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Relevance. At present, the problem of soil pollution with heavy metals, which are accumulated in the body of animals and plants, causing various toxic effects, is especially acute. Despite the existence of various methods of reclamation of disturbed lands, as a rule, their application is inefficient or expensive, especially when it comes to abnormally high concentrations of heavy metals. Thus, an extremely urgent task is to find effective and inexpensive ways to recultivate lands contaminated with high concentrations of heavy metals. The article considers one of the promising areas for the reclamation of such lands using a mixture obtained from the accumulated waste of lignin-containing sediments from the pulp and paper industry of Baikal Pulp and Paper Mill as sorbents. Aim. To study and evaluate the effectiveness of using a mixture, which includes frozen lignin-containing sediments of Baikal Pulp and Paper Mill, as heavy metal sorbent. Methods. To assess the sorption efficiency of the obtained sorbent from the frozen sediments of sludge-lignin, the samples of anomalously contaminated soils were taken from the industrial site of the former battery plant "Vostsibelement", located in Svirsk, Irkutsk region. To determine the surface structure of the obtained sorbent for the presence of micro-, meso-, and macropores, its surface was surveyed using a JEOL two-beam system. IR spectroscopy was used to establish the types of bonds between the sorbent and the extracted metals. Results. The studies have shown that the resulting sorbent from the frozen lignin-containing sediments of Baikal Pulp and Paper Mill has a porous structure with a predominance of mesopores, sorbing heavy metal ions, while a large number of micropores contributes to the occurrence of chemical sorption. The obtained IR spectra indicate the possibility of chemical sorption of lead as a result of the reaction of substitution of a hydrogen atom in various hydroxyl groups of the sorbent of the group of aromatic or carboxyl structures. At the same time, the resulting sorbent in terms of its sorption properties is not inferior to commercial natural sorbents – bentonite clay and grassroots peat. The conducted studies allow us to make a positive conclusion about the possibility of using the developed mixture as a sorbent for the immobilization of heavy metals during the reclamation of lands that are contaminated with high levels of heavy metals, including lead.

The relevance. The waste of Baikal Pulp and Paper Mill causes a real danger of a social and environmental disaster for Lake Baikal and the entire Southern Baikal region, therefore, the problem of developing integrated solutions for dumping the accumulation of lignin-containing waste is especially acute. One of the promising areas for processing this type of waste is the use of natural processes, for example, freezing in winter, temperature detection or self-overgrowth of the occurrence of natural succession. The main aim of the research is to develop an environmentally friendly technology for processing colloidal lignin-containing waste from the pulp and paper industry. Methods: pilot tests at the Solzan industrial site of Baikal Pulp and Paper Mill for freezing lignin-containing wastes and obtaining soils from them by mixing with additives; performing quantitative chemical analysis using the methods of atomic absorption and atomic emission spectrometry, high performance liquid chromatography, toxicological analysis. Results. Pilot tests have shown that after freezing, the colloidal structure of lignin-containing sediments is destroyed with a decrease in volume up to 40 %, humidity up to 60 %, and also with a decrease in toxicity – from the third (moderately hazardous) to the fourth (low hazardous) and fifth class (practically non-hazardous) of hazard of the waste depending on its composition. After freezing, the resulting sludge with the introduction of various additives (CHP ash, sewage treatment plant sludge) can be used as soil ground and fertilizers for reclamation of disturbed lands and crops. Thus, an environmentally friendly technology was developed for processing waste from the pulp and paper industry to obtain soil ground, which is low-energy and does not contain expensive imported equipment.

The relevance of the research is caused by the need to assess the level of impact of a large pulp and paper enterprise located north of the Ezhvinsky district of Syktyvkar on the basis of ecochemical analysis of winter precipitation (snow), to show the feasibility of using this approach in environmental studies. The main aim is to show the dynamics of the aerotechnogenic load on the territory near the Syktyvkar timber industry complex based on the data on snow cover chemical composition during the monitoring period. Objects: snowpack samples, selected in the zone of influence of emissions of Mondi Syktyvkar JSC and conditionally background areas. Methods: snow survey using transect, adhering to constant sampling points, application of analytical methods according to the air pollution control manual (GD 52.04.186-89), cartographic methods for estimating the spread of pollution in the snow cover using the interpolation method (inverse weighted distance method), application of map algebra for calculating the areas of impact zones. Results. The authors present the results of ecochemical monitoring of snow cover in the zone of aerotechnogenic impact of emissions Mondi Syktyvkar JSC for a multi-year period. A general description of the distribution of individual components of emissions relative to the emission center is given. Long-term monitoring of snow cover in the impact and sanitary protection zones of the enterprise allowed us to analyze the dynamics of the aerotechnogenic load on the territory. The results of the calculation of the modules of substances entering the territory of the enterprise in 2019 showed the lowest level of contamination of the snow cover for the entire observation period, 66 % compared to the volumes of 2002. A significant decrease in the content of components in the snow was noted, starting in 2016 after the reconstruction of the enterprise. Samples of snowmelt water outside the territory of the sanitary protection zone do not exceed the sanitary and hygienic standards for fisheries reservoirs for all components. In general, based on the results of ecochemical monitoring of snow cover, the trend towards reducing the aerogenic impact of the enterprise on the adjacent territory is shown.

Relevance. А simple and up-to-date methodology is needed to assess the potential of electricity that can be obtained from solar power plants installed in different regions. The difficulty in assessing the potential of solar energy lies in the presence of some factors that affect electricity generation and depend on random events. Such factors include, first of all, the sky clarity, the direction of photovoltaic panels strictly to the Sun, dustiness, and ambient temperature. The literature uses different approaches to assess the potential of solar energy. This paper presents a methodology for evaluating the generation of electricity by a solar panel having a continuous solar tracking system, taking into account the dustiness and temperature of photovoltaic panels. The technique has been tested on an existing physical model. Aim. To study the existing methods for assessing the potential of solar energy and to select the most suitable ones for the central part of Russia. Object. Solar power plants. Methods. Empirical and analytical methods. Using data obtained from an operating solar station, the adequacy of the proposed methodology was assessed. Results. The selected methods take into account the hourly sky clarity index, which made it possible, with sufficient accuracy for engineering techniques, to determine the daily power generation of a solar station with different angles of inclination of solar panels. This will improve the accuracy of estimating the potential of electricity generated by solar power plants, both with stationary photovoltaic panels and with solar tracking systems. Based on the conducted computational experiments and the analysis of data obtained from an operating solar station, the authors concluded that the technique presented in this paper allows us to determine with high enough accuracy the potential of electricity that can be produced in Russia by solar stations.

Relevance. The article provides an overview of the problem of drilling wells for oil and gas in conditions of permafrost. When constructing wells for various purposes in conditions of permafrost rocks, special requirements are imposed on the selection of the optimal drilling fluid. Deposits in the permafrost zone have significant differences from conditions where rocks have a positive temperature. Aim. For permafrost conditions, the choice of optimal drilling technology plays an important role. The temperature of the drilling fluid during drilling should be equal to the temperature of the rocks being drilled or be slightly lower. Methods. An analysis of the types of flushing agents used for drilling permafrost has been carried out, and the main technologies used in this case have been considered. A description of the developed flushing liquid is given, and its optimal composition is determined. Results and conclusions. The objectives are solved by developing a clay-free polymer drilling fluid with antifreeze additives, which has a freezing point of minus 7°C. The paper considers the issues of reverse freezing of wells and the use of a thermal case in order to improve the thermal regulation of wells. The choice of thermal insulation equipment is outlined based on predicting temperature changes in the properties of rocks. It was shown that reverse freezing of rocks during the construction of oil and gas wells leads to leaks and collapse of casing columns, freezing of casing columns to the walls of the well, and failure of columns to reach a given design depth. The paper introduces the formula to determine the pressure, at which the stress in the casing reaches the yield point and collapse of the casing occurs. The article shows the diagram of the hydration of ions of the proposed drilling fluid with permafrost and the main causes of complications. Using the laboratory studies, the optimal composition of the drilling fluid was determined. The introduction of the proposed drilling fluid into the practice of permafrost drilling will make it possible to successfully construct oil and gas wells.

Relevance. Territorial planning of cities determines the reduction or prevention of possible or existing losses of the population, economic facilities and the environment from technoprirodnye hazards of different genesis. The effectiveness of planning regulations for urban development depends on the degree of validity of identification and forecasts of the occurrence and evolution of hazardous natural and technogenic processes in time and space. This, in its turn, is determined by the reliability of our ideas about the patterns of their formation and regional distribution. Aim. To identify geological hazards and propose the main engineering and geological constraints in urban planning on the example of Gomel. Objects. Natural and technical system "geological environment – technogenic impacts – hazardous natural and technoprirodnye processes". Methods. Systematic approach to the analysis of patterns of formation of hazardous natural and technoprirodic processes in the city; numerical modeling of geofiltration and geomigration processes based on the geofiltration model "GOMEL". Results. The most characteristic dangerous natural and technoprirodnye processes have been established on the example of the city of Gomel. Priority areas for the introduction of planning restrictions: tectonic situation; man-made flooding, were identified. Soil conditions are considered separately as one of the factors effecting the precipitation of natural and artificial bases under the influence of loads from civil and industrial buildings and structures. The authors have revealed the presence of disjunctive, as well as plicative in the form of flexures, age-varying and multi-scale dislocations forming the block structure of the upper part of the earth's crust of the city. It is shown that from the point of view of the stability of engineering structures, the absolute values of the velocities of long-period unidirectional block displacements are dangerous during long-term operation of structures located in interblock active zones. At the same time, short-period multidirectional movements in the active geodynamic zones of the articulation of blocks cause a change in the slope and bending of the foundations of structures. The paper introduces the engineering-geological features of the most common surface deposits: the terrigenous gray-colored formation of the Paleogene; glacial, periglacial and extraglacial formations of anthropogenic origin and their facies-genetic complexes. The authors identified the potential natural and technological hazards associated with the marked deposits. The paper demonstrates the causes and mechanisms of the formation of technogenic flooding of the city, as well as the genesis of the decrease in the deformation properties of moraine sandy loam with a technogenic increase in humidity. It is concluded that when establishing land use regulations for a city, as a rule, general measures cannot be taken, both for its entire territory and for certain stages of construction activity. The paper introduces the corresponding restrictions on the use of subsoil.

