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Date submitted2024-03-11
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Date accepted2024-11-07
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Date published2025-03-06
Geochemical characteristics of weathering crusts on the Dzhezhimparma Ridge and the Nemskaya Upland (South Timan)
Numerous local varieties of weathering crusts are known in the South Timan. They differ in their position in the section, type of weathering products, substrates, and occurrence. The aim of the research is to identify patterns in the distribution of rock-forming, rare and rare earth elements and the composition of clay minerals in clay formations of the weathering crusts. The main task is to describe the occurrence and geochemical features that enable determining the genetic type and formation conditions of weathering crusts. The paper presents the results of a study of the distribution of petrogenic, rare earth, rare elements, and clay minerals in weathering crust of different ages, genetic types and occurrence conditions on the Dzhezhimparma Ridge and the Nemskaya Upland in the South Timan. We found that hydromica-kaolinite-type weathering crust is developed after the Late Riphean Dzhezhim Fm. rocks in the basement-cover contact zone on the Dzhezhimparma Upland, and the layer of fine-grained rock at the base of the Devonian section previously considered a weathering crust was formed as a result of mechanical destruction of the Devonian sandstones during movement in the thrust zone. In the Vadyavozh quarry located on the Nemskaya Upland, we studied and described the formations of Mesozoic-Cenozoic areal and linear weathering crusts after the Late Riphean Dzhezhim Fm. rocks. We found that micaceous siltstones in the siltstone-sandstone strata of the Dzhezhim Fm. are associated with the Riphean stage of crust formation and are composed of weathering crust material redeposited in the epicontinental basin.
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Date submitted2024-03-29
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Date accepted2024-11-07
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Date published2025-02-26
Well killing with absorption control
The development of new fields with low-permeability reservoirs required the introduction of new production technologies, of which the most significant for well killing and underground repair were multi-ton hydraulic fracturing, the simultaneous operation of two or three development sites by one well grid, and an increase in the rate of fluid extraction. These global decisions in field development have led to the need to search for new effective materials and technologies for well killing. The article is devoted to the analysis of problems associated with the process of killing production wells in fields characterized by increased fracturing, both natural and artificial (due to hydraulic fracturing), with reduced reservoir pressure and a high gas factor. The relevance of the analysis is due to the increase in the number of development sites where complications arise when wells are killed. Particular attention is paid to technical solutions aimed at preserving the filtration and capacity properties of the bottomhole formation zone, preventing the absorption of process fluid, and blocking the manifestation of gas. The classification of block-packs used in killing is given, based on the nature of the process fluid. Suspension thickened water-salt solutions are considered, forming a waterproof crust on the surface of the rock, which prevents the penetration of water and aqueous solutions into the formation. This approach ensures the safety and efficiency of killing operations, especially when working with formations in which maintaining water saturation and preventing the ingress of the water phase are of critical importance. Modern trends in the development of technology are revealed, and promising areas for further improvement of well killing with absorption control are outlined.
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Date submitted2024-05-17
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Date accepted2024-10-14
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Date published2024-11-12
Black shales – an unconventional source of noble metals and rhenium
The content of noble metals and rhenium in the Lower Paleozoic black shales of the eastern Baltic paleobasin in Russia was estimated. Shales are enriched in platinoids (PGM to 0.12 g/t) and rhenium (to 1.54 g/t). The main accessory elements of noble metals and Re are U, V, Mo, Cu, and Ni. Black shales consist of organic (9-26 rel.%), clay (40-60 rel.%), and silt-sandy (25-50 rel.%) components and a nodule complex (2-5 rel.%) (carbonate, sulfide, phosphate and silicate nodules). Noble metals occur sporadically in the silt-sandy admixture as native forms and intermetallics: Aunat, Au-Ag, Au-Cu, Au-(Cu)-Hg, Au-Hg, Ag-Cu, Pt-Fe. Micromineral phases of noble metals were found in diagenetic sulfides: Aunat, chalcopyrite with Au admixture, pyrite with platinoid admixture. Clay fraction is 10-fold enriched in noble metals as compared to shale – to 0.28 g/t Au, 0.55 g/t Pt, 1.05 g/t Pd, and 1.56 g/t Re. Organic matter sorbs noble metals to a limited extent but accumulates rhenium. Pore space of black shales contains a colloidal salt component (submicron fraction) which is represented by particles smaller than 1,000 nm. The share of submicron fraction in black shales is 0.1-6 wt.%. The submicron fraction contains on average: PGM – 14 g/t, Au – 0.85 g/t, and Re – 4.62 g/t. The geochemical resource of noble metals (Au, Pt, Pd), Re and the accessory elements (U, V, Mo, Cu, and Ni) for black shales as a whole and their submicron fraction was estimated. Black shales are recommended as an integrated source of raw materials.
