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Date submitted2018-11-10
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Date accepted2019-01-17
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Date published2019-04-25
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 submitted2018-11-20
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Date accepted2018-12-28
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Date published2019-04-25
REFINED ASSESSMENT OF SEISMIC MICROZONATION WITH A PRIORI DATA OPTIMISATION
- Authors:
- I. B. Movchan
- A. A. Yakovleva
The work is devoted to the issues of seismic microzonation representativeness, which is amongst the mandatory assessments that precedes civil and industrial construction. In addition to the practical approach and in accordance with the normative documentation, the authors propose parametric interpretation of the remote basis by means of tracing geodynamic zones and elements of the geoblock structure, where the leading marker of seismogenic risk zones is the anomaly of spatial variability of the geofield, coinciding with the discordant intersection of localised land structures. Verification of this marker is achieved by displaying a cartographic distribution image within the range of the seismic point increment, detailed on the basis of approximation dependencies.
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Date submitted2018-11-23
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Date accepted2019-01-03
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Date published2019-04-25
STRUCTURAL MODEL AND TECTONIC EVOLUTION OF THE FAULT SYSTEM IN THE SOUTHERN PART OF THE KHUR AREA, CENTRAL IRAN
- Authors:
- A. Sohrabi
- A. Nadimi
- I. V. Talovina
- H. Safaei
In the southern part of the Khur area, there is faults system with predominantly North-West strike. This network of tectonic disturbances is one of the most important fault systems in Central Iran which crosses Paleozoic metamorphic rocks, Cretaceous limestones, and Eocene volcanic rocks. Interpretation of satellite imagery ETM+ (Enhanced Thematic Mapper plus, Landsat) and field observations showed the presence of left-lateral shifts along with fault system. This formed the structure of the branch faults at the northeast end of the main fault. Another feature associated with shear dislocations is the rotation of blocks in the northeastern and southwestern segments of the area under study. There are several basins and positive structures within the area such as a series of uplifts and thrusts, indicating the presence of compressional and extensional tectonics. Another part of the work is devoted to the study of the correlation between active faults and earthquakes. Processing of satellite images, field observations, records of micro-earthquakes within a radius of 17 km made it possible to analyze the earthquakes parameters and the position of tectonic disturbances, and, as a result, confirm the presence of active faults in the region. In addition, we have identified three successive stages of the Khur area tectonics: rifting, contraction, change of convergence and uplift direction.
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Date submitted2018-11-09
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Date accepted2019-01-22
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Date published2019-04-25
DETERMINING THE STABILITY OF THE BOREHOLE WALLS AT DRILLING INTERVALS OF LOOSELY COUPLED ROCKS CONSIDERING ZENITH ANGLE
- Authors:
- P. A. Blinov
During development of drilling projects, a whole array of data is needed considering the properties of rocks and the conditions of their bedding. Accounting for geomechanical processes occurring in the near-wellbore zone allows avoiding many complications associated with the violation of the wellbore walls stability at all stages of its construction and operation. Technological and technical factors such as vibration and rotation of the drilling string, formation of launders during the descent and ascent of the assembly, pressure pulsation during the start and stop of pumps, hydrostatic and hydrodynamic pressure of the drilling fluid, its composition and properties, have a great influence on the stress-strain state of the medium opened by the well. The washing fluid circulating in the well should provide backpressure to the reservoir, not interact with the rocks chemically, colmatage channels in porous and fractured rocks, preventing penetration of the mud into the medium, by creating an impermeable barrier at drilling clay seams that are prone to swelling, cracking, etc. The article discusses the method for determining the stability of the directed well walls, taking into account the penetration of drilling mud into the pores and fractures of rocks. The technique will allow adjusting the zenith angle of the well during the workout of an unstable interval at the design stage, or selecting a drilling fluid composition to ensure fail-safe drilling.