Relevance. Insufficient validity of the quantitative criteria of the regional, local and current forecast of the impact hazard of the coal seams being developed, the absence of algorithms linking the use of geophysical and direct geomechanical methods in forecasting. Aim. To develop a comprehensive method of geodynamic forecasting, including determining the extent of an impact-prone area identified by the results of a regional forecast based on the registration data of the GITS seismic monitoring system, for conducting local and current forecasts of impact hazard by regulatory methods. Object. An array of rocks of the excavation column 4-1-5-7 of the Osinnikovskaya mine during mining operations in the zone of a group of tectonic disturbances and the intersection of advanced workings. Methods. Regional geomechanical forecast by the geophysical method of seismic activity registration (GITS system), local (current) forecast by natural electromagnetic radiation methods (Angel-M equipment) and the output of drilling fines. Results. The paper introduces the results of complex studies in the excavation column 4 1-5-7 of the Osinnikovskaya mine to establish a correlation between seismic activity and the parameters of the stress-strain state of the array. The authors have introduced the concept of integral indicators of the considered parameters IF and Ikσ. They take into account the area of the zone for the i-th range according to the complex parameter of seismic activity F and the coefficient of vertical stresses in the roof of the formation Kσ. It is established that the informative value of the integral indicators is almost twice as high as the informative value of the initial parameters. Experimental nomograms и are presented to determine the category "DANGEROUS/NON-DANGEROUS" for the regional forecast of impact hazard according to the GITS seismic monitoring system. The authors developed a general algorithm for predicting the impact hazard during clean-up operations. This algorithm uses an integrated approach that includes a regional forecast for recording seismic activity within the mine field and local forecasting methods, both geophysical and direct, to clarify the boundaries of seismic energy release zones and confirm the category of impact hazard. Thу paper introduces the example of determining the width of the zone of increased seismic energy release in the mine closest to the seismically active zone. The dynamics of the occurrence, development and decrease of the seismic energy release zone in the considered areas in the mine workings is shown. The authors give the examples of the implementation of a local forecast of impact hazard in previously established potentially dangerous areas by methods of recording natural electromagnetic radiation of rocks and by the output of drilling fines.

Relevance. The urgent need to eliminate environmental pollution from industrial emissions of various solid particles. At the same time, maximum attention is paid to cleaning exhaust gases from particles of 2.5 microns in size or less. One of the most promising ways to increase the efficiency of existing gas purification equipment in capturing such particles is their coagulation by exposing the gas flow to high-intensity acoustic vibrations of ultrasonic frequency. However, at low concentrations, even at the maximum permissible sound pressure level, the coagulation efficiency of particles smaller than 2.5 microns is insufficient to increase the recovery rate of gas cleaning equipment. Therefore, there is an urgent need to find new ways to further improve the efficiency of ultrasonic coagulation of particles smaller than 2.5 μm. Aim. To determine the conditions for the formation of vortex flows in ultrasonic fields with the maximum ultrasonic influence in terms of sound pressure level. Conducting comparative studies of the coagulation of particles with a size of 2.5 microns with and without vortex flows. This will make it possible to determine the real values of increasing the efficiency of ultrasonic coagulation during turbulization of a gas-dispersed flow by acoustic flows in comparison with coagulation in a uniform ultrasonic field and without it. Objects. Coagulation of particles under the influence of homogeneous and inhomogeneous ultrasonic fields. Methods. Computer modeling of the formed ultrasonic field by the finite element method using harmonic acoustic analysis. The paper considers the experimental method for studying the process of combining particles under the influence of ultrasonic vibrations. To determine the characteristics of an aerosol during experimental studies, a TIPAS-1 meter based on the small-angle scattering method and the spectral transparency method was used. Results. The paper introduces the results of studies of coagulation of particles with a size of 2.5 microns or less in an ultrasonic field formed in resonant gaps by oscillating disk emitters. The authors proposed to increase the efficiency of coagulation in resonant gaps through the use of ultrasonic disk emitters capable of forming alternating zones of maximum and minimum amplitude oscillations in the resonant gaps. The creation of such zones ensured the formation of vortex-type acoustic flows capable of moving particles within the nodal regions of a standing wave and between them. The involvement of small particles in the formed flows made it possible to increase the probability of their collision. It was established that more effective ultrasonic coagulation provides an increase in the degree of inertial capture for particles of 2.5 microns in size by 6% – from 89 to 95%, for particles of 1.5 microns in size by 7% – from 85 to 92%, and for particles of 0.5 microns by 9% – from 76 to 85%.

Relevance. The use of anti-turbulent additives for transporting hydrocarbon liquids through main pipelines allows reducing significantly the energy consumption of pumping power stations. Aim. Comparative analysis of the anti-turbulent efficiency of high-molecular polymers and compositions of surfactants. Methods. Laboratory-scale experimentation aimed to study the flow of dilute polymer solutions and dispersed surfactant systems through a cylindrical channel of a turbulent rheometer. Results. The author has carried out the comparative experimental studies of the anti-turbulent efficiency of extremely dilute solutions of polymers and colloidal systems. The results were obtained that suggest a higher anti-turbulent efficiency of high-molecular-weight polymers compared to micellar surfactant systems. Solutions of high molecular weight polybutadiene and aluminum polyhydroxydicarboxylates in gasoline were used as samples for the experimental comparison of hydrodynamic efficiency. The paper describes the laboratory setup, on which the studies were carried out, and introduces the formulas used for quantitative calculations. The structure of polymer solutions and colloidal systems is considered and a theoretical explanation is given for the preferential use in industrial practice of high-molecular polymers in extremely low concentrations in real pipelines. It was found out that the mechanisms of degradation of antiturbulent properties of polymer solutions and dispersed surfactant systems are different. This is due to the difference in the structure of macromolar coils of polymer with an immobilized solvent and that of micelles from low molecular amphiphilic compounds. The paper introduces the arguments that explain the degradation of the antiturbulent properties of polymers not by the destruction of carbon-chain macromolecules, but by decomposition in a turbulent flow of the original large associates, consisting of a large number of chains, into individual and smaller macromolecular coils with an immobilized solvent.

Relevance. Transportation of Russian coal by rail is an important link in coal supply for export. It is essential for the country economy and of high social significance for coal mining regions. Aim. To assess the state of the railway infrastructure for coal transportation, identify limitations and opportunities for improving coal transportation. Objects. Volumes and technologies of coal transportation by foreign and Russian exporters; state of the railway infrastructure of the eastern range of Russia; measures taken by coal mining companies to overcome restrictions on coal transportation; potential volumes of coal transportation for export and risks associated with reduction in coal exports. Methods. Methods of system analysis: classification, structuring and restructuring, analysis, formalization and concretization. Results. The paper considers the current state of coal transportation by rail in Russia with allocation of coal-mining eastern regions of Russia and Western Siberia. The importance of Russian railways in coal transportation is presented. The authors have outlined the problems of the railway infrastructure of the Eastern range of Russian railways due to its insufficient capacity. The changed geopolitical conditions created additional difficulties in transporting coal for export by rail. The paper introduces the state and prospects for modernization of the Eastern range of the Russian Railways. The authors gave an overview of activities of coal mining companies to overcome restrictions on coal transportation by rail. A brief review of the world experience in coal transportation state in the main coal exporting countries is made. The demanded volumes of coal transportation for export by rail was assessed. The paper considers the risks associated with the reduction of coal exports. The authors noted the need to harmonize programs for development of railway infrastructure, the coal industry and other industries that ensure coal extraction, transportation and consumption, reduce import dependence and the need to develop coal transportation technologies.

Relevance. The need to develop energy-saving approaches through the use of data mining tools to improve the efficiency of management decision-making and more optimal use of energy resources. Forecasting the amount of electric energy generated by a solar power plant will allow optimal electricity distribution in decentralized systems. Information about the amount of electricity generated by a solar power plant and transmitted to a grid at every hour will allow planning the use of generated electricity and its distribution more reasonably. Also, the presence of a reliable forecast will allow embedding a predictive model into the micro-grid management subsystem. This will facilitate the integration of centralized electrical networks and distributed generation facilities. Aim. To analyze scientific papers containing proposals to improve the accuracy of determining the amount of electricity generated by solar power plants; to create machine learning models that allow you to create a short-term forecast of electricity generation by a solar power plant. Objects. Solar power plant named after A.A. Vlaznev (Sakmarskaya SPP), Orenburg region, Orsk, Oktyabrsky district, geographical coordinates: 51.266023, 58.474689. Methods. Analytical method, methods of mathematical statistics, methods of machine learning, complex generalization of scientific achievements and practical experience in the use of data processing tools in the tasks of forecasting electricity generation by solar power plants. Results. The authors have carried out the review of literature sources reflecting the results of using modern data mining tools in predicting the magnitude of electricity generation by solar power plants. The paper considers various approaches to forecasting electricity generation at solar power plants. The analysis of factors used in forecasting is carried out. The authors obtained the results of theoretical and applied nature. The results consist in recommendations on using exogenous variables in predicting power generation at SPP, as well as some machine learning algorithms in construction of predictive models. These recommendations were obtained in generalizing the results of the applied research.

Relevance. The need to develop new technical and technological solutions to improve the efficiency of water isolation in wells with horizontal termination in reservoirs with layered heterogeneity of the formation. Aim. To identify and propose a promising gel-forming composition for conducting water isolation in wells with horizontal termination in reservoirs with layered heterogeneity of the formation. Object. A well with a horizontal termination in reservoirs with layered heterogeneity of the formation. Methods. Laboratory and bench studies of the gel-forming composition for isolating water inflow in wells with different reservoir permeability by modifying it with functional additives and further adapting its application to various mining and geological conditions of the well; technology of injection of compositions with different viscosity in wells with horizontal termination in reservoirs with layered heterogeneity of the formation. Results. The paper considers the theoretical aspects of a hydrophobic layer formation on a watered reservoir surface effected by a hydrophobic composition, when it enters the reservoir. The paper introduces the mechanism of a water-insulating screen formation during injection of a gel-forming composition. The authors have defined the basic requirements for the gel-forming composition. They developed the formulation of the gel-forming composition with a different gelation time from 1 to 8 hours. Due to the composition injection, a water insulation screen is formed that can withstand significant water flow pressure. The water breakthrough pressure varies and depends on the initial permeability: with an increase in gas permeability from 0.1 to 1 mm2 of the breakthrough pressure it decreases by water and ranges from 4.5 to 11.5 MPa/m.

