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Date submitted2023-06-25
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Date accepted2024-11-07
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Date published2025-02-25
Study of wormhole channel formation resulting from hydrochloric acid treatment in complex-type reservoirs using filtration and X-ray computed tomography methods
- Authors:
- Andrei A. Аbrosimov
The primary function of hydrochloric acid treatment (HAT) is to create the maximum number of high-conductivity channels in the near-wellbore zone of the reservoir to restore its permeability and enhance hydraulic connectivity between the undisturbed part of the formation and the well. The objective of this study is to physically model HAT on core samples from the Orenburg oil and gas condensate field and to research the impact of such treatment on the structure of the pore space of rocks related to complex-type reservoirs. The complexity of the rock's pore space and the low permeability of the formations are distinguishing features of the study object. For this reason, HAT is a widely applied method for production intensification, necessitating the verification of acid injection rates, where the success criterion is the formation of high-conductivity filtration channels (wormholes) in the near-wellbore zone. These channels significantly expand the drainage area of wells, thereby bringing additional reservoir sections into development. The study examined the characteristics of filtration channel development resulting from acid treatment. Their structure was characterized and analyzed using X-ray computed tomography. The complex study confirmed the accuracy of the selected injection rate and provided practical recommendations for enhancing the efficiency of HAT.
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Date submitted2023-07-04
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Date accepted2024-05-02
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Date published2025-02-25
Study of the pore structure in granite and gabbrodolerite crushed stone grains of various sizes
- Authors:
- Elena E. Kameneva
- Viktoriya S. Nikiforova
The results of a study on the pore structure of crushed stone grains of various sizes, obtained through staged disintegration of gabbrodolerite and microcline granite – rocks differing in texture, structure, and mineral composition – are presented. Research conducted using X-ray computed microtomography revealed that disintegration leads to changes in the pore structure of the rocks. The increase in overall porosity and pore concentration in the crushed stone grains is associated with the formation of newly developed pores of various sizes and sphericity. A clear relationship between the porosity of the crushed stone grains and their size is absent, which is due to the textural and structural characteristics as well as the mineral composition of the original rocks. The scale factor is evident only in the case of gabbrodolerite, which is characterized by a fine-grained structure, massive texture, and stable mineral composition. Fine gabbrodolerite grains exhibit lower pore concentration compared to larger grains, which aligns with the statistical theory of rock strength, according to which the probability of defects (pores and microcracks) decreases as the sample size diminishes – the smaller the grain size, the higher its strength. In contrast, for porphyritic granites with an uneven grain size, the trend is reversed – smaller grains are more porous. A study of the porosity of individual rock-forming minerals in granite showed that pores are unevenly distributed in the granite crushed stone grains. The highest concentration of pores is typical for microcline. The presence of brittle and porous microcline inclusions in the granite crushed stone grains leads to the formation of new pores and microcracks, whose number increases with the repeated application of load during staged disintegration.
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Date submitted2023-03-14
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Date accepted2023-06-20
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Date published2023-07-19
The wireless charging system for mining electric locomotives
The electric vehicles development has a high potential for energy saving: an energy-saving traffic control can reduce energy resource consumption, and integration with the power grid provides the ability of daily load pattern adjustment. These features are also relevant for underground mining. The critical element of vehicle-to-grid integration is the charging infrastructure, where wireless charging is promising to develop. The implementation of such systems in underground mining is associated with energy efficiency issues and explosion safety. The article discusses the development and research of a wireless charging system for mining electric locomotive A-5.5-600-U5. The analytic hierarchy process is used for justification of the circuitry and design solution by a comparison of different technical solutions based on energy efficiency and safety criteria. A complex computer model of the wireless charging system has been developed that gives the transients in the electrical circuit of a wireless charging system and the high-frequency field density distribution near the transmitting and receiving coils in a 3D setting. An approach to ignition risk evaluation based on the analysis of high-frequency field density in the charging area between the coils of the wireless charging system is proposed. The approach using a complex computer model is applied to the developed system. The study showed that the wireless charging system for mining electric locomotives operating in the gaseous-and-dusty mine is technically feasible and there are designs in which it is explosion safe.
