scholarly journals Measurement of CO2 diffusion coefficients in both bulk liquids and carven filling porous media of fractured-vuggy carbonate reservoirs at 50 MPa and 393 K

RSC Advances ◽  
2021 ◽  
Vol 11 (32) ◽  
pp. 19712-19722
Author(s):  
Zhixing Wang ◽  
Jirui Hou
Keyword(s):  
Porous Media ◽  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Carbonate Reservoirs ◽  
Pressure Decay ◽  
Co2 Diffusion

Herein, the pressure decay method was improved to obtain the CO2 diffusion coefficient in fractured-vuggy carbonate reservoirs at 393 K and 50 MPa and obtained good correlation results between bulk and porous media by porosity and tortuosity.

Diffusion velocity lattice Boltzmann formulation applied to transport in macroscopic porous media

2014 ◽  
Vol 25 (12) ◽  
pp. 1441006 ◽  
Author(s):  
Janez Perko ◽  
Ravi A. Patel
Keyword(s):  
Porous Media ◽  
Diffusion Coefficient ◽  
Lattice Boltzmann ◽  
Diffusion Coefficients ◽  
Effective Diffusion ◽  
Hydrodynamic Dispersion ◽  
Traditional Treatment ◽  
Dissipative Term ◽  
Diffusion Velocity ◽  
Variable Diffusion

This paper describes the application of a single relaxation time (SRT) lattice Boltzmann scheme to the transport in porous media with large spatial variations of diffusion coefficients. Effective diffusion coefficients can vary substantially within porous media because of their dependence on porosity and tortuosity which can span over several orders of magnitude, depending on pore size and connectivity. Moreover, when mass is transported with pore-water in porous media, the hydrodynamic dispersion, which depends on Darcy's velocity, contributes additionally to the usually anisotropic variation of the dissipative term. In contrast to the traditional treatment of spatially variable diffusion coefficient by the variation of a SRT, here the variability is accommodated through the use of diffusion velocity formulation which allows for larger variabilities of diffusion coefficient. The volume averaged properties of mass transport in macroscopic porous media are resolved through the additional source term which is similar to the existing force adjusting methods. The applicability of both the proposed schemes is demonstrated on two examples. The first demonstrates that the method is accurate for the large variation of diffusion coefficients and porosities. The second example introduces mass diffusion in a real, geometrically complex system with spatially contrasting properties.

Experimental and Theoretical Determination of Diffusion Coefficients of CO2-Heavy Oil Systems by Coupling Heat and Mass Transfer

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Sixu Zheng ◽  
Daoyong Yang
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Heat And Mass Transfer ◽  
Heavy Oil ◽  
Diffusion Coefficients ◽  
Binary Interaction ◽  
Co2 Diffusion ◽  
Explicitly Correlated ◽  
Different Temperatures ◽  
Binary Interaction Parameters

By treating heavy oil as multiple pseudocomponents, techniques have been developed to experimentally and theoretically determine diffusion coefficients of CO2-heavy oil systems by coupling heat and mass transfer together with consideration of swelling effect. Experimentally, diffusion tests have been conducted for hot CO2-heavy oil systems with three different temperatures under a constant pressure by using a visualized pressure-volume-temperature (PVT) setup. The swelling of liquid phase in the PVT cell is continuously monitored and recorded during the measurements. Theoretically, a two-dimensional (2D) mathematical model incorporating the volume-translated Peng–Robinson equation of state (PR EOS) with a modified alpha function has been developed to describe heat and mass transfer for hot CO2-heavy oil systems. Heavy oil sample has been characterized as three pseudocomponents for accurately quantifying phase behavior of the CO2-heavy oil systems, while the binary interaction parameters (BIPs) are tuned with the experimentally measured saturation pressures. The diffusion coefficient of hot CO2 in heavy oil is then determined once the discrepancy between the experimentally measured dynamic swelling factors and theoretically calculated ones has been minimized. During the diffusion experiments, heat transfer is found to be dominant over mass transfer at the beginning and reach its equilibrium in a shorter time; subsequently, mass transfer shows its dominant effect. The enhanced oil swelling mainly occurs during the coupled heat and mass transfer stage. CO2 diffusion coefficient in heavy oil is found to increase with temperature at a given pressure, while it can be explicitly correlated as a function of temperature.

Suggesting a numerical pressure-decay method for determining CO2 diffusion coefficient in water

2015 ◽  
Vol 211 ◽  
pp. 31-39 ◽  
Author(s):  
Yasin Gholami ◽  
Reza Azin ◽  
Rouhollah Fatehi ◽  
Shahriar Osfouri
Keyword(s):  
Diffusion Coefficient ◽  
Pressure Decay ◽  
Co2 Diffusion

scholarly journals The Performance of Low-Pressure Seawater as a CO2 Solvent in Underwater Air-Independent Propulsion Systems

2020 ◽  
Vol 8 (1) ◽  
pp. 22
Author(s):  
Eun-Young Park ◽  
Jungho Choi
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Treatment Process ◽  
Operating Conditions ◽  
Dissolution Time ◽  
Propulsion Systems ◽  
Gas Treatment ◽  
Weapon Systems ◽  
Co2 Diffusion ◽  
Residual Gas

Air-independent propulsion systems have improved the performance and decreased the vulnerability of underwater weapon systems. Reforming systems, however, generates large amounts of water and CO2. The recovery or separation of CO2, a residual gas component generated in vessels, entails considerable cost and energy consumption. It is necessary to understand the characteristics of the interaction between CO2 and seawater under the conditions experienced by underwater weapon systems to design and optimize a CO2 treatment process for dissolving CO2 in seawater. In this study, numerical analysis was conducted using the derived experimental concentration and MATLAB. The diffusion coefficient was derived as a function of temperature according to the CO2 dissolution time. Experiments on CO2 dissolution in seawater were conducted. The concentration of CO2 according to the reaction pressure and experimental temperature was obtained. The diffusion coefficient between CO2 and seawater was found to be 6.3 × 10−5 cm2/s at 25 °C and 7.24 × 10−5 cm2/s at 32 °C. CO2 concentration could be estimated accurately under vessel operating conditions using the derived CO2 diffusion coefficients. Optimal design of the residual gas treatment process will be possible using the derived seawater–CO2 diffusion coefficients under the actual operating conditions experienced by underwater weapon systems.

Determining CO2 diffusion coefficient in heavy oil in bulk phase and in porous media using experimental and mathematical modeling methods

Fuel ◽  
2020 ◽  
Vol 263 ◽  
pp. 116205 ◽  
Author(s):  
Xiang Zhou ◽  
Qi Jiang ◽  
Qingwang Yuan ◽  
Liehui Zhang ◽  
Jianwei Feng ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Porous Media ◽  
Diffusion Coefficient ◽  
Heavy Oil ◽  
Bulk Phase ◽  
Modeling Methods ◽  
Co2 Diffusion

scholarly journals A Study on CO2 Diffusion Coefficient in n-decane Saturated Porous Media by MRI

2014 ◽  
Vol 61 ◽  
pp. 603-606 ◽  
Author(s):  
Ying Teng ◽  
Yu Liu ◽  
Yongchen Song ◽  
Lanlan Jiang ◽  
Yuechao Zhao ◽  
...  
Keyword(s):  
Porous Media ◽  
Diffusion Coefficient ◽  
Saturated Porous Media ◽  
Co2 Diffusion
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