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Date submitted2018-11-18
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Date accepted2019-01-17
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Date published2019-04-25
CALCULATION OF ELASTOVISCOPLASTIC DISPLACEMENT OF WELL WALLS IN TRANSVERSAL AND ISOTROPIC ROCKS
- Authors:
- A. G. Gubaidullin
- A. I. Moguchev
The relevance of the work is justified by the need to improve the technical and economic indicators of well construction based on forecasting and preventing drilling tools sticking due to the narrowing of an open well bore in the intervals of transversely isotropic rocks. A mathematical model of elastic-viscous-plastic displacement of the walls of inclined and horizontal wells has been developed during the narrowing of the open borehole due to rock creep in the intervals of transversely isotropic rocks. In the program developed based on this mathematical model, the calculation of the elastic-viscous-plastic displacement of the walls of an obliquely directed and horizontal well in the reservoir of argillite from the Western Siberia deposit was carried out. As a result of the calculation, it was established that after opening the rock with bits, the cross-section of the open borehole due to the rock creep eventually takes the form of an ellipse, the small axis of which is in the plane of the upper wall of the well and decreases with time.
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Date submitted2018-11-03
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Date accepted2019-01-16
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Date published2019-04-25
INTERPRETATION OF THE TRACER INVESTIGATION RESULTS CONSIDERING CONVECTIVE MASS TRANSFER
- Authors:
- V. A. Korotenko
- S. I. Grachev
- A. B. Kryakvin
The paper discusses the results of interpreting well tracer studies. It is shown that from the law of mass conservation it follows that when filtering a volume of an indicator, part of the injected tracer flows into the matrix. With the flow of fluid containing the indicator from the low-filtration resistance channel (LFR) into the surrounding matrix, the linear dimensions of the flow area depend on the permeability and porosity properties of the high-permeability channel and the matrix. While another part of the tracer moves toward the production well, its mass is lost due to diffusion processes. From the solution of the diffusion equation, it follows that the initial concentration of the tracer decreases in the course of filtration along the LFR channel. To interpret the results of the tracer studies, different cases of the LFR channels' location in the volume of the productive formation are considered. The varied parameter w allows characterizing the presence of several peaks in the concentration of the indicator and calculation the filtration parameters of the LFR channels. Depending on the known technological indices, several methods for determining pore volumes in the LFR channels have been proposed. To reduce the water cut in producing wells and to apply the technology of changing or aligning the injectivity profiles, calculations of the pore channels' radii in the mass of highly permeable seams are presented. It is shown that the volume of the chemical reagent pumped into the injection well to isolate the LFR channel is affected by the linear dimensions of the drainage area for the aqueous solution of indicator. Examples of the calculation for the permeability and porosity parameters of the LFR, the volume of pore channels necessary to isolate water inflow, and the radii of pore filtration channels, which influence the selection of the size of chemical reagent molecules, are given.
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Date submitted2018-11-20
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Date accepted2019-01-14
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Date published2019-04-25
LOW-DENSITY CEMENT COMPOSITIONS FOR WELL CEMENTING UNDER ABNORMALLY LOW RESERVOIR PRESSURE CONDITIONS
- Authors:
- N. I. Nikolaev
- E. L. Leusheva
The paper considers variants of lightweight cement compositions with additives of various substances, such as clay components, ash systems, silica additives, kerogen, gilsonite, microspheres, as well as the process of cement slurry aeration. Recommendations on the use of compositions in different conditions are presented. A decrease in the density of the solution is achieved not only due to the low density of the materials used, but also as a result of an increase in the water-cement ratio. In such conditions, it is not possible to ensure the formation of a durable and impermeable cement stone in the well, which creates high quality inter-reservoir insulation. The characteristics of the physical and mechanical properties of existing lightening additives are given, which allows determining the most rational conditions for the use of cement slurries for improvement of the well cementing quality.
