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  • Average publication time
    114 days
  • Average review time
    19 days
  • Rejection rate (%)
    48
  • Total Articles
    8471

Top 10 articles by citing

Mining education: traditions and perspectives in the XXI century
  • Date submitted
    2017-06-28
  • Date accepted
  • Date published
    2017-06-25

Mining education in the XXI century: global challenges and prospects

An analysis of development prospects for the world mining industry is presented, requirements to mining technologies are formulated, as well as key trends of technologic development in the mineral resources complex. The paper demonstrates the role of mining industry and professional education as essential components of sustainable territorial development. Global challenges have been formulated, which must be taken into account when forming general approaches to the development of mining education. Distinctions of mining education in Russia, Germany, USA and other leading mining countries have been analyzed. Professional standards for mining engineers have been reviewed for different countries, along with their relation to educational standards. It has been shown, what role professional communities play in the development of professional education and stimulation of continuous professional development of mining engineers. Authors point out the need for international integration in the issues of training and continuous professional development of mining specialists, as well as international accreditation of educational programs for mining engineers and their certification. Information is presented on international organizations, performing the function of international accreditation of engineering educational programs, history of their establishment and role within the context of economic globalization. The paper contains examples of successful international cooperation and modern integration processes among universities, aimed at unification of requirements and improvement of existing systems of training and continuous professional development of mining engineers.

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Electromechanics and mechanical engineering
  • Date submitted
    2017-08-29
  • Date accepted
  • Date published
    2017-08-27

Dynamic stabilization of machining process based on local metastability in controlled robotic systems of CNC machines

The paper describes an effective method, which permits to control the machining of hard-to-handle materials under local pre-strain and facilitates generation of structural metastability on the outer layer of the process material. Authors propose a new approach to creating local metastability in the machined material using thermal, plastic and cryogenic treatment. Changes in material properties, occurring under local deformation, are presented in a widely used graphic form of a stress-strain curve. In experimental tests, performed under local plastic strain, the authors observed normal vibration displacement of the tool in relation to the surface of the workpiece, made of medium-carbon steel (0.45 % C). Theoretical and experimental results confirmed the possibility to control the cutting process and to deliver dynamic stability for high-precision machining. The study allows to improve existing technologies for a wide range of materials and cutting modes, to implement segmentation and breaking of the chip in the shear zone, and to apply controlled robotic systems on CNC machines.

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Mining
  • Date submitted
    2018-07-10
  • Date accepted
  • Date published
    2019-04-25

FEATURES OF ELEMENTARY BURST FORMATION DURING CUTTING COALS AND ISOTROPIC MATERIALS WITH REFERENCE CUTTING TOOL OF MINING MACHINES

The paper considers the cutting of brittle coals and rocks by a single cutter of a mining machine, in contrast to the generally accepted integral approach, different from the standpoint of the formation of successive elementary bursts that make up the cut. The process of the formation of an elementary bust in time is viewed as successive phases. Due to the complexity and multi-factor nature of the process, preference is given to experimental bench studies using reference cutters, isotropic materials, and real rock blocks. The bursting parameters values greatly influence the time of static forces action, the peculiarities of the formation of stress fields in the undercutter zone of the rock mass and the conditions for the emergence and development of main cracks in the near-cut zones during the cutting process. The accepted phase-energy method of analyzing the process, which most closely matches the structure of the studied process, revealed a more significant, than previously expected, effect on the cutting process, variability of cutting speed and potential energy reserve in the cutter drive. The paper discusses the possibility of purposeful formation of the parameters of elementary bursts. It describes new ways to improve the efficiency of cutting coal and rocks, in particular, reducing the maximum loads and specific energy consumption. It also considers the possibility of reducing the grinding of the rock mass and dust formation.

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Mining
  • Date submitted
    2017-06-28
  • Date accepted
  • Date published
    2017-06-25

Status and directions of improvement of development systems of coal seams on perspective Kuzbass coal mines

The article presents the results of the analysis of the Russian coal mines experience in using the variant of the long-pillar development system with the abandonment of coal pillars in the mined out areas of longwall faces. In the Kuzbass mines, this option accounts for 90-95 % of the total volume of coal mined by the underground method. It is pointed out that it is necessary to take into account the negative influence of the pillars left in the worked out space on the geomechanical conditions of conducting mining operations in the overworked (underworked) seams. A significant negative effect of the pillars is shown in combination with selective extraction of the adjacent layers on reduction of the balance reserves. The measures allowing to increase the efficiency of the use of long pillar mining systems for the development of adjacent series of seams are considered.

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Electromechanics and mechanical engineering
  • Date submitted
    2018-02-27
  • Date accepted
  • Date published
    2018-02-25

Uninterruptible power supply system for mining industry enterprises

Immediate problem of compensating falls and deviations of voltage in the power supply systems of mining enterprises in order to ensure the proper level of power supply reliability for the most important technological consumers is substantiated in the article. The main causes of the voltage falls and deviations occurrence in the power supply systems of mining enterprises have been identified. The degree of different nature voltage falls and deviations influence on the dynamic and static stability of power supply systems is established. The necessity of ensuring an uninterrupted and guaranteed power supply mode for continuous technological processes of mining production is shown. The analysis of the existing regulatory documentation in the field of guaranteed and uninterrupted power supply is carried out. Based on the results of experimental studies and mathematical modeling, a relationship has been revealed between formally independent sources of electricity supply from the viewpoint of existing regulatory documentation. The expression allowing determination of cohesion coefficient of two power supply sources is given. The necessity of taking into account the degree of sources interconnection in the synthesis of uninterruptible power supply systems for mining enterprises is justified. The analysis of existing technical means and solutions for reserving power supply for mining enterprises, including modern uninterruptible online power supply systems, own needs power plants, as well as dynamic voltage distortion compensators, is done. The classification of the consumers categories related to possibility of their complete or partial shutdown in emergency modes in case of voltage falls and interruptions is given. System of uninterruptible power supply for mining enterprises based on the combined use of alternative and renewable energy sources, uninterruptible power supply sources and a multi-step automatic reserve transition system, which allows ensuring uninterrupted mode of energy supply for the most responsible consumers of mining enterprises, was developed. 

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Mining
  • Date submitted
    2017-08-29
  • Date accepted
  • Date published
    2017-08-27

Mathematical modeling of seismic explosion waves impact on rock mass with a working

In the article, within the framework of the dynamic theory of elasticity, a mathematical model of the impact of seismic blast waves on rock mass is presented, including a working. The increase in the volume of mining operations in complex mining and geological conditions, taking into account the influence of the explosion energy, is closely connected with the analysis of the main parameters of the stress-strain state of the rock massif including a working. The latter leads to the need to determine the safe parameters of drilling and blasting operations that ensure the operational state of mining. The main danger in detonation of an explosive charge near an active working is a seismic explosive wave which characteristics are determined by the properties of soil and parameters of drilling and blasting operations. The determination of stress fields and displacement velocities in rock mass requires the use of a modern mathematical apparatus for its solution. For numerical solution of the given boundary value problem by the method of finite differences, an original calculation-difference scheme is constructed. The application of the splitting method for solving a two-dimensional boundary value problem is reduced to the solution of spatially one-dimensional differential equations. For the obtained numerical algorithm, an effective computational software has been developed. Numerical solutions of the model problem are given for the case when the shape of the working has a form of an ellipse.

