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Showing papers on "Permeability (earth sciences) published in 2000"


Journal ArticleDOI
TL;DR: In this article, the hydraulic conductivity of geosynthetic clay liners (GCLs) permeated with non-standard liquids (i.e., liquids other than water) is discussed and supported with test data.

453 citations


Journal ArticleDOI
TL;DR: In this paper, a numerical finite element code was used to compare single and dual-permeability approaches for modeling variably saturated flow and transport in two-dimensional heterogeneous soil systems.

193 citations


Journal ArticleDOI
TL;DR: In this article, the authors measured the permeability of a clay-bearing fault gouge under total confining pressures ranging up to 200 MPa and pore pressures of 40 MPa at room temperature.
Abstract: Quantification of fluid transport through fault zones is critical for the understanding of fault mechanics and prediction of subsurface fluid flow. The permeability of clay-bearing fault gouge has been determined using first argon then water as pore fluids under total confining pressures ranging up to 200 MPa and pore pressures of 40 MPa at room temperature. Use of the two pore fluids allows interactions between the gouge and pore fluids to be examined. Natural clay-bearing fault gouge recovered from surface exposures of the Carboneras fault zone in southeastern Spain was used and was collected in such a way that the in situ microstructure was preserved. Cores were collected in directions relative to the well-developed planar fabrics seen in these types of fault rock. The mineralogy of the gouges included muscovite/illite, chlorite, and quartz, with minor amounts of gypsum, albite, and graphite. Glycolation of the gouge showed no discernible amounts of swelling phases. Grain size analyses revealed a bimodal grain size distribution, with the 50 wt %) This fraction contained predominantly clay phases. Permeabilities in the range of 10 -17 m -22 to 10 m 2 were measured. Experimental results show that the previous highest in situ effective pressure to which the fault gouge had been subjected (overconsolidation pressure) could not be determined from changes in permeability. Differences between water and argon permeabilities determined on the same sample amounted to ∼1 order of magnitude, even if the sample had been pressure cycled (reduction to zero and reapplication of both confining and pore pressure) using argon as pore fluid until asymptotic values for permeability had been attained. Volumetric strain measurements showed no enhanced compaction due to the introduction of water as the pore fluid, leading to the conclusion that the reduction in permeability must be due to physicochemical interactions of the water with the fault gouge. The low permeabilities measured support models invoking high fluid pressure weakening of large faults with minimal fluid loss. The stability of structured water films with varying temperature, water pressure and water chemistry may produce a heterogeneous permeability profile with depth in fault zones.

185 citations



Journal ArticleDOI
TL;DR: In this article, the hydraulic and electrical conductivities of shaly sandstones are described using a capillary approach for a granular, clay bearing material, where clays are assumed to occur as shale shells uniformly coating the insulated sand grains.

145 citations


Journal ArticleDOI
TL;DR: In this paper, the extent of this reduction is addressed using results from both experimental and theoretical investigations, where a sandy soil commonly used as a filter or drainage layer was subjected to pore fluids containing polystyrene or kaolinite particles, and their permeability reductions were determined in terms of the pore fluid suspension parameters.
Abstract: Soil filters, which are commonly used to provide stability to the base soils in subsurface infrastructure, are prone to long-term accumulation of fine micron-sized particles. This causes reduction in the permeability, which in turn may lead to intolerable decreases in their drainage capacity. In this paper, the extent of this reduction is addressed using results from both experimental and theoretical investigations. In the experimental phase, a sandy soil commonly used as a filter or drainage layer was subjected to pore fluids containing polystyrene or kaolinite particles, and their permeability reductions were determined in terms of the pore fluid suspension parameters. In the theoretical phase of the investigation, a representative elemental volume of the soil filter was modeled as an ensemble of capillary tubes and the permeability reduction due to physical clogging was simulated using basic principles of flow in cylindrical tubes. The results from the experimental and theoretical investigations were in good agreement. In general, the permeability reduced by more than one order of magnitude, even when the migrating particles were smaller than the majority of the soil filter pores. The concentration of particles in the pore stream affected the rate at which the permeability reduced. Self-filtration of particles, which is prominent at higher flow rates, may itself lead to a 20% reduction in the permeability for these sands.

