Analysis of Pore Space Evolution Due to Chemically Active Fluid Flooding: A Numerical Study

This numerical study focuses on the determination of macroscopic (effective) properties from pore scale calculation. These results will be applied to heat exchangers design. The computational domain -representative of heat exchanger section- is a parallelepiped filled with metallic foam, heated on one face and crossed by a forced fluid flow. Conjugate heat transfer and fluid flow are computed using finite volume approach on the actual solid matrix and pore space topology obtained from X-ray tomograms. Calculated heat transfer coefficient and flow law parameters are in good agreement with literature data. An active foam length is defined and measured in order to provide optimal design characteristic for foamed heat exchanger.

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Investigation of the structure of borehole zones at various stages of development of saline reservoirs with textural wettability

Georesursy ◽

10.18599/grs.2021.1.12 ◽

2021 ◽

Vol 23 (1) ◽

pp. 112-117

Author(s):

Leonid A. Gaydukov

Keyword(s):

Numerical Study ◽

Pore Space ◽

Dynamic Change ◽

Synergetic Effect ◽

Production Well ◽

Stages Of Development ◽

Permeability Distribution ◽

Saline Formation ◽

The Moment ◽

Object Of Study

A laboratory and numerical study of the mechanisms that affect the structure and physical properties of the borehole zone of a production well at various stages of development of a saline formation with textural wettability was conducted. It is shown that for the object of study is characterized by the formation of complex borehole vicinity of the structure and dynamic change of properties which define the specific geotechnical effects: desalinization; pinched adscititious water in the pore space; the decompression and the strain on the washed areas; precipitation of solid salt sediment at the moment of breaking through the highly mineralized front of the injected water. The synergetic effect of these effects leads to the formation of complex, including non-monotonic, permeability distribution profiles in the near-well zone.

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Mathematical modeling of the process of magma formation in the Earth’s crust

10.5194/egusphere-egu21-16346 ◽

2021 ◽

Author(s):

Ivan Utkin ◽

Yury Podladchikov ◽

Oleg Melnik

Keyword(s):

Energy Minimization ◽

Numerical Study ◽

Pore Space ◽

Coupled Model ◽

Magmatic Fluid ◽

Filtration Flow ◽

Mantle Rock ◽

The Earth ◽

Minimization Approach ◽

Melting And Crystallization

<p>One of the mechanisms of magma generation in the Earth's crust is the reaction of dehydration during subduction process. Water is released from subducting lithosphere which leads to the lowering of the melting temperature of mantle rock by hundreds of degrees.</p><p>In this work, we present a numerical study of the formation and rise of magma to the Earth's surface, considering partial melting and crystallization of rocks and chemical differentiation of magma. We develop a coupled model of the filtration flow of melt and magmatic fluid through deformable permeable rocks and a thermodynamic model of plagioclase melting based on Gibbs energy minimization approach. The formation of regions with a high melt concentration due to spontaneous focusing of filtration flow being the result of viscoplastic (de)compaction of the pore space is shown. The influence of mechanical properties of rocks and chemical composition of the system on the dynamics of the process is investigated.</p>

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Frequency-dependent attenuation and dispersion caused by squirt flow: Three-dimensional numerical study

Geophysics ◽

10.1190/geo2019-0519.1 ◽

2020 ◽

Vol 85 (3) ◽

pp. MR129-MR145 ◽

Cited By ~ 6

Author(s):

Yury Alkhimenkov ◽

Eva Caspari ◽

Boris Gurevich ◽

Nicolás D. Barbosa ◽

Stanislav Glubokovskikh ◽

...

Keyword(s):

Fluid Flow ◽

Analytical Solution ◽

Analytical Solutions ◽

Numerical Study ◽

Numerical Models ◽

Pore Space ◽

Fluid Pressure ◽

Frequency Dependent ◽

Attenuation And Dispersion ◽

Dispersion And Attenuation

Seismic waves may exhibit significant dispersion and attenuation in reservoir rocks due to pore-scale fluid flow. Fluid flow at the microscopic scale is referred to as squirt flow and occurs in very compliant pores, such as grain contacts or microcracks, that are connected to other stiffer pores. We have performed 3D numerical simulations of squirt flow using a finite-element approach. Our 3D numerical models consist of a pore space embedded into a solid grain material. The pore space is represented by a flat cylinder (a compliant crack) whose edge is connected with a torus (a stiff pore). Grains are described as a linear isotropic elastic material, whereas the fluid phase is described by the quasistatic linearized compressible Navier-Stokes momentum equation. We obtain the frequency-dependent effective stiffness of a porous medium and calculate dispersion and attenuation due to fluid flow from a compliant crack to a stiff pore. We compare our numerical results against a published analytical solution for squirt flow and analyze the effects of its assumptions. Previous interpretation of the squirt flow phenomenon based mainly on analytical solutions is verified, and some new physical effects are identified. The numerical and analytical solutions agree only for the simplest model in which the edge of the crack is subjected to zero fluid pressure boundary condition while the stiff pore is absent. For the more realistic model that includes the stiff pore, significant discrepancies are observed. We identify two important aspects that need improvement in the analytical solution: the calculation of the frame stiffness moduli and the frequency dependence of attenuation and dispersion at intermediate frequencies.

