scholarly journals Streaming Potential in Unconsolidated Samples Saturated with Monovalent Electrolytes

2018 ◽  
Vol 34 (1) ◽  
Author(s):  
Luong Duy Thanh
Keyword(s):  
Electrolyte Concentration ◽  
Effective Conductivity ◽  
Empirical Relation ◽  
Streaming Potential ◽  
Formation Factor ◽  
Potential Coefficient ◽  
Silica Surfaces ◽  
Fluid Concentration ◽  
The Difference ◽  
Rock Parameters

The streaming potential coefficient of liquid-rock systems is theoretically a very complicated function depending on many parameters including temperature, fluid concentration, fluid pH, as well as rock parameters such as porosity, grain size, pore size, and formation factor etc. At a given porous media, the most influencing parameter is the fluid conductivity or electrolyte concentration. Therefore, it is useful to have an empirical relation between the streaming potential coefficient and electrolyte concentration. In this work, the measurements of the streaming potential for four unconsolidated samples (sandpacks) saturated with four monovalent electrolytes at six different electrolyte concentrations have been performed. From the measured streaming potential coefficient, the empirical expression between the streaming potential coefficient and electrolyte concentration is obtained. The obtained expression is in good agreement with those available in literature. Additionally, it is seen that the streaming potential coefficient depends on types of cation in electrolytes and on samples. The dependence of the streaming potential coefficient on types of cation is qualitatively explained by the difference in the binding constant for cation adsorption on the silica surfaces. The dependence of the streaming potential coefficient on samples is due to the variation of effective conductivity and the zeta potential between samples.

scholarly journals Streaming Potential Coefficient Measurements in Porous Rocks Saturated by Divalent Electrolytes

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Luong Duy Thanh ◽  
Nguyen Manh Hung ◽  
Dang Thi Minh Hue ◽  
Tran Thi Chung Thuy
Keyword(s):  
Electric Double Layer ◽  
Electrolyte Concentration ◽  
Empirical Relation ◽  
Streaming Potential ◽  
Solid Surfaces ◽  
Experimental Result ◽  
Porous Rocks ◽  
Similar Form ◽  
Potential Coefficient ◽  
Rock System

Streaming potential in a water-rock system is generated by the relative motion between water and solid surfaces and is directly related to the existence of an electric double layer between water and solid grain surfaces of porous media. The streaming potential measurements have great potential in geophysical applications. Most porous rocks are filled by ground water containing various types of electrolytes. Therefore, it is important to understand the variation of the streaming potential with types of electrolytes for specific rocks. In this work, we have carried out streaming potential measurements for three consolidated rocks saturated by three divalent electrolytes at different electrolyte concentrations. The experimental result shows that the streaming potential coefficient in magnitude of all samples decreases with increasing electrolyte concentration. Additionally, an empirical relation between the streaming potential coefficient and the electrolyte concentration is obtained and it has a similar form to those available in literature for monovalent electrolytes.

scholarly journals Frequency-Dependent Streaming Potentials: A Review

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
L. Jouniaux ◽  
C. Bordes
Keyword(s):  
High Frequency ◽  
Streaming Potential ◽  
Low Frequency ◽  
Transition Frequency ◽  
Formation Factor ◽  
Potential Coefficient ◽  
Frequency Dependent ◽  
Streaming Potentials ◽  
Dynamic Permeability ◽  
Inertial Flow

The interpretation of seismoelectric observations involves the dynamic electrokinetic coupling, which is related to the streaming potential coefficient. We describe the different models of the frequency-dependent streaming potential, mainly Packard's and Pride's model. We compare the transition frequency separating low-frequency viscous flow and high-frequency inertial flow, for dynamic permeability and dynamic streaming potential. We show that the transition frequency, on a various collection of samples for which both formation factor and permeability are measured, is predicted to depend on the permeability as inversely proportional to the permeability. We review the experimental setups built to be able to perform dynamic measurements. And we present some measurements and calculations of the dynamic streaming potential.