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Date submitted2024-04-24
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Date accepted2024-09-24
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Date published2024-11-12
Study and justification of the combination of beneficiation processes for obtaining flake graphite from technogenic carbon-containing dusts
The most important task of modern production development is to provide the mineral and raw materials sector of the economy with resources included in the list of strategic raw materials, including flake graphite. In addition to natural raw materials, the source of its obtaining can be metallurgical production wastes not involved in processing. Development of metallurgical dust beneficiation technology will solve the problem of obtaining high-purity flake graphite with a crystal structure close to ideal and in demand in the production of high-tech materials. It will allow creating a renewable raw material base of graphite and utilising metallurgical production wastes. The research included the study of dust beneficiation by coarseness, magnetic and flotation methods, the influence of dust disintegration processes on beneficiation indicators. Based on the established technological properties of the components of dusts, magnetic, flotation and gravity beneficiation methods can be applied for their separation in different sequence. It is shown that dusts from different sites have different enrichability by these methods, and it should be taken into account when developing a complex technology of their processing. The degree of beneficiation increases in a row of dusts from the blast furnace shop (BF) – electric steel smelting shop (ESS) – oxygen-converter shop (OCS). The method of grinding has a significant influence on the separation indicators – at dry grinding in a centrifugal-impact mill with subsequent pneumatic classification the quality of graphite concentrates increases by 22.7 % of carbon for BF dust and by 13.48 % of carbon for ESS dust. OCS dust beneficiation indicators are high at coarse grinding with steel medium – mass fraction of carbon 96.1 %.
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Date submitted2023-09-29
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Date accepted2023-10-25
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Date published2024-08-26
Laboratory studies of transformation of porosity and permeability and chemical composition of terrigenous reservoir rocks at exposure to hydrogen (using the example of the Bobrikovskii formations in the oil field in the northeast Volga-Ural oil and gas province)
The article describes the methodology for laboratory studies of reservoir rock exposure to hydrogen. The stages of sample research and the instruments used in the experiments are considered. A comparative analysis of the results of studies on porosity and permeability of core samples was performed. It was shown that after exposure to hydrogen, the porosity decreased by 4.6 %, and the permeability by 7.9 %. The analysis of correlation dependencies demonstrated a typical change in the relationship of these characteristics: after the samples exposure to hydrogen the scatter of the values increased and the correlation coefficient decreased, which indicates a change in the structure of the void space. Based on the research results, it was concluded that the decrease in porosity and permeability of the core samples occurred due to their minor compaction under the action of effective stresses. The chemical analysis of the rock showed no major difference in the composition of the basic oxides before and after exposure to hydrogen, which points to the chemical resistance of the studied formation to hydrogen. The experimental results showed that the horizon under consideration can be a storage of the hydrogen-methane mixture.
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Date submitted2023-08-14
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Date accepted2023-12-27
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Date published2024-12-25
Modelling of compositional gradient for reservoir fluid in a gas condensate deposit with account for scattered liquid hydrocarbons
In oil and gas reservoirs with significant hydrocarbon columns the dependency of the initial hydrocarbon composition on depth – the compositional gradient – is an important factor in assessing the initial amounts of components in place, the position of the gas-oil contact, and variations of fluid properties throughout the reservoir volume. Known models of the compositional gradient are based on thermodynamic relations assuming a quasi-equilibrium state of a multi-component hydrodynamically connected hydrocarbon system in the gravity field, taking into account the influence of the natural geothermal gradient. The corresponding algorithms allow for calculation of changes in pressure and hydrocarbon fluid composition with depth, including determination of the gas-oil contact (GOC) position. Above and below the GOC, the fluid state is considered single-phase. Many oil-gas-condensate reservoirs typically have a small initial fraction of the liquid hydrocarbon phase (LHC) – scattered oil – within the gas-saturated part of the reservoir. To account for this phenomenon, a special modification of the thermodynamic model has been proposed, and an algorithm for calculating the compositional gradient in a gas condensate reservoir with the presence of LHC has been implemented. Simulation cases modelling the characteristic compositions and conditions of three real oil-gas-condensate fields are considered. The results of the calculations using the proposed algorithm show peculiarities of variations of the LHC content and its impact on the distribution of gas condensate mixture composition with depth. The presence of LHC leads to an increase in the level and possible change in the type of the fluid contact. The character of the LHC fraction dependency on depth can be different and is governed by the dissolution of light components in the saturated liquid phase. The composition of the LHC in the gas condensate part of the reservoir changes with depth differently than in the oil zone, where the liquid phase is undersaturated with light hydrocarbons. The results of the study are significant for assessing initial amounts of hydrocarbon components and potential efficiency of their recovery in gas condensate and oil-gas-condensate reservoirs with large hydrocarbon columns.