Relevance. Copper-pyrite ores of Russia are the basis of the mineral resource base of the country's metallurgical industry, primarily providing copper and zinc, and metals such as Pb, Au, Ag, etc. Today, about 25 % of the total balance reserves of zinc of the country is in the composition of copper pyrite ores, the role of the main component in which is performed by copper. The result of the flotation enrichment of copper pyrite ores is the production of substandard copper concentrates (Cu content ⁓15–20 %, Zn content ≥5 %). The pyrometallurgical processing of such materials into blister copper is characterized by high costs, as well as irretrievable losses of valuable components. Today, the issues of studying the characteristics of raw materials and deposits, developing technologies for processing copper- and zinc-containing materials, as well as analyzing existing and promising processing options are relevant and, as a result, can have positive effect both in terms of the complexity of using raw materials, improving the quality of the resulting products and the degree of their extraction, and, consequently, from an economic point of view. The aim: analysis of the characteristics of copper zinc-bearing ores, in particular, the ores of the Uchalinsky and Verkhneuralsky copper ore regions enriched at the Uchalinsky mining and processing plant, mineralogical assessment of the concentrates of the Uchalinsky mining and processing plant, followed by the selection of promising options for processing low-grade copper concentrates based on hydrometallurgical processing methods. Methods. The analysis of data on the main types of copper deposits, the characteristics of copper pyrite ores in Russia, as well as more detailed data on ores enriched at the mining and processing plant was carried out on the basis of a review of domestic and foreign literary and information sources. Also, an analysis of the concentrate and middlings of the Uchalinsky mining and processing plant was carried out. Due to the information obtained through the combination of the above methods, an assessment was made and information on possible options for improving the processing technologies of the studied raw materials was presented. Results. Thanks to the study and development of more integrated approaches in processing materials with a low content of useful components and complex raw materials, in particular, studied in this work, in the future it will be possible to achieve improved technological performance from both an economic and environmental point of view. In this paper, the raw materials and products used and obtained, respectively, at the Uchalinsky mining and processing plant, the Republic of Bashkiria, will be considered in more detail.Relevance. Copper-pyrite ores of Russia are the basis of the mineral resource base of the country's metallurgical industry, primarily providing copper and zinc, and metals such as Pb, Au, Ag, etc. Today, about 25 % of the total balance reserves of zinc of the country is in the composition of copper pyrite ores, the role of the main component in which is performed by copper. The result of the flotation enrichment of copper pyrite ores is the production of substandard copper concentrates (Cu content ⁓15–20 %, Zn content ≥5 %). The pyrometallurgical processing of such materials into blister copper is characterized by high costs, as well as irretrievable losses of valuable components. Today, the issues of studying the characteristics of raw materials and deposits, developing technologies for processing copper- and zinc-containing materials, as well as analyzing existing and promising processing options are relevant and, as a result, can have positive effect both in terms of the complexity of using raw materials, improving the quality of the resulting products and the degree of their extraction, and, consequently, from an economic point of view. The aim: analysis of the characteristics of copper zinc-bearing ores, in particular, the ores of the Uchalinsky and Verkhneuralsky copper ore regions enriched at the Uchalinsky mining and processing plant, mineralogical assessment of the concentrates of the Uchalinsky mining and processing plant, followed by the selection of promising options for processing low-grade copper concentrates based on hydrometallurgical processing methods. Methods. The analysis of data on the main types of copper deposits, the characteristics of copper pyrite ores in Russia, as well as more detailed data on ores enriched at the mining and processing plant was carried out on the basis of a review of domestic and foreign literary and information sources. Also, an analysis of the concentrate and middlings of the Uchalinsky mining and processing plant was carried out. Due to the information obtained through the combination of the above methods, an assessment was made and information on possible options for improving the processing technologies of the studied raw materials was presented. Results. Thanks to the study and development of more integrated approaches in processing materials with a low content of useful components and complex raw materials, in particular, studied in this work, in the future it will be possible to achieve improved technological performance from both an economic and environmental point of view. In this paper, the raw materials and products used and obtained, respectively, at the Uchalinsky mining and processing plant, the Republic of Bashkiria, will be considered in more detail.

The relevance. Increasing requirements for reliability and safety of gas pipelines. One of the promising methods to ensure compliance with these requirements is to equip gas pipelines with aeroacoustics monitoring systems. These systems make it possible to detect leaks and mechanical impacts on a pipe by registering aeroacoustics oscillations, propagating in the transported gas. At the same time, the issue of improving the accuracy of such systems remains relevant. It can be achieved by better consideration of a gas flow impact on aeroacoustics oscillations, taking into account the effect of convective amplification. This effect was revealed in studies of propagation of aeroacoustics oscillations in air ducts, turbines, as well as in studies of sound propagation from moving aircraft and high-speed trains. But it has not been described in relation to gas pipelines. This article presents experimental data confirming the convective amplification impact on the amplitude of aeroacoustics oscillations in the main gas pipeline, quantitative description of influence of this effect. The paper demonstrates the possibility of improving the accuracy of aeroacoustics monitoring systems, taking into account the convective amplification. The main aim. Confirm the presence of the convective amplification effect while the aeroacoustics oscillations propagating in the main gas pipeline. Object. A linear part of the main gas pipeline. Methods. Use of the aeroacoustics monitoring system for registration of aeroacoustics oscillations in the gas pipeline during the movement of a cleaning gauge and at leaks simulation; comparison of the amplitude of aeroacoustics oscillations, propagating up and down the transported gas. Results. The authors confirmed in field experiments the presence of the convective amplification effect during the cleaning gauge movement and leaks simulating. They carried out a quantitative assessment of the convective amplification influence on the aeroacoustics oscillations amplitude. The paper introduces the example of the convective amplification impact on the accuracy of the source of acoustic oscillations location in a gas pipeline. Conclusions. When propagating upstream of the gas the aeroacoustics oscillations amplitude is higher than when propagating downstream of the gas at the same distance from the source. The value in the amplitude difference is comparable to the value of the convective amplification in quantitative terms. Taking into consideration of the convective amplification effect improves the accuracy of determining the linear coordinate of the acoustic oscillations source in the gas pipeline.

Relevance. Mining of potash ore using borer miners is characterized by a high degree of dust emission. The main sources of dust emission are the processes of destruction of the massif, loading of the broken-off rock mass and further overloading of ore. Long-term presence of miners in an area where the maximum permissible concentration for potash dust is exceeded negatively affects their health. In terms of economic losses, ore regrinding also has a negative effect. Particles of a useful component less than 250 micrometers in size do not lend themselves to enrichment and go to the dump. Often, the amount of raw ore at the entrance to the processing plant reaches 18 % of the total supplied mass. In this regard, it is necessary to take measures to reduce dust concentration in the working area of the borer miner operator and to reduce the amount of non-enriched fraction. The purpose of this work is to develop and implement measures to change the executive bodies of roadheaders, which will help reduce dust emissions in the bottomhole working area of potash mines. The object of the study is the executive body of a roadheader with a cutting tool. Results. The paper proposes constructive changes to the executive body of the borer miners. The new flat planetary-disk cutting unit will make it possible to implement a cross cutting scheme with a more stable geometry than the existing cutting sequence for Ural-20R borer miners. The design changes proposed in this paper take into account the previous problems described in the literature.

Relevance. The construction sector is currently one of the largest consumers of raw materials and a major source of environmental pollution, accounting for about 40 % of energy consumption and about 30 % of greenhouse gas emissions. As a result of emissions into the atmosphere of combustion products of coal, oil and gas, irreparable damage is caused to the environment. One of the promising ways to solve this problem is the introduction of «energy efficient building» technology. The key task of designing energy-efficient buildings is the development of a power supply system, which largely determines the level of comfort and technical and economic indicators of the entire facility. The complexity of this task is caused by the fact that installations based on renewable energy sources, characterized by stochastic generation, are mainly used as power sources, and energy-efficient buildings themselves can differ significantly from each other in a number of parameters: purpose, architecture, size and number of storeys, composition of consumers etc. The article proposes an engineering technique for designing such objects and the results of its testing. The aim of study is to develop an engineering methodology for designing power supply systems for autonomous energy-efficient buildings based on renewable energy sources. Methods: methods of statistical processing of time series of data, mathematical and computer modeling using the MatLab/Simulink software environment. Results. The authors have proposed an engineering methodology for designing power supply systems for autonomous objects, focused on the design of «active» buildings with the maximum possible use of renewable energy sources. The paper describes the main design stages, which include calculation and analysis of the energy balance, choice of the main electrical equipment and development of a structural diagram of the electric power system, optimization of the composition and sizes of the main electrical equipment, selection of switching and protective devices, conductor products, development of circuit diagrams. The paper considers the practical example of application of the proposed methodology for designing the power supply system of an autonomous energy-efficient building in the Kursk region.

The relevance of the research consists in search for methods for methods for increasing oil recovery aimed at growing the coverage of oil reservoirs developed by flooding, which will allow continuing the operation of fields with high depletion of reserves at the last stages of development. Involvement in the development of complexly localized non-drainable reserves due to the injection of polymer compositions will extend the life cycle of depleted fields and increase the final oil recovery factor. Purpose: to study the impact of injection of polymer compositions on the change in the filtration flows of an oil reservoir in order to increase the final oil recovery factor. Objects: sand layers of the Yu1 horizon of the Vasyugan suite, distinguished by their heterogeneity, inconsistency in thickness, and different permeability along the section. Methods: analysis of the recovery of oil reserves in terms of displacement characteristics, as well as analytical dependencies; analysis of the current state of development; assessment of the effectiveness of the formed waterflooding system; analytical calculations using the filtration equation; laboratory studies on a filtration model; analytical evaluation of the results of testing the selected compositions at the oil field «Х». Results. The article summarizes the results of experimental studies of the effect of adding polymeric reagents to the composition of the fluid injected into the formation on changing the reservoir properties of the productive formation. The paper introduces the results of laboratory studies to determine the technologies and compositions for the implementation of the program for the injection of polymers into the Yu12+3 formation of the oil field «Х». The filtration model of a real reservoir was created from core samples of the field under consideration especially for the research in laboratory conditions; the conditions for fluid filtration through the core column are as close as possible to reservoir ones. The paper introduces the results of pilot work on application of the technology of injection of polymer compositions into the Yu12+3 reservoir of the oil field «Х». The authors carried out the analysis of the effectiveness of the work, made the recommendations for further use of the technology of injection of polymer compositions into the reservoir.

The relevance of the work is caused by the need to solve the problems arising in the development of oil fields: reducing the production rate; deterioration of reservoir filtration properties; increasing water cut of produced oil. The impact on the formation of elastic vibrations in a wide frequency range is considered a promising technology to stimulate and increase oil production. However, the large-scale introduction of such methods is constrained by insufficient understanding of the physics of the processes involved. Objective: to identify mechanisms of improving the permeability of porous media and reservoirs under acoustic influence on them based on theoretical and experimental studies, field tests; to identify priorities for future scientific and practical developments in the application of acoustic technologies to intensify oil production. Methods: analysis of the results of laboratory studies and generalization of experience in the application of acoustic and ultrasonic impact methods on productive formations to intensify oil production. Objects: productive formations of oil fields; contaminated bottomhole zone of wells; samples of porous medium from terrigenous and carbonate reservoirs. Results. The paper introduces the review of the results of theoretical, laboratory, and field studies of methods to improve the efficiency of oil production due to the wave action on the environment by elastic oscillations. The authors analyzed the phenomena occurring during this action in the productive formation. It is noted that most studies in this area refer to the ultrasonic exposure and mainly in laboratory conditions. The paper considers the phenomenon leading to increase in porous media permeability under this impact. In particular, the propagation of elastic vibrations contributes to the prevention of deposition of organic and inorganic sediments, restoration and increase of permeability of saturated porous media, removal of plugs and various deposits in carbonate and terrigenous reservoirs. The directions of promising research are formulated; recommendations for improving oil production through acoustic impact are given. The conducted analysis and generalization confirm that the impact of elastic oscillations in a wide range of frequencies activates various chemical and physical processes, affects the filtration-capacitive properties of productive formations and contributes to oil production intensification.

The relevance of the problem of increasing the efficiency of using the metallic mineral resources extracted from the bowels on the earth's surface is explained by the increasing demand of industrial metals to meet the vital queries of the human. The aim of the study is to develop environment-friendly and resource-saving technologies of extracting metals from sub-standard raw materials in underground mining of metallic mineral deposits. Research methodology includes a set of methods that collectively define the feasibility of involvement in production of non-conforming metallic resources using hydrometallurgical technologies and increasing the extraction of metals compared to traditional washing technology. The main method is semi-experimental leaching of uranium ore in the pile. The results of the research allow us to optimize the organization of work on leaching metals by controlling the process parameters at all stages of leaching of off-grade mineral raw materials in the stacks with a differentiated assessment of the influence of major processes on leaching rates. The paper introduces the data on consumption of reagents and materials, extraction of metals into solution and out of solution and neutralization of the mother liquor. It is shown that leaching in the pile does not radically improve performance of traditional methods of extraction of metals, but only reduces the metal content in the secondary tails. The paper identifies the deficiencies of existing methods of assessing the impact of mining on the environment. The conclusion from the results of the study is that leaching in a stack does not solve the problem of non-waste, essentially increasing the exposure time of chemically hazardous products to living matter.

