Dual-physics modeling and inversion of electrical resistivity and relative permittivity

2018 ◽  
Author(s):  
Alireza Shahin ◽  
Mike Myers ◽  
Lori Hathon
Keyword(s):  
Electrical Resistivity ◽  
Relative Permittivity ◽  
Physics Modeling ◽  
And Inversion

scholarly journals ELECTRICAL AND ACOUSTIC PARAMETERS OF LOWER PERMIAN CARBONATE ROCKS (WESTERN PART OF THE HLYNSKO-SOLOKHIVSKYI OF GAS-OIL-BEARING DISTRICT OF THE DNIEPER-DONETS BASIN)

2020 ◽  
pp. 49-58
Author(s):  
S. Vyzhva ◽  
V. Onyshchuk ◽  
I. Onyshchuk ◽  
M. Reva ◽  
O. Shabatura
Keyword(s):  
Electrical Resistivity ◽  
Relative Permittivity ◽  
Donets Basin ◽  
Lower Permian ◽  
Atmospheric Conditions ◽  
Reservoir Water ◽  
P Waves ◽  
Reservoir Conditions ◽  
Specific Electrical Resistivity ◽  
Formation Resistivity

The main objective of this article is to study electrical parameters of Lower Permian carbonate rocks of Western part of the Hlynsko-Solokhivskyi gas-oil-bearing district of the Dnieper-Donets Basin (DDB) in normal (atmospheric) and modeling (reservoir) conditions. In atmospheric conditions it has been revealed that the resistivity of dry extracted limestones (the specific electrical resistivity of framework of grains was measured) varies from 12.147 kΩ⋅m to 111.953 MΩ⋅m (mean 1.542 MΩ⋅m). The resistivity of saturated limestone samples with kerosene varies from 44.478 kΩ⋅m to 14.449 MΩ⋅m (mean 1.435 MΩ⋅m). The resistivity of dry and saturated with kerosene samples is almost the same. The resistivity of limestones saturated with model of reservoir water (salinity M = 190 g/l) is lower and varies from 1.11 Ω⋅m to 23.16 Ω⋅m (mean 3.12 Ω⋅m). It has been determined that formation resistivity factor of limestones in atmospheric conditions varies from 13.5 to 230 Ω⋅m (mean 32.5 Ω⋅m). In addition to resistivity, the parameter of relative permittivity of investigated limestones was studied. It was determined that relative permittivity of dry limestones varies from 3.0 to 7.5 (mean 4.2). Relative permittivity saturated samples of limestones with kerosene varies from 2.8 to 8.8 (mean 4.5) and practically does not differ from dry ones but significantly lower than values of samples saturated with model of reservoir water (from 655 to 9565, mean 4280). That means when pores of limestones are saturated with NaCl solution their relative permittivity increases rapidly – from hundreds to thousands times (on average 944 times). It can be explained by the high conductivity of model of reservoir water. Limestones saturated with NaCl solution have velocities of P-waves in the range from 3346 m/s to 4388 m/s (mean 4030 m/s), and velocities of Swaves – from 1753 m/s to 2121 m/s (average 1942 m/s). If rocks are saturated with kerosene then velocities have strictly higher values – P-waves from 3433 m/s to 4514 m/s (mean 4011 m/s) and S-waves – from 2137 m/s to 2464 m/s (average 2344 m/s). Physical modelling of reservoir conditions (temperature 50 °С, pressure 30 MPa) showed that the specific electrical resistivity varies from 0.81 Ω⋅m to 13.19 Ω⋅m (mean 2.67 Ω⋅m), and limestones – from 0.49 Ω⋅m to 7.81 Ω⋅m (mean 1.95 Ω⋅m). Also, "specific electrical resistivity – pressure" connection was investigated. Due to the closure of microcracks and the deformation of the pore space, the electrical resistance of rocks increases with increase of pressure. The regression dependence of the formation resistivity enlargement factor with pressure for the studied rocks has a linear character. It was determined that in reservoir conditions the range of the formation resistivity factor for limestones varied from 17.3 to 271.9 Ω⋅m (mean 50.7 Ω⋅m), and range of variation of porosity coefficient was from 0.040 to 0.169 Ω⋅m (mean 0.118 Ω⋅m). The comprehensive analysis of petrophysical data has been resulted in a set of correlation ratios between reservoir, electric and elastic parameters of studied limestones in normal and modeling conditions.