The diffusion of 75Se(IV) in Beishan granite – temperature, oxygen condition and ionic strength effects

2018 ◽  
Vol 107 (1) ◽  
pp. 39-54
Author(s):  
Chunli Wang ◽  
Xiaoyu Yang ◽  
Jiangang He ◽  
Fangxin Wei ◽  
Zhong Zheng ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Effective Diffusion ◽  
Aerobic Condition ◽  
Double Layers ◽  
Solution Viscosity ◽  
Formation Factor ◽  
Experimental Conditions ◽  
Beishan Granite ◽  
Oxygen Condition ◽  
The Difference

Abstract To explore the diffusion behavior of 75Se(IV) in Beishan granite (BsG), the influences of temperature, oxygen condition and ionic strength were investigated using the through-diffusion experimental method. The effective diffusion coefficient De of 75Se(IV) in BsG varied from 4.21×10−14 m2/s to 3.19×10−13 m2/s in our experimental conditions, increased with increasing temperature. The formation factor Ff of BsG was calculated to be nearly constant in the range of temperatures investigated, suggesting that the inner structure of BsG had no significant change in the temperature range of 20–55°C. Meanwhile, the De values of 75Se(IV) in BsG under anaerobic condition was significantly larger than that under aerobic condition, which may be attributed to the difference in the sorption characteristics and species distribution of Se and pH values. Moreover, the diffusion of 75Se(IV) was promoted with ionic strength increased from 0.01 M to 0.1 M, and then decreased at 0.5 M, mainly due to the combined effects of reduced double layers with increased ionic strength and increase of the solution viscosity at higher ionic strength.

scholarly journals ELECTROKINETIC PHENOMENA

1931 ◽  
Vol 14 (5) ◽  
pp. 563-573 ◽  
Author(s):  
H. A. Abramson ◽  
E. B. Grossman
Keyword(s):  
Streaming Potential ◽  
Experimental Comparison ◽  
Consistent Difference ◽  
Real Difference ◽  
Electrokinetic Phenomena ◽  
Egg Albumin ◽  
Streaming Potentials ◽  
The Difference

1. The conditions are described which are necessary for the comparison of certain types of electrokinetic potentials. An experimental comparison is made of (a) electrophoresis of quartz particles covered with egg albumin; and (b) similar experiments by Briggs on streaming potentials. A slight, consistent, difference is found between the electrophoretic potential and the streaming potential. This difference is probably due to the difference in the protein preparations used rather than to real difference in the electrophoretic and streaming potentials. 2. Data are given which facilitate the measurements and enhance the precision of the estimation of electrical mobilities of microscopic particles.

Moments of the Flow Variables, Part II : The Effective Conductivity

2003 ◽  
Author(s):  
Yoram Rubin
Keyword(s):  
Steady State ◽  
Boundary Conditions ◽  
Effective Conductivity ◽  
Effective Property ◽  
Flow Equation ◽  
Laplace’S Equation ◽  
Flow Conditions ◽  
Laplace's Equation ◽  
Head Gradient ◽  
The Difference

Many applications require primary information such as average fluxes as a prelude to more complex calculations. In water balance calculations one may be interested only in the average fluxes. For both cases the concept of effective conductivity is useful. The effective hydraulic conductivity is defined by where the angled brackets denote the expected value operator. The local flux fluctuation is defined by the difference qi(x) — (qi(x)). Its statistical properties as well as those of the velocity will be investigated in chapter 6. To qualify as an effective property in the strict physical sense, Kef must be a function of the aquifer’s material properties and not be influenced by flow conditions such as the head gradient and boundary conditions (Landauer, 1978). Our goal in this chapter is to explore the concept of the effective conductivity Kef and to relate it to the medium’s properties under as general conditions as possible. Additionally, we shall explore the conditions where this concept is irrelevant and applicable, the important issue being that Kef is defined in an ensemble sense, but for applications we need spatial averages. Several methods for deriving Kef will be described below. The general approach for defining Kef includes the following steps. First, H is defined as an SRF and is expressed with the aid of the flow equation in terms of the hydro-geological SRFs (conductivity, mostly) and the boundary conditions. The H SRF is then substituted in Darcy’s law and an expression in the form equivalent to (5.1) is sought. If and only if the coefficient in front of the mean head gradient is not a function of the flow conditions will it qualify as Kef. The derivation of the effective conductivity employs the flow equation. In steady-state incompressible flow, for example, Laplace’s equation is employed. Solutions derived under Laplace’s equation are applicable, under appropriate conditions, for other physical phenomena governed by the same mathematical model. For example, the electrical field in steady state is also described by Laplace’s equation.

