Electrical conductivity of partially saturated porous media containing clay: An improved formulation

Abstract

[1] Prediction of the bulk DC electrical conductivity of partially saturated porous media containing clay has remained a significant challenge. A variety of models have been proposed; however, no single model has yet been shown to be entirely satisfactory. In this paper, we propose an improved formulation to account for partial saturation by extending an earlier proposed effective medium formulation. In order to test the performance of the proposed formulation, 28 data sets are extracted from the literature and analysed by our model. The results are then compared with the results from the original effective medium formulation, the Waxman and Smits model as well as the original and recently extended Volume Average (VA) model. The new formulation shows a strong improvement compared to the original formulation with an average R-square of 0.996 for 28 data sets compared to 0.506 for the original formulation. Detailed comparison of the five fitted models shows that the new formulation and the extended VA model both perform very well and in a similar fashion. Simplifying assumptions made during the fitting process of the models allow the application of these two models with data commonly measured in the field.

Transport of water and ions in partially water-saturated porous media. Part 3. Electrical conductivity

“…This formulation is consistent with the work done by Greve et al (2013) who analyzed a large database of experimental data at partial saturations to conclude that the Dukhin number should scaled according to Eq. (99) .…”

Reply to ‘Comment on “Dependence of shear wave seismoelectrics on soil textures: a numerical study in the vadose zone by F.I. Zyserman, L.B. Monachesi and L. Jouniaux” by Revil, A.’

“…The total charge density of the diffuse and Stern layer Q V can be deduced from CEC measurements as performed by Waxman & Smits (1968), Waxman & Thomas (1974) and Vinegar & Waxman (1984). Q V is usually determined from the ratio of the cation exchange capacity per unit pore volume of rock, expressed in meq ml −1 , with 1 meq ml −1 = 96.32 × 10 6 C m −3 (Greve et al 2013). In Fig.…”

Biogas desaturation and bio-gelation methods for mitigation of sand liquefaction

“…These influencing factors have been well investigated by previous studies (Kalinski & Kelly, 1994;Saarenketo, 1998;Samouëlian et al, 2005;Long et al, 2012;Ondruška et al, 2018). To bridge the gap between the electrical resistivity and soil properties, serval empirical models have been proposed (Archie, 1942;Waxman & Smits, 1968;Rhoades et al, 1989;Mojid et al, 2007;Greve et al, 2013;Hasan et al, 2018). For the sandy soil, the most famous and widely adopted model is still the one proposed by Archie (1942) and is usually called Archie's law.…”

“…If the hypothesis is true, it means the accumulation of gas bubbles in the shallow layer could help mitigate Electrical resistivity of soil is sensitive to temperature, porosity, degree of saturation (moist content), particle and pore size distribution, pore water salinity and so on (Kibria & Hossain, 2012). Serval models have been proposed to describe the relationship (Archie, 1942;Waxman & Smits, 1968;Rhoades et al, 1989;Mojid et al, 2007;Greve et al, 2013;Hasan et al, 2018), but the most popular model used for describing sandy soil is still the one proposed by Archie (1942) which is usually called Archie's law. In this model, sand particles are regarded as insulator and the conductivity of electrical current is only dominated by microscopic structure of void space and pore water salinity.…”