Electrokinetic Phenomena in Porous Media

1995 ◽  
Vol 407 ◽  
Author(s):  
David B. Pengra ◽  
Po-Zen Wong

ABSTRACTElectrokinetic phenomena, such as electroosmosis (fluid-flow induced by applied electric fields) and streaming potential (the complementary process) are known to exist in brine-saturated porous media, but are very difficult to measure. With modern instrumentation and an ac method, we can now determine these transport coefficients accurately, and use them to characterize the permeability k1, the effective throat radius Re, and the electric potential at the slip-plane, or ζ-potential. Our study shows that permeability can be determined by two different means: by combining the dc values of the streaming potential, electroosmotic pressure and conductivity; or from the frequency response of ac electroosmosis alone. The high sensitivity of the method allows us to measure k over the 0.1–10,000 millidarcy range with less than lOkPa applied pressure. This article reviews some of the basics of electrokinetics and describes our methods. We also discuss effects of brine salinity and possible effects due to the fractal nature of the pore surface.

1996 ◽  
Vol 463 ◽  
Author(s):  
David B. Pengra ◽  
Po-Zen Wong

ABSTRACTElectrokinetic phenomena in brine-saturated porous media, such as electroosmosis (fluid-flow induced by applied electric fields) and streaming current (the complementary process) depend on the density of ions adsorbed on the pore surface and the characteristic thickness of the diffuse space-charge layer λ. These, in turn, depend on brine chemistry, ambient temperature and possibly other parameters. We report on a series of measurements of natural rock and synthetic glass-bead samples: for one sample group, we varied the temperature over 0–50 ° C; for another, we changed the brine cation species. We find that the electrokinetic coefficients depend only weakly on temperature; this is shown to follow from the expected trends in λ, η, and σ. The chemistry dependence follows qualitatively but not quantitatively the predictions of the Debye-Hiickel approximation.


1994 ◽  
Vol 366 ◽  
Author(s):  
David B. Pengra ◽  
Liang Shi ◽  
Sidney Xi Li ◽  
Po-Zen Wong

ABSTRACTIn brine-saturated porous media the existence of a space-charge layer at the solid/liquid interface leads to a coupling between fluid and electric currents. This coupling is seen as a streaming potential (STP) across a porous plug when the fluid flows through it, or conversely, as electroosmosis (ELO) of the fluid when an electric field is applied. The magnitude of these electrokinetic effects depends on the thickness of the space-charge layer relative to the pore size, which in turn depends upon the salinity of the brine. From electrokinetic measurements one can obtain an effective hydraulic radius Reff and an effective zeta-potential at the slipplane ζeff. We have developed a high-sensitivity AC technique that can detect these small coupling effects, and have measured them in a suite of natural and artificial rock samples. We find that Reff and ζeff depend on salinity in ways which may be attributed to the roughness of the pore surfaces.


Author(s):  
Dan Huang ◽  
Zhongyu Ren ◽  
Xiaoyu Li ◽  
Qi Jing

Chitosan-stabilized nano zero-valent iron (CTS-nZVI) prepared by the liquid-phase reduction method has been shown to achieve a good dispersion effect. However, there has been little analysis on the mechanism affecting its stability and transport in saturated porous media. In this paper, settling experiments were conducted to study the stabilization of CTS-nZVI. The transport of CTS-nZVI in saturated porous media at different influencing factors was studied by sand column experiments. The stability mechanism of CTS-nZVI was analyzed from the point of view of colloidal stability by settling experiments and a zeta potential test. The theoretical model of colloidal filtration was applied for the calculation of transport coefficients on the basis of the column experiments data. Considering attachment–detachment effects, a particle transport model was built using HYDRUS-1D software to analyze the transport and spatial distribution of CTS-nZVI in a sand column.


2018 ◽  
Vol 40 (2) ◽  
pp. 109-116
Author(s):  
Luong Duy Thanh ◽  
Rudolf Sprik

