scholarly journals NUMERICAL SIMULATING THE CHEMICAL INTERACTION OF FLUID WITH ROCK AT THE PORE SCALE

2021 ◽  
Vol 2 (3) ◽  
pp. 46-54
Author(s):  
Tatyana S. Khachkova ◽  
Vadim V. Lisitsa
Keyword(s):  
Porous Medium ◽  
Fluid Flow ◽  
Reactive Transport ◽  
Chemical Interaction ◽  
Pore Space ◽  
Heterogeneous Reactions ◽  
Pore Scale ◽  
Active Components ◽  
Flow And Transport ◽  
The Finite Difference Method

The article presents a numerical algorithm for modeling the chemically reactive transport in a porous medium at a pore scale. The aim of the study is to research the change in the geometry of the pore space during the chemical interaction of the fluid with the rock. First, fluid flow and transport of chemically active components are simulated in the pore space. Heterogeneous reactions are then used to calculate their interactions with the rock. After that, the change in the interface between the liquid and the solid is determined using the level-set method, which allows to handle changes in the topology of the pore space. The algorithm is based on the finite-difference method and is implemented on the GP-GPU.

scholarly journals The transport of liquids in softwood: timber as a model porous medium

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
H. C. Burridge ◽  
G. Wu ◽  
T. Reynolds ◽  
D. U. Shah ◽  
R. Johnston ◽  
...  
Keyword(s):  
Experimental Data ◽  
Porous Medium ◽  
Fluid Flow ◽  
Transport Properties ◽  
Pore Space ◽  
Construction Material ◽  
Sustainable Construction ◽  
Natural Material ◽  
Full Potential ◽  
Treatment Processes

AbstractTimber is the only widely used construction material we can grow. The wood from which it comes has evolved to provide structural support for the tree and to act as a conduit for fluid flow. These flow paths are crucial for engineers to exploit the full potential of timber, by allowing impregnation with liquids that modify the properties or resilience of this natural material. Accurately predicting the transport of these liquids enables more efficient industrial timber treatment processes to be developed, thereby extending the scope to use this sustainable construction material; moreover, it is of fundamental scientific value — as a fluid flow within a natural porous medium. Both structural and transport properties of wood depend on its micro-structure but, while a substantial body of research relates the structural performance of wood to its detailed architecture, no such knowledge exists for the transport properties. We present a model, based on increasingly refined geometric parameters, that accurately predicts the time-dependent ingress of liquids within softwood timber, thereby addressing this long-standing scientific challenge. Moreover, we show that for the minimalistic parameterisation the model predicts ingress with a square-root-of-time behaviour. However, experimental data show a potentially significant departure from this $$\sqrt{{\boldsymbol{t}}}$$t behaviour — a departure which is successfully predicted by our more advanced parametrisation. Our parameterisation of the timber microstructure was informed by computed tomographic measurements; model predictions were validated by comparison with experimental data. We show that accurate predictions require statistical representation of the variability in the timber pore space. The collapse of our dimensionless experimental data demonstrates clear potential for our results to be up-scaled to industrial treatment processes.

scholarly journals Numerical modeling of chemical interaction between a fluid and rocks

2019 ◽  
pp. 457-470
Author(s):  
К.А. Гадыльшина ◽  
Т.С. Хачкова ◽  
В.В. Лисица
Keyword(s):  
Numerical Modeling ◽  
Fluid Flow ◽  
Boundary Conditions ◽  
Chemical Interaction ◽  
Pore Space ◽  
Immersed Boundary ◽  
Finite Difference Schemes ◽  
Rock Interaction ◽  
Convection Diffusion ◽  
Level Set Function