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Mechanism of air entry during collapse of saturated and unsaturated columns of transparent granular soil

10.5194/egusphere-egu2020-20756 ◽

2020 ◽

Author(s):

Alexander Taylor-Noonan ◽

Natalie Arpin ◽

Miguel Cabrera ◽

Greg Siemens ◽

W Andrew Take

Keyword(s):

Volume Change ◽

Numerical Study ◽

Pore Space ◽

Soil Mechanics ◽

Fluid Pressure ◽

Soil Condition ◽

Saturation Regime ◽

Column Collapse ◽

Triggering Mechanisms ◽

Granular Column

<div>The granular column collapse experiment, which consists of the rapid removal of lateral support to a column of granular material, is an important benchmark case for the physical and numerical study of transitional mass flows. While other researchers have focussed on the link between the aspect ratio of the column to mobility of the flow, these experiments are also an important platform to evaluate frameworks for triggering of slope failures.</div><div>&#160;</div><div>Critical state soil mechanics centers around the theory that initially dense soils will dilate, and initially loose soils will contract upon shearing. If the soil is sheared at a rate which exceeds the rate which fluids can be expelled or drawn into the pore space between particles, the shearing is considered to be occuring at constant volume and termed &#8220;undrained&#8221;. This state is associated with a rise in pore fluid pressure and a reduction in intergranular normal effective stress. The authors have conducted experiments varying the time scales of the volume change and dissipation processes. In these experiments, a novel transparent soil mixture comprised of quartz and mineral oil was utilized to visualize the saturation regime of soils during the granular column collapse experiment. Particular attention was paid to triggering mechanisms and the transition between the metastable state and avalanche regimes. The transparent material allowed visual confirmation of the volume change during shearing and important insights were gained into the role of the unsaturated soil condition in temporary strength. These observations have implications beyond the column collapse experiment, including the initiation of debris flow experiments as well as analysis of triggering mechanisms of unstable slopes in the field.</div>

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Correlation of Pore Structure and Permeability by SEM-Image Analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100180896 ◽

1990 ◽

Vol 48 (1) ◽

pp. 428-429

Author(s):

C. A. Callender ◽

Wm. C. Dawson ◽

J. J. Funk

Keyword(s):

Image Analysis ◽

Pore Structure ◽

Imaging System ◽

Pore Space ◽

Simulation Models ◽

Image Analyzer ◽

Imaging Data ◽

Sem Images ◽

Thin Sections ◽

Rock Types

The geometric structure of pore space in some carbonate rocks can be correlated with petrophysical measurements by quantitatively analyzing binaries generated from SEM images. Reservoirs with similar porosities can have markedly different permeabilities. Image analysis identifies which characteristics of a rock are responsible for the permeability differences. Imaging data can explain unusual fluid flow patterns which, in turn, can improve production simulation models.Analytical SchemeOur sample suite consists of 30 Middle East carbonates having porosities ranging from 21 to 28% and permeabilities from 92 to 2153 md. Engineering tests reveal the lack of a consistent (predictable) relationship between porosity and permeability (Fig. 1). Finely polished thin sections were studied petrographically to determine rock texture. The studied thin sections represent four petrographically distinct carbonate rock types ranging from compacted, poorly-sorted, dolomitized, intraclastic grainstones to well-sorted, foraminiferal,ooid, peloidal grainstones. The samples were analyzed for pore structure by a Tracor Northern 5500 IPP 5B/80 image analyzer and a 80386 microprocessor-based imaging system. Between 30 and 50 SEM-generated backscattered electron images (frames) were collected per thin section. Binaries were created from the gray level that represents the pore space. Calculated values were averaged and the data analyzed to determine which geological pore structure characteristics actually affect permeability.

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Numerical study of the low-frequency atomic dynamics in a Lennard-Jones glass

Philosophical Magazine B ◽

10.1080/014186398259572 ◽

1998 ◽

Vol 77 (2) ◽

pp. 473-484 ◽

Cited By ~ 3

Author(s):

M. Sampoli, P. Benassi, R. Dell'Anna,

Keyword(s):

Numerical Study ◽

Low Frequency ◽

Lennard Jones

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