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Date submitted2022-05-12
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Date accepted2022-09-06
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Date published2022-11-03
Morphometric parameters of sulphide ores as a basis for selective ore dressing
To assess the possibility of selective disintegration and reduction of overgrinding of hard-to-reproduce ores, optical microscopic and X-ray microtomographic studies were carried out and quantitative characteristics of morphological parameters of disseminated and rich cuprous ore samples from Norilsk-type Oktyabrsky deposit were identified. Among quantitative morphological parameters the most informative are area, perimeter, edge roughness, sphericity, elongation and average grain spacing for disseminated copper-nickel ores; area, perimeter, edge roughness and elongation for rich cuprous ores. The studied parameters are characterized by increased values and dispersion in ore zones, which is especially important for fine-grained ores, which are difficult to diagnose by optical methods. Three-dimensional modelling of the internal structure of sulphide mineralisation samples was carried out using computed X-ray microtomography, which allows observation of quantitative parameters of grains, aggregates and their distribution in the total rock volume and interrelationship with each other. The evaluation of rock pore space by computer microtomography made it possible to compare the results obtained with the strength characteristics of rocks and ores, including those on different types of crushers. The obtained quantitative characteristics of structural-textural parameters and analysis of grain size distribution of ore minerals allow us to evaluate the possibility of applying selective crushing at various stages of ore preparation
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Date submitted2015-08-18
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Date accepted2015-10-06
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Date published2016-04-22
Energy- efficient control of asynchronous motor drive with current refinement of the loss minimum on the basis of fuzzy logic
- Authors:
- O. B. Shonin
- V. S. Pronko
Currently, asynchronous electric drive on the basis of semiconductor frequency converters is widespread because of the relative simplicity and reliability of the design, the use of digital control systems, providing the accuracy and flexibility of process control, which allows for a significant increase in product quality, reduction in energy consumption and improvement of the enterprise profitability. In spite of these advantages, the problem of ensuring high energy efficiency of the drive in wide range of its operational modes is still not solved in full scale. The paper is devoted to the reduction of losses in the asynchronous drive on the basis of en-ergy-saving control algorithms that aim to ensure the desired mode of the driven mechanism while minimizing losses in copper and steel of the motor. On the basis of the motor model, taking into account magnetic losses, dependences of losses in the copper and steel, as well as the total loss from the absolute slip have been derived for different operating points of the drive. The optimal values of the absolute slip for different speeds of the rotor have been obtained for use in the con-trollers ensuring operation of the drive at maximum efficiency, highest power factor and minimum of the stator current. For minimizing the losses in the drive when changing the motor parameters it has been offered the combined method based on the method of loss model and iterative method of searching the minimum of power consumption. The effectiveness of the proposed control system using fuzzy logic is confirmed by comparing the graphs of losses and efficiency, obtained at using a traditional control law and the optimal control law.
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Date submitted2009-10-28
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Date accepted2009-12-25
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Date published2010-09-22
Prediction of dynamic manifestations of rock pressure in the all over automated longwalls
- Authors:
- M. Roiter
- V. Kurfyurst
- K. Mairkhofer
- J. Veksler
The support control system «MARCO» has programs for the estimation of a geomechanical situation around the face by continuous measurements of pressure in the legs of support. The analysis of the face convergence allows to predict the possibility of a rock burst. The seam’s reaction on the shearer or plough influence may be the dangerous main roof collapse into the mine-out space of longwall.
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Date submitted2009-09-16
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Date accepted2009-11-17
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Date published2010-06-25
Information technology usage during linguistic competitions in technical higher school conducting
- Authors:
- E. V. Terentyeva
This article is devoted to the issue of IT technologies usage for teaching methods in humanities. The article is covering the experience of carrying out the linguistic creative contest among the students of the Mining Institute with the help of the soft «My test». Advantages and disadvantages of the mentioned programme for such kind of workshop are noted in the article. The conclusion for improving of teaching methods with the help of IT technologies is made.
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Date submitted2009-08-23
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Date accepted2009-10-17
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Date published2010-02-01
Reseach of cutoff grade influence on economic performances of mining
- Authors:
- M. D. Morozov
Research of cutoff grade influence on economic performances of mine as well as parameters and configuration of ore deposits with the help of the advanced geoinformation system were carried out. Computer modeling of an ore chute was made; the results of calculation were presented, involvement is given.
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Date submitted2009-08-07
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Date accepted2009-10-09
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Date published2010-02-01
Predictive calculations for grinding flowsheets
- Authors:
- A. O. Romashev
The optimizing and predicting computer packages are extremely important in the theory and practice of processes of crushing, allowing to solve variety of the problems, concerning calculation of schemes, a choice of the equipment, definition of power expenses, automation etc.
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Date submitted2009-07-28
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Date accepted2009-09-14
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Date published2010-04-22
The use of computer technologies аt the stages of prospecting, mining and conservation of mineral deposits
- Authors:
- K. V. Morozov
- S. V. Lukichev
The article described the methods for the use of specialized application of software on the stages of exploration, design, planning and maintenance of mining operations and also in abandonment or conservation of mineral resources deposits.