scholarly journals A review of open software resources in python for electrical resistivity modelling

2022 ◽  
Vol 9 (1) ◽  
Author(s):  
Yonatan Garkebo Doyoro ◽  
Ping-Yu Chang ◽  
Jordi Mahardika Puntu ◽  
Ding-Jiun Lin ◽  
Tran Van Huu ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Geophysical Research ◽  
Resistivity Tomography ◽  
Subsurface Structures ◽  
Data Inversion ◽  
Scripting Language ◽  
And Inversion ◽  
Geoelectric Data ◽  
Insight Into

AbstractGeophysical modelling performs to obtain subsurface structures in agreement with measured data. Freeware algorithms for geoelectrical data inversion have not been widely used in geophysical communities; however, different open-source modelling/inversion algorithms were developed in recent years. In this study, we review the structures and applications of openly Python-based inversion packages, such as pyGIMLi (Python Library for Inversion and Modelling in Geophysics), BERT (Boundless Electrical Resistivity Tomography), ResIPy (Resistivity and Induced Polarization with Python), pyres (Python wrapper for electrical resistivity modelling), and SimPEG (Simulation and Parameter Estimation in Geophysics). In addition, we examine the recovering ability of pyGIMLi, BERT, ResIPy, and SimPEG freeware through inversion of the same synthetic model forward responses. A versatile pyGIMLi freeware is highly suitable for various geophysical data inversion. The SimPEG framework is developed to allow the user to explore, experiment with, and iterate over multiple approaches to the inverse problem. In contrast, BERT, pyres, and ResIPy are exclusively designed for geoelectric data inversion. BERT and pyGIMLi codes can be easily modified for the intended applications. Both pyres and ResIPy use the same mesh designs and inversion algorithms, but pyres uses scripting language, while ResIPy uses a graphical user interface (GUI) that removes the need for text inputs. Our numerical modelling shows that all the tested inversion freeware could be effective for relatively larger targets. pyGIMLi and BERT could also obtain reasonable model resolutions and anomaly accuracies for small-sized subsurface structures. Based on the heterogeneous layered model and experimental target scenario results, the geoelectrical data inversion could be more effective in pyGIMLi, BERT, and SimPEG freeware packages. Moreover, this study can provide insight into implementing suitable inversion freeware for reproducible geophysical research, mainly for geoelectrical modelling.

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.

scholarly journals Testing alternative uses of electromagnetic data to reduce the prediction error of groundwater models

2016 ◽  
Vol 20 (5) ◽  
pp. 1925-1946 ◽  
Author(s):  
Nikolaj Kruse Christensen ◽  
Steen Christensen ◽  
Ty Paul A. Ferre
Keyword(s):  
Electrical Resistivity ◽  
Hydraulic Conductivity ◽  
Prediction Error ◽  
Model Calibration ◽  
Hydrologic Model ◽  
Geophysical Data ◽  
Model Parameters ◽  
Calibration Data ◽  
Groundwater Model ◽  
And Inversion

Abstract. In spite of geophysics being used increasingly, it is often unclear how and when the integration of geophysical data and models can best improve the construction and predictive capability of groundwater models. This paper uses a newly developed HYdrogeophysical TEst-Bench (HYTEB) that is a collection of geological, groundwater and geophysical modeling and inversion software to demonstrate alternative uses of electromagnetic (EM) data for groundwater modeling in a hydrogeological environment consisting of various types of glacial deposits with typical hydraulic conductivities and electrical resistivities covering impermeable bedrock with low resistivity (clay). The synthetic 3-D reference system is designed so that there is a perfect relationship between hydraulic conductivity and electrical resistivity. For this system it is investigated to what extent groundwater model calibration and, often more importantly, model predictions can be improved by including in the calibration process electrical resistivity estimates obtained from TEM data. In all calibration cases, the hydraulic conductivity field is highly parameterized and the estimation is stabilized by (in most cases) geophysics-based regularization. For the studied system and inversion approaches it is found that resistivities estimated by sequential hydrogeophysical inversion (SHI) or joint hydrogeophysical inversion (JHI) should be used with caution as estimators of hydraulic conductivity or as regularization means for subsequent hydrological inversion. The limited groundwater model improvement obtained by using the geophysical data probably mainly arises from the way these data are used here: the alternative inversion approaches propagate geophysical estimation errors into the hydrologic model parameters. It was expected that JHI would compensate for this, but the hydrologic data were apparently insufficient to secure such compensation. With respect to reducing model prediction error, it depends on the type of prediction whether it has value to include geophysics in a joint or sequential hydrogeophysical model calibration. It is found that all calibrated models are good predictors of hydraulic head. When the stress situation is changed from that of the hydrologic calibration data, then all models make biased predictions of head change. All calibrated models turn out to be very poor predictors of the pumping well's recharge area and groundwater age. The reason for this is that distributed recharge is parameterized as depending on estimated hydraulic conductivity of the upper model layer, which tends to be underestimated. Another important insight from our analysis is thus that either recharge should be parameterized and estimated in a different way, or other types of data should be added to better constrain the recharge estimates.