scholarly journals Electro-Osmotic Behavior of Polymeric Cation-Exchange Membranes in Ethanol-Water Solutions

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 692
Author(s):  
V. María Barragán ◽  
Juan P. G. Villaluenga ◽  
Víctor Morales-Villarejo ◽  
M. Amparo Izquierdo-Gil
Keyword(s):  
Cation Exchange ◽  
Streaming Potential ◽  
Membrane System ◽  
Electrolyte Solutions ◽  
Joule Effect ◽  
Potential Coefficient ◽  
Water Solutions ◽  
Onsager Reciprocity ◽  
Ethanol Content ◽  
Reciprocity Relations

The aim of this work is to apply linear non-equilibrium thermodynamics to study the electrokinetic properties of three cation-exchange membranes of different structures in ethanol-water electrolyte solutions. To this end, liquid uptake and electro-osmotic permeability were estimated with potassium chloride ethanol-water solutions with different ethanol proportions as solvent. Current–voltage curves were also measured for each membrane system to estimate the energy dissipation due to the Joule effect. Considering the Onsager reciprocity relations, the streaming potential coefficient was discussed in terms of ethanol content of the solutions and the membrane structure. The results showed that more porous heterogeneous membrane presented lower values of liquid uptake and streaming potential coefficient with increasing ethanol content. Denser homogeneous membrane showed higher values for both, solvent uptake and streaming coefficient for intermediate content of ethanol.

scholarly journals Saturation Dependence of the Streaming Potential Coefficient

2020 ◽  
pp. 73-100
Author(s):  
Laurence Jouniaux ◽  
Vincent Allègre ◽  
Renaud Toussaint ◽  
Fabio Zyserman
Keyword(s):  
Streaming Potential ◽  
Potential Coefficient

scholarly journals Atomic hydrogen III—The energy efficiency of atom production in a glow discharge

1937 ◽  
Vol 163 (914) ◽  
pp. 424-454 ◽  
Keyword(s):  
Glow Discharge ◽  
Closed System ◽  
Atomic Hydrogen ◽  
Empirical Relation ◽  
Power Input ◽  
Degree Of Dissociation ◽  
Recombination Processes ◽  
Dark Space ◽  
The Difference ◽  
Three Body

There seems to have been a tendency amongst workers on the use of the glow discharge as a source of atomic hydrogen to regard the current or power as determining the degree of dissociation of the gas, i. e. the equi­librium H 2 ⇌2H. It is clear, however, that the discharge itself determines only the rate of production of atoms, whereas the degree of dissociation depends also on the rate of removal of atoms by pumping and by recombina­tion processes which are independent of the discharge. The two homogeneous recombination processes are those resulting from three-body collisions be­tween three atoms and between two atoms and a molecule; in addition, there is a heterogeneously catalysed reaction in which the walls of the tube act as the energy acceptor. Attempts to connect electrical conditions with degree of dissociation have been made by Crew and Hulburt (1927) and by Wrede (1929), but the above remarks show that only empirical relationships can be hoped for. In Crew and Hulburt’s experiments, the degree of dissociation was estimated by measuring the change of pressure in a closed system on passing a discharge. A correction for temperature was applied, which was based on the erroneous idea that the rise of temperature due to discharge in helium is about the same as that in hydrogen at the same pressure and power input. The method of determining the pressure depended on an empirical relation between pressure and the length of the cathode dark space in an auxiliary discharge connected to the main system ; but since the cathode dark space has not a sharply defined boundary, and the degree of dissociation is calculated from the difference of two pressures measured in this way, considerable error is possible. Furthermore, in a closed system, the rate of production of atoms is equal to the rate of recombination; and since these workers relied on a water-on-glass film to inhibit heterogeneous recombination, and as the power input was 200-1000 W, the catalytic activity of the walls must have been very variable and large (Part II). Crew and Hulburt’s curves con­necting degree of dissociation with pressure and power input cannot, there­fore, be credited with quantitative significance.

