Streaming potential coupling coefficient in unsaturated carbonate rocks

2017 ◽  
Vol 210 (1) ◽  
pp. 291-302 ◽  
Author(s):  
A. Cerepi ◽  
A. Cherubini ◽  
B. Garcia ◽  
H. Deschamps ◽  
A. Revil
Keyword(s):  
Coupling Coefficient ◽  
Carbonate Rocks ◽  
Streaming Potential

scholarly journals Streaming Potential Coupling Coefficient and Transport Properties of Unsaturated Carbonate Rocks

2018 ◽  
Vol 17 (1) ◽  
pp. 180030 ◽  
Author(s):  
A. Cherubini ◽  
B. Garcia ◽  
A. Cerepi ◽  
A. Revil
Keyword(s):  
Transport Properties ◽  
Coupling Coefficient ◽  
Carbonate Rocks ◽  
Streaming Potential

Measurement Of Streaming Potential Coupling Coefficient On Carbonate Rocks For Downhole Monitoring In Smart Wells

2012 ◽  
Author(s):  
Mohd Zaidi Jaafar ◽  
Ali Pourbasirat
Keyword(s):  
Fluid Flow ◽  
Coupling Coefficient ◽  
Carbonate Rocks ◽  
Carbonate Rock ◽  
Streaming Potential ◽  
Carbonate Reservoirs ◽  
Potential Measurement ◽  
Smart Wells ◽  
Downhole Monitoring ◽  
Downhole Sensors

Telaga pintar merujuk kepada telaga yang mengandungi downhole sensors dan injap kawalan aliran masuk (ICV) yang dipasang pada tiub pengeluaran. Telaga ini membenarkan pengendali untuk merekodkan kadar aliran bendalir, suhu dan tekanan yang berterusan semasa pengeluaran. Baru–baru ini, pengukuran streaming potential dalam telaga pintar telah dicadangkan untuk memantau pencerobohan air. Walau bagaimanapun, masih terdapat ketidakpastian yang signifikan yang dikaitkan dengan tafsiran ukuran, terutamanya mengenai pekali gandingan streaming potential. Ini adalah ciri petrofizik utama yang menentukan magnitud streaming potential untuk potensi bendalir yang tertentu. Magnitud streaming potential pada asasnya berkait dengan kadar aliran bendalir, sifat–sifat bendalir (khususnya kemasinan), dan sifat–sifat matriks batuan. Pekali gandingan telah diukur secara uji kaji dalam teras batu pasir yang tepu dengan kemasinan air garam yang berbeza, tetapi sangat sedikit hasil ujikaji telah diterbitkan bagi batuan karbonat. Bilangan reservor karbonat yang besar di seluruh dunia menyarankan bahawa pengukuran streaming potential dalam batuan karbonat juga penting. Dalam kajian ini, kami kemukakan nilai pekali gandingan streaming potential bagi batu karbonat yang tepu dengan berbagai kemasinan air garam. Seperti yang kami jangkakan, streaming potential bagi teras itu adalah kecil tetapi masih boleh diukur, dan kemasinan yang lebih tinggi memberikan pekali gandingan streaming potential yang lebih kecil. Keputusan yang diperolehi adalah konsisten hasil penggunaan elektrod yang direka khas dan ujikaji pam berpasangan untuk menghapuskan potensi elektrik palsu. Kami mendapati bahawa pekali gandingan streaming potential di dalam batu karbonat adalah lebih rendah berbanding dengan yang ada di teras batu pasir yang ditepukan dengan kemasinan air garam yang sama. Pemerhatian ini boleh dijelaskan dengan membandingkan perbezaan titik caj sifar (pzc) di antara kedua–dua jenis batu. Secara kualitatif, hasil ujikaji menunjukkan bahawa pengukuran streaming potential boleh digunakan untuk memantau pencerobohan air di dalam reservor karbonat, sama seperti ia digunakan untuk reservor batu pasir. Kata kunci: Streaming potential; elektrokinetik; pemantauan bawah telaga; telaga pintar; water encroachment; kawalan pengeluaran air; batu karbonat Smart wells refer to wells containing downhole sensors and inflow control valves (ICV) mounted on the production tubing. These wells allow the operator to record fluid flow rates, temperature and pressure incessantly. Recently, streaming potential measurement in smart wells has been proposed to monitor water encroachment. However, there are still significant uncertainties associated with the interpretation of the measurements, particularly concerning the streaming potential coupling coefficient. This is a key petrophysical property that dictates the magnitude of the streaming potential for a given fluid potential. Streaming potential magnitude is basically related to the fluid flow rate, fluid properties (particularly salinity), and the rock matrix properties. The coupling coefficient has been measured experimentally in sandstone cores saturated with different brine salinities, but very little works have been published on carbonate rocks. The huge number of carbonate reservoirs around the world suggests that measurement of streaming potential in carbonate rocks is also important. In this study, we present value of streaming potential coupling coefficient in a carbonate rock saturated with various salinities of brine. As we expected, streaming potential in such core is small but measurable and higher salinity gives smaller streaming potential coupling coefficient. Consistent results are obtained using specially designed electrodes and paired pumping experiments to eliminate spurious electrical potentials. We noticed that streaming potential coupling coefficient in carbonate rock is lower compared to the one in sandstone cores saturated with the same salinity of brine. This observation could be explained by comparing the difference in Point of zero charges (pzc) between those two types of rock. Qualitatively, the result suggests that measurements of streaming potential could be applied for monitoring water encroachment in carbonate reservoirs, in the same manner it is applied for sandstones reservoirs. Key words: Streaming potential; electrokinetics; downhole monitoring; intelligent wells; water encroachment; produced water control; carbonate rocks

