Characterization of Electrical Daily Variations Induced by Capillary Flow in the Non-saturated Zone

Perrier, Frédéric; Morat, Pierre

doi:10.1007/pl00001118

Cited by 80 publications

(121 citation statements)

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“…This formulation avoids the introduction of the zeta potential in describing the electrokinetic properties of porous media as done in most alternative models [3][4][5][6][7]. Our formulation emphasizes the role of the velocity of the water phase in playing a key-role in the electrokinetic properties of the porous material rather than focusing on the pressure field of the water phase.…”

Section: Volume-averaging the Streaming Current Densitymentioning

confidence: 99%

“…In geosciences, examples include water transport in unsaturated parts of the porous soils [3,4,5], monitoring of the oil / water interface in reservoir engineering [6,7], remediation (by electro-osmotic pumping) of soils contaminated by nonaqueous phase liquids (NAPLs) [8], monitoring of CO 2 sequenstration in the ground, healing of cracks of unsaturated clay-rocks by electro-osmotic pumping in civil engineering, and the study of diffusion of ionic species in unsaturated clay-rocks used as host formations for long-term storage of toxic wastes. To the best of our knowledge, our model is the first rigorous attempt to derive the governing equations that describe the effect of water saturation upon streaming potential and electro-osmosis.…”

Section: Introductionmentioning

confidence: 99%

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Electrokinetic coupling in unsaturated porous media

Revil

Linde

Cérepi

et al. 2007

Journal of Colloid and Interface Science

214

337

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Abstract. We consider a charged porous material that is saturated by two fluid phases that are immiscible and continuous at the scale of a representative elementary volume. The wetting phase for the grains is water and the non-wetting phase is assumed to be an electrically insulating viscous fluid. We use a volume averaging approach to derive the linear constitutive equations for the electrical current density as well as and the seepage velocities of the wetting and non-wetting phases at the scale of a representative elementary volume. These macroscopic constitutive equations are obtained by volume-averaging Ampère's law together with the Nernst-Planck equation and the Stokes equations. The material properties entering the macroscopic constitutive equations are explicitly described as a function of the saturation of the water phase, the electrical formation factor, and parameters that describe the capillary pressure function, the relative permeability function, and the variation of electrical conductivity with saturation. New equations are derived for the streaming potential and electro-osmosis coupling coefficients. A primary drainage and imbibition experiment is simulated numerically to demonstrate that the relative streaming potential coupling coefficient depends not only on the water saturation, but also on the material properties of the sample as well as the saturation history. We also compare the predicted streaming potential coupling coefficients with experimental data from four dolomite core samples. Measurements on these samples include electrical conductivity, capillary pressure, the streaming potential coupling coefficient at various level of saturation, and the permeability at saturation of the rock samples. We found a very good agreement between these experimental data and the model predictions.

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Section: Volume-averaging the Streaming Current Densitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electrokinetic coupling in unsaturated porous media

Revil

Linde

Cérepi

et al. 2007

Journal of Colloid and Interface Science

214

337

View full text Add to dashboard Cite

show abstract

“…SP data could then be used to evaluate, by comparing the data with those acquired at neighboring unrestored sites, the effect of river restoration on hydrological subsurface processes. Another more general motivation is that better understanding of near-surface SP sources can help to remove SP signals of shallow origin when investigating deeper phenomena, such as, volcanic activity (Friedel et al, 2004), earthquake precursors (Park, 1983), or processing magnetotelluric data (Perrier and Morat, 2000).…”

Section: Introductionmentioning

confidence: 99%

Self-potential investigations of a gravel bar in a restored river corridor

Linde

Doetsch

Jougnot

et al. 2011

Hydrol. Earth Syst. Sci.

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Abstract. Self-potentials (SP) are sensitive to water fluxes and concentration gradients in both saturated and unsaturated geological media, but quantitative interpretations of SP field data may often be hindered by the superposition of different source contributions and time-varying electrode potentials. Self-potential mapping and close to two months of SP monitoring on a gravel bar were performed to investigate the origins of SP signals at a restored river section of the Thur River in northeastern Switzerland. The SP mapping and subsequent inversion of the data indicate that the SP sources are mainly located in the upper few meters in regions of soil cover rather than bare gravel. Wavelet analyses of the timeseries indicate a strong, but non-linear influence of water table and water content variations, as well as rainfall intensity on the recorded SP signals. Modeling of the SP response with respect to an increase in the water table elevation and precipitation indicate that the distribution of soil properties in the vadose zone has a very strong influence. We conclude that the observed SP responses on the gravel bar are more complicated than previously proposed semi-empiric relationships between SP signals and hydraulic head or the thickness of the vadose zone. We suggest that future SP monitoring in restored river corridors should either focus on quantifying vadose zone processes by installing vertical profiles of closely spaced SP electrodes or by installing the electrodes within the river to avoid signals arising from vadose zone processes and time-varying electrochemical conditions in the vicinity of the electrodes.Correspondence to: N. Linde

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“…Perrier and Morat (2000) were the first to propose that the SPC depends on the relative permeability.…”

Section: Effect Of Water Contentmentioning

confidence: 99%

A review on electrokinetically induced seismo-electrics, electro-seismics, and seismo-magnetics for Earth sciences

Jouniaux

Zyserman

2016

Solid Earth

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Abstract. The seismo-electromagnetic method (SEM) can be used for non-invasive subsurface exploration. It shows interesting results for detecting fluids such as water, oil, gas, CO 2 , or ice, and also help to better characterise the subsurface in terms of porosity, permeability, and fractures. However, the challenge of this method is the low level of the induced signals. We first describe SEM's theoretical background, and the role of some key parameters. We then detail recent studies on SEM, through theoretical and numerical developments, and through field and laboratory observations, to show that this method can bring advantages compared to classical geophysical methods.

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Characterization of Electrical Daily Variations Induced by Capillary Flow in the Non-saturated Zone

Cited by 80 publications

References 0 publications

Electrokinetic coupling in unsaturated porous media

Electrokinetic coupling in unsaturated porous media

Self-potential investigations of a gravel bar in a restored river corridor

A review on electrokinetically induced seismo-electrics, electro-seismics, and seismo-magnetics for Earth sciences

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