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Date submitted2020-05-28
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Date accepted2021-07-27
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Date published2021-10-21
On the applicability of electromagnetic monitoring of hydraulic fracturing
The purpose of this work is to assess the possibilities of using electromagnetic monitoring to study the development of a fracture system generated by hydraulic fracturing (HF) with a specified position of the controlled source. The option with the source (a vertical electric dipole) located in the interval of the oil-bearing formation and ground-based measurements was chosen as the most promising monitoring plan. We have built a geoelectric model equivalent to the system of hydraulic fractures, divided into 11 zones corresponding to HF stages. For the selected model, mathematical simulation was performed by solving the direct problem considering the impact of the steel casing, the presence of which reduced the effect. Despite this fact, no strong distortion of electromagnetic field anomaly was observed above the HF zone. Analysis of the simulation results at different HF stages showed that as new hydraulic fractures appeared and were filled with electrically conductive proppant, the total effect increased. The data on electric field anomaly demonstrated maximum deviation from the background level of more than 2 %. Provided that the studied formation is characterized by sufficient electrical conductivity, its magnetic field also becomes informative.
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Date submitted2021-01-20
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Date accepted2021-03-15
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Date published2021-04-26
Improving the quality of electricity in the power supply systems of the mineral resource complex with hybrid filter-compensating devices
- Authors:
- Yurii A. Sychev
- Roman Yu. Zimin
The urgency and necessity of choosing and justifying the structures of hybrid filter-compensating devices based on series and parallel active filters to improve the quality of electricity in the power supply systems of enterprises of the mineral resource complex is shown. Mathematical models of hybrid filter compensating devices based on parallel and series active filters have been developed. Based on these mathematical models, computer simulation models of the indicated hybrid structures have been developed. The results of simulation showed the effectiveness of the correction of power quality indicators in terms of reducing the level of higher harmonics of current and voltage, as well as voltage deviations. The degree of influence of filter-compensating devices on the power quality indicators, which determine the continuity and stability of the technological process at the enterprises of the mineral resource complex, have been revealed. It has been established that a hybrid filter-compensating device based on a parallel active filter can reduce the level of higher harmonics of current and voltage by more than 90 and 70 %, respectively, and based on a series active filter, it can reduce the level of higher harmonics of voltage by more than 80 %. Based on the simulation results, the possibility of compensating for the reactive power of a hybrid structure based on parallel active and passive filters has been revealed. The possibility of integrating hybrid filter-compensating devices into more complex multifunctional electrical systems for the automated improvement of the quality of electricity is substantiated, as well as the expediency and prospects of their use in combined power supply systems based on the parallel operation of centralized and autonomous sources of distributed generation.
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Date submitted2019-07-11
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Date accepted2019-09-04
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Date published2019-12-24
Recent scientific research on electrothermal metallurgical processes
- Authors:
- E. Baake
- V. A. Shpenst
A wide range of industrial metallurgical heating and melting processes are carried out using electrothermal technologies. The application of electrothermal processes offers many advantages from technological, ecological and economical point of view. Although the technology level of the electro heating and melting installations and processes used in the industry today is very high, there are still potentials for improvement and optimization due to the increasing complexity of the applications and the strong requirements regarding the performance and quality of the products but also regarding the reduction of time and costs for the development of new processes and technologies. In this paper recent applications and future development trends for efficient heating and melting by electrothermal technologies in metallurgical processes are described along selected examples like induction heating for forging or rolling of billets, heat treatment of strips and plates, press-hardening processes, induction surface hardening of complex geometries, induction welding as well as induction melting processes.
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Date submitted2018-11-10
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Date accepted2019-01-17
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Date published2019-04-23
AMT soundings in the dead band within the Chukotka region (Russian Far East)
The article analyzes the amplitude spectra of audio magnetotelluric sounding (AMTs) data. Particular attention is focused on the frequency range from 1 to 5 kHz, which is called dead band. We analyzed the data of base stations used in the fieldwork during the summer and autumn seasons in 2013, 2014, and 2017. The area of work is located in the Chukotka Autonomous Area beyond the Arctic Circle. Previous researchers noted that a reliable signal in the dead band can only be obtained at nighttime. The authors of the article found that in Chukotka region in the daytime against the minimum signal within the dead band there is a local maximum at a frequency of 2.4 kHz. When registering a field for more than 3 hours during daytime, in most cases, it is possible to restore the frequencies of 2.2 and 2.6 kHz. These frequencies are reliable benchmarks, allowing in some cases to restore the AMT curve using the correlation between amplitude and phase. We have proposed ways to improve data quality in the dead band when measured during the daytime.