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Date submitted2023-04-13
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Date accepted2023-10-25
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Date published2025-02-25
Assessment of the ecological state of aquatic ecosystems by studying lake bottom sediments
- Authors:
- Mariya A. Chukaeva
- Tatyana V. Sapelko
The article presents the results of coupled palynological and geochemical studies of five various genesis lakes, located along the route of the expedition “In the footsteps of Alexander von Humboldt in Siberia, Altai and Eastern Kazakhstan”, dedicated to the double anniversary: the 190th anniversary of the expedition across Russia of the famous scientist and his 250th birthday. A geochemical analysis of water and bottom sediments of Ik Lake (Siberia), Lakes Kolyvanskoe and Beloe (Altai), Lake Bezymyannoe (Kazakhstan) and Nagornyi Pond (Altai) was carried out. Based on their results an assessment of studied lakes ecological state was given through single and integral criteria. A high level of pollution was noted for Nagornyi Pond and Lake Bezymyannoe, which is caused by a significant technogenic load from nearby mines. This is consistent with the data of palynological research. The aquatic ecosystems of Lakes Kolyvanskoe and Beloe are characterized by a satisfactory ecological situation, but they experience an increased recreational load. The results of spore-pollen analysis and analysis of non-pollen palynomorphs showed the low ability of these lakes to self-healing. The most favorable ecological state and high self-cleaning capacity were noted for Lake Ik, which is consistent with the data of palynological studies. It is being confirmed with the results of palynological studies. It was therefore concluded about the ability to make a quick assessment of the aquatic ecosystems’ ecological state by studying lakes using coupled palynological and geochemical analysis.
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Date submitted2022-09-26
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Date accepted2023-09-20
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Date published2024-04-25
Technology of absorption elimination with cross-linking plugging material based on cement and cross-linked polymer
The peculiarity of the geological structure of carbonate reservoirs is their complex permeability and porosity characteristics, reflecting the simultaneous presence of cavities variety (fractures, caverns, pores). Loss of circulation during penetration of fractured rock intervals significantly increases well construction time due to lack of efficient plugging isolation compositions. The main disadvantages of traditional compositions are high sensitivity to dilution in the process of their injection into the absorption zone, as well as insufficient structural strength to prevent the isolation composition from spreading during the induction period. For efficient isolation of catastrophic absorption zones in conditions of high opening of absorption channels a new cross-linking plugging isolation composition has been developed, which allows to exclude disadvantages of traditional isolation compositions. Application of the composition will allow to reduce the injection volume of the isolation composition and the time of isolation works due to its resistance to dilution and movement of formation water in the absorption interval.
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Date submitted2022-12-01
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Date accepted2023-01-19
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Date published2023-12-25
Inclusions of diamond crystals in the tourmaline of the schorl-uvite series: problems of genesis
The mineralogical and geochemical features of diamond-bearing tourmaline crystals (schorl-uvite series) from garnet-clinopyroxene rocks of the Kumdy-Kol deposit (Northern Kazakhstan) have been studied in detail. The formation of the main rock-forming minerals (garnet + K-bearing clinopyroxene) occurred in the diamond stability field at 4-6 GPa and 950-1000 °C. Crystallization of K-bearing clinopyroxene at these parameters is possible in the presence of an ultra-potassic fluid or melt formed because of crustal material melting in subduction zones. Tourmaline crystals (up to 1 cm) containing diamond inclusions perform veins crosscutting high-pressure associations. The composition of individual zones varies from schorl to uvite within both a single grain and the sample as a whole. The potassium content in this tourmaline does not exceed 0.1 wt.% K2O, and the isotopic composition of boron δ11B varies from –10 to –15.5 ‰, which significantly differs from the previously established isotopic composition of boron in maruyamaite crystals (δ11B 7.7 ‰ in the core and –1.2 ‰ in the rim) of the same deposit. Analysis of the obtained data on δ11B in the tourmalines from the diamond-grade metamorphic rocks within the Kumdy-Kol deposit suggests the existence of two boron sources that resulted in crystallization of K-bearing tourmaline crystals (maruyamaite-dravite series) and potassium-free tourmalines of the schorl-uvite series.