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Date submitted2018-11-05
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Date accepted2019-01-01
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Date published2019-04-25
Features of elementary burst formation during cutting coals and isotropic materials with reference cutting tool of mining machines
- Authors:
- V. V. Gabov
- D. A. Zadkov
- Khac Linh Nguyen
The paper considers the cutting of brittle coals and rocks by a single cutter of a mining machine, in contrast to the generally accepted integral approach, different from the standpoint of the formation of successive elementary bursts that make up the cut. The process of the formation of an elementary bust in time is viewed as successive phases. Due to the complexity and multi-factor nature of the process, preference is given to experimental bench studies using reference cutters, isotropic materials, and real rock blocks. The bursting parameters values greatly influence the time of static forces action, the peculiarities of the formation of stress fields in the undercutter zone of the rock mass and the conditions for the emergence and development of main cracks in the near-cut zones during the cutting process. The accepted phase-energy method of analyzing the process, which most closely matches the structure of the studied process, revealed a more significant, than previously expected, effect on the cutting process, variability of cutting speed and potential energy reserve in the cutter drive. The paper discusses the possibility of purposeful formation of the parameters of elementary bursts. It describes new ways to improve the efficiency of cutting coal and rocks, in particular, reducing the maximum loads and specific energy consumption. It also considers the possibility of reducing the grinding of the rock mass and dust formation.
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Date submitted2018-11-14
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Date accepted2019-01-06
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Date published2019-04-25
PROSPECTS OF GEOMECHANICS DEVELOPMENT IN THE CONTEXT OF NEW TECHNOLOGICAL PARADIGM
- Authors:
- V. L. Trushko
- A. G. Protosenya
The article describes the role of geomechanics for forecasting the development of geosystems and ensuring the safety of mining operations during the transition to a new technological paradigm. The state and prospects of development of the mineral resource base, including the Arctic zone of the Russian Federation, are considered. The directions of technological breakthroughs and the possibility of transforming industrial production based on «cross-cutting» technology and the digital economy are presented. The analysis of geomechanical problems was carried out considering advanced technological changes and the rapid growth of requirements for the preservation of the Earth’s interior and natural landscapes. The concept of the development of geomechanics and geodynamics to ensure rational subsoil use in terms of the use of «breakthrough» technology is proposed, and the need to integrate scientific and industry collaboration into the system of engineering and professional education is shown.
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Date submitted2018-11-03
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Date accepted2019-01-21
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Date published2019-04-25
ESTIMATION OF CRITICAL DEPTH OF DEPOSITS BY ROCK BUMP HAZARD CONDITION
- Authors:
- V. N. Tyupin
During the development of minerals by the underground method, dynamic manifestations of rock pressure occur at a certain depth, which significantly reduces the safety of mining operations. Regulatory documents prescribe at the exploration and design stages to establish the critical depth for classifying a deposit as liable to rock bumps. Currently, there are a number, mainly instrumental, methods for determining the liability of rock mass to rock bumps and methods based on the determination of physical and technical properties and the stress-strain state of rock massifs. The paper proposes a theoretical method for determining the critical depth for classifying a deposit as liable to rock bumps. A formula for determining the critical depth of the rock bump hazard condition is obtained. A mathematical analysis of the influence of the physical and technical parameters of the formula on the critical depth is carried out. Its physical and mathematical validity is substantiated. The numerical calculations of the critical depth for 17 developed fields were carried out using a simplified formula. It also provides a comparison of calculated and actual critical depth values. It is established that the variation of the actual and calculated critical depth is due to the lack of actual data on the value of the friction coefficient and parameters of fracturing of the rock mass in the simplified formula. A simplified calculation formula can be used to estimate the critical depth of a field at the survey and design stages. More accurate results can be obtained if there are actual data on fracture parameters, friction coefficients and stress concentration near the working areas.