The Determination of Electrokinetic Coupling-Coefficient and Zeta Potential of Rock Samples by Electrokinetic Measurements

2012 ◽  
Vol 516-517 ◽  
pp. 1870-1873 ◽  
Author(s):  
Jun Wang ◽  
Heng Shan Hu
Keyword(s):  
Zeta Potential ◽  
Coupling Coefficient ◽  
Streaming Potential ◽  
Potential Method ◽  
Surface Conductivity ◽  
Reliable Estimate ◽  
Surface Conductance ◽  
Streaming Current ◽  
Low Concentrations

The electrokinetic effects are important in the understanding of electric properties in porous medium. In this study, the streaming potential and streaming current of saturated samples are measured at different concentrations, then three methods are applied to obtain the zeta-potential and electrokinetic coupling coefficient. The study shows that the results obtained from streaming potential and streaming current methods agree well with each other, but the results obtained from simplified streaming potential method become seriously inaccurate at low concentrations due to the influence of surface conductance. This experimental study also provides a reliable estimate of the surface conductivity and its contribution to zeta-potential at given concentrations.

scholarly journals Forward Modeling and validation of a new formulation to compute self-potential signals associated with ground water flow

2007 ◽  
Vol 11 (5) ◽  
pp. 1661-1671 ◽  
Author(s):  
A. Bolève ◽  
A. Revil ◽  
F. Janod ◽  
J. L. Mattiuzzo ◽  
A. Jardani
Keyword(s):  
Ground Water ◽  
Current Density ◽  
Coupling Coefficient ◽  
Streaming Potential ◽  
Water Phase ◽  
Flow In Porous Media ◽  
Seepage Velocity ◽  
Streaming Current ◽  
New Formulation ◽  
Self Potential

Abstract. The classical formulation of the coupled hydroelectrical flow in porous media is based on a linear formulation of two coupled constitutive equations for the electrical current density and the seepage velocity of the water phase and obeying Onsager's reciprocity. This formulation shows that the streaming current density is controlled by the gradient of the fluid pressure of the water phase and a streaming current coupling coefficient that depends on the so-called zeta potential. Recently a new formulation has been introduced in which the streaming current density is directly connected to the seepage velocity of the water phase and to the excess of electrical charge per unit pore volume in the porous material. The advantages of this formulation are numerous. First this new formulation is more intuitive not only in terms of establishing a constitutive equation for the generalized Ohm's law but also in specifying boundary conditions for the influence of the flow field upon the streaming potential. With the new formulation, the streaming potential coupling coefficient shows a decrease of its magnitude with permeability in agreement with published results. The new formulation has been extended in the inertial laminar flow regime and to unsaturated conditions with applications to the vadose zone. This formulation is suitable to model self-potential signals in the field. We investigate infiltration of water from an agricultural ditch, vertical infiltration of water into a sinkhole, and preferential horizontal flow of ground water in a paleochannel. For the three cases reported in the present study, a good match is obtained between finite element simulations performed and field observations. Thus, this formulation could be useful for the inverse mapping of the geometry of groundwater flow from self-potential field measurements.

