New Pore-Size Parameter Characterizing Transport in Porous Media

Johnson, David Linton; Koplik, Joel; Schwartz, Lawrence M.

doi:10.1103/physrevlett.57.2564

Cited by 441 publications

(328 citation statements)

References 15 publications

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“…Johnson et al (1986) derived a linear relationship between bulk, fluid, and surface conductivities that provides a theoretical basis for this empirical expression and gives physical meaning to the constants in the expression. This theory has been shown to apply to clay-bearing rocks (e.g., Sen et al, 1988), but it has not been used previously for unconsolidated materials.…”

Section: Methods and Resultsmentioning

confidence: 99%

“…This theory has been shown to apply to clay-bearing rocks (e.g., Sen et al, 1988), but it has not been used previously for unconsolidated materials. We quantified the influence of microstructural properties on electrical properties for our sand-clay samples by calculating formation factors, Lambda-parameters, and surface conductances from our data, and then we compared our surface conductances to estimates from the theory of Johnson et al (1986). We obtained good agreement, and we found that high and low bounds on the expected surface and bulk conductance in a sand-clay system can be determined from measurements made on samples having a few different microgeometries, including dispersed clay, clay layers, and clay clusters.…”

Section: Methods and Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Final Report U.S. Department of Energy Joint Inversion of Geophysical Data for Site Characterization and Restoration Monitoring

Berge¹,

Berryman²,

Bertete‐Aguirre³

et al. 2000

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Section: Methods and Resultsmentioning

confidence: 99%

Section: Methods and Resultsmentioning

confidence: 99%

Final Report U.S. Department of Energy Joint Inversion of Geophysical Data for Site Characterization and Restoration Monitoring

Berge¹,

Berryman²,

Bertete‐Aguirre³

et al. 2000

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“…The ratio ppuid :&,& is the formation factor F. Equation 1 assumes that the contribution of surface conduction to bulk conduction is negligible. If that is not the case, it has been found in theoretical (Johnson et al, 1986) and experimental work (Waxman and Smits, 1968;Sen et al, 1988;and Sen and Goode, 1992) that Archie's law has to be modified to include a surface-conduction term, Johnson et al (1986) defined a length parameter A, which is a weighted volumeto-surface-area ratio (a measure of the dynamically interconnected pore size) defined as (2) E(r) is the electric potential field at point Y, VP is the pore volume, and S is the surface area (i.e., the pore-solid interface). /I has units of length and is a parameter characteristic of the geometry of the porous medium.…”

Section: Introductionmentioning

confidence: 95%

“…Under certain conditions, the n-parameter can be correlated with the hydraulic permeability k and the formation factor F (Johnson et al, 1986;Kostek et al, 1992):…”

Section: Electrical Parametersmentioning

confidence: 99%

Influence of Microstructural Properties on Geophysical Measurements in Sand‐Clay Mixtures

Carlberg¹,

Roberts²,

Wildenschild³

1999

Symposium on the Application of Geophysics to Engineering and Environmental Problems 1999

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We have performed a series of laboratory experiments on saturated sand-clay mixtures. Measurements include frequency-dependent electrical properties using the four-electrode technique (10 niHz to 1 MHz), permeability, porosity, and acoustic velocities. We mixed clean Ottawa (quartz) sand with Na-montmorillonite (Wyoming bentonite) in a number of different configurations containing 0 to 10% clay: as a dispersed mixture, as discrete clay clusters, and arranged in distinct layers. Solutions of CaCl, ranging from 0.0005 N to 0.75 N (0.05 to 64 mS/cm) and deionized water were used as saturating fluids. We found the electrical properties to be dependent on clay content, fluid conductivity, and microstructure in a complex fashion. Increasing fluid conductivity and increasing clay content generally resulted in higher electrical conductivity. For an individual sample, two main regions of conduction exist: a region dominated by surface conduction and a region where the ionic strength of the saturating fluid controlled conduction. The sample geometry (dispersed, nondispersed, or layered clay configuration) was found to greatly affect the magnitude of the surface conductance in the range of low fluid conductivity.

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“…In biomedical imaging, magnetic field correlation was examined for a potential quantitative assessment of iron in brain [12]. It was shown that the magnetic field correlation function is closely related to the structure factor of the pore space [13,14]. Thus it is desirable to devise an experimental method to directly measure the correlation function of the electromagnetic field in such media.…”

mentioning

confidence: 99%

NMR Measurement of the Magnetic Field Correlation Function in Porous Media

Cho

Song

2008

Phys. Rev. Lett.

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The structure factor provides a fundamental characterization of porous and granular materials as it is the key for solid crystals via measurements of x-ray and neutron scattering. Here, we demonstrate that the structure factor of the granular and porous media can be approximated by the pair correlation function of the inhomogeneous internal magnetic field, which arises from the susceptibility difference between the pore filling liquid and the solid matrix. In-depth understanding of the internal field is likely to contribute to further development of techniques to study porous and granular media. DOI: 10.1103/PhysRevLett.100.025501 PACS numbers: 76.60.Jx, 61.05.Qr, 61.43.Gt, 75.75.+a Sand piles, rocks, and colloids share a common structure element that they are examples of materials formed by aggregation of granular particles in another medium. Their physical properties are critically dependent on the grain-grain interactions and the structure of the grain arrangement [1][2][3]. Details of the packing are important for the presence of heterogeneous force causing jamming [4,5], unique acoustic properties [6], and clustering [1]. It was found that the spatial correlation functions of the electromagnetic fields in such porous media can be useful to predict fluid flow and structure factor. For example, twodimensional images have been used to construct the spatial correlation functions of porous media and to infer material properties [7][8][9][10], and it was shown that correlation length of electric field is similar to the hydraulic radius [11]. In biomedical imaging, magnetic field correlation was examined for a potential quantitative assessment of iron in brain [12]. It was shown that the magnetic field correlation function is closely related to the structure factor of the pore space [13,14]. Thus it is desirable to devise an experimental method to directly measure the correlation function of the electromagnetic field in such media.In this Letter, we present a NMR method to measure the spatial magnetic correlation function in model porous materials. When a granular sample is placed in a uniform magnetic field, the solid grain and the interstitial material are magnetized differently due to a susceptibility contrast, producing an inhomogeneous magnetic field in the pore space -often called internal field. We use nuclear spins to probe the magnetic field difference between two positions by the following method. First, we employ pulsed field gradient (PFG) NMR to select spins by their translational diffusion displacement. For this experiment, the effect of the internal field is nullified. Then, we perform a similar experiment but with the internal field effect. The field difference between the two positions causes a signal decay that is related to the magnetic field correlation at that displacement. We show that the method is robust for different grain sizes, diffusion, encoding times, and displacement resolution and reliably obtains surface-to-volume ratio (SVR).Conventional translation diffusion measurements ofte...

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New Pore-Size Parameter Characterizing Transport in Porous Media

Cited by 441 publications

References 15 publications

Final Report U.S. Department of Energy Joint Inversion of Geophysical Data for Site Characterization and Restoration Monitoring

Final Report U.S. Department of Energy Joint Inversion of Geophysical Data for Site Characterization and Restoration Monitoring

Influence of Microstructural Properties on Geophysical Measurements in Sand‐Clay Mixtures

NMR Measurement of the Magnetic Field Correlation Function in Porous Media

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