Link for citation: Buglov N.A., Pushmin P.S. Determination of the conditions for the implementation of the deformed drilling layout rotation in the mode of stabilization of the borehole direction. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр.17-25.In Rus. The relevance of the study is caused by the need to create a general methodology for determining the eccentricity of the inertia center of the core set cross-section, which will significantly reduce the irrational material and energy costs of drilling wells drilled in conditions of natural curvature of their trunks, as well as optimize the technical and economic indicators of drilling operations. Objective: to increase the productivity of geological exploration when working in conditions of natural curvature of boreholes. Objects: drilling well, column set, drilling shell, drill string, natural curvature of the borehole, the trajectory of the borehole. Methods: analysis of literature sources on the research topic; processing data of production organizations; graphoanalytic method. Results. To eliminate some of the shortcomings currently available in the issue of maintaining the trajectory of the borehole drilled in conditions of natural curvature, a general technique is proposed that ensures minimization of the deflecting force on the rock-breaking tool during the deepening. The proposed technique is divided into two components: the use of pre-deformed core sets; the creation of a direct precession with continuous contact of the half-wave crest with the well wall during rotation of the arrangement. To implement the first case, the paper presents a method for determining the value of residual or preliminary deformation of a rectilinear core pipe. Practically, the proposed technique is implemented by sequentially performing three basic operations: the plane of deformation of the core set is determined during drilling; the parameters of the core set are adjusted by its residual deformation by the calculated value; the well is drilled with a pre-deformed core set. To implement the second case, the paper presents a method for determining the magnitude of the eccentricity of the inertia center of the column set cross-section. In this case, in order to implement the method, it is necessary: to make a rational arrangement of the lower part of the drill string; to carry out the drilling process at the maximum possible rotation frequencies of the drill shaft; to use emulsion washing fluids; to reduce the amount of bending moment due to the operation of diamond crowns that work effectively at low axial forces. Both proposed methods are justified and supported by the results of experimental work. Conclusions. The conducted research allowed us to present and justify a fundamentally new method of reducing the curvature of boreholes based on the use of pre-deformed core sets, as well as to obtain a dependence for determining the optimal value of their residual initial bending, which guarantees a deflection force close to zero on a rock-breaking tool. The magnitude of the eccentricity of the stabilizing arrangement, which guarantees the operation of the guide section in the mode of direct precession: is directly proportional to the force of its interaction with the walls of the well; is inversely proportional to its mass and rotational speed; is directly proportional to the coefficient of sliding friction.

Link for citation: Mohammad Almohammad Alnayef, Zain Alabidin Dalfi Abd Ali Khalaf, Gnidan E.V. Experience of using acid treatments in the oil field Suwaydiya (Syria). Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр. 50-58. In Rus. Relevance of the research is caused by the need to increase oil recovery from wells developed in the fields of Syria, in the carbonate reservoirs of the Massif and Shiranish formation, for which there is a natural drop in production rates due to decrease in reservoir pressure, water cut, opening of reservoirs with low reservoir properties and increase in the share of hard-to-recover reserves. The main aim of the study is to analyze the results of acid treatments to improve oil recovery in the field of Suwaydia, Syria. The object of study is the carbonate complexes in the Upper Cretaceous deposits of the Massif formation and the Shiranish formation, Syria. Methods: review of domestic and foreign experience in treating the bottomhole formation zone using acid compositions and analysis of production, technological, lithological, geological, geophysical, and field data of wells treated with acids. Results. The paper introduces the advantages of the acid treatments method, such as improving the reservoir permeability and decreasing the skin factor by increasing the pore space and fracture channels, as well as removing the filter cake and various inorganic sediments that prevent oil flow. The undesirable effects of acid treatments: corrosion, secondary sedimentation, water cut, are indicated. The geological and physical conditions of the well and reservoir for choosing a treatment technology are considered. They are: reservoir temperature, filtration, and reservoir properties of rocks, granulometric (fractional) and mineralogical composition of rocks, chemical composition of reservoir fluids. The main directions of measures for solving geological and technological complications that arise during acid treatments using inhibitors, new multicomponent compositions of acid agents, special additives, and multi-stage treatments are noted. The paper introduces the technology and results of the application of acid treatments: hydrochloric acid treatment and foam hydrochloric acid treatment of the bottomhole zone of wells located in the north-east of the Syrian Arab Republic, which belong to the two oil field – Suwaydia and Zarba – of the Al-Hasakah Oil Fields Administration. It was noted that the use of a simple hydrochloric acid treatment of several wells did not lead to the predicted increase in oil recovery, and the use of an acid mixture (HCL at a concentration of 15 %, HF at a concentration of 3 %) in well no. 462 of the Suwaydia oil field showed an increase in productivity of 1,5 times. Recommendations are given for improving acid treatments at the Suwaydia, Syria fields to intensify oil production.

Link for citation: Popova M.S., Neskoromnykh V.V., Zotov Z.G., Liu Baochang. Modern basis of automation of diamond drilling control. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 6, рр.103-112. In Rus. The relevance. Diamond drilling is one of the promising and versatile methods of well drilling, which makes it possible to achieve high drilling speeds at great depths of work. At the same time, an expensive diamond tool needs to save a resource. The developed method for managing diamond drilling based on a comprehensive analysis of criteria using the method of a full factorial experiment is effective if it is implemented in real time. Thus, the problem of developing an automated control system for the diamond drilling mode, which makes it possible to save the resource of the tool while ensuring high rates of mechanical drilling speed and minimal power consumption, is topical. This approach will improve the technical and economic results of diamond drilling. The aim of the work is to develop a reliable interactive system of ground sensors and a computer complex that allows implementing automated control of diamond drilling based on a comprehensive analysis of criteria that fully characterize complex drilling and operate in real time. Objects: diamond drilling, interactive systems, devices and sensors of the latest generation. Methods: analytical research, computer simulation, full factorial experiment. Results. The paper introduces the system of sensors and computing unit, consisting of computers and software, capable of collecting and processing information in detail, which makes it possible to give a full assessment of the work of the tool at the bottomhole. The authors describe the scheme of interaction of devices for automation of diamond drilling. The paper introduces the detailed description of the software operation from the sensor signal to the display of the results on the display screen and the characteristic of the result of the application of an automated control system for diamond drilling.

The relevance of the research is determined by the need to understand the features of the hydrodynamics of viscous flows in the annular space between drillpipes and wellbore including changes in the shape of the cross section and wall surfaces; to detail intra- and interfacial processes of momentum and mass transfer during the flow of dispersed media with complex rheology in the fields of action of specific internal and external forces in annular eccentric pipes; to establish the capabilities of models, approaches, methods for predicting the evolution of the structure of the flow of mixtures; to develop practical recommendations for personnel on effective wellbore cleaning. The aim of the research is to study, within the framework of CFD methods, the features of the three-dimensional laminar and turbulent flow of a mixture of drilling fluid with solid particles in the coaxial and eccentric inlet area of the well, as well as to establish the patterns of complex viscous flow accompanying the transport of cuttings along the wellbore and cleaning its horizontal sections. Methodology is dominated by the approaches of complex physical-mathematical and computer modeling of processes in the mechanics of homogeneous and heterogeneous continuums, widely tested on internal complex viscous flows, as well as successfully validating and verifying the results under appropriate conditions and close to the flow regimes, heat and mass transfer, performed by other authors on the analysis of technological processes of drilling and cleaning wells. Results. The paper introduces the critical analysis of the current state of the problems of computer modeling of cuttings transport processes in drilling technologies. The features and effects formed by the presence of rotation of the drill pipe, which affect the structure of the flow, are noted. The authors have formulated in detail the problem of hydrodynamics and mass transfer of a turbulent spatially developing dispersed flow of a liquid with solid particles of cuttings in coaxial eccentric pipes of arbitrary rheology, as well as methods for studying it. The paper introduces the remarks on the formalism of the closures of the constitutive equations of the model in the framework of CFD. Calculations revealed the patterns of changes in local and integral parameters of flows and mass transfer associated with an increase in the annular, mass-average velocities resulting from a decrease in the free flow cross section due to the accumulation of cuttings. The trends towards regularization of the effects that create the cleaning are determined. The features of changes in the structure of a complex flow of a mixture in the framework of the Euler-Eulerian and Euler-Lagrangian approaches are disclosed. In conclusion, proposals for engineering prediction of flows in the horizontal section of the well are presented. The applied value of the results is determined by the possibility of making a number of generalizations that eliminate uncertainties caused by taking into account the details of the geometric and hydrodynamic configurations of the problem, as well as using the parameters of real drilling and cleaning modes.

Link for citation: Popov S.N., Chernyshov S.E., Krivoshchekov S.N. Comparative analysis of the analytical and numerical methods for calculating the stress-strain state of the near-wellbore zone based on the elastic model taking into account the main structural elements of the well. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 5, рр.94-102. In Rus. The relevance of the research is caused by the scientific interest in calculating the near-wellbore zone stress-strain state to improve the development of oil and gas fields, to predict the casing stability and the safety of the cement stone. The main aim: based on a comparative analysis of the methods of analytical and numerical simulation of stress calculation near a vertical well using an elastic model, determine the distribution of radial and tangential stresses, compare the accuracy of their calculation by different methods and identify the advantages and disadvantages of each of them. Objects: near-wellbore zone of the terrigenous reservoir of the Achimov deposits of one of the fields of the Khanty-Mansiysk autonomous region. Methods: analytical and numerical finite element methods for stress-strain state calculating of the near-wellbore zone, taking into account the main structural elements of the well and using a linear elastic model. Results. The paper considers the analytical relationships used to calculate the radial and tangential stresses in the casing, cement stone and reservoir rock, as well as the equations used in numerical finite element modeling of stresses near a vertical well. The authors have developed a finite element scheme of the near-wellbore zone, including its main structural elements. The paper introduces the results of calculation of the main components of the stress tensor in the structural elements of the well depending on the radial coordinate for the bottom hole pressure of 20, 40 and 60 MPa. The authors carried out the comparative analysis of the stress calculations results by the methods used. It is shown that the largest discrepancy between the analytical and numerical methods was 2 % that corresponds to radial stresses for the calculation option with a bottom hole pressure of 20 MPa. On average, the discrepancies were: for radial stresses – 0,04 %, for tangential stresses – 0,72 %. It is concluded that when using the model of a linearly elastic medium and under boundary conditions in the form of fixing the model in the upper and lower parts along the normal to the surface, and also without taking into account the pressure distribution in the depression funnel of the model, it is sufficient to use the analytical method of calculation. If it is supposed to use combined boundary conditions, a poroelastic model, taking into account viscoplastic deformations, then it is most preferable to use the numerical simulation method.