134 citations


Journal ArticleDOI
TL;DR: In this article, a numerical method as well as a theoretical study of non-Darcy fluid flow through porous and fractured reservoirs is described, where the authors use a three-dimensional, multiphase flow reservoir simulator, while the model formulation incorporates the Forchheimer equation for describing single-phase or multi-phase flow and displacement.
Abstract: A numerical method as well as a theoretical study of non-Darcy fluid flow through porous and fractured reservoirs is described. The non-Darcy behavior is handled in a three-dimensional, multiphase flow reservoir simulator, while the model formulation incorporates the Forchheimer equation for describing single-phase or multiphase non-Darcy flow and displacement. The non-Darcy flow through a fractured reservoir is handled using a general dual-continuum approach. The numerical scheme has been verified by comparing its results against those of analytical methods. Numerical solutions are used to obtain some insight into the physics of non-Darcy flow and displacement in reservoirs. In addition, several type curves are provided for well-test analyses of non-Darcy flow to demonstrate a methodology for modeling this type of flow in porous and fractured rocks, including flow in petroleum and geothermal reservoirs.

128 citations


Book ChapterDOI
TL;DR: In this article, a fractal model for porous media was developed which adjusted the measure of the specific surface and of the grain radius to the resolution length appropriate for the hydraulic process, and these equations were calibrated by a large data set for permeability, formation factor, and porosity determined on sedimentary rocks.
Abstract: Permeability is one of the key rock properties for the management of hydrocarbon and geothermal reservoirs as well as for aquifers. The fundamental equation for estimating permeability is the Kozeny-Carman equation. It is based on a capillary bundle model and relates permeability to porosity, tortuosity and an effective hydraulic pore radius which is defined by this equation. Whereas in clean sands the effective pore radius can be replaced by the specific surface or by the grain radius in a simple way, the resulting equations for permeability cannot be applied to consolidated rocks. Based on a fractal model for porous media, equations were therefore developed which adjust the measure of the specific surface and of the grain radius to the resolution length appropriate for the hydraulic process. These equations are calibrated by a large data set for permeability, formation factor, and porosity determined on sedimentary rocks. This fractal model yields tortuosity and effective pore radius as functions of porosity as well as a general permeability-porosity relationship, the coefficients of which are characteristic for different rock types. It can be applied to interpret the diagenetic evolution of the pore space of sedimentary rocks due to mechanical and chemical compaction with respect to porosity and permeability.

128 citations


Journal ArticleDOI
TL;DR: In this paper, an architectural analysis of the Cretaceous frontier formation of central Wyoming has been conducted to evaluate the relative importance of different types of geologic variability on prediction of subsurface fluid flow.
Abstract: An architectural analysis documents variations in bedding geometry and rock properties within a tide-influenced deltaic sandstone exposed in the Cretaceous Frontier Formation of central Wyoming, USA. Digital maps of bedding, lithofacies, and diagenetic cements, as well as vertical logs of grain size, lithofacies, and permeability, describe rock properties that potentially influence fluid flow behavior. These records are used to construct simulation models that assess the relative importance of different types of geologic variability on prediction of subsurface fluid flow. Two 25-meter-thick tide-influenced deltaic sandstone bodies coarsen upward and contain inclined beds that reflect episodic delta-front progradation. Decimeters- to meters-thick beds within bodies alternate between cross-stratified sandstones formed during rapid flows and shales deposited during more quiescent conditions. Down depositional dip, bed-draping shales are more continuous and lithofacies within sandstone beds become finer-grained and increasingly heterolithic. As sandstone beds fine down dip, mean permeability values decrease and coefficients of variation increase, permeability values change from nearly normal distributions to highly right-skewed, and permeability values become more strongly spatially correlated. Nodular cements also affect permeability. All of these variations were modeled using stratigraphic cornerpoint grids that preserve stratal geometry and gridblocks with properties assigned using a combination of rock property maps and statistical models based on rock property logs. Simulations predict effects on fluid flow of geologic heterogeneity at different scales, the influences of process variables, and the effects of different methods of grid construction and rock property assignment. Flow simulations of water flooding through a 22 m thick by 360 m long segment of a deltaic sandstone oil reservoir predict that: (1) rapid flow through coarser-grained deposits at the top of the sandstone body tends to draw water upward; (2) thin shales draping sandstone beds shunt downdip-directed flow downward and updip-directed flow upward; (3) cement nodules cause more tortuous flow patterns but have little effect on recovery efficiency; (4) Methods of predicting intrafacies correlation of permeability have little effect on flow behavior at this scale. A simulation model constructed using a high-resolution Cartesian grid did not resolve the effects of inclined shales, demonstrating the usefulness of stratigraphic cornerpoint grids for modeling flow through complex geologic deposits. Flow simulations of tracer flow through a meter-thick cross-stratified bed within the deltaic sandstone body showed that at this scale shale drapes and models of the intrafacies distribution of permeability have statistically significant effects.