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Electromechanics and mechanical engineering
  • Date submitted
    2017-10-25
  • Date accepted
  • Date published
    2017-10-25

Increase of electric power quality in autonomous electric power systems

With the constant development of electronics for control and monitoring of the work for significant and important elements of electric power systems, the requirements to the quality of electric power also increase. The issues of increasing the quality of electricity are solved in the field of power supply systems, which are the backbone of any electric network, because of their wider distribution and usage, unlike the autonomous electric power systems. In turn, with the development of the marine and river fleet, as well as appearance of such a promising direction for mining operations, like the Arctic zone, the autonomous electric power plants become especially important. One of the main problems of such systems is an insufficient research of the problem of the quality of electric power. The article presents a model of an autonomous electric power system. To simulate such systems, the MathLab package with the Simulink application is being widely used. The developed model provides an assessment of the quality of electricity in it, a comparison of the assessment obtained in existing systems, and a modern solution is proposed to improve the quality of electricity.

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Metallurgy and concentration
  • Date submitted
    2017-10-25
  • Date accepted
  • Date published
    2017-10-25

Topicality and possibilities for complete processing of red mud of aluminous production

In the aluminum industry, the largest amount of waste is red mud (RM). that is a solid bauxite residue after hydrochemical processing and extraction of alumina. The topicality of its processing was shown by the ecological catastrophe in Hungary (2010), where the bund wall of the slurry storage was destroyed and the viscous mass of fine red mud fell on thousands of hectares of land. The risks of a recurrence of such a catastrophe increase due to the increased natural disasters: earthquakes, torrential rains and floods, as well as terrorist attacks. Therefore, it is proposed to exclude the storage of red mud in sludge storages and organize its shipment in transportable form to processing complexes. The article presents the results of scientific research and the experience of complex processing of red sludge on an industrial scale with the production of new types of marketable products.

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Geoecology and occupational health and safety
  • Date submitted
    2017-10-26
  • Date accepted
  • Date published
    2017-10-25

On development of system for environmental monitoring of atmospheric air quality

The article suggests the directions for development of the system of environmental monitoring of atmospheric air quality in the Russian Federation, namely: an increase in the number of stationary control posts for atmospheric pollution in each specific city; expansion of the list of cities where constant measurements of pollutant concentrations are conducted; expansion of the list of controlled impurities through the introduction of automated air quality monitoring systems, the development of computational methods for monitoring air quality, including not only information on pollution levels in terms of compliance with hygienic standards, but also assessment of pollution levels from the perspective of environmental risk to the health of the population. There is a great sensitivity of plants to the low quality of atmospheric air in comparison with the sensitivity of animals and humans. The air quality standards for vegetation are given. It is proposed to evaluate the quality of atmospheric air not only from the point of view of the impact on human health, but taking into account the impact on vegetation, to include in the program route observations carried out by mobile atmospheric air monitoring laboratories, territories with public green areas, which will increase the information content of atmospheric air monitoring and the state of green spaces. In connection with the increasing noise level in large cities and the lack of a permanent noise monitoring system, it is proposed to equip existing and new monitoring stations with noise level meters to provide reliable information for the development of relevant environmental measures.

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Oil and gas
  • Date submitted
    2018-07-18
  • Date accepted
  • Date published
    2019-02-25

JUSTIFICATION OF THE TECHNOLOGICAL PARAMETERS CHOICE FOR WELL DRILLING BY ROTARY STEERABLE SYSTEMS

Paper presents the analysis of the investigation results of vibrational accelerations and beating amplitudes of the downhole drilling motor, which help to define the ranges of optimum energy characteristics of the gerotor mechanism, ensuring its stable operation. Dependencies describing the operation of the «drilling bit – rotary steerable system with power screw section – drilling string» system and the values of the self-oscillation boundaries and the onset of system resonance when it is used jointly, were defined as a result of computational and full-scale experimental research. A mathematical model is proposed, which allows determining the optimal range of technological parameters for well drilling, reducing the extreme vibration accelerations of the bottomhole assembly by controlling the torque-power and frequency characteristics of the drilling string, taking into account the energy characteristics of the power screw section of the rotary steerable system. Recommendations on the choice of drilling mode parameters were given.

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Mining
  • Date submitted
    2018-07-10
  • Date accepted
  • Date published
    2019-04-25

FEATURES OF ELEMENTARY BURST FORMATION DURING CUTTING COALS AND ISOTROPIC MATERIALS WITH REFERENCE CUTTING TOOL OF MINING MACHINES

The paper considers the cutting of brittle coals and rocks by a single cutter of a mining machine, in contrast to the generally accepted integral approach, different from the standpoint of the formation of successive elementary bursts that make up the cut. The process of the formation of an elementary bust in time is viewed as successive phases. Due to the complexity and multi-factor nature of the process, preference is given to experimental bench studies using reference cutters, isotropic materials, and real rock blocks. The bursting parameters values greatly influence the time of static forces action, the peculiarities of the formation of stress fields in the undercutter zone of the rock mass and the conditions for the emergence and development of main cracks in the near-cut zones during the cutting process. The accepted phase-energy method of analyzing the process, which most closely matches the structure of the studied process, revealed a more significant, than previously expected, effect on the cutting process, variability of cutting speed and potential energy reserve in the cutter drive. The paper discusses the possibility of purposeful formation of the parameters of elementary bursts. It describes new ways to improve the efficiency of cutting coal and rocks, in particular, reducing the maximum loads and specific energy consumption. It also considers the possibility of reducing the grinding of the rock mass and dust formation.

Read more
Oil and gas
  • Date submitted
    2018-07-18
  • Date accepted
  • Date published
    2019-02-25

JUSTIFICATION OF THE TECHNOLOGICAL PARAMETERS CHOICE FOR WELL DRILLING BY ROTARY STEERABLE SYSTEMS

Paper presents the analysis of the investigation results of vibrational accelerations and beating amplitudes of the downhole drilling motor, which help to define the ranges of optimum energy characteristics of the gerotor mechanism, ensuring its stable operation. Dependencies describing the operation of the «drilling bit – rotary steerable system with power screw section – drilling string» system and the values of the self-oscillation boundaries and the onset of system resonance when it is used jointly, were defined as a result of computational and full-scale experimental research. A mathematical model is proposed, which allows determining the optimal range of technological parameters for well drilling, reducing the extreme vibration accelerations of the bottomhole assembly by controlling the torque-power and frequency characteristics of the drilling string, taking into account the energy characteristics of the power screw section of the rotary steerable system. Recommendations on the choice of drilling mode parameters were given.