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Date submitted2018-10-31
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Date accepted2018-12-30
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Date published2019-04-25
PRODUCTION OF SILVER RUBLE AND PARTICIPATION OF THE SAINT-PETERSBURG MINING UNIVERSITY IN THE DEVELOPMENT OF MONETARY INDUSTRY OF RUSSIA
The article is a continuation of the research on the production of silver rubles and the development of Russian coinage. Graduates of the Saint-Petersburg Mining University contributed to the reputation and history of the Saint-Petersburg Mint as an advanced and high-tech production. The article describes the beginning of the development of silver ruble production, the use of ores from the Nerchinskoye deposit in the Transbaikalia to produce the main raw material in the form of concentrates and a silver alloy. The materials for the study used unique exhibits of the Mining Museum of the Saint-Petersburg Mining University, which are associated with the history of coinage and the Saint-Petersburg Mint. Some samples of lead-silver ores cast billets, and stamped coins were studied to determine the technological features of their manufacture. An analytical study of the features of minting and obtaining the first Russian silver coins according to some data of the royal decrees was carried out. The current level of technology and knowledge, as well as the special equipment of the laboratories of the Saint-Petersburg Mining University, made it possible to re-evaluate the characteristic features of the production of silver coins.
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Date submitted2018-11-09
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Date accepted2019-01-08
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Date published2019-04-25
EFFECT OF CHALK THERMAL TREATMENT MODE ON ITS STRENGTH
- Authors:
- V. A. Lipin
- D. A. Trufanov
Natural chalk is characterized by a fine-grained structure. The processing of chalk in conditions traditional for calcium carbonate baking is accompanied by its almost destruction and the formation of a huge amount of dust. The paper presents strength characteristics of chalk and chalky stone baking obtained with different temperature-time conditions of heating the raw material to a temperature of 450-600 °C. The uniaxial compression method was used to determine the strength depending on variable factors. Based on the experimental data, a model was constructed that determines the dependence of chalk strength on time and heating temperature. In the temperature range of 450-600 °C, the strength of chalk stone increases with increasing temperature and decreases with the increasing heating rate. In the process of isothermal heating, several factors will immediately affect the strength of a chalky stone: the formation and growth of calcite crystals, the evaporation of water, and the agglomeration of calcite grains. With an increase in the heating temperature from 450 to 600 °C, the average size of the crystals significantly increases and crystals with an estimated size of more than 4 microns are detected. An increase in the size of crystals is associated with an increase in their growth rate. The agglomeration of grains occurs at a temperature of 600 °C.
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Date submitted2018-10-28
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Date accepted2018-12-30
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Date published2019-04-25
DEVELOPMENT AND RESEARCH OF FORMATION TECHNOLOGIES ON SPECIALIZED PRESSES WITH SUBSEQUENT SINTERING OF HIGH-DENSITY DETAILS FROM IRON-BASED POWDERS
- Authors:
- A. M. Dmitriev
- N. V. Korobov
- A. Zh. Badalyan
Creating shifts of the lyaers in a deforming workpieces improves the quality of the product produced by pressure treatment. qual-channel angular pressing and precipitations of a cylindrical billet with a rotating turnaround were developed by specialists earlier and became basic for scientists engaged in nanotechnology. One of the most modern schemes for creating nanostructures by processing on presses is the «Cyclic Extrusion Compression» scheme (in Russia – «Hourglass»), which has significant drawbacks. To date, research on the creation of layer shifts in compacted metal powders is substantially less than in compaction of compact blanks. The article developed compaction schemes for presses of blanks from iron-based powders that have a certain analogy with the «Hourglass», while lacking the disadvantages inherent in the named scheme and implemented on the created samples of specialized hydraulic presses. The results of the studies of density, strength and microhardness before sintering the samples molded from a number of domestic and imported powders on iron base, including those doped with carbon and other alloying components, are described. It has been established that with the use of the formation schemes for powders providing large shifts between particles, the density of the preforms increases on average by 10-12 %. With an average stress (16.32 MPa) of the transverse section of the molded specimen prior to its sintering, molding with shifts between particles increases this stress by 78 %. The strength after sintering of samples made using the compaction schemes developed by the authors of the article increases approximately by 2 times. Magnetic pulse treatment (MPT) of a molded sample prior to its sintering increases its resistance to shearing before sintering, regardless of the molding pattern. When MPT of both the powder and the molded sample is executed, the most uniform distribution of microhardness in the sample is achieved, and after subsequent sintering, the most uniform distribution of the mechanical characteristics of the product. The results of all studies are described by regression equations.
