scholarly journals A hybrid pore-scale and continuum-scale model for solute diffusion, reaction, and biofilm development in porous media

2015 ◽  
Vol 51 (3) ◽  
pp. 1846-1859 ◽  
Author(s):  
Youneng Tang ◽  
Albert J. Valocchi ◽  
Charles J. Werth
Keyword(s):  
Porous Media ◽  
Diffusion Reaction ◽  
Solute Diffusion ◽  
Scale Model ◽  
Pore Scale ◽  
Continuum Scale ◽  
Biofilm Development

A Predictive Pore-Scale Model for Non-Darcy Flow in Porous Media

SPE Journal ◽  
2009 ◽  
Vol 14 (04) ◽  
pp. 579-587 ◽  
Author(s):  
Matthew T. Balhoff ◽  
Mary F. Wheeler
Keyword(s):  
Porous Media ◽  
Darcy Flow ◽  
Flow In Porous Media ◽  
Scale Model ◽  
Pore Scale ◽  
Pore Scale Model

Coupling pore-scale networks to continuum-scale models of porous media

2007 ◽  
Vol 33 (3) ◽  
pp. 393-410 ◽  
Author(s):  
Matthew T. Balhoff ◽  
Karsten E. Thompson ◽  
Martin Hjortsø
Keyword(s):  
Porous Media ◽  
Pore Scale ◽  
Scale Models ◽  
Continuum Scale

Convection-diffusion-reaction of CO2-enriched brine in porous media: A pore-scale study

2019 ◽  
Vol 125 ◽  
pp. 19-29 ◽  
Author(s):  
Hassan Dashtian ◽  
Sahar Bakhshian ◽  
Sassan Hajirezaie ◽  
Jean-Philippe Nicot ◽  
Seyyed Abolfazl Hosseini
Keyword(s):  
Porous Media ◽  
Diffusion Reaction ◽  
Pore Scale ◽  
Convection Diffusion

scholarly journals A numerical study on oxygen adsorption in porous media of coal rock based on fractal geometry

2020 ◽  
Vol 7 (2) ◽  
pp. 191337
Author(s):  
Xianzhe Lv ◽  
Xiaoyu Liang ◽  
Peng Xu ◽  
Linya Chen
Keyword(s):  
Porous Media ◽  
Scaling Laws ◽  
Spontaneous Combustion ◽  
Numerical Study ◽  
Nitrogen Adsorption ◽  
Oxygen Adsorption ◽  
Scale Model ◽  
Pore Scale ◽  
Coal Rock ◽  
Pore Scale Model

In order to explore the factors affecting coal spontaneous combustion, the fractal characteristics of coal samples are tested, and a pore-scale model for oxygen adsorption in coal porous media is developed based on self-similar fractal model. The liquid nitrogen adsorption experiments show that the coal samples indicate evident fractal scaling laws at both low-pressure and high-pressure sections, and the fractal dimensions, respectively, represent surface morphology and pore structure of coal rock. The pore-scale model has been validated by comparing with available experimental data and numerical simulation. The present numerical results indicate that the oxygen adsorption depends on both the pore structures and temperature of coal rock. The oxygen adsorption increases with increased porosity, fractal dimension and ratio of minimum to maximum pore sizes. The edge effect can be clearly seen near the cavity/pore, where the oxygen concentration is low. The correlation between the oxygen adsorption and temperature is found to obey Langmuir adsorption theory, and a new formula for oxygen adsorption and porosity is proposed. This study may help understanding the mechanisms of oxygen adsorption and accordingly provide guidelines to lower the risk of spontaneous combustion of coal.

Phenomenological understanding of poroelasticity via the micromechanics of a simple digital-rock model

Geophysics ◽  
2019 ◽  
Vol 84 (4) ◽  
pp. WA161-WA182 ◽  
Author(s):  
Gary D. Couples
Keyword(s):  
Pore Pressure ◽  
Effective Stress ◽  
Scale Model ◽  
External Boundary ◽  
Equivalent Material ◽  
Clear Understanding ◽  
Pore Scale ◽  
Digital Rock ◽  
Rock Model ◽  
Continuum Scale

Poroelasticity is a material concept that expresses the reversible, macroscale process interactions that occur in a porous material, such as rocks. These process interactions take place between the pore fluids and the rock framework (or “skeleton”) that contains the pores. The phenomenological basis of poro-elasticity is examined via a micromechanics analysis, using a simplified digital-rock model that consists of solid elements in a lattice arrangement, and which hosts a well-connected, lattice-like network of simply shaped pore elements. The quasistatic poromechanical bulk response of this model is defined fully by closed-form equations that provide a clear understanding of the process interactions and that allow key effects to be identified. Several external boundary conditions (nonisotropic strain and stress) are analyzed, with drained and undrained pore-fluid conditions, along with arbitrary pore pressure states. The calculated responses of the pore-scale model, when translated into continuum-scale equivalent behaviors, indicate significant problems with the existing theories of poroelasticity that are rooted in an enriched-continuum perspective. Specifically, the results indicate that the principle of effective stress (and the Biot coefficient alpha) is wrongly attributed to a deficiency in the role of pore pressure. Instead, the micromechanics-based phenomenological understanding identifies the change of effective stress, in a characteristically confined setting, as being the result of changes in the stress components, with a key dependency on the specifics of the far-field constraints. Thus, poroelasticity is not a material characteristic; instead, it is a description of a nonlinear system operating at the pore scale. The analysis reveals a discrepancy between the stress states within the model domain and the external stress state. This yet remains to be addressed, to translate the microscale behavior into an equivalent material law.

scholarly journals Numerical Simulation on Hydromechanical Coupling in Porous Media Adopting Three-Dimensional Pore-Scale Model

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jianjun Liu ◽  
Rui Song ◽  
Mengmeng Cui
Keyword(s):  
Finite Element ◽  
Porous Media ◽  
Pore Pressure ◽  
Three Dimensional ◽  
Confining Pressure ◽  
Scale Model ◽  
Micro Ct ◽  
Pore Scale ◽  
Hydromechanical Coupling ◽  
Rock Matrix

A novel approach of simulating hydromechanical coupling in pore-scale models of porous media is presented in this paper. Parameters of the sandstone samples, such as the stress-strain curve, Poisson’s ratio, and permeability under different pore pressure and confining pressure, are tested in laboratory scale. The micro-CT scanner is employed to scan the samples for three-dimensional images, as input to construct the model. Accordingly, four physical models possessing the same pore and rock matrix characteristics as the natural sandstones are developed. Based on the micro-CT images, the three-dimensional finite element models of both rock matrix and pore space are established by MIMICS and ICEM software platform. Navier-Stokes equation and elastic constitutive equation are used as the mathematical model for simulation. A hydromechanical coupling analysis in pore-scale finite element model of porous media is simulated by ANSYS and CFX software. Hereby, permeability of sandstone samples under different pore pressure and confining pressure has been predicted. The simulation results agree well with the benchmark data. Through reproducing its stress state underground, the prediction accuracy of the porous rock permeability in pore-scale simulation is promoted. Consequently, the effects of pore pressure and confining pressure on permeability are revealed from the microscopic view.

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