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Date submitted2021-02-12
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Date accepted2022-07-26
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Date published2022-11-10
Manifestation of incompatibility of marine residual fuels: a method for determining compatibility, studying composition of fuels and sediment
- Authors:
- Radel R. Sultanbekov
- Andrey M. Schipachev
The results of studying the problem of active sediment formation when mixing residual fuels, caused by manifestation of incompatibility, are presented. A laboratory method has been developed for determining the compatibility and stability of fuels allowing identification of a quantitative characteristic of sediment formation activity. Laboratory studies were performed, and incompatible fuel components were identified. Tests were made to determine the quality indicators of samples and group individual composition of fuels. Results on the content of total and inorganic carbon in the obtained sediments were determined using Shimadzu TOC-V SSM 5000A. Chemical composition was determined and calculated on LECO CHN-628 analyser. Group composition of hydrocarbon fuels contained in the sediment was studied by gas chromato-mass spectrometry on GCMS-QP2010 Ultra Shimadzu. To obtain additional information on the structural group composition of fuel sediment, IR spectrometry was performed on IR-Fourier spectrometer IRAffinity-1. X-ray diffraction analysis of sediment samples was made using X-ray diffractometer XRD-7000 Shimadzu; interplanar distances d002 and d100 as well as Lс and Lа crystallite sizes served as the evaluation criteria. Microstructural analysis of total sediment was performed by scanning electron microscopy. The results of the research confirmed that the content of normal alkanes in the fuel mixture mainly affects sediment formation. Recommendations were drawn on preserving the quality of fuels and reducing sediment formation during storage and transportation.
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Date submitted2022-04-11
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Date accepted2022-06-15
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Date published2022-07-26
Magma feeding paleochannel in the Monchegorsk ore region: geochemistry, isotope U-Pb and Sm-Nd analysis (Kola region, Russia)
A comprehensive study of a 340 m thick lenticular-sheet body of ultramafic composition penetrated by structural well M-1 at a depth of about 2.2 km was accomplished. Its main volume is composed of plagioharzburgite; fine-grained rocks of norite and orthopyroxenite chilling zones are preserved on endocontacts. The rocks of the body are similar in composition to the rocks near the underlying ore-bearing layered intrusion – the Monchepluton. The age of intrusion of the ultramafic body is 2510 ± 9 Ma (U-Pb, ID-TIMS, zircon) and, taking into account analytical errors, is comparable with the formation period of the Monchepluton (2507-2498 Ma). According to the study of the Sm-Nd system in rocks and minerals, a positive value of the e Nd (+1.1) parameter was established, similar to that in dunites and chromitites of the Monchepluton. Based on these results, the ultramafic body penetrated at depth was assigned to the magma feeding paleochannel through which the ultramafic, weakly contaminated magma entered the overlying magma chamber. This body is a unique example of a magma-feeding system for the ore-bearing layered intrusion of Precambrian age.
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Date submitted2021-09-17
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Date accepted2022-04-07
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Date published2022-12-29
Technique for calculating technological parameters of non-Newtonian liquids injection into oil well during workover
Technique for automated calculation of technological parameters for non-Newtonian liquids injection into a well during workover is presented. At the first stage the algorithm processes initial flow or viscosity curve in order to determine rheological parameters and coefficients included in equations of rheological models of non-Newtonian fluids. At the second stage, based on data from the previous stage, the program calculates well design and pump operation modes, permissible values of liquid flow rate and viscosity, to prevent possible hydraulic fracturing. Based on the results of calculations and dependencies, a decision is made on the necessity of changing the technological parameters of non-Newtonian liquid injection and/or its composition (components content, chemical base) in order to prevent the violation of the technological operation, such as unintentional formation of fractures due to hydraulic fracturing. Fracturing can lead to catastrophic absorptions and, consequently, to increased consumption of technological liquids pumped into the well during workover. Furthermore, there is an increased risk of uncontrolled gas breakthrough through highly conductive channels.
