Aggregate formation dynamics driven by 3D fluid flow in natural porous media

2020 ◽  
Author(s):  
Thomas Ritschel ◽  
Kai Totsche
Keyword(s):  
Porous Media ◽  
Fluid Flow ◽  
Reactive Transport ◽  
Colloidal Particles ◽  
Pore Space ◽  
Three Dimensional ◽  
Space Distribution ◽  
Aggregate Formation ◽  
Undisturbed Soil ◽  
Pore Networks

<p>Fluid flow and reactive transport in natural porous media take place in a three-dimensional, hierarchically organized network of voids and pores in the size range of sub-micrometers inside small aggregates to several millimeters in, e.g., earthworm burrows or cracks. Thus, fluid flow regimes are manifold with consequences not only for the transport of solutes, but also for the displacement of colloidal particles and organic matter and thus, for their inclusion into soil aggregates. Therefore, we incorporated the simulation of three-dimensional fluid flow in pore networks typical for natural porous media into our recent approach to model soil aggregate formation using DLVO theory and diffusion-limited aggregation to overcome its previous limitation to suspensions at rest. To visualize the model capabilities, we simulated aggregation in pore networks that were either synthetically designed to represent certain structural features such as pore junctions and dead-end pores, or taken directly from X-ray µ-CT measurements of undisturbed soil cores. We explored the development of structural aggregated features that evolve in response to flow, transport and the topology of the soil pore space. The resulting three-dimensional arrangement of compounds and the entire aggregates were classified according to their morphological metrics, e.g. the pore space distribution, and functional properties, e.g. the water retention capacity, that are provided by these structures. By this fusion of complementary modeling approaches, we significantly contribute to the fundamental mechanistic understanding of the complex interplay and feedback of structure, interactions and functions on the scale of (micro-)aggregates.</p>

Multiphase-Flow and Reactive-Transport Validation Studies at the Pore Scale by Use of Lattice Boltzmann Computer Simulations

SPE Journal ◽  
2017 ◽  
Vol 22 (03) ◽  
pp. 940-949 ◽  
Author(s):  
Edo S. Boek ◽  
Ioannis Zacharoudiou ◽  
Farrel Gray ◽  
Saurabh M. Shah ◽  
John P. Crawshaw ◽  
...  
Keyword(s):  
Porous Media ◽  
Multiphase Flow ◽  
Capillary Pressure ◽  
Computer Simulations ◽  
Relative Permeability ◽  
Lattice Boltzmann ◽  
Reactive Transport ◽  
Pore Space ◽  
Processing Unit ◽  
Space Images

Summary We describe the recent development of lattice Boltzmann (LB) and particle-tracing computer simulations to study flow and reactive transport in porous media. First, we measure both flow and solute transport directly on pore-space images obtained from micro-computed-tomography (CT) scanning. We consider rocks with increasing degree of heterogeneity: a bead pack, Bentheimer sandstone, and Portland carbonate. We predict probability distributions for molecular displacements and find excellent agreement with pulsed-field-gradient (PFG) -nuclear-magnetic-resonance (NMR) experiments. Second, we validate our LB model for multiphase flow by calculating capillary filling and capillary pressure in model porous media. Then, we extend our models to realistic 3D pore-space images and observe the calculated capillary pressure curve in Bentheimer sandstone to be in agreement with the experiment. A process-based algorithm is introduced to determine the distribution of wetting and nonwetting phases in the pore space, as a starting point for relative permeability calculations. The Bentheimer relative permeability curves for both drainage and imbibition are found to be in good agreement with experimental data. Third, we show the speedup of a graphics-processing-unit (GPU) algorithm for large-scale LB calculations, offering greatly enhanced computing performance in comparison with central-processing-unit (CPU) calculations. Finally, we propose a hybrid method to calculate reactive transport on pore-space images by use of the GPU code. We calculate the dissolution of a porous medium and observe agreement with the experiment. The LB method is a powerful tool for calculating flow and reactive transport directly on pore-space images of rock.

Immiscible Displacement at Pore Level for Correlated Porous Media

1998 ◽  
Vol 09 (06) ◽  
pp. 837-849 ◽  
Author(s):  
A. M. Vidales ◽  
J. L. Riccardo ◽  
G. Zgrablich
Keyword(s):  
Porous Media ◽  
Pore Space ◽  
Three Dimensional ◽  
Immiscible Displacement ◽  
Porous Network ◽  
Buoyancy Forces ◽  
Correlation Strength ◽  
Pore Level

Immiscible displacement at pore level on a three-dimensional correlated porous network is simulated allowing flow of the wetting phase along crevices of the pore walls (possibility of snap-off in throats) and advance through the centers of the pore space with different pore and throat filling conditions, leading to a cooperative filling. When these two mechanisms compete, different patterns arise. We study the effect of the correlation strength on the onset of each pattern. We do not take buoyancy forces into account.