Laboratory Measurements and Numerical Modeling of Streaming Potential for Downhole Monitoring in Intelligent Wells

SPE Journal ◽  
2011 ◽  
Vol 16 (03) ◽  
pp. 625-636 ◽  
Author(s):  
M.D.. D. Jackson ◽  
J.. Vinogradov ◽  
J.H.. H. Saunders ◽  
M.Z.. Z. Jaafar
Keyword(s):  
Coupling Coefficient ◽  
New Technology ◽  
Streaming Potential ◽  
Oil Field ◽  
Concentration Limit ◽  
Sample Type ◽  
Electrical Potentials ◽  
Seawater Salinity ◽  
Intelligent Wells ◽  
Downhole Monitoring

Summary Downhole monitoring of streaming potential, using electrodes mounted on the outside of insulated casing, is a promising new technology for monitoring water encroachment toward an intelligent well. However, there are still significant uncertainties associated with the interpretation of the measurements, particularly concerning the streaming potential coupling coefficient. This is a key petrophysical property that dictates the magnitude of the streaming potential for a given fluid potential. We present the first measured values of streaming potential coupling coefficient in sandstones saturated with natural and artificial brines relevant to oilfield conditions at higher-than-seawater salinity. We find that the coupling coefficient in quartz-rich sandstones is independent of sample type and brine composition as long as surface electrical conductivity is small. The coupling coefficient is small in magnitude, but still measurable, even when the brine salinity approaches the saturated concentration limit. Consistent results are obtained from two independent experimental setups, using specially designed electrodes and paired pumping experiments to eliminate spurious electrical potentials. We apply the new experimental data in a numerical model to predict the streaming potential signal that would be measured at a well during production. The results suggest that measured signals should be resolvable above background noise in most hydrocarbon reservoirs. Furthermore, water encroaching on a well could be monitored while it is several tens to hundreds of meters away. This contrasts with most other downhole monitoring techniques, which sample only the region immediately adjacent to the wellbore. Our results raise the novel prospect of an oil field in which the wells can detect the approach of water and can respond appropriately.

scholarly journals A New Modified Model of the Streaming Potential Coupling Coefficient Depends on Structural Parameters of Soil-Rock Mixture

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xin Zhang ◽  
Mingjie Zhao ◽  
Kui Wang
Keyword(s):  
Experimental Data ◽  
Coupling Coefficient ◽  
Permeability Coefficient ◽  
Prediction Accuracy ◽  
Structural Parameters ◽  
Streaming Potential ◽  
Potential Effect ◽  
Structure Evolution ◽  
Embankment Dam ◽  
Modified Model

The streaming potential effect in soil-rock mixture (SRM) is related to the compactness and rock content, but there is no model to quantitatively describe this behavior. In this paper, the Kozeny–Carman (KC) equation is modified by using the compactness and rock content. Then, the modified KC equation is substituted into the equation of streaming potential coupling coefficient. A new modified model of streaming potential coupling coefficient that depends on the compactness, rock content, particle shape, and particle gradation is proposed. The reliability of the new modified model is tested by experiments, and the applicable scope of the model is obtained. The results show that when the rock content is 30%, the permeability coefficient prediction accuracy of the modified KC equation is higher in the range of 85–95% compactness. The new modified model of the streaming potential coupling coefficient represents well the control of the compactness (75–95%) on the coupling coefficient. When the compactness remains 85%, the permeability coefficient calculated by the modified KC equation in the range of 10–70% rock content is consistent with the experimental data. The influence of the rock content (10–90%) on the coupling coefficient is well described by the new modified model of the streaming potential coupling coefficient. The new modified model of streaming potential coupling coefficient is helpful to quantitatively evaluate the internal structure evolution of embankment dam by using streaming potential phenomenon.

scholarly journals Examination of a Theoretical Model of Streaming Potential Coupling Coefficient

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
D. T. Luong ◽  
R. Sprik
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Zeta Potential ◽  
Coupling Coefficient ◽  
Electrolyte Concentration ◽  
Streaming Potential ◽  
Data Sets ◽  
Fluid Temperature ◽  
Potential Measurement ◽  
Streaming Potentials

Seismoelectric effects and streaming potentials play an important role in geophysical applications. The key parameter for those phenomena is the streaming potential coupling coefficient, which is, for example, dependent on the zeta potential of the interface of the porous rocks. Comparison of an existing theoretical model to experimental data sets from available published data for streaming potentials has been performed. However, the existing experimental data sets are based on samples with dissimilar fluid conductivity, pH of pore fluid, temperature, and sample compositions. All those dissimilarities may cause the observed deviations. To critically assess the models, we have carried out streaming potential measurement as a function of electrolyte concentration and temperature for a set of well-defined consolidated samples. The results show that the existing theoretical model is not in good agreement with the experimental observations when varying the electrolyte concentration, especially at low electrolyte concentration. However, if we use a modified model in which the zeta potential is considered to be constant over the electrolyte concentration, the model fits the experimental data well in a whole range of concentration. Also, for temperature dependence, the comparison shows that the theoretical model is not fully adequate to describe the experimental data but does describe correctly the increasing trend of the coupling coefficient as function of temperature.

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