Improvement of electrical-resistivity model for polycrystalline films of metals with non-spherical Fermi surface: A case for Os films

2017 ◽  
Vol 121 (13) ◽  
pp. 134503 ◽  
Author(s):  
S. L. Li ◽  
Q. Y. Zhang ◽  
C. Y. Ma ◽  
C. Zhang ◽  
Z. Yi ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Fermi Surface ◽  
Polycrystalline Films ◽  
Resistivity Model

scholarly journals Numerical Evaluation of the Resistivity of Polycrystalline Metal Films With the Mayadas-Shatzkes Model

1974 ◽  
Vol 1 (1) ◽  
pp. 77-80 ◽  
Author(s):  
E. E. Mola ◽  
J. M. Heras
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Numerical Evaluation ◽  
Metal Films ◽  
Polycrystalline Films ◽  
Polycrystalline Metal ◽  
Resistivity Model ◽  
Gauss Method

Numerical Tables are given in order to allow a direct comparison of the electrical resistivity model for polycrystalline films proposed by Mayadas–Shatzkes with experimental data.The tables have been calculated extending the Gauss method for one variable to many variables.

Effect of Proximity of Permeable and Impermeable Lenses on Well Performance

1964 ◽  
Vol 4 (04) ◽  
pp. 285-290
Author(s):  
Edward P. Miesch ◽  
Paul B. Crawford
Keyword(s):  
Electrical Resistivity ◽  
Steady State ◽  
Production Capacity ◽  
Oil Reservoirs ◽  
Reservoir Rock ◽  
Unsteady State ◽  
Mathematical Study ◽  
Thermal Models ◽  
State Data ◽  
Resistivity Model

Abstract A study was made of the effect of permeable and impermeable lenses in a reservoir on the production capacity of a well. Both steady-state and unsteady-state data were obtained. An electrical resistivity model was used to obtain the steady- state data and thermal models were constructed to obtain the unsteady-state data. The productivity of a well is affected very greatly only when the lenses are close to the well. The effect of circular lenses on the Productivity ratio can be correlated with the distance from the center of the lens to the center of the well divided by the radius of the lens. Then this dimensionless distance is equal to six or greater, the effect of the lenses on production capacity will be negligible. The pseudo steady-state productivity of a heterogeneous reservoir can be predicted using steady- state data. Introduction Many analytical solutions of reservoir behavior assume that reservoir rock is uniform and homogeneous. Although this assumption is used, all of the data from core analyses and well logging indicate that the reservoirs are heterogeneous. Very little work has been done on the performance of heterogeneous reservoirs. The work of Landrum, et al. showed that transient phenomena in oil reservoirs could be studied with thermal models. Pickering and Cotman used thermal models to study flow in stratified reservoirs and investigated the effect of inhomogeneities in oil reservoirs on transient flow performance. Loucks made a mathematical study of the pressure build-up in a system composed of two concentric regions of different permeability. Root, Silberberg and Pirson studied the effect of me growth of the flooded region on water influx predictions using a thermal model consisting of three concentric cylindrical regions of different thermal properties which simulated the aquifer, the flooded region and the unflooded portion of the original hydrocarbon region. Tomme, et al. made a mathematical study of vertical fractures. The object of this investigation was to study the effect of highly permeable and impermeable lenses in the vicinity of the wellbore on the pressure depletion history of the well. Steady- state data were obtained for both conductive and nonconductive lenses that completely penetrated the formation. The lenses were symmetrically located at various distances from the wellbore. The unsteady-state data were obtained on seven thermal models. EXPERIMENTAL EQUIPMENT AND PROCEDURE STEADY-STATE DATA The steady-state data were obtained from an electrical resistivity model 30 in. in diameter and approximately 1 1/2 in. deep. The outside of the model was lined with a 30-in. diameter copper strip, which served as the outer boundary of the reservoir. The bottom was covered with a sheet of plexiglass so that it would be nonconductive. The model was filled with a slightly saline solution. The well size was varied from an 0.064-in. diameter copper wire to a 10-in. diameter copper cylinder. Readings were taken with an impedance bridge using AC current to prevent polarization at the contacts. Copper and wax lenses were used to represent infinitely conductive and nonconductive lenses, respectively. The resistance was first measured for each well diameter with no lenses in the reservoir. Then the conductive and nonconductive lenses were spaced symmetrically at various distances from the well and the resistance read from each lens location. The diameters of the conductive lenses were 3, 1.022 and 0.624 in., and those of the nonconductive lenses were 3, 2.25 and 1.563 in. SPEJ P. 285ˆ

scholarly journals A 3-D electrical resistivity model beneath the focal zone of the 2008 Iwate-Miyagi Nairiku earthquake (M 7.2)

