scholarly journals Fractional Current Flow in the Subsurface Using Electrical Resistivity Method: A Laboratory Approach

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
James Adeyemo Adegoke ◽  
Gideon Oluyinka Layade ◽  
Temitayo Kadir

Abstract The authors describe electrical resistivity method using a laboratory experiment, which was conducted in order to calculate the percentage of current that penetrated each layer of soil arranged in a container using Schlumberger array. Four soil samples arranged in three different set-ups were used. The apparent resistivity obtained was interpreted using curve matching techniques and WinResist iteration yielding types A curve, H curve and A curve, respectively. The interpreted data gave the resistivity of each layer and its thicknesses. The thicknesses obtained from the interpretation were at variance with the actual thicknesses arranged in the container. A multiplier was obtained which serves as a constant in other to obtain the actual thickness. The effective penetration depth of current was determined through the calculated thickness of each layer and the known electrode spacing (AB). The percentage of current that penetrates the layers was found to depend on the electrode spacing as well as the thickness of that layer. Thus, a layer with relatively small thickness has a small percentage of current passing through it compared to a thicker layer.

2018 ◽  
Vol 65 (6) ◽  
pp. 637-645
Author(s):  
Amobi C. Ekwe ◽  
Alexander I. Opara ◽  
Obialo S. Onwuka

Purpose The corrosivity and competence of soils within Uburu and Okposi areas of the Southern Benue Trough, Nigeria, were evaluated using the electrical resistivity method. This paper aims to provide information that will aid pre-design of subsurface iron/steel pipe networks for distribution of pipe-borne water and construction of subsurface structures for agricultural and environmental purposes. Design/methodology/approach In total, 22 vertical electrical soundings (VES) in the Schlumberger configuration were acquired with Allied Ohmega™ Terrameter with a maximum half current (AB/2) electrode spacing of 200 m. Layer parameters were determined using partial curve matching techniques, using the Schlumberger master curves, while processing and modelling were done with the IPI2win™ software. The VES results were interpreted qualitatively and quantitatively to obtain various curve types and layer parameters, respectively, which were used to categorize the area into different competence and corrosivity zones. The first layer isoresistivity and competence maps were used to delineate four zones (A,B,C and D) with varying apparent resistivities and competences. Findings Incompetent soils with resistivity values ranging from 24.3-88.7 Om are found in Zone A. The soils in Zone A are mainly expansive clays which swell on absorption of water. Zone B contains moderately competent soils with resistivity values ranging from 273-308.6 Om, while Zones C and D are underlain by sandstones and contain competent to highly competent soils with resistivity values ranging from 511-750 Om and 835-1,525 Om, respectively. Zone E contains highly corrosive (24.3 Om) to mildly corrosive (102 Om) soils; Zone F contains soils that are essentially non-corrosive with resistivity values ranging from 271-1,525 Om, while the corrosivity of soils within Zone G varies from corrosive to mildly corrosive, with resistivity values ranging from 44.3-114 Om. Research limitations/implications Some of the areas are not accessible because of community restrictions. Practical implications These findings are essentially very significant and should be taken into consideration when materials that are susceptible to corrosion are being considered for engineering, agricultural and environmental purposes in the area. Social implications The findings will aid water resource planners and developers on how to protect metal pipes from corrosion, when used for water reticulation and agricultural purposes. Originality/value This paper fulfils an identified need to study the corrosivity of soils in the study area with a view to providing adequate protection to metal objects when being considered for water reticulation for domestic and agricultural purposes in the area.


2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Sixtus Nwachukwu ◽  
Rasaq Bello ◽  
Ayomide O. Balogun

Abstract An investigation has been made of the groundwater potentials of Orogun Town, Ughelli North Local Government Area of Delta State, Nigeria, using electrical resistivity survey. This study motivated to determine electrical resistivity parameters of the area. The aim of this work is to use electrical resistivity method to explore the groundwater potentials of Orogun Town with the determination of its Dar Zarrouk parameters. A total of eight vertical electrical sounding (VES) were conducted with maximum electrode spacing of 150 m. The data were acquired using ABEM SAS 4000 Terrameter and processed using IPI2win and Interpex softwares. The groundwater potentials of the area are evaluated based on the longitudinal conductance (S), transverse resistance (T), coefficient of electrical anisotropy (λ), resistivity for the formation ($$\rho_{\text{m}}$$ρm), reflection coefficient (RC) and resistivity contrast (FC). The results reveal four subsurface geoelectric layers in seven of the eight VES while one VES revealed three subsurface geoelectric layers. Resistivity values for all the layers in the study area are very high, higher than what is expected in a sedimentary basin as we have in the study area. The resistivity values range from 8470 Ωm (layer 1, VES 7) to 118,030,000 Ωm (layer 3, VES 8). Depth to aquifer in the study area ranged from 1.61 m (VES 2) to 12.41 m (VES 1), while resistivity values of the aquifer ranged from 64,182 Ωm (VES 3) to 118,030,000 Ωm (VES 8). The results from the formation parameters evaluated showed that the area has good groundwater potential but might have been highly contaminated, especially from hydrocarbon sources and other man-made pollutants. The suggested contamination of the aquifer is as a result of the high values of resistivity of the aquifer layers.