125 citations


Journal ArticleDOI
TL;DR: In this article, the authors apply low-order statistical information (porosity, two-point correlation function), obtained from 2D micrographs of real porous media, to derive stochastic replicas of their 3D pore networks.

117 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present a model based on the assumption that permeability is zero when a cell is below some failure condition, and very large locally (e.g. nearest neighbors) when the failure condition is met.

Journal ArticleDOI
TL;DR: In this article, the authors proposed to compute a coarse scale permeability field that minimizes the error, measured in a global norm, in the velocity and pressure fields. But this method is not stable.
Abstract: This paper presents a new technique for computing the effective permeability on a coarse scale. It is assumed that the permeability is given at a fine scale and that it is necessary to reduce the number of blocks in the reservoir model. Traditional upscaling methods depend on local boundary conditions. It is well known that the permeability may depend heavily on the local boundary condition chosen. Hence the estimate is not stable. We propose to compute a coarse scale permeability field that minimises the error, measured in a global norm, in the velocity and pressure fields. This leads to stable problems for a large number of reservoirs. We present several algorithms for finding the effective permeability values. It turns out that these algorithms are not significantly more computational expensive than traditional local methods. Finally, the method is illustrated by several numerical experiments.

Journal ArticleDOI
TL;DR: In this article, the authors modified Darcy's law by introducing general memory formalisms operating on the flow as well as on the pressure gradient, which imply a filtering of the pressure gradients without singularities.
Abstract: Some data on the flow of fluids in rocks exhibit properties which may not be interpreted with the classic theory of propagation of pressure and of fluids in porous media [Bell and Nur, 1978; Roeloffs, 1988] based on Darcy's law, which states that the flux is proportional to the pressure gradient. Concerning the fluids, some may react chemically with the medium enlarging the pores; some carry solid particles, which may obstruct some of the pores; and finally, some may precipitate minerals in the pores diminishing their size or even closing them as in geothermal areas. These phenomena create a spatially variable pattern of mineralization and permeability changes that can be localized. In order to obtain a better representation of the flux and of the pressure of fluids, Darcy's law is modified, introducing general memory formalisms operating on the flow as well as on the pressure gradient, which imply a filtering of the pressure gradient without singularities. We also modify the second constitutive equation of diffusion, which relates the density variations of the fluid to the pressure, by introducing a rheology in the fluid also represented by memory formalisms operating on the pressure as well as on the density variations. The memory formalisms are then specified as derivatives of fractional order. The equations used here for the diffusion of fluids are different from the classic ones; however, the equation governing the diffusion of the pressure is the same as that of the flux, as in the classic case. For technical reasons the majority of the studies on diffusion is devoted to the diffusion of the pressure of the fluid rather than to the flux; in this paper we shall devote our attention to studying the flux and its spectral properties in a practical example seeing that the memory used implies a low-pass filtering of the flux or a band pass centered in the low-frequency range. A half space is considered where the boundary values are applied to the plane limiting it, and the problems solved are the computation of the Green function of the flux in the cases when (1) a pressure constant in time is applied on the boundary plane and (2) a periodic pressure is applied to the boundary plane while the half space is initially at zero pressure in both cases. We found closed form formulae for the flux and its spectrum. A discussion follows concerning the mode of determination of the parameters of memory formalisms ruling the diffusion using the observed pressure and/or the flux at several frequencies in problem 2. Concerning the flux, it is tentatively seen that when the medium is oil rock and the fluid is water, for a pressure of 105 Pa at the boundary and derivative of order 0.1, the flux at a distance of 0.1 km from the boundary plane is 1700 kg h−1.