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Date submitted2021-08-05
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Date accepted2021-11-30
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Date published2021-12-27
Morozkinskoye gold deposit (southern Yakutia): age and ore sources
The paper presents the results of the comprehensive isotope geochemical (Re-Os, Pb and δ 34 S) study of sulfide mineralization of the Morozkinskoye deposit. The ore zones of the deposit are localized in the syenite massif of Mount Rudnaya, which is located within the Central Aldan ore region (southern Yakutia). Gold mineralization is represented by vein-disseminated or vein type mineralization and is manifested in acidic low-temperature metasomatites – beresites (Qz-Ser-Ank-Py). For the first time we obtained an age estimate of the gold mineralization ~ 129 ± 3 Ma, which the synchronism of the hydrothermal ore process in the beresites, which formed the Morozkinskoye deposit, and magmatic crystallization of the syenites of Mount Rudnaya (~130 Ma). The osmium initial isotopic composition of the studied sulfides indicates a mixed mantle-crustal source of sulfide mineralization. New lead isotopic data of syenites indicate the predominance of mantle lead and an insignificant role of the lower – crust lead, while the isotopic composition of pyrite denotes the presence of the upper crustal material in the ore genesis. The sulfide δ 34 S values vary from –2.3 to +0.6 ‰ and indicate a predominantly magmatic source of sulfur in the ores.
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Date submitted2021-04-27
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Date accepted2021-11-30
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Date published2021-12-27
Regularities of electrochemical cleaning of oil-contaminated soils
Electrochemical cleaning of oil-contaminated soils is a promising area of environmental safety, as it can be easily organized even in locations remote from settlements. For this purpose, a power source and a system of electrodes are necessary as equipment. It is possible to use an electric generator if there are no power supply lines nearby. The material of electrodes affects the features of redox processes, which can affect the energy consumption and the degree of soil cleansing from oil or oil products. Therefore, the correct choice of electrode materials is one of the important tasks in the field of engineering electrochemical methods of purification. Changes in the main parameters (humidity, temperature, degree of acidity) in an oil-contaminated model soil, similar in composition to one of the oil fields, were investigated. Measurements of parameters when using graphite and metal electrodes were carried out at several fixed sections of the interelectrode space depending on the treatment time. The established patterns of parameter changes in the purification of oil-contaminated soils allow us to draw conclusions about the stages of the electrochemical process, its speed, and energy efficiency. The results obtained form a basis for designing industrial facilities for soil treatment.
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Date submitted2021-04-30
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Date accepted2021-11-30
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Date published2021-12-27
Methodology for testing pipeline steels for resistance to grooving corrosion
- Authors:
- Viktor I. Bolobov
- Grigoriy G. Popov
The methodology for testing pipeline steels is suggested on the assumption that for the destruction of pipes in field oil pipelines by the mechanism of grooving corrosion the simultaneous fulfillment of such conditions as the occurrence of scratches on the lower generatrix of the pipe, eventually growing into a channel in the form of a groove, emulsion enrichment with oxygen, presence of pipe wall metal in a stressed state, presence of chlorine-ion in the oil-water emulsion is required. Tests are suggested to be carried out in 3 % aqueous solution of NaCl with continuous aeration by air on bent plates 150×15×3 mm, made of the analyzed steel, the middle part of which is under the action of residual stresses σ res , close to the level of maximum equivalent stresses σ eqv in the wall of the oil pipeline, with the presence of a cut on this part on the inner side of the plate as an initiator of additional mechanical stresses. Using the value of the modulus of normal elasticity of the analyzed steel, the degree of residual strain of the elastic-plastic body from this material, corresponding to the value σ res ≈ σ eqv is calculated, based on which the plates are bent to the required deflection angle, after which the cut is applied to them. After keeping the plates in the corrosive medium for each of them the increase in depth of the cut as a result of corrosion of the walls by the corrosive medium is analyzed, from which the rate of steel K by the mechanism of grooving corrosion is calculated taking into account the duration of tests. Corrosion rate values for two pipe steel grades determined by the suggested procedure are given. The comparison of K values obtained leads to the conclusion about the higher resistance to grooving corrosion of 09G2S steel.