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Date submitted2018-05-05
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Date accepted2018-07-18
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Date published2018-10-24
Calculations of dynamic operating modes of electric drives self-propelled mining machines
- Authors:
- E. K. Eshchin
The task of improving the calculations of the dynamic modes of electric drives of self-propelled mining machines, particulary, tunneling machines, is considered. Attention is drawn to the possibility to opearte in dynamic modes of a spatial change in the an asynchronous electric motor stator housing position, included in the electric drive, around the axis of its rotor due to the ultimate rigidity of the supports of the mining machine. In connection to this, it is possible to change the absolute angular velocity of rotation of the electromagnetic field of the stator of this electric motor. The necessity of introducing into existing mathematical models that determine the state and behavior of asynchronous electric motors, additional differential and algebraic relations for calculating the absolute speed of the electromagnetic field of the stator and the nature of the motion of the stator housing of the electric motor as part of the mining machine is noted. The results of calculations of the idle start mode of the electric motor of the executive body of the mining combine are shown, showing the difference in the nature of its electromagnetic moment variation, rotor rotation speed, as well as efforts in individual reducer elements of the driving body driving the stator body from similar calculation results without taking into account the stator body movement. The conclusion is made about the possible discrepancy between the calculated and experimental results in the study of the dynamic modes of self-propelled mining machines.
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Date submitted2017-09-20
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Date accepted2017-11-09
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Date published2018-02-22
Development of the system for air gap adjustment and skip protection of electromagnetic lifting unit
- Authors:
- B. A. Zhautikov
- A. A. Aikeeva
The efficiency of the electromagnetic lifting system is ensured by the well-coordinated work of all its parts and elements, namely those providing the strictly vertical movement of the skip. The deviation of the skip movement from the vertical axis can lead to a stop and damage of both the skip and the unit. Therefore, the air gap adjustment and skip protection system of the electromagnetic lifting system, which includes determining the size of the air gap between the electromagnet of the skip and the electromagnet of the aligning device, and the development of a stabilization system to ensure a constant air gap and regulate the current in the electromagnet winding, provide both a strictly vertical movement skip, and its protection. The article is devoted to the theoretical determination of the air gap between the electromagnets of the aligning device and the skip using the Biot – Savar – Laplace law.
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Date submitted2016-10-30
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Date accepted2017-01-02
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Date published2017-04-14
Result of combining data from impulse electrical prospecting and aeromagnetic prospecting for groundwater exploration in the south of Yakutia
In 2014 in the south of Yakutia in the course of groundwater exploration works a complex of geophysical methods was tested: aeromagnetic and electrical prospecting was carried out using near-field transient sounding and electromagnetic sounding with induced polarization. Prospective structures for hydrogeological drilling are zones of discontinuous tectonic faults. In order to identify them, data from aeromagnetic and electrical prospecting were used. Results of drilling confirmed the presence of watered areas; however, analysis of obtained information allowed to come to the conclusion that the amount of water in the faults has no direct connection to electrical conductivity.
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Date submitted2016-11-18
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Date accepted2016-12-28
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Date published2017-04-14
Frequency electromagnetic sounding with industrial power lines on Karelia-Kola geotraverse
The paper describes theory, method and first experimental results of research on the interaction between electromagnetic waves of extremely low and ultra low frequency (0.1-200 Hz), the Earth crust and ionosphere in the field of two mutually orthogonal industrial power lines, 109 and 120 km long, in the course of FENICS experiment (Fennoscandian Electrical conductivity from Natural and Induction Control Source soundings). The main focus was on the observation results along the line of Karelia-Kola geotraverse over a distance of 700 km from the source. High horizontal homogeneity of geoelectrical lithosphere section has been detected in the eastern part of the Baltic shield at depth range from 10-15 to 50-70 km. Parameters of «regular» lithosphere section have been specified to the depth of 60-70 km. As a result of inverse problem solution for the western part of Karelia and Central Finland, a zone of decreased transverse resistivity has been detected at the depth of 50-60 km, corresponding to the area, detected by seismic methods, where Moho boundary reaches the same depth.