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Geology
  • Date submitted
    2019-02-01
  • Date accepted
  • Date published
    2019-04-25

REFINED ASSESSMENT OF SEISMIC MICROZONATION WITH A PRIORI DATA OPTIMISATION

The work is devoted to the issues of seismic microzonation representativeness, which is amongst the mandatory assessments that precedes civil and industrial construction. In addition to the practical approach and in accordance with the normative documentation, the authors propose parametric interpretation of the remote basis by means of tracing geodynamic zones and elements of the geoblock structure, where the leading marker of seismogenic risk zones is the anomaly of spatial variability of the geofield, coinciding with the discordant intersection of localised land structures. Verification of this marker is achieved by displaying a cartographic distribution image within the range of the seismic point increment, detailed on the basis of approximation dependencies.

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Oil and gas
  • Date submitted
    2019-05-27
  • Date accepted
  • Date published
    2019-12-25

Improving the efficiency of using resource base of liquid hydrocarbons in Jurassic deposits of Western Siberia

Under conditions of the same type of oil deposits with hard-to-recover reserves in Jurassic terrigenous reservoirs of the West Siberian oil and gas province, a study was made about the influence of the geological structure features of objects and water flooding technologies on the response degree of production wells to water injection. Response degree of the wells was determined by analyzing the time series of production rates and injection volumes of injection wells with the calculation of inter-correlation function (ICF) values. It was believed that with ICF values in a given injection period of more than 0.5, production well responds to the injection. Factors that have a prevailing effect on water flooding success have been identified. Among them: effective oil-saturated thickness of the formation in production wells; relative amplitude of the self polarization of the formation in both production and injection wells; grittiness coefficient of the formation in injection wells; monthly volume of water injection and distance between wells. Methodological approach is proposed based on the application of the proposed empirical parameter of water flooding success, which involves the use of indirect data in conditions of limited information about the processes occurring in the formation at justification and selection of production wells for transferring them to injection during focal flooding; drilling of additional production and injection wells – compaction of the well grid; shutdown of injection and production wells; use of a transit wells stock; use of cyclic, non-stationary flooding in order to change the direction of filtration flows; determining the design of dual-purpose L-shaped wells (determining length of the horizontal part); limitation of flow rate in highly flooded wells with a high degree of interaction; determination of decompression zones (without injection of indicators), stagnant zones for drilling sidetracks, improving the location of production and injection wells, transferring wells from other horizons; choosing the purpose of the wells during implementation of the selective water flooding system in order to increase the efficiency of using the resource base of liquid hydrocarbons.

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Metallurgy and concentration
  • Date submitted
    2018-07-24
  • Date accepted
  • Date published
    2019-02-25

ASSESSMENT OF REFRACTORY GOLD-BEARING ORES BASED OF INTERPRETATION OF THERMAL ANALYSIS DATA

The article presents the results of a study on the possibility to assess refractory gold-bearing ores using thermal analysis data. It studies the flotation concentrates obtained during the enrichment of double refractory sulfide gold-bearing ores. This type of ore is complicated by the fine impregnation of gold in sulphide minerals and the presence of sorption-active scattered carbonaceous matter, which is in close association with sulphides. The results of thermogravimetric and mass spectrometric studies of refractory gold-bearing ores are presented. The obtained fragments for kerogen CH (m/z = 15), C 2 H (m/z = 29) and C 3 H (m/z = 43) indicate the presence of various types of carbonaceous matter in the studied samples. It is justified that the degree of sorption activity of carbonaceous matter depends on the presence of kerogen and bitumen in the ore. High sorption activity of scattered carbonaceous material significantly affects the processing technology of ores and concentrates, both flotation and pyro- and hydrometallurgical methods. Thermogravimetric and mass spectroscopic analyzes can be used to determine the degree of preg-robbing of refractory gold-bearing ores. The obtained results predetermine the direction of creating new methods and technologies in the field of decarburization of refractory gold-bearing ores in the integrated development of solid minerals in the mining regions of Russia.

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Oil and gas
  • Date submitted
    2020-05-13
  • Date accepted
    2020-06-24
  • Date published
    2020-10-13

Barriers to implementation of hydrogen initiatives in the context of global energy sustainable development

Modern trends in the global energy market linked to the Sustainable Development Goals often lead to the adoption of political decisions with little basis in fact. Stepping up the development of renewable energy sources is an economically questionable but necessary step in terms of its social and ecological effects. However, subsequent development of hydrogen infrastructure is, at the very least, a dangerous initiative. In connection with mentioned above, an attempt to examine hydrogen by conducting an integral assessment of its characteristics has been made in this article. As a result of the research conducted, the following conclusions concerning the potential of the widespread implementation of hydrogen in the power generation sector have been made: as a chemical element, it harms steel structures, which significantly impedes the selection of suitable materials; its physical and volume characteristics decrease the general efficiency of the energy system compared to similar hydrocarbon solutions; the hydrogen economy does not have the necessary foundation in terms of both physical infrastructure and market regulation mechanisms; the emergence of widely available hydrogen poses a danger for society due to its high combustibility. Following the results of the study, it was concluded that the existing pilot hydrogen projects are positive yet not scalable solutions for the power generation sector due to the lack of available technologies to construct large-scale and geographically distributed infrastructure and adequate international system of industry regulation. Thus, under current conditions, the risks of implementing such projects considerably exceed their potential ecological benefits.

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Electromechanics and mechanical engineering
  • Date submitted
    2018-12-04
  • Date accepted
  • Date published
    2019-06-25

The Concept of Development of Monitoring Systems and Management of Intelligent Technical Complexes

Conceptual approaches to improving the system of monitoring and managing the functional capabilities of intelligent technical complexes of buildings and transport and technological machines of mining enterprises are defined. Criteria are proposed for the efficiency of functioning of automatic systems for controlling the movement of transport-technological machines, taking into account the probabilistic nature of system-forming factors. The scheme of scientific and methodological research on the improvement of automation systems and traffic control in the automotive transport is presented. The perspective directions of the formation of control functions for the movement of vehicles based on the use of intelligent automated systems are substantiated. The stages of the life cycle of technical systems for monitoring the movement of vehicles, taking into account the features of their operation. A technique has been developed for the optimal use of technical means of control in the field of providing control and supervisory functions in the operation of vehicles, and the dependence of determining the financial costs of maintaining their efficiency has been determined.