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Date submitted2021-02-09
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Date accepted2021-07-27
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Date published2021-10-21
Development of an algorithm for determining the technological parameters of acid composition injection during treatment of the near-bottomhole zone, taking into account economic efficiency
Relevance of the research is due to the low proportion of successful hydrochloric acid treatments of near-bottomhole zones of carbonate reservoirs in the Perm region caused by insufficiently careful design and implementation of measures to stimulate oil production. Within the framework of this article, the development of a program is presented, which is based on an algorithm that allows determining the volume and rate of injection for an acid composition into a productive formation corresponding to the maximum economic efficiency during hydrochloric acid treatment. Essence of the proposed algorithm is to find the greatest profit from measures to increase oil recovery, depending on the cost of its implementation and income from additionally produced oil. Operation of the algorithm is carried out on the principle of enumerating the values of the volume and rate of injection for the acid composition and their fixation when the maximum difference between income and costs, corresponding to the given technological parameters of injection, is reached. The methodology is based on Dupuis's investigations on the filtration of fluids in the formation and the results of the experiments by Duckord and Lenormand on the study of changes in the additional filtration resistance in the near-well zone of the formation when it is treated with an acid composition. When analyzing and including these investigations into the algorithm, it is noted that the developed technique takes into account a large number of factors, including the lithological and mineralogical composition of rocks, technological parameters of the injection of a working agent and its properties, well design, filtration properties of the formation, properties of well products. The article provides an algorithm that can be implemented without difficulty using any programming language, for example, Pascal. Selection of the optimal values for the volume and rate of injection is presented in this paper, using the example of a production well at the Chaikinskoye oil field, located within the Perm region. Introduction of the developed algorithm into the practice of petroleum engineering will allow competent and effective approach to the design of hydrochloric acid treatments in carbonate reservoirs without a significant investment of time and additional funds.
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Date submitted2021-02-20
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Date accepted2021-05-21
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Date published2021-09-20
Analysis of the screw press mouthpiece parameters for 3D extrusion of peat pieces of tubular type
The results of theoretical and experimental studies on the creation of a screw press composite mouthpiece screw press for 3D-forming of peat pieces of a tubular type in the field for intensifying the process of field drying of material in a complex mechanized pit are presented. The main purpose of the study was to substantiate the geometric and design parameters of the screw press composite mouthpiece of the spread machine for the production of peat-agglomerated products of the tubular type. The parameters of the mouthpiece are selected based on the geometric characteristics of the peat pieces. An increase in moisture loss during drying of peat-agglomerated products is provided by forming a peat piece in the form of a thick-walled pipe made of a peat raw materials composed of low and high decomposition degrees in a ratio of 1:3. Additive production of polymer-fiber peat composites by extrusion allows to produce products with improved mechanical properties in comparison with non-reinforced raw materials. The vertical arrangement of the peat tubular piece on the drying field allows to increase the loading of the field area by 10 %, increase the convective heat supply to the piece and reduce the contact coefficient of the piece with the field by three times in comparison with the peat spreading of the pieces in the form of a horizontal tape. Based on the analysis of the shape and size of the agglomerated products, the design of a screw press composite mouthpiece consisting of two conditional molding zones of various configurations has been developed. The article presents a parametric analysis of the volumetric productivity of a screw press with a composite mouthpiece of a tubular type, the energy intensity of mechanical processing is determined, the degree of mechanical processing of peat raw materials is estimated with the optimization of the screw parameters for the production of agglomerated products of a tubular type.
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Date submitted2020-06-16
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Date accepted2021-03-29
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Date published2021-09-20
Empirical regularities investigation of rock mass discharge by explosion on the free surface of a pit bench
- Authors:
- Igor A. Alenichev
- Ruslan A. Rakhmanov
Minimizing the discharge of blasted rock mass into the developed space of the pit is a very relevant area for study, as it allows to increase the processability of work and reduce the cost of mining. The article presents the results of experimental industrial explosions, during which the study of this issue was conducted. The main purpose of the work was to establish the key factors affecting the volume of rock mass discharge to the pit haulage berm. During the analysis of the world experience of research on this topic, the key factors affecting the formation of collapse and discharge – natural and technological – are identified. The method of conducting experiments and collecting data for analyzing the influence of technological parameters of location, charging and initiation of wells on the volume of rock mass discharge is described. It is established that the main discharge to the pit haulage berm is formed by the volume of rock mass limited by the prism of the slope angle. With a sufficient rock mass displacement from the edge of the bench crest towards the center of the block, only the wells of the 1st and 2nd rows participate in the discharge formation. Empirical dependences of the total volume of rock mass discharge on the length of the block along the bench crest, the specific consumption of explosives, the size of a rock piece P 50 and the rate of rock breaking are obtained. The obtained results can be used to design the parameters of the drilling and blasting operations (DBO), as well as to predict and evaluate the possible consequences of a mass explosion in similar mining and geological conditions.