Relevance. At present, the study of Suprasenomanian deposits, including deposits of the Lower Berezovskaya subformation of Cognac-Santonian age, composed of siliceous rocks, has moved from the category of theoretical interest to the category of practically important research. This is due to the fact that industrial gas content was confirmed at six sites (Van-Egansky – NB1 formation, Vyngapurovsky – NB4, Medvezhy – NB3–NB4, Novo-Chaselsky – NB3, Komsomolsky – NB1, Kharampursky – NB1). There are four layers of the Lower Berezovskaya subformation (the NB horizon), however, criteria for determining the boundaries of these layers have not yet been identified. In this paper, the substantiation of lithological-mineralogical and commercial-geophysical criteria for stratigraphic dissection of the section of the Nizhneberez subformation is given. The object of the study is the Berezovskaya formation, which deposits in the north of Western Siberia contain significant gas resources, considered as a reserve for «prolonging the life» of deposits during the development of highly productive Cenomanian deposits. The aim: improving the efficiency of geological exploration to identify gas deposits in siliceous rocks of xenon by clarifying the stratigraphic structure of the rocks of the Berezovskaya formation. Methods. The dissection of the sections was carried out on wells drilled in recent years, with continuous core sampling and with an expanded complex of geophysical studies of wells (GIS), including electrical, radioactive, acoustic, nuclear magnetic methods. The mineral composition was determined by studying the core by X-ray diffraction analysis (more than 300 samples), infrared spectroscopy (220 samples). The composition of chemical elements in rocks was determined by X-ray fluorescence analysis (more than 300 samples) and inductively coupled plasma mass spectrometry (70 samples). Results. It is shown that the boundary between the NB2 and NB3 layers does not have unambiguous GIS criteria. At the Medvezhye field, this boundary is determined by the abrupt change in the readings of the nuclear magnetic and acoustic logs, at the Vyngapurovskoe field such abrupt changes in the curves of these methods are not noted. The paper shows that the boundary between the B3 and B2 layers has a clear characteristic of the mineral composition of rocks and is determined by a sharp decrease in the proportion of zeolites (clinoptilolite) during the transition from NB3 to NB2. Along with a decrease in the content of clinoptilolite at the boundary between the B3 and B2 layers, there is also a sharp change in the chemical composition of rocks, in particular, a sharp decrease in the proportion of strontium is noted. This tendency to decrease the proportion of clinoptilolite and strontium in rocks can be explained by the attenuation of volcanic activity in the south-east of Western Siberia.

Relevance. The present paper is devoted to the practical issues of ensuring uninterrupted and quality power supply for standalone industrial facilities and quick response of power supply systems that become increasingly important in the context of continuously growing portion of renewable generation, such as wind turbines, solar photovoltaic arrays, tidal power units, characterized by inconsistency and randomness of power generation periods. At same time, the load also has an unpredictable nature of consumption, which consists in unbalanced connection, abrupt power drops and surges, and the introduction of non-linear consumers, which affects the quality of the voltage in the power supply system. The main aim. The paper presents a method to develop a quick-response control strategy for a standalone three-phase power supply system for mineral mining and processing facilities to ensure the generated balanced voltages with sinusoidal waveforms. Objects: standalone power supply system; PWM four-leg full-bridge inverter, single-/three-phase load. Methods: quaternion algebra, noncommutative multiplication rules for imaginary units, closed-loop control, cascade systems. Results. The authors have developed basic concept covering the organization and implementation of a standalone AC generation system based on three-phase voltage quaternion decomposition into a balanced sinusoidal component and other components caused by amplitude-phase unbalance and nonlinear loads. The described continuous law provides a high speed of instantaneous compensation of distortions at abruptly variable load. Experimental studies were carried out on various kinds and configurations of loads: single-phase, three-phase symmetric, and also two-phase, one phase of which has a non-linear character of current consumption.

Relevance of the research is determined by the need to understand modern achievements in modeling the processes of sludge transport in real conditions of drilling operations that increase drilling speed and the efficiency of well cleaning; to establish the advantages/disadvantages of existing approaches, modern models and complex methods for describing the dynamics of systems with particles in order to effectively choose the rheological properties of drilling fluids and eliminate the reasons of equipment loss. The aim of this work is to understand the modern experience of modeling the processes of cleaning wells with complex geometries, mainly lying in the horizontal plane; to study the features of the flow of mixtures in the annular space with a circular core; providing recommendations for the practice of modeling and calculating hydrodynamic processes that increase hole cleaning efficiency. Methodology. Theoretical and practical research methods from related fields of hydrodynamics and heat and mass transfer in rheologically and physically complex systems; methods for numerical modeling of laminar and turbulent flows under conditions of direct-flow and swirling flows created by a co-axially or orbitally rotating wall, which affect the formation of a layer of cuttings and the dynamics of particles of a dispersed mixture. Results. The paper introduces the results of modern numerical studies of cleaning wells with horizontal sections and the information on aspects of detailed hydrodynamic and diffusion modeling of complex flows in inclined wells. The applied models and methods used to study the characteristics of flow and heat and mass transfer in homogeneous and heterogeneous media in internal systems are formulated. Aspects of modeling the processes of cuttings transport in the framework of Euler/Lagrangian approaches are discussed, taking into account the features introduced by the effects of interfacial interaction/rotation. The paper introduces the changes in cuttings concentration based on rheological properties (power-law or Herschel–Bulkley), different shapes/sizes of particles, flow regimes and inertial forces. The problems of improving the accuracy of cuttings transport modeling, the possibilities of new technologies, original turbulence models and their two-parameter dynamic bases used for increasing the intensification and efficiency of cleaning processes are analyzed. The authors have given the recommendations for their solution in the considered hydrodynamic and geometric configurations. The results and problems that are of fundamental and applied significance and constitute an independent subject of prospective research are indicated.

The relevance of the work is caused by the wide use of porous media, both in the design and optimization of compact heat exchangers and in the engineering calculations of the characteristics of heat and mass transfer in the channels with a grainy medium and when flowing around the bodies immersed in the porous medium. The main aim of the research is the experimental study of heat transfer in an annular channel filled with a granular medium at various modes of liquid filtration; to obtain semi-empirical correlations for heat transfer in the inertial mode of fluid filtration in an annular channel. Objects: annular channel with a porous insert consisting of glass beads of the same diameter with different types of both regular and chaotic pakings. Methods: experimental methods for finding the patterns of heat exchange processes. In experiments, using thermocouples, the temperature of the heated outer wall of the annular channel was measured in four sections and the temperature of the heater at two different points. The temperatures at the inlet to the working station and at the output of it were measured as well. Simultaneously with thermal investigation, the fluid flow was measured when filtering through a porous insert. Porosity was determined by the usual weighty way. In special calibration experiments, the heat losses of the working section were determined separately. The calculation of the heat transfer coefficient was carried out according to the flow of heat to the outer wall of the annular channel, taking into account heat losses and, along the difference in the measured wall temperature and the medium-mass fluid temperature in this section. The paper introduces the results of the experimental study of liquid filtration flow heat exchange with the walls of the annular channel filled with a porous medium at constant heat flux on the outer wall. The study was conducted on ring channels with different widths. The width of the channel was laid either one layer of the balls of one diameter with two types of packages: cubic and rhombohedral, or several layers of balls, but already with arbitrary packaging (from 3 to 10 ball width). When processing the experimental data, hydraulic grain diameter is selected as the determining geometric parameter. It is shown that, depending on the filtration mode, various laws of heat exchange exist through a porous insert. So for the turbulent filtering mode, the obtained data for heat exchange is well summarized by the universal «law of two-thirds». The paper introduces the comparison with the data of other authors, both for heat exchange in the annular channel and in a round tube. It is shown that in the inertial mode of filtration, the heat exchange corresponds to the regularity of Nu~Re1/2.

The work is devoted to the laboratory investigation of the causes of cryopeg formation – objects of cryolitosones of natural or man-made character, which are lenses of supercooled pore solution in the environment of frozen fluid stop. In particular, processes promoting cryogenic concentration of salts, as well as peculiarities of laboratory experiment are considered. The paper describes the experimental installation and procedure of experiment on controlling freezing–thawing of soil in closed volume – vertical heat-insulated cylinder, in which heat transfer was carried out through end sides according to preset algorithm. The experiment repeated the situation typical for the autumn-spring period: the daily freezing and thawing of wet soil contaminated with easily soluble salts. Four series of experiments were carried out with different number of repeated cycles of freezing front and thawing front motion in soil saturated with concentrated salt solution NaCl directed from top to bottom at a distance of 70-80% from cylinder height. At the same time, the lower area was always supported in the thawed form. The paper considers the phenomena and introduces the probable explanation for processes accompanying soil freezing and thawing, such as decrease of freezing start temperature in vertical section, formation of thermal barrier in direction of freezing front movement in low-temperature area, redistribution of salt ions along vertical section, dependence of concentration gradient on number of freezing – thawing cycles, deviation of melting temperature value in comparison with freezing start temperature. Numerical values of moisture redistribution and solution concentration in soil after each series of experiments were obtained. Methods of modernization of experimental installation and carrying out the experiment are proposed.

The relevance of the research is caused by the widespread application of geology models to study oil and gas reservoirs. At present time, by the government regulations in Russia, all field development projects must be done with geology and simulation models. The main aim of the research is to study and describe evolution of 3D geomodeling as a main method of oil and gas geology. Commonly used geology modeling packages history and features were revealed in order to determine industry interests and trends, advantages and drawbacks of existing software. Object of the research is 3D geology modeling as a method to study oil and gas reservoirs. Methods: study and compilation of the published papers and internet sources on the topic of geology modeling and appropriate software evolution. Results. The paper describes the main steps of 3D geology modeling evolution and the existing software for geology models creation. There are four stages of geology modeling history. First stage is related to recognition of importance of math modeling to describe geology systems. The second stage took part in 1950–1970-s and lay occurrence of such branch of science as mathematical geology and its branch – geostatistics. In early 1980-s first 3D reservoir models were created and used for oil and gas pools study. It inferred active development of geomodeling and occurrence of first software to reservoir modeling in 1980-s. In early 1990-s geology modeling started to enter industry and many geologists used it to study and evaluate oil and gas reservoirs. During 1990-s and 2000-s most of commonly used gemodeling methods and procedures were developed. At present time there is a trend in geomodeling to integrade all geoscience data into one project which should include geology, seismic, simulation, geomechanics and other aspects of reservoir study. Since 2018 the corporate software for geology modeling is created in Rosneft oil company. All determined advantages and new methods are integrated or going to be integrated into new geomodeling package «RN-Geosim».

The relevance of the article is caused by the need to develop new mathematical models, methods, experimental approaches when investigating migration problems of deep hydrocarbon fluids from underground reservoirs of the oil and gas basin. The aim of the research is to develop a universal physical and mathematical model of a detailed forecast of migration over a limited space of a ground collector of arbitrary geometry; make recommendations to the practice of studying the problems of hydrodynamics and heat- and mass transfer in these conditions and to compare the relative values of forces that cause the migration of deep fluids in vertical and lateral directions. Methods of the research are based on general principles of mechanics of continuous homogeneous and heterogeneous media, hydrodynamics and heat and mass transfer. Results. The paper introduces the data of analysis of effects accompanying hydro- and gas dynamics, and heat- and mass transfer at flows of homogeneous and heterogeneous rheologically simple and complex viscous mixtures in fields of action of external forces from underground regions with arbitrary geometry of slot and pore space. The authors have carried out the analysis of the correctness of the physical modeling of the problem on underground hydrocarbons migration and establishment of determining mechanisms for their lifting from large depths. It was found that upward migration is formed under the defining influence in the resulting force: floating force (Fв), which takes into account the features of changes in the fields of thermodynamic parameters (composition (ci), temperature (T), pressure (P)); gravity (FG): phase phenomena and processes at the boundaries of the analysed volume of the hydrocarbon medium, as well as pressure gradient force (FPR), the behavior of which is complicated by the distribution of the entire spectrum of external and internal forces in the conjugated system. The paper introduces the conclusions on details of fluid flow modeling, formulations of defining numbers and criteria within the framework of the theory of similarity of the considered problems, useful for understanding and clarifying the essence of effects, processes, forces, mechanisms accompanying migration. The results can be used to predict migration especially at the conditions complicated by: abnormal phase and rheological small-scale diffusion changes in composition; conjugated heat and mass transfer between rock and mixture; instability of modes in local areas of fluid flow at arbitrary thermodynamic and geometric configurations of underground collector.