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Electromechanics and mechanical engineering
  • Date submitted
    2018-11-29
  • Date accepted
  • Date published
    2019-06-25

Determination of the Operating Time and Residual Life of Self-propelled Mine Cars of Potassium Mines on the Basis of Integrated Monitoring Data

Statistical data on the reliability of self-propelled mine cars (SPMC), operating in the potassium mines of the Verkhnekamskoye potassium and magnesium salts deposit are analyzed. Identified the main nodes that limit the resource SPMC. It has been proven that the most common failures of self-propelled cars are the failure of wheel hubs, bevel gears and traveling electric motors. The analysis of the system of maintenance and repair of mine self-propelled cars. It is indicated that the planning and preventive system of SPMC repairs is characterized by low efficiency and high material costs: car maintenance is often carried out upon the occurrence of a failure, which leads to prolonged downtime not only of a specific haul truck, but of the entire mining complex. A method for assessing the technical condition of the electromechanical part of a mine self-propelled car by the nature of power consumption is proposed. This method allows you to control the loading of the drives of the mine self-propelled car, as well as to assess the technical condition of the drives of the delivery machines in real time. Upon expiration of the standard service life of a mine propelled car specified in the operational documentation, its further operation is prohibited and the car is subject to industrial safety expertise. As part of the examination, it is necessary to determine the operating time and calculate the service life of a mine self-propelled car outside the regulatory period. A method has been developed for determining the residual service life of mine car on the basis of instrumentation control data in the conditions of potash mines.

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Electromechanics and mechanical engineering
  • Date submitted
    2018-08-07
  • Date accepted
  • Date published
    2019-02-25

OPERATION EXPERIENCE OF CENTRIFUGAL SINGLE-STAGE PUMPS IN «ALROSA» JOINT STOCK COMPANY

When mining diamond-bearing raw materials and further extracting diamonds from it in the joint-stock company ALROSA, which is a city-forming enterprise in the north-east of the Russian Federation, various pumping equipment is used, in particular, centrifugal single-stage pumps. In the present work, it is noted that the least reliable in terms of absence of failures of centrifugal single-stage pumps used in the joint-stock company ALROSA are the impellers, seals and bearing assemblies. Using linear correlation and regression analysis, it was found that the durability of the seals and bearing assemblies of the investigated pumps largely depends on the durability of their impellers. In the course of research, it was found that unbalancing the pump rotor due to excessive hydroabrasive wear of the impeller also leads to deformation and fracture of the shaft. In general, residual deformations and destructions are characteristic of the shafts of domestic pulp pumps of GrAT, GrT and Gr types. The most loaded sections of shafts of centrifugal single-stage pumps are installed. The most effective from the point of view of application among the pulp (ground, slurry and sand) pumps are pulp pumps of the Finnish company «Metso». When working on highly mineralized water (brines), the «X» type pumps have proven to be the best among centrifugal single-stage pumps.

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Geoeconomics and Management
  • Date submitted
    2019-10-01
  • Date accepted
  • Date published
    2019-12-25

Stakeholders management of carbon sequestration project in the state – business – society system

Prevention of catastrophic effects of climate change is one of the most pressing challenges of this century. A prominent place in the low-carbon development system today is carbon capture and storage technology (CCS). This technology can significantly reduce greenhouse gas emissions, leading to global warming. Effectiveness of technology has been proven through successful implementation of a number of CCS projects. CCS projects are implemented in the context of national and often international interests, consolidating efforts of many parties. Sequestration projects involve government bodies, public, industrial and scientific sectors, as well as a number of other business structures. Each participant presents his own expectations for results of the project, which can compete among themselves, creating threats to its successful implementation. World experience in implementing CCS projects indicates that opposition from a certain group of stakeholders can lead to closure of a project, therefore, interaction with environment is one of the key elements in managing such projects. This study focuses on specifics of stakeholder management in implementation of CO 2 sequestration projects. Based on the analysis of world experience, role of the state, business and society in such projects is determined, their main expectations and interests are summarized. The main groups of stakeholders of CCS and CCUS (carbon capture, utilization and storage) projects were identified, differences in their interests and incentives to participate were analyzed. It is proved that system of interaction with stakeholders should be created at the early stages of the project, while management of stakeholders is a continuous process throughout the life cycle. An author’s tool is proposed for assessing degree of stakeholder interest, the use of which allowed us to determine interaction vectors with various groups of stakeholders.

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Oil and gas
  • Date submitted
    2020-05-13
  • Date accepted
    2020-06-24
  • Date published
    2020-10-13

Barriers to implementation of hydrogen initiatives in the context of global energy sustainable development

Modern trends in the global energy market linked to the Sustainable Development Goals often lead to the adoption of political decisions with little basis in fact. Stepping up the development of renewable energy sources is an economically questionable but necessary step in terms of its social and ecological effects. However, subsequent development of hydrogen infrastructure is, at the very least, a dangerous initiative. In connection with mentioned above, an attempt to examine hydrogen by conducting an integral assessment of its characteristics has been made in this article. As a result of the research conducted, the following conclusions concerning the potential of the widespread implementation of hydrogen in the power generation sector have been made: as a chemical element, it harms steel structures, which significantly impedes the selection of suitable materials; its physical and volume characteristics decrease the general efficiency of the energy system compared to similar hydrocarbon solutions; the hydrogen economy does not have the necessary foundation in terms of both physical infrastructure and market regulation mechanisms; the emergence of widely available hydrogen poses a danger for society due to its high combustibility. Following the results of the study, it was concluded that the existing pilot hydrogen projects are positive yet not scalable solutions for the power generation sector due to the lack of available technologies to construct large-scale and geographically distributed infrastructure and adequate international system of industry regulation. Thus, under current conditions, the risks of implementing such projects considerably exceed their potential ecological benefits.

Read more
Mining
  • Date submitted
    2020-02-19
  • Date accepted
    2020-04-17
  • Date published
    2020-10-13

Decrease in coal losses during mining of contiguous seams in the near-bottom part at Vorkuta deposit

The problem of formation of extended zones with high rock pressure (HRP) from safety pillars at the boundaries of extraction pillars formed due to the mine layout of complex geometry is considered at the example of JSC Vorkutaugol mines. A detailed analysis of the remaining reserves of the near-bottom part of the deposit was carried out to estimate losses and the impact of HRP zones from the Chetvertyi protective seam to mining operations on the Troinoi upper seam along with the possibilities for the reduction of sizes of HRP zones at the account of expanding the underworked space. Due to research on the near-bottom part of the Vorkuta deposit, within the framework of the accepted layout, a zone at the Komsomolskaya mine and two zones at the Zapolyarnaya-2 mine were singled out, at which losses at the boundaries of the extraction pillars amount up to 13-22 % of the total resources of the mine field. The high volume of losses in these pillars indicates the relevance of research on the priority extraction impact of protective seams on the efficiency and safety of mining operations in the working area of underworked and HRP zones. Based on the analysis of foreign and Russian experience in the pillar cleaning-up at the boundaries of working areas and the methodical guidelines and instructions, a technological scheme was developed that allows increasing the coal mining recovery factor in the near-bottom part of the Vorkuta deposit from 0.75 to 0.9 without fundamental changing of the ventilation and transport networks and also without purchasing any additional mining equipment. The conducted economic calculations confirmed the effectiveness of implementing the new technological scheme for cleaning-up reserves at the boundaries of extraction districts. The economic effect is from 0.079 to1.381 billion rubles of additional profit from coaxial extraction pillars, depending on the mining and geological conditions and the size of the pillars.