Measurement and inversion schemes for single borehole-to-surface electrical resistivity tomography surveys

2011 ◽  
Vol 8 (4) ◽  
pp. 487-497 ◽  
Author(s):  
Panagiotis Tsourlos ◽  
Richard Ogilvy ◽  
Constantinos Papazachos ◽  
Philip Meldrum
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Resistivity Tomography ◽  
And Inversion

scholarly journals Inversion of Electrical Resistivity Data by VES Method for Water Exploring Case Study: South West of Iran

2014 ◽  
Vol 3 (5) ◽  
pp. 68-77
Author(s):  
Ahmad Alvandi ◽  
Mojtaba Babaei
Keyword(s):  
Electrical Resistivity ◽  
Water Resources ◽  
Data Processing ◽  
Specialized Software ◽  
Methods Of Calculation ◽  
South West ◽  
Geological Information ◽  
And Inversion ◽  
Schlumberger Array

The purpose of this research is to explore the water in the south west of Hamedan which has many environmental problems and very few water resources. Also in the area, due to the lack of awareness, the farmers excavate the wells with high cost that results in declining water table. The collected data was investigated via the electrical probing at the Schlumberger array and Jointed with the wells data and geological information. The data processing was performed by conventional methods of calculation and utilized specialized software WINSEV, RES2D, RES3D, 2WIN at direct and inversion states. Finally the results of the research are acceptable and pleasant.

scholarly journals Complex Electrical Resistivity and Dielectric Permittivity Responses to Dense Non-aqueous Phase Liquids' Imbibition and Drainage in Porous Media: A Laboratory Study

2020 ◽  
Vol 25 (4) ◽  
pp. 557-567
Author(s):  
Mohammad Ali Iravani ◽  
Jacques Deparis ◽  
Hossein Davarzani ◽  
Stéfan Colombano ◽  
Roger Guérin ◽  
...  
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Electrical Resistivity ◽  
Dielectric Permittivity ◽  
Aqueous Phase ◽  
Relative Permittivity ◽  
Time Domain Reflectometry ◽  
High Resistivity ◽  
Complex Resistivity ◽  
Phase Saturation

The effective techniques for remediation of sites polluted by dense non-aqueous phase liquids (DNAPLs) remains a challenge. Among the various technical monitoring methods, there is an increasing interest in studying the geophysical characteristics of contaminated soils, as indicators of the progress in clean-up programs. This work sought to investigate the variation of the electrical complex resistivity and the relative permittivity by analyzing the results obtained from spectral induced polarization (SIP) and time domain reflectometry (TDR). Different series of measurements during drainage and imbibition of DNAPLs in porous media were done to validate the clean-up process on sites polluted by DNAPLs. Therefore, a methodology based on laboratory work was designed and carried out to study the electrical complex resistivity (both in magnitude and phase) in the frequency range 0.183 Hz to 20 kHz, and the relative dielectric permittivity at 70 MHz. The experiments were done on small 1D cells. In these cells, glass beads were used as a porous medium. Two different fluid couples, i.e., coal tar (CT)/water and canola oil (CO)/salty ethanol (SE), were used to produce two-phase flow. Our findings highlight that due to the high resistivity of CO and CT, an increase in water saturation led to decrease in amplitude and phase. Saturation change of SE had the same effect on resistivity but no relationship was found for phase and saturation for the mixture CO and SE. It is also showed that the complex resistivity and relative permittivity measurements were compatible with generalized Archie's law and complete complex refractive index method (CRIM) model as two empirical models for defining the correlation between the electrical resistivity, relative permittivity, and saturation of each phase in the multiphase porous medium.

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