Journal ArticleDOI
TL;DR: In this article, the authors used CT scanning to measure the oil and water relative permeabilites for three-phase gravity drainage in fractionally-wet sandpacks, and found that the gas relative permeability is approximately half as much in a oilwet medium than in an oil-wetter medium at the same gas saturation.
Abstract: We study three-phase flow in water-wet, oil-wet, and fractionally-wet sandpacks. We use CT scanning to measure directly the oil and water relative permeabilites for three-phase gravity drainage. In an analogue experiment, we measure pressure gradients in the gas phase to determine the gas relative permeability. Thus we find all three relative permeabilities as a function of saturation. We find that the gas relative permeability is approximately half as much in a oil-wet medium than in an water-wet medium at the same gas saturation. The water relative permeability in the water-wet medium and the oil relative permeability in the oil-wet medium are similar. In the water-wet medium the oil relative permeability scales as k ro ∼ S o 4 for S o > S or, where S or is the waterflood residual oil saturation. With octane as the oil phase, k ro ∼ S o 2 for S o < S or, while with decane as the oil phase, k ro falls sharply for S o < S or. The water relative permeability in the oil-wet medium resembles the oil relative permeability in the water-wet medium for a non-spreading oil such as decane. These observations can be explained in terms of wetting, spreading, and the pore scale configurations of fluid.

Journal ArticleDOI
TL;DR: In this paper, the authors briefly review the basic theory used to calculate diffusive gas flux F g, and introduce an experimental procedure to evaluate, in the laboratory, the effective diffusion coefficient D e which controls this flux.

Proceedings ArticleDOI
01 Jan 2000
TL;DR: In this article, the authors developed a new clustering technique that is unbiased and easy to apply to identify the hydraulic flow units, and a procedure for determining the optimal number of clusters that should be used in the HFU technique was introduced.
Abstract: Knowledge of permeability is critical to developing an effective reservoir description. Permeability data can be obtained from well tests, cores or logs. Normally, using well log data to derive estimates of permeability is the lowest cost method. To estimate permeability, we can use values of porosity, pore size distribution, and water saturation from logging data and established correlations. One benefit of using wireline log data to estimate permeability is that it can provide a continuous permeability profile throughout a particular interval. This paper will focus on the evaluation of formation permeability for a sandstone reservoir in Central Arabia from well log data using the concept of Hydraulic Flow Units (HFU). Cluster analysis is used to identify the hydraulic flow units. We have developed a new clustering technique that is unbiased and easy to apply. Moreover, a procedure for determining the optimal number of clusters that should be used in the HFU technique will be introduced. In this procedure, the sum of errors squared method was used as criterion for determining the required number of HFU's to describe the reservoir. In our work, the statistically derived hydraulic flow units were compared with the core description made at the well site by a geologist. The grain size classes from core description match very well with the statistically derived clusters from the HFU method. Our results indicate that hydraulic flow units correspond to different rock types in this Central Arabian Reservoir. Of course, direct measurement of rock properties using cores is the ideal method to determine HFU's. However, because the costs to cut and analyze cores are so high, few core measurements are routinely available. Hence, it is crucial to extend the flow unit determination to the un-cored intervals and wells. The relationship between core flow units and well log data was established by non-parametric regression in cored wells, and then was used as a tool to extend the flow units prediction to un-cored intervals and wells. Permeability estimation using the HFU method was extended to un-cored wells by implementing the Alternating Conditional Expectation (ACE) algorithm. ACE provides a data-driven approach for identifying the functional forms for the well log variables involved in the correlation. The reservoir porosity vs. permeability relationship was represented with single equation by using the different HFU's as indictor variables. Permeability profiles generated by HFU's using well log data agree with core data. A computer program was developed to perform hydraulic flow unit analysis. In the computer program, three main processing options were integrated, which are: ○ sensitivity runs are made to determine the optimal number of HFU's; ○ the analysis is then based on the optimal number of HFU's (or any user-defined number of HFU's); and ○ regression analysis is performed using the different HFU's as dummy variables to predict values permeability.

Journal ArticleDOI
TL;DR: In this paper, the hydraulic conductivity of a nonplastic till from northern Quebec was examined and it was shown that hydraulic conductivities are strongly influenced by the compaction degree of saturation.
Abstract: The paper examines the hydraulic conductivity of a nonplastic till from northern Quebec. It is shown that the hydraulic conductivity is strongly influenced by the compaction degree of saturation, a...