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Mining
  • Date submitted
    2020-05-08
  • Date accepted
    2020-06-12
  • Date published
    2020-12-25

Gas-dynamic roof fall during the potash deposits development

In the development of practically all potash salt deposits, the study of gas-dynamic phenomena (GDP) is one of the most difficult tasks to ensure mining safety. Sudden salt and gas outbursts, dynamic breakdown, which are accompanied by intense gas release and possible broken rock carry-over into the mine workings, are associated with GDP. Geological preconditions for the GDP development are often the layered structure of the salt rock mass, the presence of interlayers and layers of salt clays. For the conditions of the Usolsky potash plant mine, complex studies of factors that characterize the possibility of gas-dynamic roof fall of the stoping rooms were carried out. In mine studies, free gases pressure and the initial velocity of gas release in the rocks of the roof workings were determined. The obtained experimental estimations were used as a parametric basis for mathematical modeling of geomechanical processes under conditions of a near-contact accumulation of free gas. The deformation of a layered salt mass produced by a room development system was described by the model of an ideal elastic-plastic medium with internal friction. The parabolic envelope of Mohr circles was used as a plasticity criterion in the compression area. In the numerical implementation, the deformation of clay contacts was modeled by Goodman contact elements. Based on the results of multivariate numerical calculations, it is established that the main factors determining the possibility of implementing GDP are the additional gas pressure at the contact, the width of the workingspan, and the distance from the roof to the first gas-containing contact. With multi-level lamination of roof rocks, there is a danger of large sources of GDP formation and the mechanism of successive fall of layers in an instant mode is implemented.

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Oil and gas
  • Date submitted
    2019-12-25
  • Date accepted
    2020-06-30
  • Date published
    2020-10-13

Accounting of geomechanical layer properties in multi-layer oil field development

Amid the ever-increasing urgency to develop oil fields with complex mining and geological conditions and low-efficiency reservoirs, in the process of structurally complex reservoir exploitation a number of problems arise, which are associated with the impact of layer fractures on filtration processes, significant heterogeneity of the structure, variability of stress-strain states of the rock mass, etc. Hence an important task in production engineering of such fields is a comprehensive accounting of their complex geology. In order to solve such problems, the authors suggest a methodological approach, which provides for a more reliable forecast of changes in reservoir pressure when constructing a geological and hydrodynamic model of a multi-layer field. Another relevant issue in the forecasting of performance parameters is accounting of rock compressibility and its impact on absolute permeability, which is the main factor defining the law of fluid filtration in the productive layer. The paper contains analysis of complex geology of a multi-layer formation at the Alpha field, results of compression test for 178 standard core samples, obtained dependencies between compressibility factor and porosity of each layer. By means of multiple regression, dependencies between permeability and a range of parameters (porosity, density, calcite and dolomite content, compressibility) were obtained, which allowed to take into account the impact of secondary processes on the formation of absolute permeability. At the final stage, efficiency of the proposed methodological approach for construction of a geological and hydrodynamic model of an oil field was assessed. An enhancement in the quality of well-by-well adaptation of main performance parameters, as well as an improvement in predictive ability of the adjusted model, was identified.

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Geoeconomics and Management
  • Date submitted
    2019-10-15
  • Date accepted
    2019-11-19
  • Date published
    2020-10-13

Oilfield service companies as part of economy digitalization: assessment of the prospects for innovative development

The digital transformation of the economy as the most important stage of scientific and technological progress and transition to a new technological structure is becoming one of the determining factors in the development and competitiveness of the domestic upstream sector. Prospects for innovative development of oilfield service companies are the key technological areas within the first project of the Hi-Tech Strategy of the German Government until 2020 – “Industry 4.0”. The purpose of this study is to assess the prospects for innovative development of the domestic oilfield service industry in the context of the digitalization of the oil and gas industry. The subject of the research is the process of the formation of key technological lines of “Industry 4.0” and their impact on the domestic oil and gas sector. The research is based on logical-theoretical and empirical analyses. The main factors that determine processes of digital transformation in the oil and gas industry are considered; the results of digitalization processes in the largest foreign and Russian industry companies of the upstream and oilfield services segments are presented. The information base is made up of data from oilfield service and oil and gas producing companies, presented on the official websites of companies in the public domain on the Internet. It has been proven that, unlike the world's leading companies in oilfield services segment, independent domestic oilfield service companies provide mainly traditional service technologies in a fairly narrow range. The limited scope of functioning and technological capabilities of Russian companies is explained by the lack of necessary investment in development and expansion of business, as well as interest on the part of the state and corporate sectors in the development and replication of domestic technologies and the formation of a full-fledged oilfield services market in Russia.

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Geology
  • Date submitted
    2020-05-17
  • Date accepted
    2020-10-05
  • Date published
    2020-12-14

Geological structure of the northern part of the Kara Shelf near the Severnaya Zemlya archipelago according to recent studies

Until recently, the North of the Kara Shelf was completely unexplored by seismic methods. Seismic and seismo-acoustic data that have appeared in recent years have made it possible to decipher features of the regional geological structure. This study solves the urgent problem of determining the prospects for the oil and gas potential of the North Kara sedimentary basin. The relevance of the research is associated with determining the prospects of the oil and gas potential of the North Kara sedimentary basin. The aim of the study is to clarify the age of the reflecting horizons using data on the geology of the island, as well as to determine the tectonic position of the sedimentary cover and basement structures in the north of the Kara shelf. The sedimentary cover is divided into three structural levels: Cambrian-Devonian, Middle Carboniferous-Cretaceous, Miocene-Quarter. The Cambrian-Devonian complex fills the deep troughs of the North Kara shelf. The most noticeable discontinuity is the base of Carboniferous-Permian rocks, lying on the eroded surface of folded Silurian-Devonian seismic complexes. The blanket-like plate part of the cover is composed of thin Carbon-Quarter complexes. The authors came to the conclusion that the fold structures of the Taimyr-Severozemelskiy fold belt gradually degenerate towards the Kara sedimentary basin and towards the continental slope of the Eurasian basin of the Arctic Ocean. A chain of narrow uplifts within the seabed relief, which correspond to narrow anticlines is traced to the West of the Severnaya Zemlya islands. Paleozoic rocks have subhorizontal bedding further to the West, within the Kara shelf. Mesozoic folding in the North of the Kara Sea is expressed exclusively in a weak activation of movements along faults. At the neotectonic stage, the shelf near Severnaya Zemlya was raised and the Mesozoic complexes were eroded. The modern seismic activity of the North Zemlya shelf is associated with the ongoing formation of the continental margin.