Streaming potential in rocks is the electrical potential developing when an ionic fluid flows through the pores of rocks. The zeta potential is a key parameter of streaming potential and it depends on many parameters such as the mineral composition of rocks, fluid properties, temperature etc. Therefore, the zeta potential is different for various rocks and liquids. In this work, streaming potential measurements are performed for five rock samples saturated with six different monovalent electrolytes. From streaming potential coefficients, the zeta potential is deduced. The experimental results are then explained by a theoretical model. From the model, the surface site density for different rocks and the binding constant for different cations are found and they are in good agreement with those reported in literature. The result also shows that (1) the surface site density of Bentheim sandstone mostly composed of silica is the largest of five rock samples; (2) the binding constant is almost the same for a given cation but it increases in the order KMe(Na+) < KMe(K+) < KMe(Cs+) for a given rock.References Corwin R. F., Hoovert D.B., 1979. The self-potential method in geothermal exploration. Geophysics 44, 226-245. Dove P.M., Rimstidt J.D., 1994. Silica-Water Interactions. Reviews in Mineralogy and Geochemistry 29, 259-308. Glover P.W.J., Walker E., Jackson M., 2012. Streaming-potential coefficient of reservoir rock: A theoretical model. Geophysics, 77, D17-D43. Ishido T. and Mizutani H., 1981. Experimental and theoretical basis of electrokinetic phenomena in rock-water systems and its applications to geophysics. Journal of Geophysical Research, 86, 1763-1775. Jackson M., Butler A., Vinogradov J., 2012. Measurements of spontaneous potential in chalk with application to aquifer characterization in the southern UK: Quarterly Journal of Engineering Geology & Hydrogeology, 45, 457-471. Jouniaux L. and T. Ishido, 2012. International Journal of Geophysics. Article ID 286107, 16p. Doi:10.1155/2012/286107. Kim S.S., Kim H.S., Kim S.G., Kim W.S., 2004. Effect of electrolyte additives on sol-precipitated nano silica particles. Ceramics International 30, 171-175. Kirby B.J. and Hasselbrink E.F., 2004. Zeta potential of microfluidic substrates: 1. Theory, experimental techniques, and effects on separations. Electrophoresis, 25, 187-202. Kosmulski M., and Dahlsten D., 2006. High ionic strength electrokinetics of clay minerals. Colloids and Surfaces, A: Physicocemical and Engineering Aspects, 291, 212-218. Lide D.R., 2009, Handbook of chemistry and physics, 90th edition: CRC Press. Luong Duy Thanh, 2014. Electrokinetics in porous media, Ph.D. Thesis, University of Amsterdam, the Netherlands. Luong Duy Thanh and Sprik R., 2016a. Zeta potential in porous rocks in contact with monovalent and divalent electrolyte aqueous solutions, Geophysics, 81, D303-D314. Luong Duy Thanh and Sprik R., 2016b. Permeability dependence of streaming potential coefficient in porous media. Geophysical Prospecting, 64, 714-725. Luong Duy Thanh and Sprik R., 2016c. Laboratory Measurement of Microstructure Parameters of Porous Rocks. VNU Journal of Science: Mathematics-Physics 32, 22-33. Mizutani H., Ishido T., Yokokura T., Ohnishi S., 1976. Electrokinetic phenomena associated with earthquakes. Geophysical Research Letters, 3, 365-368. Ogilvy A.A., Ayed M.A., Bogoslovsky V.A., 1969. Geophysical studies of water leakage from reservoirs. Geophysical Prospecting, 17, 36-62. Onsager L., 1931. Reciprocal relations in irreversible processes. I. Physical Review, 37, 405-426. Revil A. and Glover P.W.J., 1997. Theory of ionic-surface electrical conduction in porous media. Physical Review B, 55, 1757-1773. Scales P.J., 1990. Electrokinetics of the muscovite mica-aqueous solution interface. Langmuir, 6, 582-589. Behrens S.H. and Grier D.G., 2001. The charge of glass and silica surfaces. The Journal of Chemical Physics, 115, 6716-6721. Stern O., 1924. Zurtheorieder electrolytischendoppelschist. Z. Elektrochem, 30, 508-516. Tchistiakov A.A., 2000. Physico-chemical aspects of clay migration and injectivity decrease of geothermal clastic reservoirs: Proceedings World Geothermal Congress, 3087-3095. Wurmstich B., Morgan F.D., 1994. Modeling of streaming potential responses caused by oil well pumping. Geophysics, 59, 46-56. 


Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1588
Author(s):  
Luong Duy Duy Thanh ◽  
Damien Jougnot ◽  
Phan Van Do ◽  
Nguyen Xuan Ca ◽  
Nguyen Thi Hien

The electrokinetics methods have great potential to characterize hydrogeological processes in porous media, especially in complex partially saturated hydrosystems (e.g., the vadose zone). The dependence of the streaming coupling coefficient on water saturation remains highly debated in both theoretical and experimental works. In this work, we propose a physically based model for the streaming potential coupling coefficient in porous media during the flow of water and air under partially saturated conditions. The proposed model is linked to fluid electrical conductivity, water saturation, irreducible water saturation, and microstructural parameters of porous materials. In particular, the surface conductivity of porous media has been taken into account in the model. In addition, we also obtain an expression for the characteristic length scale at full saturation in this work. The proposed model is successfully validated using experimental data from literature. A relationship between the streaming potential coupling coefficient and the effective excess charge density is also obtained in this work and the result is the same as those proposed in literature using different approaches. The model proposes a simple and efficient way to model the streaming potential generation for partially saturated porous media and can be useful for hydrogeophysical studies in the critical zone.


Author(s):  
Murilo Camargo ◽  
Pedro Cleto ◽  
Eduardo Alexandre Rodrigues ◽  
Heber Agnelo Antonel Fabbri ◽  
Osvaldo Luís Manzoli

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