The relevance of the research is determined by the need to take into account the surface properties (wettability) when conducting laboratory studies on the core represented by non-hydrophilic reservoir rocks. In relation to the increased volume of research on the study of these rocks, there is a great need to develop and search for new solutions aimed at ultimately obtaining the most reliable data. The main aim of the research is to develop a complex of special petrophysical studies on core samples of reservoir rocks with non-hydrophilic properties. Object: core samples from one of the fields of the Timan-Pechersk oil and gas province. The field is characterized by a complex structure of the hollow space of deposits and a large amount of resinous-asphaltene components in oil. Results. The authors have carried out the typification of the main kinds of wettability described in the literature. The paper considers the complex of different methods for preparing core samples for research and describes the method for determining the wettability parameter on core samples by the Amott-Harvey method. The results of determining the wettability parameter on core samples prepared by different methods: non-extracted samples, standard extraction, «mild» extraction, «aging» of the core are shown. The authors built the diagrams of comparison of the wettability parameter on core samples depending on the preparation method and open porosity. The paper introduces the results of special studies of the core to determine the relative phase permeabilities on the core sample prepared by various methods with the construction of a comparison graph. The conclusions about the significant influence of the methods of preparing core samples during laboratory research are presented.

The relevance of the research is related to the regional specificity of the coal deposit load and objects of the coal complex on water bodies. The data obtained make it possible to expand the understanding of the general regularities in the element’s distribution in the «water – coal bearing rock» system and further use them in various ecological and exploration studies. The aim of the research is to study the features of the component maximum amount distribution in the natural waters of the region and the composition of the host rocks, to estimate the rate of chemical element leaching from the rocks. Objects: surface and groundwater of the Naryksko-Ostashkinskaya area in the Kemerovo region, the most promising for coalbed methane production. Methods: modern methods for determining the water and rock chemical composition, including inductively coupled plasma mass spectrometry, as well as standard hydrogeochemical methods for calculating the concentration factors and water migration. Results. The paper introduces the data on 59 elements, including the micro-components of rivers, lakes and groundwater of different water exchanges: active, upper part and lower part (coal bearing rocks) of passive. When the water–rock interaction time increases, the salinity and the major ion and trace element concentrations increase as well. The calculated concentration coefficients relative to the average for groundwater leaching in a moderate climate made it possible to distinguish elements with a high level of accumulation: from major components, these are C, Na, Cl, Fe and the trace elements are Ga, Ba, Li, Zr, Pb, B, Sc, Ni, Br, Rb, Sr, Nb, Mo, I, Ag, Cd, Cs, Hg. The paper introduces as well the data on 48 elements of the coal bearing sandstones and siltstones, which, together with the literature data on some other elements, made it possible to obtain interesting relationships. For example, in a percentage relative to the total salinity, groundwaters of active water exchange contain 1–2 orders of magnitude more than in rocks: Cu, Ag, Cd, Sr, Sn, Sb, I, Cs, Hg, Pb. Taking into account water and rock composition, the coefficients of water migration were calculated, the series of migration of different types of waters were compiled, which did not reveal any fundamental differences. In all natural waters, they are highly mobile: Na, C, Cl, I, B, N, Br, Sr, Cd, Cu, Li, Mo, Ge, Zn; weakly mobile: Al, Ti, Zr, V, Nb, Eu, Mn, Si, Cr, Co, Fe, Rb.

The relevance of this research is determined by the widespread use of water georesources as working fluids in hydro- and heat power engineering, in heat supply and cooling systems.In this case, it is often required to carry out technological water treatment before using in the main production cycle. In particular, water needs to be cleaned of colloidal, scale-forming and gaseous impurities. The greatest difficulty is the water treatment from hardness salts, that is, its softening. Calcium and magnesium salts usually precipitate on heat exchange surfaces with the formation of scale, that leads to a sharp decrease in the efficiency of the heat exchange equipment, excessive fuel consumption and frequent stops for cleaning. Descaling is usually done by acid washing of the internal heat exchange surfaces or mechanically. All these methods involve the use of a large number of chemical reagents, and strongly pollute wastewater from water treatment units. In addition, it significantly increases operating costs. The purpose of this research is to theoretically describe the electrochemical processes that occur in installations with permanent toroidal magnets when passing a stream of water with hardness salts dissolved in it, as well as to analyze the practical operation experience of such installations. Objects: toroidal magnetic system, magnetic field, salt ions contained in water, magnetic water treatment units. Methods: toroidal electrodynamics; experiments on the interaction of toroidal electromagnetic objects; hypotheses about electrochemical processes occurring in a water stream flowing along the axis of a magnetic toroid; experiments to test these hypotheses; theory explaining magnetic water treatment technology; analysis of the «Magnust» apparatus long-term operating. Results. The paper introduces the theoretical explanation of the magnetic water treatment technology using toroidal magnetic installations and describes the electrochemical processes occurring at the stage of magnetic treatment and the subsequent stage of heating magnetized water. It is shown that ions of different signs drift in mutually opposite directions in the magnetic field presence. For this reason, the formation of calcium and magnesium hydrocarbonate on the heat exchange surface is difficult. As a result, the deposition of carbonates on heated surfaces does not occur. The authors have determined the most effective design of the magnetic installation and its optimal parameters as well. The paper introduces the information on the «Magnust» apparatus operation at several civil and industrial facilities.

The study is relevant due to the rapid growth of mining exploration and production activities in the permafrost regions of Russia over the last forty years. This paper presents the characteristics of the soils of the settling ponds of the Elgacoal field in the Republic of Sakha (Yakutia) on vulnerability of the geological environment to contamination. An engineering-geological evaluation is necessary in order to prepare decision making on land planning and land use of the area as well as to ensuresmaller negative impact of industrial and infrastructure development on environment and reducing hazards and damage to constructions, people and property. This study aims to establish the vulnerability of the territory to man-made pollution based on the study of engineering and geological conditions of the sites of settling ponds. Object of research is the geological environment. The paper considers the main natural components, which influence land use planning and development, such as lithology; topography; seismotectonic; geotechnic; hydrology-hydrogeology and permafrost. This study includes a brief review of relevant literature, and a summary of information obtained from geological survey company files. All information layers about the natural environmentwere manipulated and combined to produce uniform engineering geological map. We produced a zoning map of the study area that shows zones with different degree of geological environment vulnerability of contamination:high, moderate, low, negligible vulnerability.

Relevance. It is known that swelling of a well wall due to the presence of water negatively affects drilling operations, causing a significant increase in their material costs. The use of various inhibitors prevents this effect and the drilling mud reacting on wellbore narrowing. In this sense, the problems of developing polymer, amino-, ionic liquid and shale inhibitors of surfactants considered in the article are very relevant and of practical interest to oil engineers in terms of the prospects for fundamental and applied researches of these issues. Aim. To study the possibilities of existing approaches and methods that determine the characteristics of the main clay swelling inhibitors, the regularities of changes in the properties of traditional and non-traditional clay materials, as well as the mechanisms of clay swelling with the identification of the most characteristic group of these inhibitors. Object. Processes of minimizing the effect of wall narrowing as a result of exposure to inhibitors. Methods. Systematic, critical and comprehensive analysis of modern data on clay swelling inhibition in the field of drilling muds. Results. The authors have carried out the detailed analysis of clay swelling. The paper discusses the characteristics of inhibitors required to prevent swelling, in the structure of which nitrogen and ionic liquids are contained. It is noted that a high-quality clay swelling inhibitor should include in its base a water-soluble bulk molecule with a distinct hydrophobic and hydrophilic structure; have characteristics, which allow replacing the hydrated cations of the intermediate layer with some hydrophobic cations, such as ammonium ions instead of sodium ions; differ in the ability to disperse multiple cations well. It was found that functional groups that support inhibitor binding to the siloxane groups of the clay are able to significantly expand clay swelling.

Relevance. The need for scientifically based regulation of impacts on wetland ecosystems taking into account their specificity and geochemical stability. Aim. To determine the geochemical stability of wetlands in the taiga zone of Western Siberia to pollutants for two typical cases associated with: 1) operation of sludge pits; 2) discharge of domestic and industrial wastewater. Methods. Mathematical modeling, statistical methods. Results and conclusions. The authors have carried out the analysis of the results of studies of the chemical composition of wetland waters and extracts from peat and mineral soils of wetlands in the taiga zone of Western Siberia (mainly in the Tomsk region, as well as in the adjacent territories of the Khanty-Mansiysk Autonomous Okrug, Novosibirsk and Omsk regions). They obtained the estimates of the average values of geochemical indicators of wetland waters and peat by the depth of the peat deposit in peat bogs with varying degrees of anthropogenic impact. The paper introduces the method for assessing the anthropogenic impact of wastewater discharge and geomigration on swamps in areas where oil and gas facilities are located (permissible concentrations in wastewater entering swamp ecosystems), taking into account the «geochemical background» and sorption capacity of peat. In particular, the authors substantiated and tested the method for assessing the values of permissible concentrations, which should be considered as a «relatively safe» level of impact on swamp ecosystems, at which secondary pollution of swamp waters is not expected. It is shown that anthropogenic changes are mainly limited vertically by the upper layer of the peat deposit up to 1–2 m, and horizontally (within the active horizon of the peat deposit) – by areas up to 100–200 m.

Relevance. In Kuzbass, a coalbed methane production project is being implemented for the first time in Russia. Formation water extracted together with coalbed methane plays an important role, since it has been in contact with the coal-bearing rocks for a long time, therefore it contains rich geochemical information. Over the period 2002–2022, new isotopic data were accumulated both on the waters of the region coal deposits and on overlying waters, including surface waters. Aim. Based on the material accumulated on the isotopic composition (δD, δ18O, δ13C, 34S, 3H, 14C) of natural waters in coal-bearing areas, create an evolutionary scheme for the formation of waters within the framework of the developed hypothesis on the interaction of water-rock-coal-methane. Objects. River, underground waters of the zone of active water exchange, upper and lower parts of the zone of slow water exchange (extracted together with coalbed methane). Methods. Studies of the isotopic composition of waters were carried out in several laboratories: in the Multielement and Isotope Research Center of the SB RAS, the Technical Branch of the Federal State Unitary Enterprise “SNIIGGIMS”, in the radiocarbon AMS laboratory based on the Center for Collective Use “Cenozoic Geochronology” and in the Pacific Oceanological Institute Far Eastern Branch Russian Academy of Sciences (POI) FEB RAS. Results and conclusions. The paper introduces the data on δD, δ18О, δ13С и δ34S for surface and groundwater in Kuzbass in coalbed methane production areas. It is shown that all the waters under consideration are infiltration based on their isotopic composition (δD and δ18О). The waters of the lower part of the slow water exchange, produced together with coalbed methane, are characterized by a positive oxygen shift and very light hydrogen. A diagram of the evolution of the isotopic composition of water-dissolved carbon in the region has been compiled according to the data obtained. It is noted that the atmospheric source of CO2 is characteristic only of river waters, and only biogenic carbon dioxide is present in groundwater. The wide range of δ13СDIC values of the latter is explained by the varying degrees of participation of light soil carbon dioxide and heavy biochemical carbon dioxide formed during methane formation in the coal seam. The heaviest values are typical for waters produced together with coalbed methane, which is associated with long-term interaction with coal and methane. The time of such interaction was determined using the radiocarbon method: 17–30 thousand years. In areas where coalbed methane is produced, an increase in δ13СDIC values for all natural waters is observed, which requires further study.