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Mining
  • Date submitted
    2020-05-24
  • Date accepted
    2020-07-23
  • Date published
    2020-12-14

Estimation of ore contour movements after the blast using the BMM system

Measurement of ore movements by blast is one of the key components of the quality control system at any mining enterprise, which allows to obtain the accuracy necessary for determining the location of ore contours. About 15 years ago, a monitoring system was developed in Australia that allows mine personnel to make three-dimensional measurements of ore blocks movement at each blast. Studies have shown that ore blocks movement is extremely variable, and it characterized by a complete absence of a deterministic component. The consequence is that modeling ore contour movements during the blast will be inaccurate, and the best results for the mining enterprise can only be achieved by directly measuring the movement. The technology of measuring ore contours movements considered in the article is based on three-dimensional movement vectors obtained in different parts of the blasted block, characterized by different movements. It is obvious that the accuracy of determining the ore contours position after the blast is proportional to the number of measurements made on the block. Currently, the movement control technology based on the BMM system is actively used by global mining companies, its use reduces losses and dilution of ore. In 2017, the pilot implementation of the BMM system was started at the Olympiadinsky GOK, and the system is being implemented in several Russian mining companies.

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Geoeconomics and Management
  • Date submitted
    2020-04-24
  • Date accepted
    2020-05-20
  • Date published
    2020-10-13

Prospects and social effects of carbon dioxide sequestration and utilization projects

The issues of global warming and occurrence of the greenhouse effect are widely discussed on a global scale. Various methods of reducing greenhouse gas emissions are actively being investigated and tested, including technologies for sequestration of carbon dioxide, the implementation of which is carried out in the form of CC(U)S (carbon capture, utilization and storage) projects related to capture, disposal and, in some cases, use of CO 2 . In Russia, CC(U)S technologies are not yet used, but there is a significant potential for their development and distribution. CC(U)S technologies acquire a special role in the context of the development of the energy and industrial sectors of Russia, which are key sources of emissions, and the geological objects belonging to them are potential carbon storages. The purpose of this study is to conceptually analyze the CC(U)S technological cycle and typify such projects, assess the prospects for their implementation in Russia, and identify social effects from the implementation of CC(U)S projects. The main results of the study are presented in the form of a typology of CC(U)S projects, a strategic analysis of the prospects for introduction of such technologies in Russia, as well as development of approaches to assessing social effects with systematization and highlighting a set of indicators for their assessment, which can serve as a basis for re-estimation of the values of CC(U)S projects. The main research methods used were methods of decomposition, systematization and typology, as well as strategic analysis with a focus on relevant practical materials on the topic of the work. Directions for further research are related to the substantiation of the methodology for assessing social effects of CC(U)S projects, including for the conditions of Russia, based on the principles of balancing the interests of key participants.

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Oil and gas
  • Date submitted
    2019-10-30
  • Date accepted
    2020-02-03
  • Date published
    2020-10-13

Concept of technology for determining the permeability and porosity properties of terrigenous reservoirs on a digital rock sample model

The aim of the article is to form the concept of technology for determining the permeability and porosity properties of terrigenous reservoirs using mathematical modeling methods on a digital rock sample model. Digital rock sample modeling is used to assess geological oil reserves. The article presents the concept of digital rock sample modeling technology, which allows carrying out qualitative investigations to determine the permeability and porosity characteristics of the formation, including modeling the pore space and filtration processes. The essence of the concept is that the simulation model of the microstructure for the digital model is formed on the basis of a large number of parameters obtained during lithological and petrographic investigations of thin sections, a study of the sludge and geophysical investigations of wells. The acquired model can be used as a basis for subsequent modeling of filtration processes. Conductivity of single channels of the formed model can be calculated using molecular dynamics methods, models of Boltzmann's lattice equations, and other mathematical models and methods. Based on the results of the study carried out, the application of stochastic packing methods for modeling the structure of the pore space in the digital rock sample model of terrigenous reservoirs is substantiated. In connection with the development of computer and nanotechnologies and their use in the oil and gas industry, solutions that allow obtaining adequate results of digital rock sample models are of high importance and relevance for the production sector. It is especially important to use digital rock sample models in the study of reservoir rocks of shelf fields in the western part of the Russian Arctic, oil shales, rocks represented by loose weakly cemented reservoirs, and others, which are complex for physical experiments.

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Oil and gas
  • Date submitted
    2019-10-30
  • Date accepted
  • Date published
    2020-02-25

Methodology for determining the parameters of drilling mode for directional straight sections of well using screw downhole motors

Article presents results of study on possibility of increasing the efficiency of drilling directional straight sections of wells using screw downhole motors (SDM) with a combined method of drilling with rotation of drilling string (DS). Goal is to ensure steady-state operation of SDM with simultaneous rotation of DS by reducing the amplitude of oscillations with adjusting the parameters of drilling mode on the basis of mathematical modeling for SDM – DS system. Results of experimental study on determination of extrema distribution of lateral and axial oscillations of SDM frame depending on geometrical parameters of gerotor mechanism and modes ensuring stable operation are presented. Approaches to development of a mathematical model and methodology are conceptually outlined that allow determining the range of self-oscillations for SDM – DS system and boundaries of rotational and translational wave perturbations for a heterogeneous rod with an installed SDM at drilling directional straight sections of well. This mathematical model of SDM – DS system's dynamics makes it possible to predict optimal parameters of directional drilling mode that ensure stable operation of borehole assembly.    

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Oil and gas
  • Date submitted
    2020-05-13
  • Date accepted
    2020-06-24
  • Date published
    2020-10-13

Barriers to implementation of hydrogen initiatives in the context of global energy sustainable development

Modern trends in the global energy market linked to the Sustainable Development Goals often lead to the adoption of political decisions with little basis in fact. Stepping up the development of renewable energy sources is an economically questionable but necessary step in terms of its social and ecological effects. However, subsequent development of hydrogen infrastructure is, at the very least, a dangerous initiative. In connection with mentioned above, an attempt to examine hydrogen by conducting an integral assessment of its characteristics has been made in this article. As a result of the research conducted, the following conclusions concerning the potential of the widespread implementation of hydrogen in the power generation sector have been made: as a chemical element, it harms steel structures, which significantly impedes the selection of suitable materials; its physical and volume characteristics decrease the general efficiency of the energy system compared to similar hydrocarbon solutions; the hydrogen economy does not have the necessary foundation in terms of both physical infrastructure and market regulation mechanisms; the emergence of widely available hydrogen poses a danger for society due to its high combustibility. Following the results of the study, it was concluded that the existing pilot hydrogen projects are positive yet not scalable solutions for the power generation sector due to the lack of available technologies to construct large-scale and geographically distributed infrastructure and adequate international system of industry regulation. Thus, under current conditions, the risks of implementing such projects considerably exceed their potential ecological benefits.