2014 ◽  
Vol 66 (1) ◽  
Author(s):  
Hiroshi Ichihara ◽  
Shin'ya Sakanaka ◽  
Masaaki Mishina ◽  
Makoto Uyeshima ◽  
Tadashi Nishitani ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Resistivity Model ◽  
Focal Zone

scholarly journals Electrical resistivity tomography applied to geologic, hydrogeologic, and engineering investigations at a former waste-disposal site

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. B231-B239 ◽  
Author(s):  
Jonathan E. Chambers ◽  
Oliver Kuras ◽  
Philip I. Meldrum ◽  
Richard D. Ogilvy ◽  
Jonathan Hollands
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Site Investigation ◽  
High Resistivity ◽  
Potential Zone ◽  
Resistivity Tomography ◽  
L2 Norm ◽  
Resistivity Model ◽  
2D And 3D ◽  
2D Resistivity

A former dolerite quarry and landfill site was investigated using 2D and 3D electrical resistivity tomography (ERT), with the aims of determining buried quarry geometry, mapping bedrock contamination arising from the landfill, and characterizing site geology. Resistivity data were collected from a network of intersecting survey lines using a Wenner-based array configuration. Inversion of the data was carried out using 2D and 3D regularized least-squares optimization methods with robust (L1-norm) model constraints. For this site, where high resistivity contrasts were present, robust model constraints produced a more accurate recovery of subsurface structures when compared to the use of smooth (L2-norm) constraints. Integrated 3D spatial analysis of the ERT and conventional site investigation data proved in this case a highly effective means of characterizing the landfill and its environs. The 3D resistivity model was successfully used to confirm the position of the landfill boundaries, which appeared as electrically well-defined features that corresponded extremely closely to both historic maps and intrusive site investigation data. A potential zone of leachate migration from the landfill was identified from the electrical models; the location of this zone was consistent with the predicted direction of groundwater flow across the site. Unquarried areas of a dolerite sill were imaged as a resistive sheet-like feature, while the fault zone appeared in the 2D resistivity model as a dipping structure defined by contrasting bedrock resistivities.

Electrically Inferred Subsurface Fractures in the Crystalline Hard Rocks of an Experimental Hydrogeological Park, Southern India

Geophysics ◽  
2021 ◽  
pp. 1-43
Author(s):  
Ved Prakash Maurya ◽  
Subash Chandra ◽  
Sahebrao Sonkamble ◽  
K. Lohith Kumar ◽  
ERUGU NAGAIAH ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Apparent Resistivity ◽  
Time Lapse ◽  
Granitic Rocks ◽  
Aquifer Recharge ◽  
Flow Paths ◽  
Resistivity Model ◽  
Subsurface Fractures ◽  
Water Saturated ◽  
And Inversion

We investigated a network of fractures forming the flow paths within the crystalline granitic rocks of an experimental hydrogeological park (EHP) with the help of electrical resistivity surveys. The experimental study located at managed aquifer recharge (MAR) site of EHP has measured a distinct variation in the apparent resistivity for deeper electrical signals that localize the presence of interconnected water-saturated fractures. Usually, profiles close to the MAR tank depict low apparent resistivity values from deep signals across in-situ fractures and resistivity amplitude increases away from the tank. We modeled and simulated the presence of water-saturated fractures by a simple three-layered model having embedded shallow heterogeneities in the saprolite layer, vertically interconnected multiple thin conductive horizontal layers in the fissured zone, and an underlain un-weathered crystalline granitic basement. These fractures produce a distinct variation in the resistivity both for modeling and inversion exercises. The decadal time-lapse electrical resistivity surveys, after the establishment of the MAR tank, mark similar repetitive main features with a distinct drop in resistivity depicting the presence of water-saturated fractures. An overview of 3D resistivity model characterizes the subsurface heterogeneities, presence of possible flow paths for shallow depths <30 m, and indicative of possible flows in the interconnected deep fractures for depths >30m.

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