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Date submitted2018-10-27
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Date accepted2019-01-04
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Date published2019-04-25
APPLICATION OF AN ACTIVE RECTIFIER USED TO MITIGATE CURRENTS DISTORTION IN 6-10 KV DISTRIBUTION GRIDS
The paper addresses issues of using the active rectifier in partially loaded variable frequency drive as active filter in the conditions of non-sinusoidal current and voltage disturbances caused by the presence of high-power non-linear load in the grid. The topology of transformless three-level converter for 6-10 kV suitable for proposed solution has been presented and its mathematical model has been de-rived. Based on the model, the direct power control algorithm with ability to compensate non-linear currents has been designed. The investigation of active rectifier efficiency was performed depending on the relation between linear and non-linear load currents of the grid node, as well as on active power load of the active rectifier. Efficiency analysis was based on the developed computer model of the grid node with connected non-linear load simultaneously with the variable frequency drive with active rectifier.
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Date submitted2018-11-05
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Date accepted2019-01-15
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Date published2019-04-25
SOME ASPECTS OF ANTIFRICTION COATINGS APPLICATION EFFICIENCY BY MEANS OF FINISHING NONABRASIVE ANTIFRICTION TREATMENT
- Authors:
- M. I. Sidorov
- A. V. Ragutkin
- M. E. Stavrovskij
The article analyzes the effectiveness of anti-friction coatings obtained by finishing anti-friction non-abrasive treatment (FANT), including processing in metal-clad technological media, in order to improve the performance of machine parts. The analysis of the application of coating technologies FANT on materials operating at elevated temperature and at high pressure, as well as with high values of energy fluxes in the environment, was carried out. The results of the application of various compositions of cladding elements and FANT technologies for various engineering products are presented. The results of studies of the use of FANT technologies developed with the participation of the authors confirm their high efficiency for improving the wear resistance of artillery gun barrel materials. Decrease in wear ranging from two to three times compare to regular technology. Field testing of anti-friction anti-wear coatings, carried out by specialists of the FSE SRI «Geodesia», confirmed the prospects of this direction for increasing the survivability of artillery barrels.
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Date submitted2018-11-13
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Date accepted2019-01-23
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Date published2019-04-25
APPLICATION OF AUTOMATION SYSTEMS FOR MONITORING AND ENERGY EFFICIENCY ACCOUNTING INDICATORS OF MINING ENTERPRISES COMPRESSOR FACILITY OPERATION
- Authors:
- A. V. Ugolnikov
- N. V. Makarov
The balance of electricity consumption a significant part is occupied by the production of compressed air at the mining enterprises. Many compressor stations of enterprises are equipped with automated parameter management systems that allow reliable, uninterrupted and safe operation of the compressor facilities. But the majority of automation systems at compressor stations do not perform the function of monitoring the energy efficiency indicators of the operation of a compressor station. The article discusses the issue of including compressed air flow sensors (flow meters) in an automated control system of a compressor station, which allows you to control the production of compressed air and the consumption of electrical energy for its production. Monitoring and recording of these parameters makes it possible, using microprocessor technology, to control one of the main indicators of energy efficiency – the specific energy consumption for producing one cubic meter of compressed air, determine how efficiently the compressor station works, and take appropriate measures to reduce specific energy consumption in time. . The use of additional functions of automated control and monitoring systems will allow the development and application of energy-saving measures aimed at improving the energy efficiency of the enterprise, which will lead to a reduction in the cost of finished products and increase their competitiveness