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 Pore-scale investigation of the displacement fluid mechanics during two-phase flows in natural porous media under the dominance of capillary forces

Georesursy ◽  
2020 ◽  
Vol 22 (1) ◽  
pp. 4-12
Author(s):  
Timur R. Zakirov ◽  
Maxim G. Khramchenkov
Keyword(s):  
Porous Media ◽  
Pore Space ◽  
Three Dimensional ◽  
Capillary Forces ◽  
High Temporal Resolution ◽  
Pore Scale ◽  
Two Phase Flows ◽  
Two Phase ◽  
Pressure Drops ◽  
Mobile Interfaces

This paper presents the results of numerical simulations of two-phase flows in porous media under capillary forces dominance. For modeling of immiscible two-phase flow, the lattice Boltzmann equations with multi relaxation time operator were applied, and the interface phenomena was described with the color-gradient method. The objective of study is to establish direct links between quantitative characteristics of the flow and invasion events, using high temporal resolution when detecting simulation results. This is one of the few works where Haines jumps (rapid invasion event which occurs at meniscus displacing from narrow pore throat to its wide body) are considered in three-dimensional natural pore space, but the focus is also on the displacement mechanics after jumps. It was revealed the sequence of pore scale events which can be considered as a period of drainage process: rapid invasion event during Haines jump; finish of jump and continuation of uniform invasion in current pore; switching of mobile interfaces and displacement in new region. The detected interface change, along with Haines jump, is another distinctive feature of the capillary forces action. The change of the mobile interfaces is manifested in step-like behavior of the front movement. It was obtained that statistical distributions of pressure drops during Haines jumps obey lognormal law. When investigating the flow rate and surface tension effect on the pressure drop statistics it was revealed that these parameters practically don’t affect on the statistical distribution and influence only on the magnitude of pressure drops and the number of individual Haines jumps.

Fabrication of a Microchannel Device With a Three-Dimensional Pore Network Using a Sacrificial Sugar Template

2020 ◽  
Author(s):  
Haipeng Zhang ◽  
Tomer Palmon ◽  
Seunghee Kim ◽  
Sangjin Ryu
Keyword(s):  
Porous Media ◽  
Fluid Flow ◽  
Pore Structure ◽  
Three Dimensional ◽  
Pore Network ◽  
Compressed Air ◽  
Microfluidic Channels ◽  
Two Phase ◽  
Flow Through ◽  
Phase Fluid

Abstract Porous media compressed air energy storage (PM-CAES) is an emerging technology that stores compressed air in an underground aquifer during the off-peak periods, to mitigate the mismatch between energy supplies and demands. Thus, PM-CAES involves repeated two-phase fluid flow in porous media, and ensuring the success of PM-CAES requires a better understanding of repetitive two-phase fluid flow through porous media. For this purpose, we previously developed microfluidic channels that retain a two-dimensional (2D) pore network. Because it was found that the geometry of the pore structure significantly affects the patterns and occupational efficiencies of a non-wetting fluid during the drainage-imbibition cycles, a more realistic microfluidic model is needed to reflect the three-dimensional (3D) nature of pore structures in the underground geologic formation. In this study, we developed an easy-to-adopt method to fabricate a microfluidic device with a 3D random pore network using a sacrificial sugar template. Instead of using a master mold made in photolithography, a sacrificial mold was made using sugar grains so that the mold could be washed away after PDMS curing. First, we made sugar templates with different levels of compaction load, and found that the thickness of the templates decreased as the compaction load increased, which suggests more packing of sugar grains and thus lower porosity in the template. Second, we fabricated PDMS porous media using the sugar template as a mold, and imaged their pore structure using micro computed tomography (micro-CT). Pores within PDSM samples appeared more tightly packed as the compacting force increased. Last, we fabricated a prototype PDMS channel device with a 3D pore network using a sugar template, and visualized flow through the pore network using colored water. The flow visualization result shows that the water was guided by the random pores and that the resultant flow pattern was three dimensional.

INTEGRAL TRANSFORMS FOR HEAT AND FLUID FLOW IN TWO- AND THREE-DIMENSIONAL POROUS MEDIA

2001 ◽  
Vol 3 (4) ◽  
pp. 14 ◽  
Author(s):  
Renato M. Cotta ◽  
H. Luz Neto ◽  
L. S. de B. Alves ◽  
Joao N. N. Quaresma
Keyword(s):  
Porous Media ◽  
Fluid Flow ◽  
Three Dimensional ◽  
Integral Transforms ◽  
Heat And Fluid Flow

scholarly journals A network model for characterizing brine channels in sea ice

2018 ◽  
Vol 12 (3) ◽  
pp. 1013-1026 ◽  
Author(s):  
Ross M. Lieblappen ◽  
Deip D. Kumar ◽  
Scott D. Pauls ◽  
Rachel W. Obbard
Keyword(s):  
Sea Ice ◽  
Network Model ◽  
Pore Space ◽  
Three Dimensional ◽  
Transport Processes ◽  
Micro Computed Tomography ◽  
Form Complex ◽  
Pore Networks ◽  
Fluid Permeability ◽  
Two Parameters

Abstract. The brine pore space in sea ice can form complex connected structures whose geometry is critical in the governance of important physical transport processes between the ocean, sea ice, and surface. Recent advances in three-dimensional imaging using X-ray micro-computed tomography have enabled the visualization and quantification of the brine network morphology and variability. Using imaging of first-year sea ice samples at in situ temperatures, we create a new mathematical network model to characterize the topology and connectivity of the brine channels. This model provides a statistical framework where we can characterize the pore networks via two parameters, depth and temperature, for use in dynamical sea ice models. Our approach advances the quantification of brine connectivity in sea ice, which can help investigations of bulk physical properties, such as fluid permeability, that are key in both global and regional sea ice models.

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