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Date submitted2013-07-19
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Date accepted2013-09-18
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Date published2014-03-17
Experience of implementing electromagnetic shielding on OJSC «Mordovcement»
- Authors:
- P. S. Sedov
- S. V. Kovshov
- Z. N. Cherkai
The negative effects of electromagnetic waves could be appear during violation of the designing established rules of installation and operating various sources of electromagnetic fields. Permanent action of electromagnetic small intensity waves have negatively influence on the enterprise’s workers. Employees feels tired, working capacity can be reduced, there is an un-reasonable irritability, periodic headaches and dream violation. This article is offers a package of measures to reduce electromagnetic load on staff of JSC «Mordovcement», by introduction of electromagnetic shielding system of the industrial frequency fields.
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Date submitted2009-08-23
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Date accepted2009-10-17
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Date published2010-02-01
Mathematical description of microwave contact level controller for liquid agent
- Authors:
- N. V. Teterin
- O. M. Bolshunova
It is shown the problem of measurement of level in oil tanks. Considered the use of a method of the sway electromagnetic radiation for the control of level of section of environments in tanks, made its mathematical description, resulted the estimation of results of practical application.
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Date submitted2008-10-15
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Date accepted2008-12-17
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Date published2009-12-11
Low frequency inductive airborne electromagnetic system em-4h
Nearly all existing airborne EM-survey systems have been tested in Russian Federation. And for today the most popular EM-system is the frequency-domain one, called EM-4H. The article gives the description of the EM-4H system, that have been developed by «Geotechnologies» JS. This instrument allows effective conductivity mapping on a 1:25000 scale. It provides performing of 100 kilometers of survey per hour on the average.
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Date submitted2008-10-23
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Date accepted2008-12-05
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Date published2009-12-11
Application of electrical prospecting in combination with seismic prospecting for the geological section prediction and search of hydrocarbon deposits
- Authors:
- V. A. Kuzin
- A. A. Korukhova
The possibility of application of electrical prospecting method SGN (sounding by field growing in the near-field zone) in combination with CDP seismic prospecting for sedimentary section investigations and hydrocarbon deposits prospecting is considered. The physical basis of the method application for hydrocarbon prospecting is the effect of higher resistance of seams, saturated by hydrocarbons. The effect is reflected in the curve of electromagnetic field growth ε(t). The procedures of field works, processing and interpretation of electrical prospecting data are presented.
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Date submitted2008-10-25
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Date accepted2008-12-29
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Date published2009-12-11
Geoelectrical investigation of promising oil and gas bearing areas in the south part of Siberian plat-form
The investigations were carried out in Eastern Siberia on the Ust-Orda national region territory using the groups of methods on direct and alternating current. Multicomponent registration of electrical and electromagnetic parameters has been used. Field data interpretation stage included adaptation of software for a concrete experimental data, substantiation of interpretational models formation methods and the analysis of all a priori information. As a result, quantitative estimations of thickness and geoelectrical parameters of geological complexes were obtained. Moreover, complex tectonic structures were allocated and the most promising areas for detailed works were chosen.
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Date submitted2008-10-07
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Date accepted2008-12-05
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Date published2009-12-11
The application of areal technology and 3d data interpretation tem sounding when constructing the volume geoelectrical model of compound medium
Analysis of possibilities of different electrical technologies is carried out. Problems of applications of one-dimension and multidimensional inversions in the process of interpretation are discussed. Example of practical application of two- and three-dimension interpretation of electrical data in the process of ore prospecting in complicated geological media is presented. The example illustrates possibilities of electrical method as original research method, which enables to develop three-dimensional models of the medium under investigation.
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Date submitted2008-10-04
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Date accepted2008-12-13
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Date published2009-12-11
1D-interpretation technology of airborne tem data
- Authors:
- A. V. Chernyshev
One-dimensional interpretation methods of airborne transient electromagnetic data are considered. Main techniques, used for adaptation of standard methods of ground electroprospecting data interpretation to airborne technique, are described. The efficiency of methods examined was analyzed on theoretical data set. An example of practical application of methods developed is presented.