tubes of various sizes. Simulated coexistence curves indicate that an effective pore size can be used to account for the effects of pore size distribution on confined phase behavior. With simulated coexistence curves from pore-scale simulation, a modified equation of state is built and applied to model the thermodynamic phase diagram of shale oil. Shifted critical properties and suppressed bubble points are observed when effects of confinement is considered. The compositional simulation shows that both predicted oil and gas production will be higher if the modified equation of state is implemented. Results are compared with those using methods of capillary pressure and critical shift.

Phase Behavior and Physical Properties of Dimethyl Ether/Water/Heavy-Oil Systems Under Reservoir Conditions

SPE Journal ◽  
2021 ◽  
pp. 1-17
Author(s):  
Desheng Huang ◽  
Ruixue Li ◽  
Daoyong Yang
Keyword(s):  
Physical Properties ◽  
Phase Behavior ◽  
Dimethyl Ether ◽  
Heavy Oil ◽  
Partition Coefficients ◽  
Binary Interaction ◽  
Binary Interaction Parameter ◽  
Translation Strategy ◽  
Wide Range ◽  
Oil Mixtures

Summary Phase behavior and physical properties including saturation pressures, swelling factors (SFs), phase volumes, dimethyl ether (DME) partition coefficients, and DME solubility for heavy-oil mixtures containing polar substances have been experimentally and theoretically determined. Experimentally, novel phase behavior experiments of DME/water/heavy-oil mixtures spanning a wide range of pressures and temperatures have been conducted. More specifically, a total of five pressure/volume/temperature (PVT) experiments consisting of two tests of DME/heavy-oil mixtures and three tests of DME/water/heavy-oil mixtures have been performed to measure saturation pressures, phase volumes, and SFs. Theoretically, the modified Peng-Robinson equation of state (EOS) (PR EOS) together with the Huron-Vidal mixing rule, as well as the Péneloux et al. (1982)volume-translation strategy, is adopted to perform phase-equilibrium calculations. The binary-interaction parameter (BIP) between the DME/heavy-oil pair, which is obtained by matching the measured saturation pressures of DME/heavy-oil mixtures, works well for DME/heavy-oil mixtures in the presence and absence of water. The new model developed in this work is capable of accurately reproducing the experimentally measured multiphase boundaries, phase volumes, and SFs for the aforementioned mixtures with the root-mean-squared relative error (RMSRE) of 3.92, 9.40, and 0.92%, respectively, while it can also be used to determine DME partition coefficients and DME solubility for DME/water/heavy-oil systems.

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