Предложен алгоритм численного моделирования процессов химического взаимодействия флюида с породой в масштабе пор. Алгоритм основан на методе расщепления задачи по физическим процессам. Предполагается, что скорость течения флюида мала, а установление потока происходит мгновенно при малых изменениях геометрии порового пространства. Таким образом, поток флюида в поровом пространстве моделируется при помощи уравнения Стокса для стационарного течения жидкости. Перенос химически активного компонента описывается уравнением конвекциидиффузии с граничными условиями третьего рода. Граница порового пространства изменяется со временем и задается неявно функцией уровня. Для численного решения уравнения Стокса и уравнения конвекциидиффузии применяется метод конечных разностей с аппроксимацией краевого условия взаимодействия жидкой и твердой фазы на погруженной границе. A new algorithm for the numerical modeling of chemical fluid-rock interaction at the pore scale is proposed. The algorithm is based on splitting the problem into physical processes. It is assumed that the fluid rate is low and the fluid flow is stabilized almost instantly in the case of small changes in the pore space geometry. In the pore space, thus, the fluid flow is modeled using the Stokes equation for steady flows. The chemical reactant transport is described by the convection-diffusion equation with Robin boundary conditions at the fluid-rock interface. The pore space boundary changes with time and is implicitly given by a level-set function. We use finite-difference schemes with immersed boundary conditions to solve the Stokes and convection-diffusion equations.

3-D Microscopic Measurement and Analysis of Chemical Flow and Transport in Porous Media

1996 ◽  
Vol 118 (3) ◽  
pp. 470-480 ◽  
Author(s):  
Mehdi Rashidi ◽  
Andrew Tompson ◽  
Tom Kulp ◽  
Loni Peurrung
Keyword(s):  
Porous Medium ◽  
Three Dimensional ◽  
Pore Geometry ◽  
Pore Scale ◽  
Volume Data ◽  
Geometric Flow ◽  
Particle Volume ◽  
Flow And Transport ◽  
Solute Fluxes ◽  
Microscopic Measurement

Chemical flow and transport have been studied at the pore-scale in an experimental porous medium. Measurements have been taken using a novel nonintrusive fluorescence imaging technique. The experimental setup consists of a cylindrical column carved out of a clear plastic block, packed with clear beads of the same material. A refractive index-matched fluid was pumped under laminar, slow-flow conditions through the column. The fluid was seeded with tracer particles or a solute organic dye for flow and chemical transport measurements, respectively. The system is automated to image through the porous medium for collecting microscopic values of velocity, concentration, and pore geometry at high-accuracy and high-resolution. Various geometric, flow, and transport quantities have been obtained in a full three-dimensional volume within the porous medium. These include microscopic (pore-scale) medium geometry, velocity and concentration fields, dispersive solute fluxes, and reasonable estimates of a representative elementary volume (REV) for the porous medium. The results indicate that the range of allowable REV sizes, as measured from averaged velocity, concentration, and pore volume data, varies among the different quantities, however, a common overlapping range, valid for all quantities, can be determined. For our system, this common REV has been estimated to be about two orders of magnitude larger than the medium’s particle volume. Furthermore, correlation results show an increase in correlation of mean-removed velocity and concentration values near the concentration front in our experiments. These results have been confirmed via 3-D plots of concentration, velocity, pore geometry, and microscopic flux distributions in these regions.

Pore-Scale Investigation of Two-Phase Drainage Process in a Microchannel

2013 ◽  
Author(s):  
Y. F. Yap ◽  
A. Goharzadeh ◽  
F. M. Vargas ◽  
J. C. Chai
Keyword(s):  
Surface Tension ◽  
Porous Medium ◽  
Level Set Method ◽  
Level Set ◽  
Pore Scale ◽  
Middle Section ◽  
Scale Level ◽  
Two Phase ◽  
Flow And Transport

This article presents a level-set method to investigate two-phase drainage of oil by water in microchannel with numerous blockages in the middle section, mimicking a porous medium of different permeability at the pore-scale level. The presented framework is intended for gaining an understanding of the nature of flow and transport at the pore-scale level. In particular, the sweeping efficiency for the drainage process is parametrically studied for system with different viscosities and surface tension.

scholarly journals Modeling of Flow and Transport in Saturated and Unsaturated Porous Media

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1088
Author(s):  
Anis Younes ◽  
Marwan Fahs ◽  
Philippe Ackerer
Keyword(s):  
Porous Media ◽  
Fluid Flow ◽  
Reactive Transport ◽  
Transport Processes ◽  
Flow And Transport ◽  
Current Trends ◽  
Process Understanding ◽  
Wide Range ◽  
Hyporheic Zones ◽  
Relevant Topic