Journal Article
TL;DR: In this paper, the effects of fault slip and effective mean stress on permeability and permeability anisotropy have been investigated during long displacement shearing of synthetic quartz, feldspar, muscovite and granitic gouges under high pressures.
Abstract: The effects of fault slip and effective mean stress on permeability and permeability anisotropy have been investigated during long displacement shearing of synthetic quartz, feldspar, muscovite and granitic gouges under high pressures. In quartzo-feldspathic gouges, permeability anisotropies up to one-and-a-half orders of magnitude were developed by heterogeneous grain crushing associated with shear sliding. In muscovite gouge, a permeability anisotropy of about one order of magnitude was first developed during initial pressurization of gouge materials due to a preferred alignment of mica basal planes. During shear sliding, rearrangement of packing and rotation of mica basal planes lead to a slight decrease in permeability anisotropy. The pressure dependency of permeability of gouge materials changes systematically with shear displacements. In quartzo-feldspathic gouges, the pressure dependency of permeability first decreased with shear sliding and then increased to a value typical for rocks containing microcracks. In contrast, the pressure dependency of permeability in muscovite gouge decreases continuously with increasing shear displacement. The evolution of permeability anisotropy and pressure dependency of permeability for different gouge materials during shear sliding implies that the distribution of fluid pressure in natural fault zones could be very heterogeneous.

01 Jan 2000
TL;DR: In this article, the porosity and permeability of unconfined carbonate aquifers were investigated as a result of dissolution, and it was found that the channels added little to the bulk porosity but that they enhanced the permeability of the fractured rock by one to three orders of magnitude.
Abstract: SPELEO BRAZIL 2001 Brasília DF, 15-22 de julho de 2001 13th International Congress of Speleology 4th Speleological Congress of Latin América and Caribbean 26th Brazilian Congress of Speleology Porosity and Permeability Enhancement in Unconfined Carbonate Aquifers as a Result of Dissolution Stephen. R. H. WORTHINGTON; Derek C. FORD; Patricia A. BEDDOWS School of Geography and Geology, McMaster University, Hamilton, ON L8S 4K1, Canada. Solution processes in carbonate aquifers that are unconfined produce networks of channels. To characterize the enhancement of porosity and permeability by dissolution, we examine four examples that are highly contrasted in their lithologic characteristics and topographic settings:a Paleozoic dolostone near Niagara Falls, Ontario; the Mill Hole basin in Paleozoic limestone in Mammoth Cave National Park, Kentucky; the Mesozoic chalk escarpments of southern England, and late TertiaryQuaternary limestones of the Caribbean coast of the Yucatan Peninsula, Mexico. In all four cases it is found that the channels add little to the bulk porosity but that they enhance the permeability of the fractured rock by one to three orders of magnitude. Similar porosity and permeability changes are predicted for all unconfined carbonate aquifers, limestone or dolostone, in both autogenic and allogenic settings, and in carbonate rocks of all ages. www.sbe.com.br Sociedade Brasileira de Espeleologia sbe@sbe.com.br

Journal ArticleDOI
TL;DR: In this paper, the authors re-examined the data from 90 tracer experiments performed in low-permeability fractured media to explore correlations among parameters controlling flow and transport.

Journal ArticleDOI
TL;DR: In this article, the general solution for the transient-pulse test is extended to consider quantitatively the transient distributions of hydraulic head and hydraulic gradient within the specimen and examine the validity of using the solution presented by Brace et al. (1968) under these conditions.
Abstract: The transient-pulse technique is a well-established laboratory method for determining the permeability of hydraulically tight rocks. Although graphical solutions to this test make it possible to evaluate both the permeability and the specific storage of a rock specimen, the attendant procedures are relatively complicated. Often, the expression introduced by Brace et al. (1968) is typically used to interpret the experimental results and arrive at a value for permeability only. In Part 1 of this study, the general solution for the transient-pulse test is extended to consider quantitatively the transient distributions of hydraulic head and hydraulic gradient within the specimen and to examine the validity of using the solution presented by Brace et al. (1968) under these conditions. Based on a series of parametric studies, some theoretical and practical considerations related to the design of a transient-pulse test are also provided. In Part 2, a relatively convenient and general approach to calculating the specific storage of a specimen from a transient-pulse test is presented and its efficiency is demonstrated through the application of this approach to experimental investigations.