Relevance. The assessment of the state of natural waters includes the determination of a number of physico-chemical indicators, on the basis of which various indices and classifications are developed. However, they do not take into account a number of pollutants that have a significant impact on the state of the reservoir, for example, polyaromatic hydrocarbons. The article considers some aspects of determining priority pollutants, which include polyaromatic hydrocarbons, according to environmental hazard criteria: toxicity, carcinogenicity, prevalence, frequency of occurrence, source of origin (anthropogenic or natural). Hydrochemical parameters such as pH, dissolved oxygen content, biological oxygen consumption (BPK5), and ion content are taken into account to determine water quality. An attempt was made to assess the impact of polyaromatic hydrocarbons on the ecological state of water bodies and to take into account their contribution to changes in the values of the water pollution index. All these data prove the relevance of the study. Aim. To establish the composition of polyaromatic hydrocarbons in the surface waters of small reservoirs of the Tomsk region to assess anthropogenic load and to show the relationship with the indices of natural water quality. Methods. Extraction, liquid adsorption chromatography, high-performance liquid chromatography, capillary electrophoresis, amperometry, titrimetry. Results. Small lakes of the Tomsk region were studied for the content of 13 polyaromatic hydrocarbons. The authors have carried out the identification by high-performance liquid chromatography with fluorimetric detection. The total content of polyaromatic compounds in the studied surface water samples varies from 0.37 to 0.54 mcg/l. In the polyaromatic hydrocarbons mixture in aqueous samples, there is an increased content of light 2–3 nuclear polyarenes with better solubility (naphthalene, fluorene and phenanthrene), as well as benz[a]anthracene. The content of inorganic components represented by cations and anions does not exceed the maximum permissible concentrations. The water pollution index was calculated; all lakes are moderately polluted, closer to polluted. The paper demonstrates the dependence of the water pollution index coefficient on the content of high-molecular polyaromatic hydrocarbons and the ratio of high-molecular to low-molecular polyaromatic hydrocarbons. It is shown that the higher the value of the water pollution index coefficient, the higher the proportion of difficult-to-oxidize components in surface waters.

Relevance. Almost all gas fields, both in Russia and in the world, are developed under water-pressure conditions, which means that sooner or later the field operator is faced with the problem of well watering and liquid accumulation at their bottom. The control methods proposed at this stage of development of science and technology and the useful models and inventions applied for this, although they show their effectiveness in removing droplet liquid from the production wellbore, do not contribute to the further advancement of the removed fluid through the system for collecting and preparing products. Because of this fact, a number of problems arise, for example, the formation of local resistance in the form of ice or hydrate plugs, the cause of which is the fluid removed from the wellbore. Aim. Development of a universal device that can be used both in the production collection and preparation system and inside production wells, capable of injecting produced water into the gas flow in order to prevent the formation of “stagnant zones” of liquid. Objects. Flooded gas wells, the gas pressure in which is not enough to remove droplet liquid from the wellbore or transport this liquid to the place of product preparation. Methods. Assessment and analysis of existing devices to prevent the formation of liquid plugs in a gas collection system, identifying their main shortcomings, as well as mathematical modeling of the proposed model, in which these shortcomings are eliminated. Results and conclusions. The paper introduces a brief description of the problem under study and studies and discusses the main methods of preventing the formation of liquid plugs, used in gas fields both in Russia and in other countries. The authors have proposed the design of a universal device, which is devoid of the main identified disadvantages of analogue devices, and carried out its simplified mathematical calculation.

Relevance. It is known that sedimentary deposits in modern lakes with high sedimentation rates contain detailed paleoclimatic, paleobiological, paleoecological and magnetic records. The study of these parameters allow creation of paleoreconstructions and prediction of future climate behavior. Aim. To identify ecological and climatic events and trends during the Late Quaternary, based on magnetic properties of rocks. Some climate-dependent parameters are not properly used, we are showing that magnetic parameters are sensitive indicators of climate change. Object. Sediments of the Lake Kandrykul (Republic of Bashkortostan). Materials and methods. A set of petromagnetic studies was carried out, including measurements of magnetic susceptibility, normal remanent magnetization in external magnetic field of up to 1.5 T, as well as differential thermomagnetic analysis on induced magnetization and scanning electron microscopy on selected samples. Normal magnetization curves were used to set apart dia-/paramagnetic, ferromagnetic and superparamagnetic components. Results. Seismoacoustic studies showed that the lake bed is smooth, without sharp changes. The maximum water depth is about 16 m, the thickness of sediments reaches 7.5 m. Magnetic susceptibility was measured for three core columns, and the results show good correlation of this parameter between all the cores. Thermomagnetic analysis was used to determine magnetic minerals composition. The Day–Dunlop plot showed the presence of single, pseudo-single and multidomain grains. The authors determined the contribution of dia/para-, ferro-, and superparamagnetic components to the overall magnetic susceptibility. The paper considers the variations in magnetic susceptibility, para-, ferromagnetic components in the context of the Holocene climate changes. Conclusions. Variations in magnetic properties reflect climate changes (i.e. deposition environment). Six zones with different depositional conditions were distinguished based on magnetic susceptibility and its component changes. Additionally, zones with single-domain particles were highlighted based on hysteresis parameters variations. These zones most likely are associated with the remains of magnetotactic bacteria. Joint analysis of paramagnetic, ferromagnetic susceptibility and hysteresis parameters produced information on the effect of total humidity on the bioproductivity of the lake.

Relevance. When operating submersible equipment for oil production in aggressive environments and transferring wells to the cyclic operation mode, a decrease in the service life of the submersible installation for oil production is observed. In the first case, this is due to the formation of salt deposits and clogging of the working parts of the electric pump with mechanical impurities. In the second case – an increase in the number of starts of the submersible electric motor. To solve the existing problems, it is possible to implement closed control systems for submersible electric motors based on state variable observers, which determines the relevance of the study. Aim. To develop an observer with operational monitoring of the angular velocity of the rotor and the moment of resistance on the shaft of a submersible asynchronous motor at inconsistency of the initial conditions in various operating modes and its testing using modeling tools. Methods. The observer is built on the basis of known engine models in a fixed coordinate system α, β, the theory of IIR-filters to obtain a forecast of estimates of the angular velocity of the rotor and the torque on the shaft and their correction in real time. Results. The authors have proposed the original structure of an observer with operational monitoring of the angular velocity of the rotor and the moment of resistance on the shaft of a submersible asynchronous motor. Conclusions. The paper demonstrates the observer performance with inconsistency of initial conditions and electric motor model data in various operating modes. In all modes, stable estimates of the speed and torque of resistance on the electric motor shaft are obtained. At the same time, the error in estimating the angular velocity under the condition of changing the load on the shaft and starting in the loaded state is no more than 1.2%, which is acceptable in submersible electric motor control systems. It is revealed that the developed observer, under the condition of changing the active resistance of the stator and rotor in the ranges from –25 to +25% of the nominal value, obtains estimates of the angular velocity with an integral error of no more than 5%, except for starting the motor with a decrease in the active resistance of the rotor by 25% of the nominal value –5.53%, which is acceptable in engineering practice.

Relevance. Polymer composite materials with carbon components have not only good functional characteristics as resistors, but also low price, low specific gravity, and relatively simple industrial manufacturing technology. This determines the expansion of the scope of their application, including in material-intensive oil and gas equipment, in high-voltage electrical and electrophisikal installations. Expanding the areas of application of such materials requires research into thermophysical characteristics and methods for controlling them to optimize thermal conditions during continuous operation of equipment containing components made of polymer composite materials with carbon fillers. Thermophysical characteristics can be formed using a wide range of parameters; the main ones are the type of electrically conductive and connecting components. However, changing the binder requires a radical change in technology, which is not always acceptable for a number of reasons. Aim. To study the effect of the electrically conductive component (carbon black) on the thermophysical characteristics of rubbers filled with carbon black; establish the dependence of the thermophysical characteristics of the composite on the type of carbon black. Object. Thermophysical characteristics of the composite material, largely determined by the electrically conductive component. Methods. Instrumental measurements of thermophysical and electrical characteristics of materials, statistical and correlation analysis. Results. The authors have experimentally established that the thermophysical characteristics of rubbers filled with carbon black (heat capacity, thermal conductivity, and thermal diffusivity) depend on the type of carbon black. They identified the patterns of changes in these characteristics. The paper analyzes their relationship with the properties of carbon black and the characteristics of the macrostructure of the composite material. Based on the conducted research, the authors developed the recommendations for selecting the grade of carbon black for composites used in such areas as: electric heating systems operating on the principles of self-regulating heaters, devices operating in non-stationary thermal conditions, etc.

Relevance. The need to study the features of aerogenic effects of the Norilsk industrial complex on the natural environment. Aim. To study the features of the aerogenic effects of the Norilsk industrial complex in the south-southwest zone at a distance of 40–60 km using lichens Cladonia rungeferina and Cetraria sp. Objects. Soil, lichens Cladonia rungeferina and Cetraria sp. Methods. Soil and lichen samples were taken 40–60 km south-southwest of the Norilsk Industrial district. Sampling was carried out according to the scheme of two profiles with a length of 14 and 20 km. The samples were analyzed using a set of methods consisting of X-ray fluorescence (S4 Pioneer Bruker AXS), atomic absorption methods (KVANT-2A, Julia-5K) and induction-coupled plasma mass spectrometry (ELEMENT-2) in the laboratory of the GIN RAS, Moscow. The concentration of Ti, V, Ni, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Rb, Cd, Sb, Ba, La was determined. Results. The authors have obtained the data on the concentration of the 21 elements in soils and lichens. The paper demonstrates the calculation of distribution of elements in soil and lichens relative to the concentration in the upper part of the continental crust. The authors calculated the enrichment factor EF for Mn, Ni, Cu, Hg, Pb and estimated the distribution of this coefficient for both profiles. It is shown that the technogenic component of the aerogenic effect for Mn, Ni, Cu, Pb to the south-southwest of the Norilsk industrial complex at a distance of 40–60 km is practically absent. The increased values of the enrichment factor EF in lichens for Hg are explained by a combination of two factors – the constant presence of mercury in significant concentrations in ecosystems and tundra fires that took place in this zone in 2019–2020, which ultimately led to the re-deposition of Hg in the burnt areas.