Modeling fluid flow and transport processes in porous media is a relevant topic for a wide range of applications. In water resources problems, this topic presents specific challenges related to the multiphysical processes, large time and space scales, heterogeneity and anisotropy of natural porous media, and complex mathematical models characterized by coupled nonlinear equations. This Special Issue aims at collecting papers presenting new developments in the field of flow and transport in porous media. The 25 published papers deal with different aspects of physical processes and applications such as unsaturated and saturated flow, flow in fractured porous media, landslide, reactive transport, seawater intrusion, and transport within hyporheic zones. Based on their objectives, we classified these papers into four categories: (i) improved numerical methods for flow and mass transport simulation, (ii) looking for reliable models and parameters, (iii) laboratory scale experiments and simulations, and (iv) modeling and simulations for improved process understanding. Current trends on modeling fluid flow and transport processes in porous media are discussed in the conclusion.

scholarly journals A “lab-on-a-chip” experiment for assessing mineral precipitation processes in fractured porous media

2020 ◽  
Author(s):  
Jenna Poonoosamy ◽  
Sophie Roman ◽  
Cyprien Soulaine ◽  
Hang Deng ◽  
Sergi Molins ◽  
...  
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Reactive Transport ◽  
Surface Passivation ◽  
Pore Scale ◽  
Mineral Precipitation ◽  
Transport Models ◽  
Mineral Transformation ◽  
Fractured Porous Medium ◽  
Fractured Medium

<p>The understanding of dissolution and precipitation of minerals and its impact on the transport of fluids in fractured media is essential for various subsurface applications including shale gas production using hydraulic fracturing (“fracking”), CO<sub>2</sub> sequestration, or geothermal energy extraction. The implementation of such coupled processes into numerical reactive transport codes requires a mechanistic process understanding and model validation with quantitative experiments. In this context, we developed a microfluidic “lab-on-chip” of a reactive fractured porous medium of 800 µm × 900 µm size with 10 µm depth. The fractured medium consisted of compacted celestine grains (grain size 4 – 9 µm). A BaCl<sub>2</sub> solution was injected into the microreactor at a flow rate of 500 nl min<sup>-1</sup>, leading to the dissolution of celestine and an epitaxial growth of barite on its surface (Poonoosamy et al., 2016). Our investigations including confocal Raman spectroscopic techniques allowed for monitoring the temporal mineral transformation at the pore scale in 2D and 3D geometries. The fractured porous medium causes a heterogeneous flow field in the microreactor that leads to spatially different mineral transformation rates. In these experiments, the dynamic evolution of surface passivation processes depends on two intertwined processes: i) the dissolution of the primary mineral that is needed for the subsequent precipitation, and ii) the suppression of the dissolution reaction as a result of secondary mineral precipitation. However, the description of evolving reactive surface areas to account for mineral passivation mechanisms in reactive transport models following Daval et al. (2009) showed several limitations, and prompt for an improved description of passivation processes that includes the diffusive properties of secondary phases (Poonoosamy et al., 2020). The results of the ongoing microfluidic experiments in combination with advanced pore-scale modelling will provide new insights regarding application and extension of the description of surface passivation processes to be included in (continuum-scale) reactive transport models.</p><p>Daval D., Martinez I., Corvisier J., Findling N., Goffé B. and Guyotac F. (2009) Carbonation of Ca-bearing silicates, the case of wollastonite: Experimental investigations and kinetic modelling. Chem. Geol. 265(1–2), 63-78.</p><p>Poonoosamy J., Curti E., Kosakowski G., Van Loon L. R., Grolimund D. and Mäder U. (2016) Barite precipitation following celestite dissolution in a porous medium: a SEM/BSE and micro XRF/XRD study. Geochim. Cosmochim. Acta 182, 131-144.</p><p>Poonoosamy J., Klinkenberg M., Deissmann G., Brandt F., Bosbach D., Mäder U. and Kosakowski G. (2020) Effects of solution supersaturation on barite precipitation in porous media and consequences on permeability: experiments and modelling. Geochim. Cosmochim. Acta 270, 43-60.</p>

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