Journal ArticleDOI
01 Dec 2000-Geology
TL;DR: In this article, a simple geometric model for the evolution of fluid permeability during the sequential growth of deformation bands in an ideal elastic-brittle porous granular medium is presented.
Abstract: We present a simple geometric model for the evolution of fluid permeability during the sequential growth of deformation bands in an ideal elastic-brittle porous granular medium. The model is based on recent mechanical and microstuctural results from laboratory experiments on large (10 cm diameter) sandstone samples that reproduce field observation. The model assumes poroelastic compaction of the rock matrix in the prefailure stage, followed either by bulk shear-enhanced dilatancy or compaction in the postfailure stage, depending on confining pressure, and a constant-porosity shear zone that accumulates slip by sequentially increasing the number of discrete bands linearly with the inelastic strain. For large permeability contrasts between matrix and the deformation band, the model quantitatively explains the entire permeability cycle observed in bulk samples, including the apparent paradox of a negative correlation of bulk permeability with porosity during dilatant slip in the postfailure stage, as observed in recent laboratory tests.


Journal ArticleDOI
Fred Kofi Boadu1
TL;DR: In this article, the hydraulic properties including porosity and permeability of fractured rock masses are estimated from seismic velocities derived from controlled numerical experiments, and the velocity ratio between the fractured and the intact rock correlates with hydraulic properties.

Journal ArticleDOI
TL;DR: In this article, a unique relationship between deformation bands and the distribution of diagenetic mineralization in the Aztec Sandstone, a reservoir and aquifer analog exposed at the surface, was found to reduce deformation band permeability by an average of 1.3 orders of magnitude relative to the surrounding rock.
Abstract: At the Valley of Fire State Park, southeastern Nevada, there is a unique relationship between deformation bands and the distribution of diagenetic mineralization in the Aztec Sandstone, a reservoir and aquifer analog exposed at the surface. Distinct diagenetic alteration fronts are refracted where they cross deformation bands. Modeling this refraction as resulting from the advective transport of a nonreactive solute, we are able to back out that deformation band permeability is reduced by an average of 1.3 orders of magnitude relative to the surrounding rock with a range of 0.7 to 2.1 orders of magnitude. The geometric relationship utilized in our approach formed in the subsurface during diagenesis and provides an in situ measurement of permeability not affected by uplift and erosion or by damage associated with collecting a sample from a well bore. Our estimation is about 1 order of magnitude lower than values reported in the literature for similar rock types.

Journal ArticleDOI
TL;DR: In this article, an integral method for analyzing transient fluid flow through a porous medium, which has pressure-dependent permeability, is presented, in which the density of the fluid, and the porosity and permeability of the formation, are treated as arbitrary functions of pressure.

Proceedings ArticleDOI
01 Oct 2000
TL;DR: In this paper, a retrograde gas condensate fluid was used to measure the decrease in gas relative permeability due to liquid dropout below the dew point and to evaluate the use of methanol to restore the gas relative percolation.
Abstract: Experiments have been done with a retrograde gas condensate fluid to measure the decrease in gas relative permeability due to liquid dropout below the dew point and to evaluate the use of methanol to restore the gas relative permeability. The methanol was found to increase the end-point gas relative permeability by a factor of 1.2 to 2.5 depending on the initial water saturation. A likely reason for the increased gas permeability is the miscible displacement of the condensate and water phases by the methanol. The use of an inexpensive solvent such as methanol to improve the productivity of gas wells that have been damaged by production below the dew point due to condensate and/or water blocking presents an attractive approach deserving further investigation.

Journal ArticleDOI
TL;DR: A series of gas permeability tests were performed on partially saturated needle-punched geosynthetic clay liners (GCLs) with nitrogen (N2) as the gas permeant medium.

Journal ArticleDOI
TL;DR: In this article, a general model of the directional permeability in homogeneous, anisotropic nonwoven structures is presented based on drag-force theory and D'Arcy's Law.
Abstract: A new general model of the directional permeability in homogeneous, anisotropic nonwoven structures is presented. It is based on drag-force theory and D'Arcy's Law. Structural parameters in the fabric are considered, including fibre diameter, porosity, and the fibre-orientation distribution. The governing equations of the local permeability in two- and three-dimensional structures are derived, which allow the permeability in any direction in the fabric to be calculated. It is demonstrated that fibre orientation is a major factor influencing the anisotropy of permeability.

Journal ArticleDOI
TL;DR: In this article, a lattice Boltzmann method is used to simulate 3D fluid flow in correlated porous media and the effect of porosity and spatial correlation on the permeability of 3D porous media is studied.