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Date submitted2020-10-13
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Date accepted2021-03-02
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Date published2021-04-26
Trace element accumulation by soils and plants in the North Caucasian geochemical province
Long-term studies of the North Caucasian geochemical province allowed to establish regional abundances and calculate accumulation (dispersion) factors for chemical elements in rocks, soils, and plants. Certain natural regional patterns characterize the province. Associations of elements in high and low concentrations are often determined by the predominant composition of rocks: carbonate-terrigenous, terrigenous, and igneous. The study of the average contents of several chemical elements in the soils of the province showed that the association of accumulated elements includes metals with different migration characteristics. Thus, despite the rather close values of the ionic radii, Pb, Zn, Cu, and Li (judging by the ionic potential) are characterized by the formation of cations, while Mn, Mo, and Zr form complex ions. Such elements as Zn, Cu, and Pb are mainly accumulated on hydrosulfuric barriers, while Mo, Co, and Mn are stopped by oxygenous barriers. For Cu, Zn, Mo, and Co, biogenic accumulation plays a significant role, while for Pb and Ni it is practically absent. The absolute dispersion of the elements did not reach environmentally hazardous values, although it indicates a fairly intensive migration. In woody plants, Ba, Nb, Sc, Sr, and Zn are accumulated most intensively.
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Date submitted2019-06-06
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Date accepted2019-08-09
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Date published2020-04-24
Studies of enrichment of sulfide and oxidized ores of gold deposits of the Aldan shield
The paper presents the analysis of studies of the enrichment of sulfide and oxidized ores in Yakutia deposits. The ore of the deposit is a mixture of primary, mixed and oxidized ores. The main useful component of the studied ore samples is gold with a content of 1.5 to 2.8 g/t, the silver content is low – 5-17 g/t. Ore minerals are represented by sulfides, among which pyrite predominates. The total sulfide content does not exceed 3-5 %. The presence in the ore of free and associated gold with a grain size from fractions of a micron to 1.5 mm. Gold is represented by nuggets in intergrowth with sulfides and also forms independent inclusions. Ores are classified as easily cyanidable. It was found that the content of amalgamable gold is 10-49, the share of cyanidable gold ranges from 66.67-91, the share of refractory gold is 9.0-33.33 %, which in absolute amount equals to 0.24-0.8 g/t. The extraction of gold in gravitation concentrate varies depending on the gold content in the ore and the yield of concentrate and for ores with a gold content of 1.5-2.8 g/t from 40 to 60 %. The direct cyanidation of all studied ore samples established the possibility of extracting gold into solution up to 86.7-92.9 %, the gold content in cyanidation cakes is 0.2-0.3 g/t. Investigations of the gravitation concentrate by the method of intensive cyanidation showed that with an initial gold content of ~ 500 g/t, up to 98.9 % is extracted into the solution. The gold content in intensive cyanide cakes will be 6-15 g/t. A set of studies carried out by the authors of the article at various institutes showed that it is advisable to process ore from the deposit using cyanidation technology with preliminary gravitational extraction of gold.