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Mining
  • Date submitted
    2020-02-19
  • Date accepted
    2020-04-17
  • Date published
    2020-10-13

Decrease in coal losses during mining of contiguous seams in the near-bottom part at Vorkuta deposit

The problem of formation of extended zones with high rock pressure (HRP) from safety pillars at the boundaries of extraction pillars formed due to the mine layout of complex geometry is considered at the example of JSC Vorkutaugol mines. A detailed analysis of the remaining reserves of the near-bottom part of the deposit was carried out to estimate losses and the impact of HRP zones from the Chetvertyi protective seam to mining operations on the Troinoi upper seam along with the possibilities for the reduction of sizes of HRP zones at the account of expanding the underworked space. Due to research on the near-bottom part of the Vorkuta deposit, within the framework of the accepted layout, a zone at the Komsomolskaya mine and two zones at the Zapolyarnaya-2 mine were singled out, at which losses at the boundaries of the extraction pillars amount up to 13-22 % of the total resources of the mine field. The high volume of losses in these pillars indicates the relevance of research on the priority extraction impact of protective seams on the efficiency and safety of mining operations in the working area of underworked and HRP zones. Based on the analysis of foreign and Russian experience in the pillar cleaning-up at the boundaries of working areas and the methodical guidelines and instructions, a technological scheme was developed that allows increasing the coal mining recovery factor in the near-bottom part of the Vorkuta deposit from 0.75 to 0.9 without fundamental changing of the ventilation and transport networks and also without purchasing any additional mining equipment. The conducted economic calculations confirmed the effectiveness of implementing the new technological scheme for cleaning-up reserves at the boundaries of extraction districts. The economic effect is from 0.079 to1.381 billion rubles of additional profit from coaxial extraction pillars, depending on the mining and geological conditions and the size of the pillars.

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Mining
  • Date submitted
    2020-05-08
  • Date accepted
    2020-06-12
  • Date published
    2020-12-25

Gas-dynamic roof fall during the potash deposits development

In the development of practically all potash salt deposits, the study of gas-dynamic phenomena (GDP) is one of the most difficult tasks to ensure mining safety. Sudden salt and gas outbursts, dynamic breakdown, which are accompanied by intense gas release and possible broken rock carry-over into the mine workings, are associated with GDP. Geological preconditions for the GDP development are often the layered structure of the salt rock mass, the presence of interlayers and layers of salt clays. For the conditions of the Usolsky potash plant mine, complex studies of factors that characterize the possibility of gas-dynamic roof fall of the stoping rooms were carried out. In mine studies, free gases pressure and the initial velocity of gas release in the rocks of the roof workings were determined. The obtained experimental estimations were used as a parametric basis for mathematical modeling of geomechanical processes under conditions of a near-contact accumulation of free gas. The deformation of a layered salt mass produced by a room development system was described by the model of an ideal elastic-plastic medium with internal friction. The parabolic envelope of Mohr circles was used as a plasticity criterion in the compression area. In the numerical implementation, the deformation of clay contacts was modeled by Goodman contact elements. Based on the results of multivariate numerical calculations, it is established that the main factors determining the possibility of implementing GDP are the additional gas pressure at the contact, the width of the workingspan, and the distance from the roof to the first gas-containing contact. With multi-level lamination of roof rocks, there is a danger of large sources of GDP formation and the mechanism of successive fall of layers in an instant mode is implemented.

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Geoeconomics and Management
  • Date submitted
    2020-05-06
  • Date accepted
    2020-05-24
  • Date published
    2020-04-26

Vs sustainable development: scenarios for the future

Issues of sustainable development began to concern mankind starting from the 20th century, when mass industrialization and the depletion of natural resource potential contributed to the formulation of environmental issues at one of the leading places in scientific discourse. However, what if the goals of sustainable development would not be achieved to 2030? What other way we can identify for humanity to survive? So, the study is about the problems of studying the understanding of the term “sustainable development”, considering the evolution of the formation of the concept of sustainable development and analyzing the modern goals of sustainable development for attainability. From an analysis of domestic and foreign experience, possible scenarios of the development of mankind are identified (such as 1. Creating an environmental framework, 2. Implementation of sustainable nature management practices in the conditions of natural and man-made objects, 3. Implementation of “geoengineering projects”, 4. Construction of autonomous ecosystems, 5. Space exploration in search of a new planet for life, provided that the goals of sustainable development would not be achieved. It has been established that today probability of achieving all the sustainable development goals by 2030 is too small, and the indicated scenarios require, firstly, the development of science and technology, and secondly, a competent assessment of the value of nature and solving the issue of specifying property rights for natural goods.

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Geology
  • Date submitted
    2020-06-13
  • Date accepted
    2020-06-14
  • Date published
    2020-06-30

Deep structure and geodynamic conditions of granitoid magmatism in the Eastern Russia

We investigated the deep structure of the lithosphere and the geodynamic conditions of granitoid magmatism in the Eastern Russia within the borders of the Far Eastern Federal District. The relevance of the work is determined by the need to establish the geotectonic and geodynamic conditions of the granitoids petrogenesis and ore genesis in the Russian sector of the Pacific Ore Belt. The purpose of the article is to study the deep structure of the lithosphere and determine the geodynamic conditions of granitoid magmatism in the East of Russia. The author's data on the magmatism of ore regions, regional granitoids correlations, archive and published State Geological Map data, survey mapping, deep seismic sounding of the earth's crust, gravimetric survey, geothermal exploration, and other geophysical data obtained along geotraverses. The magma-controlling concentric geostructures of the region are distinguished and their deep structure is studied. The connection of plume magmatism with deep structures is traced. The chain of concentric geostructures of Eastern Russia controls the trans-regional zone of leucocratization of the earth's crust with a width of more than 1000 km, which includes the Far Eastern zone of Li-F granites. Magmacontrolling concentric geostructures are concentrated in three granitoid provinces: Novosibirsk-Chukotka, Yano-Kolyma, and Sikhote-Alin. The driving force of geodynamic processes and granitoid magmatism was mantle heat fluxes in the reduced zones of the lithospheric slab. The distribution of slab windows along the Pacific mobile belt's strike determines the location of concentric geostructures and the magnitude of granitoid magmatism in the regional provinces. Mantle diapirs are the cores of granitoid ore-magmatic systems. The location of the most important ore regions of the Eastern Russia in concentric geostructures surrounded by annuli of negative gravity anomalies is the most important regional metallogenic pattern reflecting the correlation between ore content and deep structure of the earth's crust.

