Electrokinetic experimental study on saturated rock samples: zeta potential and surface conductance

Modeling of the coseismic electromagnetic fields observed during the 2004 Mw 6.0 Parkfield earthquake

“…To quantitatively describe the electrokinetic effect, we use equations from Pride [] (referred to hereafter as Pride's equations), which couple the elastodynamic equations depicting elastic wave propagation in fluid‐saturated porous media [ Biot , ] and Maxwell equations describing the propagation of the EM waves. The coupling between the seismic and EM wavefields is controlled by the electrokinetic coupling coefficient that can be experimentally measured [e.g., Jaafar et al , ; Wang et al , ] or theoretically estimated [e.g., Pride , ; Revil et al , ]. Based on Pride's equations, several algorithms were developed to simulate the seismoelectromagnetic wavefields in the unbounded full space and horizontally layered media generated by various sources [e.g., Pride and Haartsen , ; Haartsen and Pride , ; Gao and Hu , , ; Hu and Gao , ; Ren et al , , ].…”

Examination of the fractal model for streaming potential coefficient in porous media

“…To examine the fractal model for the SPC, experimental data reported in [39] for ten cylindrical sandstone samples (25 mm in diameter and around 20 mm in length) saturated by six different salinities (0.02, 0.05, 0.1, 0.2, 0.4 and 0.6 mol/l NaCl solutions) are used. Parameters of the sandstone samples are reported in [39] and re-shown in Table 1. The measured SPC at the different salinities presented in [39] is also re-shown in Table 2.…”

Dynamic Fluid in a Porous Transducer-Based Angular Accelerometer

“…The measurement range is ±2000 mV with an accuracy of ±(0.2% + 250 μV). Although the magnitude of the streaming potential coupling coefficient, $C_{sp}$, shows differences due to the liquid selection, the non-dimensional results would still be analogous [25,26,27]. Therefore, a NaCl solution served as the test fluid in our experiment.…”

“…The hydrodynamic resistance of the transducer, $R_h$, is inversely proportion to the permeability and further affects the differential pressure and velocity (Equations (7) and (8)). The streaming potential coupling coefficient $C_{sp}$ (the ratio of the streaming potential, $E_s$, to the differential pressure, $\mathrm{sans-serif\Delta }p$), which could be used to serve as the model of the electrical molecular system, is influenced by permeability [26,27,28,29], and one model [29] gives: $C_{sp}=\frac{E_s}{\Delta p}=\frac{{\epsilon }_0{\epsilon }_r\varsigma }{\eta \left({\sigma }_0+{\mathrm{\Sigma }}_s\sqrt{c}/\sqrt{kF}\right)}$ where ${\epsilon }_0$ and ${\epsilon }_r$ are the permittivity of vacuum and the relative permittivity of the fluid respectively, $\varsigma$ is the zeta potential at the fluid-solid interface, ${\sigma }_0$ is the bulk conductivity of the fluid, ${\mathrm{\Sigma }}_s$ denotes the surface conductance of the fluid-solid interface, $c$ is a constant parameter determined by the pore shape and $F={\varphi }^{-m}$ is the formation factor of the porous medium, where $\varphi$ is the bulk porosity and $m$ is the cementation exponent of the porous transducer and assumed to be $m=1.5$ for spherical packing media [27]. As a result, the dynamic characteristics of the permeability can produce marked effects on the dynamic performance of the fluidic system, as well as the electrical molecular system of the sensor.…”