Seismo-electric Conversion in Sandstones and Shales using 2 Different Experimental Approaches, Modelling and Theory

2020 ◽  
Author(s):  
Paul Glover ◽  
Rong Peng ◽  
Piroska Lorinczi ◽  
Bangrang Di
Keyword(s):  
Zeta Potential ◽  
Numerical Modelling ◽  
Clay Minerals ◽  
Shale Gas ◽  
Streaming Potential ◽  
Oil Reservoirs ◽  
Low Permeability ◽  
Experimental Measurements ◽  
Frequency Range ◽  
Potential Coefficient

<p>The development of seismo-electric (SE) exploration techniques relies significantly upon being able to understand and quantify the strength of frequency-dependent SE conversion. However, there have been very few SE measurements or modelling carried out. In this paper we present two experimental methods for making such measurements, and examine how the strength of SE conversion depends on frequency, porosity, permeability, and why it is unusual in shales. The first is based on an electromagnetic shaker and can be used in the 1 Hz to 2 kHz frequency range. The second is a piezo-electric water-bath apparatus which can be used in the 1kHz to 500 kHz frequency range.</p><p>The first apparatus has been tested on samples of Berea sandstone. Both the in-phase and in-quadrature components of the streaming potential coefficient have been measured with an uncertainty of better than ±4%. The experimental measurements show the critical frequency at which the quadrature component is maximal, and the frequency of this component is shown to agree very well with both permeability and grain size. The experimental measurements have been modelled using several different methods.</p><p>The second apparatus was used to measure SE coupling as a function of porosity and permeability, interpreting the results using a micro-capillary model and current theory. We found a general agreement between the theoretical curves and the test data, indicating that SE conversion is enhanced by increases in porosity over a range of different frequencies. However, SE conversion has a complex relationship with rock permeability, which changes with frequency, and which is more sensitive to changes in the petrophysical properties of low-permeability samples. This observation suggests that seismic conversion may have advantages in characterizing low permeability reservoirs such as tight gas and tight oil reservoirs as well as shale gas reservoirs.</p><p>We have also carried out SE measurements on Sichuan Basin shales (permeability 1.47 – 107 nD), together with some comparative measurements on sandstones (0.2 – 60 mD). Experimental results show that SE conversion in shales is comparable to that exhibited by sandstones, and is approximately independent of frequency in the seismic frequency range (<1 kHz). Anisotropy which arises from bedding in the shales results in anisotropy in the streaming potential coefficient. Numerical modelling has been used to examine the effects of varying zeta potential, porosity, tortuosity, dimensionless number and permeability. It was found that SE conversion is highly sensitive to changes in porosity, tortuosity and zeta potential in shales. Numerical modelling suggests that the cause of the SE conversion in shales is enhanced zeta potentials caused by clay minerals, which are highly frequency dependent. This is supported by a comparison of our experimental data with numerical modelling as a function of clay mineral composition from XRD measurements. Consequently, the sensitivity of SE coupling to the clay minerals suggests that SE exploration may have potential for the characterization of clay minerals in shale gas and shale oil reservoirs.</p>

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