Relevance. The need to ensure safe working conditions in the working areas of underground mines. Stagnant zones with low air velocities can be formed in large section blind heading behind the ore bulk when ore is shipped by mining machines. There is a possibility of the formation of local gas accumulations and their abrupt removal later in such stagnant zones due to the unsteadiness of accumulation and transfer of gas impurities in a blind heading. A sharp removal of gas will lead to contamination of the load-haul-dump operators’ workplace. Aim. To identify removal of exhaust gases in large section blind headings in conditions of changing ore load size. Objects. Large section blind headings with of complex geometry. Methods. Three-dimensional numerical simulation of unsteady turbulent flow of a gas-air mixture in the Ansys CFX, visualization and analysis of simulation data in the Wolfram Mathematica. Results. The paper presents the results of mathematical modeling of ventilation of large section blind headings of complex geometry under conditions of changing ore load size formed during mining operations by the load-haul-dump machines with an internal combustion engine. It is shown that either a single vortex is formed that ventilates the blind headings space, or a stagnant zone behind the bulk ore, which is characterized by a relatively low intensity of mass transfer. Vortex formation depends on the height of the ore bulk. The authors have obtained the dependences of the change in the average concentration of exhaust gases at the outlet of the blind headings space on the operating time of the machine. They determined the dependence of the correction volume coefficient on the geometric parameters of the blind headings. An analytical model of the removal of gases from the blind headings space under conditions of changing bulk ore volume is obtained. The expression of increment in gas concentration on an operator’s workplace makes it possible to derive formula to find maximum time of load-haul dump operation in a stope such that gas concentration is never higher than maximum allowable concentration.

Relevance. While performing the operation processes, the technological equipment emits vibration. Vibration is a consequence of increased dynamic loads in structural elements and interfaces between systems and their elements. The development of fatigue damage can significantly accelerate. Therefore, the solution of the problems related to reducing vibration levels is always relevant. Each type of protective system has a linear law of changing the stiffness. This does not allow the effective damping of low-frequency vibrations. Thus, the information review demonstrates the future of the research according to the creation of the vibration protection systems, constantly improving their parameters in the following aspects: minimizing overall dimensions and number of parts; increasing reliability, especially in resonant mode; providing the ability to operate in modes with low stiffness. The last factor determines the good damping of vibration emitted by the source. Aim. To study the possibility of the vibration protection system development with quasi-zero stiffness with the ability to effectively dampen low-frequency vibrations. Methods. Information and analytical review in the field of the research, search for the constructive solutions, preliminary design calculations and 3D modeling, description of the device being developed and its operating principles. Results. The research presents the results of development of the vibration protection system with quasi-zero stiffness and a fragment of an information review of existing vibration protection systems. The authors indicated the main shortcomings specific to all vibration protection systems: relatively large sizes, large number of elements, insufficient operating frequency range. The authors proposed a constructive solution for creating a vibration damping system with a nonlinear law of change in stiffness. This solution allows eliminating the above shortcomings and providing the possibility of effective damping of low-frequency vibrations. The authors created the method for calculating the constructive parameters of a vibration damping system. An example of calculation is given in the paper. This system differs from existing vibration protection devices in its low stiffness and small dimensions, and a wide operating frequency range of vibration damping. The efficiency of the system operating with nonlinear and quasi-zero stiffness is proved.

Timeliness. Investigation into the issues and existing prerequisites for development of a system of consolidated recording of the bulk of coal in the form of the reserves in place, the mined raw material and the goods to be sold proved the implementability of the task. The consolidated recording will facilitate a proper assessment of the country’s resource potential, as well as that of individual mineral developers, making it transparent and comprehensive for international investors. On the other hand, the recording eliminates the discrepancies in the governmental regulation of taxes imposed for the use of subsoil. The aim of the research is to offer an approach to development of a consolidated classification of coals for the typification of reserves. Objects: the fields of mineral, brown and anthracite coal. The approbation was performed using coal of different grade compositions mined by «Resurs» Company from the existing mine sites located in Erunakovsky and Prokopievsk-Kiselyovsk geological and economic districts. The approach offered is based on the existing regulatory frame work containing the standards used in the CIS countries, including GOST 25543-2013. Methods: comparative analysis of the existing approaches to coal classification, use of grades, process groups and types of usage as the criteria for typification of reserves. Results. The paper demonstrates the issues of understanding the advanced processing as the criterion for evaluation of coals and the need to introduce it as a requirement for proper performance of geological prospecting intended to identify and outline the coals having different process properties. The criterion, as well as other indicators of coal value, is required to typify coals depending on the degree of their processing. The paper contains recommendations on rating of coals based on process groups, as well as the typification of coal reserves. The division of coal reserves by areas of coal use, used as an evaluation criterion, provides the correct justification and design of exploration within the boundaries of the licensed area.

The article relevance is caused by the critical estimation of the data presented in domestic and foreign publications on problems related to modeling of viscous fluid streams while interacting with particles of a dispersed material and with walls of the devices intended for performance of drilling operations; clearing of wellbores from cuttings taking into account well inclination and drillpipe eccentricity. The main aim is to introduce the bibliographic analysis of hole cleaning and cuttings transport, focused on finding ways to efficiently increase operational efficiency; to work out approaches and methods to model the cuttings transport in vertical and horizontal holes; to explain modern data on numerical modeling of cuttings transport problems; to provide recommendations to increase hole cleaning efficiency. The research methods are theoretical and practical ones, characterizing fluid flow in systems, containing particles and the legitimacy of idealization of transport phenomena in mixtures; as well as the methods borrowed from other disciplines aimed at calculating the influence of flow regime and drillpipe rotation and eccentricity on location and behavior of dispersed particles. The general concepts of hydrodynamic and heat- and mass transfer principles in rheological complex media are not discussed in detail, and explained only to that degree which is required for clarity and completeness. The experimental material contains data on applicability of the theory to real physical systems. Most investigations are based on analyzing particle movement through fluid in common lumps as it originates at sedimentation as well as when particles remain more or less motionless, as in densely packed beds; or the relative motion of particles and fluid with complex turbulent distribution; at motion of particles relative to each other when the flow of the carrying medium is a complex shear flow. Results. The paper introduces the analysis of experimental and theoretical results, important for applications related to cuttings transport phenomena, and the features accompanying processes of momentum, mass and energy during the flow of rheologically complex homogeneous and heterogeneous viscous mixtures in the annular space between a rotating eccentric inner pipe and a non-rotating outer pipe. Cuttings accumulation and difficulties in its transportation have major real world applications in drilling inclined and horizontal wellbores. Modeling results and the existing empirical relationships for cuttings behavior are critically analyzed. Advantages and the legitimacy of assumptions of some turbulent models and their closing relationships and dynamic, diffusive properties are presented. Also the parameters and mechanisms modeling the formation, accumulation, sedimentation, transport and separation of slime cuttings from a liquid in which they are suspended are given. The last 25–30 years have seen the numerous advances in numerical methods of multi-parameter and multidimensional modeling of hydrodynamics in dispersed mixtures (suspension, foam, powders). The analysis of experimental works shows that observation of dynamics of solid and liquid particles interaction by contactless means of registration can provide valuable information for validation and verification of the modern Reynolds Shear Stresses (RSS)-models of turbulence and specific turbulent fluxes for streams based on kL-, kε-equations, capable to predict complex turbulent flow of a mixture. The paper introduces the prospects of developing a universal algorithm with the possibility of a detailed prediction of effects: cutting bed formations in arbitrary points of annular spaces; determination of the minimum speed necessary for its formation and removal. The latter can be used in further research for determination of maximum admissible Rate Of Penetration (ROP); optimum values pump output; establishing field guidelines on duration and sequence of well cleaning operations, and the frequency of tripping operations.

The relevance of the research. Currently, most of oil fields of Russia have entered the late stage of development. As there is the depletion of easily recoverable oil reserves, more and more efforts are directed at creating technologies and development methods that allow producing hydrocarbons in difficult conditions. For further development of fields with hard-to-recover reserves, the introduction of new methods for increasing oil recovery and the use of new reagents are required. A significant role in this matter is given to chemical methods, in particular the use of solutions of surfactants. Exposure of aqueous surfactant solutions improves the rheological and filtration characteristics of oil by reducing interfacial tension and increasing wetting ability. in this relation, the task of choosing a surfactant for use in the waterflooding system of reservoirs, as well as the development of methodological approaches for their selection, is of current interest. The main aim of the research is toform a methodological approach to study the surfactants used in the waterflooding system to increase oil recovery. Object: carbonate collectors of Udmurt Republic. Methods: laboratory studies of compositions, device for determining the surface tension of surfactant solutions – stalagmometer «Rubin-02 A», filtration units with simulation of formation conditions of UIP-5VG and AFS-300, centrifuge process. Results. The paper identifies the urgent problem – the process of selecting surfactant technology for effective application in the waterflooding system for achieving the highest oil recovery. The surface-active substances that have found active industrial use in the fields of Russia and beyond are analyzed. The physicochemical and technological properties of Russian-made surfactants were evaluated in accordance with the passport characteristics, the requirements of the Provisions of a subsurface user enterprise, and the suitability of chemicals for further use was determined. The paper considers the methodology and results of determining the coefficient of oil displacement with aqueous surfactant solution on core samples taken from deposits in the Udmurt Republic. An express method for assessing the oil-displacing ability of a surfactant is proposed. It is more economical and energy-efficient in comparison with standard filtration studies. According to the results of filtration tests on the core, it was found that the proposed method is comparable with the studies. In general, the proposed methodology for the choice of surfactant composition is possible for implementation in local regulatory documents of a subsoil user enterprise and for use in order to select the necessary reagent to increase oil recovery.

The relevance of the research is caused by the need to increase the reliability and resource of progressing cavity pumps, used in complicated well operating conditions, since they have low reliability in comparison with electrical submersible pumps, that limits their application. Progressing cavity pumps are used in well conditions characterized by a high viscosity of the pumped fluid (more than 30 mPa·s) and a high content of solid particles in it (the coefficient of suspended particles is more than 500 mg/liter). Experience in operating progressing cavity pumps shows that the reliability of pumping installations depends primarily on the reliability of the rod string. In addition to the torque load required to transfer the rotation from the induction motor to the screw pump, immersed on more than one kilometer from the wellhead, the sucker string experiences tensile loads from the weight of the pump rods and the axial load of the screw pump, as well as bending loads caused by the spatial curvature of the wellbore . The paper proposes the implementation of methodology for calculating the sucker rod columns of progressing cavity pumps with regard to axial, torsional and bending loads in the Python programming language. The proposed method for calculating the rod column of a screw pumping unit takes into account the rod column friction on tubing pipes arising from the Eulerian forces pressing the rods to the pipes due to the spatial curvature of the wellbore. Using software implemented in the python programming language, the authors have made calculations that showed the influence of various complicating factors on the magnitude of the loads on the rod string. As a result of calculations of the fatigue strength of the pump rods, cyclic loads during the rotation of the rods in the local sections of the local curvature of the wellbore was shown. The developed software allows you to take into account the degree of influence of complicated well operating conditions at the design stage, and thus, significantly increase the turnaround time of the rod screw pumping units. The main aim of the research is to assess the influence of various operating factors on the loads acting on the string of pump rods during well operation, as well as on the fatigue strength of the pump rods. Methods. Using software implemented in the python programming language, calculations were performed that showed the influence of various complicating factors on the magnitude of the loads on the rod string. The paper demonstrated the effect of loads on the fatigue strength of sucker rods caused by cyclic loads during rotation of the rods in the areas of local curvature of the wellbore. The developed software allows taking into account the degree of influence of complicating factors at the stage of selecting the layout of a PCP, as well as during operation, and thereby significantly increasing the overhaul period of PCP operation.