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Geology
  • Date submitted
    2019-07-29
  • Date accepted
    2020-06-10
  • Date published
    2020-04-26

Petrographic structures and Hardy – Weinberg equilibrium

The article is devoted to the most narrative side of modern petrography – the definition, classification and nomenclature of petrographic structures. We suggest a mathematical formalism using the theory of quadratic forms (with a promising extension to algebraic forms of the third and fourth orders) and statistics of binary (ternary and quaternary, respectively) intergranular contacts in a polymineralic rock. It allows constructing a complete classification of petrographic structures with boundaries corresponding to Hardy – Weinberg equilibria. The algebraic expression of the petrographic structure is the canonical diagonal form of the symmetric probability matrix of binary intergranular contacts in the rock. Each petrographic structure is uniquely associated with a structural indicatrix – the central quadratic surface in n-dimensional space, where n is the number of minerals composing the rock. Structural indicatrix is an analogue of the conoscopic figure used for optical recognition of minerals. We show that the continuity of changes in the organization of rocks (i.e., the probabilities of various intergranular contacts) does not contradict a dramatic change in the structure of the rocks, neighboring within the classification. This solved the problem, which seemed insoluble to A.Harker and E.S.Fedorov. The technique was used to describe the granite structures of the Salminsky pluton (Karelia) and the Akzhailau massif (Kazakhstan) and is potentially applicable for the monotonous strata differentiation, section correlation, or wherever an unambiguous, reproducible determination of petrographic structures is needed. An important promising task of the method is to extract rocks' genetic information from the obtained data.

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Oil and gas
  • Date submitted
    2019-12-25
  • Date accepted
    2020-06-30
  • Date published
    2020-10-13

Accounting of geomechanical layer properties in multi-layer oil field development

Amid the ever-increasing urgency to develop oil fields with complex mining and geological conditions and low-efficiency reservoirs, in the process of structurally complex reservoir exploitation a number of problems arise, which are associated with the impact of layer fractures on filtration processes, significant heterogeneity of the structure, variability of stress-strain states of the rock mass, etc. Hence an important task in production engineering of such fields is a comprehensive accounting of their complex geology. In order to solve such problems, the authors suggest a methodological approach, which provides for a more reliable forecast of changes in reservoir pressure when constructing a geological and hydrodynamic model of a multi-layer field. Another relevant issue in the forecasting of performance parameters is accounting of rock compressibility and its impact on absolute permeability, which is the main factor defining the law of fluid filtration in the productive layer. The paper contains analysis of complex geology of a multi-layer formation at the Alpha field, results of compression test for 178 standard core samples, obtained dependencies between compressibility factor and porosity of each layer. By means of multiple regression, dependencies between permeability and a range of parameters (porosity, density, calcite and dolomite content, compressibility) were obtained, which allowed to take into account the impact of secondary processes on the formation of absolute permeability. At the final stage, efficiency of the proposed methodological approach for construction of a geological and hydrodynamic model of an oil field was assessed. An enhancement in the quality of well-by-well adaptation of main performance parameters, as well as an improvement in predictive ability of the adjusted model, was identified.

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Geoeconomics and Management
  • Date submitted
    2020-04-24
  • Date accepted
    2020-05-20
  • Date published
    2020-10-13

Prospects and social effects of carbon dioxide sequestration and utilization projects

The issues of global warming and occurrence of the greenhouse effect are widely discussed on a global scale. Various methods of reducing greenhouse gas emissions are actively being investigated and tested, including technologies for sequestration of carbon dioxide, the implementation of which is carried out in the form of CC(U)S (carbon capture, utilization and storage) projects related to capture, disposal and, in some cases, use of CO 2 . In Russia, CC(U)S technologies are not yet used, but there is a significant potential for their development and distribution. CC(U)S technologies acquire a special role in the context of the development of the energy and industrial sectors of Russia, which are key sources of emissions, and the geological objects belonging to them are potential carbon storages. The purpose of this study is to conceptually analyze the CC(U)S technological cycle and typify such projects, assess the prospects for their implementation in Russia, and identify social effects from the implementation of CC(U)S projects. The main results of the study are presented in the form of a typology of CC(U)S projects, a strategic analysis of the prospects for introduction of such technologies in Russia, as well as development of approaches to assessing social effects with systematization and highlighting a set of indicators for their assessment, which can serve as a basis for re-estimation of the values of CC(U)S projects. The main research methods used were methods of decomposition, systematization and typology, as well as strategic analysis with a focus on relevant practical materials on the topic of the work. Directions for further research are related to the substantiation of the methodology for assessing social effects of CC(U)S projects, including for the conditions of Russia, based on the principles of balancing the interests of key participants.

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Geology
  • Date submitted
    2020-05-12
  • Date accepted
    2020-05-24
  • Date published
    2020-04-26

Composition and probable ore igneous rocks source of columbite from alluvial deposits of Mayoko district (Republic of the Congo)

The article presents the results of optical, electron microscopic and electron microprobe studies of columbite group minerals, collected during heavy mineral concentrate sampling of alluvial deposits in the Mayoko region (Republic of the Congo). The aim of the study is revealing tantalum niobates ore body in this region. We found that these minerals in loose deposits are represented by two grain-size groups: less than 1.6 mm (fine fraction) and 1.6-15 mm (coarse fraction). The grains of both fractions belong mainly to columbite-(Fe), less often to columbite-(Mn), tantalite-(Mn) and tantalite-(Fe), contain impurities of Sc, Ti, and W. The crystals have micro-scaled zoning (zones varies slightly in the Ta/Nb ratio values) and contains a lot of mineral inclusions and veins represented by zircon, pyrochlore supergroup minerals and others. Columbite-(Fe) and columbite-(Mn) are characterized by an increased content of Ta 2 O 5 up to the transition to tantalite-(Fe) and tantalite-(Mn). This allows us to exclude the formation of subalkaline rare-metal granites, their metasomatites (albitites and greisenes) and carbonatites, from the list of possible columbite ore rocks source in the Mayoko district. Thus, beryl type and complex spodumene subtype rare-element pegmatites of the mixed petrogenetic family LCT-NYF (according to P.Černý) should be considered as a probable root source. The results of the research should be taken into account when developing the methodology for prospecting in this area.

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Oil and gas
  • Date submitted
    2019-10-30
  • Date accepted
  • Date published
    2020-02-25

Methodology for determining the parameters of drilling mode for directional straight sections of well using screw downhole motors

Article presents results of study on possibility of increasing the efficiency of drilling directional straight sections of wells using screw downhole motors (SDM) with a combined method of drilling with rotation of drilling string (DS). Goal is to ensure steady-state operation of SDM with simultaneous rotation of DS by reducing the amplitude of oscillations with adjusting the parameters of drilling mode on the basis of mathematical modeling for SDM – DS system. Results of experimental study on determination of extrema distribution of lateral and axial oscillations of SDM frame depending on geometrical parameters of gerotor mechanism and modes ensuring stable operation are presented. Approaches to development of a mathematical model and methodology are conceptually outlined that allow determining the range of self-oscillations for SDM – DS system and boundaries of rotational and translational wave perturbations for a heterogeneous rod with an installed SDM at drilling directional straight sections of well. This mathematical model of SDM – DS system's dynamics makes it possible to predict optimal parameters of directional drilling mode that ensure stable operation of borehole assembly.    

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