Author(s):  
K. O. Ozegin

The ultimate aim of the electrical resistivity survey is to determine the resistivity distribution with depth on the basis of surface measurements of the apparent resistivity and to interpret it in terms of geology. Marble deposit was investigated with the application of electrical resistivity method using Vertical Electrical Sounding (VES) technique with the aim of characterising this deposit in parts of Okpella. Six (6) VES were acquired using the Schlumberger array for data acquisition with current electrode spacing varying from 1.0 to 150.0 m. The VES data obtained were interpreted using ipi2win Software. The results showed three layers indicating subsurface geologic sequence probed 26.4 m and beyond with clay/clayey sand (23.3 – 219.1 Ωm), sand (423 - 2040 Ωm) and marble (12661 - 404498 Ωm). The occurrence of marble deposit was revealed at VES points at 1, 2 and 5 in the studied area.  This study concluded that the study area had occurrence of the marble deposits, which would be of economic importance, if exploited.


2014 ◽  
Vol 510 ◽  
pp. 185-192 ◽  
Author(s):  
Mohd Hazreek Zainal Abidin ◽  
Rosli Saad ◽  
Devapriya Chitral Wijeyesekera ◽  
Fauziah Ahmad ◽  
Nur Azwin Ismail

Electrical resistivity technique has become a popular alternative tool by the geotechnical engineers in subsurface investigation. This study presents the influence of soil electrical resistivity value (ERV) due to the different types of electrical resistivity array used in practice. The dissimilarity of ERV was become a popular debate by the engineers which posses less fundamental knowledge in this area. In the past, the theory of electrical resistivity technique was less being discovered by the engineer which creates lots of black boxes during the utilization of electrical resistivity method (ERM) in engineering purposes. Hence, the result which produced from the ERM was difficult to deliver in a sound of definitive ways due to lack of knowledge and experienced of most engineers. Hence, this study presents the influence of soil ERV due to the different types of array used with particular reference to as Dipole-dipole and Pole-dipole. A line of electrical resistivity imaging was performed on small embankment of sandy and lateritic soil with different types of array using ABEM SAS (4000) equipment. Three in line of soil samples were tested for moisture content (w) test immediately after the electrical resistivity data acquisition was completely measured. Moreover, particle size distribution test also was performed for all soil samples in order to support the findings. It was found that the ERV was never be the same for each types of array used even on the same particular location of the survey line. However, it was found that there was a consistent relationship between ERV and moisture content for both types of soil tested which can be represent by ERV 1/w. Hence, it was found that ERV produced was relative to the types of array used during the field measurement. Each types of array were applicable to be used in subsurface profiling and its selection was subjected to the target of interest.


Geophysics ◽  
1967 ◽  
Vol 32 (2) ◽  
pp. 302-310 ◽  
Author(s):  
Walter W. Hays ◽  
Otto W. Nuttli ◽  
Leroy Scharon

Gish‐Rooney type electrical resistivity equipment was employed to map the location and structural attitude of gilsonite veins in the Uinta Basin, southeast of Vernal, Utah. Horizontal profiles at right angles to the strike of the dike‐like gilsonite veins were made using the Wenner electrode configuration. Very sharp anomalies with a peak apparent resistivity value of the order of 20,000–25,000 ohm‐cm were observed. The peak values were measured over the center of the vein, but smaller auxiliary highs were also observed, symmetrically spaced on each side of the vein. The position of the auxiliary high varied as a function of the electrode spacing and was found to occur when the current stake was located in the gilsonite. The observed field profiles were compared with various theoretical profiles computed from theoretical apparent resistivity expressions derived through the use of images. The best correlation was obtained when the theoretical model was assumed to have an infinite resistivity relative to that of the surrounding material. This correlation supports the conclusion that the gilsonite veins, because of their extremely large resistivity and their vertical attitude, act as a vertical insulating sheet to the flow of electrical current in the ground.


2021 ◽  
Vol 11 (3) ◽  
pp. 1053-1067
Author(s):  
C. C. Onyekwelu ◽  
C. N. Onwubuariri ◽  
T. I. Mgbeojedo ◽  
L. S. Al-Naimi ◽  
B. I. Ijeh ◽  
...  

AbstractThe electrical resistivity method was used to determine the groundwater potential of Ogidi and its environs. Thirteen soundings were carried out at thirteen different locations using the ABEM terrameter (SAS 1000), and adopting the Schlumberger configuration with maximum current electrode spacing of 1000 m. The lithologic logs for the boreholes were used to delineate the geologic sections. The results revealed six to nine geo-electric layers comprising laterite, clayey sandstone, sandstone, water-saturated sandstone and shale. The water-saturated sandstone forms the aquiferous unit. This unit was found to have resistivity values ranging from 363Ωm to 9107Ωm. It is deeply seated in some areas with a depth of 33.2–103 m. It was observed that the hydraulic conductivity varies between 0.001 and 0.066 m/day, while the transmissivity values vary between 0.01 and 4.7 m2/day. Among all the VES points studied, it was observed that VES 1 has the highest transmissivity value and the highest aquifer thickness. In view of the foregoing, it is expected that water will flow more from aquifer in VES 1 since groundwater flow from an aquifer is directly proportional to transmissivity.


2016 ◽  
Vol 33 (3) ◽  
Author(s):  
Eduardo M.S. Amarante ◽  
Olivar A.L. de Lima ◽  
Susana S. Cavalcanti

ABSTRACT. To investigate the subsurface geological and hydrological conditions around the area of the Alagoinhas county cemetery – Bahia State, Brazil, 38 vertical electrical soundings using Schlumberger electrode array were performed to a maximum AB/2 spacing... RESUMO. Para investigar as condições geológicas e hidrológicas da subsuperfície na área do entorno do Cemitério Municipal de Alagoinhas, Bahia, foram realizadas 38 sondagens elétricas verticais centradas em pontos acessíveis da área. As sondagens foram...


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