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Date submitted2018-12-28
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Date accepted2019-03-24
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Date published2019-06-25
Modern physicochemical equilibrium description in Na2O–Al2O3–H2O system and its analogues
Equilibrium and non-equilibrium states of systems Na 2 O–Al 2 O 3 –H 2 O and K 2 O–Al 2 O 3 –H 2 O are crucial for establishing key technological parameters in alumina production and their optimization. Due to a noticeable discrepancy between experimental results and thermodynamic calculations based on materials of individual researchers the necessity of systematization and statistical processing of equilibrium data in these systems to create a reliable base of their physicochemical state, analysis and mathematical modeling of phase equilibria is substantiated. The tendency to a decrease of the hydration degree of solid sodium aluminates with increasing temperature and the transition of systems from the steady state of gibbsite to equilibrium with boehmite is revealed. The paper contains approximating functions that provide high-precision description of equilibrium isotherms in technologically significant area of Na 2 O–Al 2 O 3 –H 2 O and K 2 O–Al 2 O 3 –H 2 O concentrations. Approximating function can be simplified by dividing the isotherm into two sections with the intervals of alkaline content 0-0.25 and 0.25-0.4 mole/100 g of solution. The differences in solubility isotherms for Na 2 O–Al 2 O 3 –H 2 O and K 2 O–Al 2 O 3 –H 2 O systems provide are associated with changes in the ionic composition solutions that depends on concentration and temperature, as well as differences connecting with alkali cation hydration, which is crucially important for thermodynamic modeling of equilibria under consideration.
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Date submitted2018-12-25
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Date accepted2019-03-02
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Date published2019-06-25
Non-linear electrical load location identification
- Authors:
- S. Pirog
- Ya. E. Shklyarskiy
- A. N. Skamyin
The article discusses the issues of identifying the location of non-linear loads in electrical networks which makes the main contribution to the distortion of the non-sinusoidal voltage and current in the distribution network of an industrial enterprise, including mining enterprises. The existing methods for determining the location of the source of higher harmonic components in voltage and current are considered, their advantages and disadvantages are revealed. The main disadvantages of the methods used include the low accuracy and incorrectness of their use in existing enterprises. When developing a new method, the authors were faced with the task of simplicity of its use in the conditions of industrial operation of electrical equipment and the absolute correctness of the results obtained. The proposed method of identifying the source of higher harmonics is based on the variation of the parameters of the power system, in particular, the change in resistance of power transformers taking into account their transformation ratio. It is shown that by varying the transformation ratio during regulation under load, the total coefficient of the harmonic components of the voltage changes. Based on the constructed dependencies, the variation of the derivative of this function with different variations of the parameters of sources of higher harmonics is analyzed and a method is developed that allows determining the share contribution of consumers to the total harmonic component of the voltage.
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Date submitted2018-07-12
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Date accepted2018-09-16
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Date published2018-12-21
Environmental Geochemical Assessment of Technogenic Soils
- Authors:
- G. I. Sarapulova
The purpose of this study was to obtain diagnostic features and criteria for the distribution of heavy metals in technogenically altered soils in the area of industrial facilities, depending on their altered geochemical properties, which make it possible to fix chemical elements in landscapes (the formation of geochemical barriers). On the basis of the geoecological assessment, disturbance of the soil buffer properties, which is reflected in the ionic composition change, alkalization, pH increase, and sulfate-chloride salinization have been revealed. This forms the heavy metals alkaline barrier. For example, in case of Cu, Pb, Zn, and N, it contributes to their accumulation and subsequent concentration in the soil layer due to the exchange interactions between chemical elements and Na + , K + , Ca 2+ cations. Soil saturation with sulphates also increases the probability of metals demobilization in the soil layer. It has been shown that intra-sectional soil migration of oil products (one of the most common pollutants of industrial areas) and chemical elements occurs at a depth of 30-50 cm, where the oil products based on a clay sorption layer form a technogenic barrier.
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Date submitted2015-12-17
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Date accepted2016-03-01
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Date published2016-12-23
Anomalous geochemistry of zircon from the Yastrebetskoe rare metal deposit (SIMS- and TOF-study)
- Authors:
- S. G. Skublov
- S.-Kh. Li
A detailed isotopic geochemical study (secondary ions mass-spectrometry – SIMS, time-of-flight mass-spectrometry – TOF) of zircon from ore-bearing syenites of the Yastrebetskoe rare metal-rare earth deposit (the Ukrainian Shield) has yielded proofs of magmatic genesis of the deposit: unaltered central parts of zircon grains typically feature characteristic magmatic spectra of REE distribution, their values of δ 18 O staying somewhat higher than the mantle value (6.5 ‰, on the average). During the final stage of forming the deposit the role of fluorine-water-bearing fluids enriched with Y, REE, Nb, Ве and heavy oxygen had increased, as directly reflected in the anomalous isotopic-geochemical characteristics of zircon rims and zones of zircon alteration (the contents of Y reaches 61874 ppm, that of Nb – 7976 ppm, Be – 1350 ppm, δ 18 O reaches 12.42‰, F – 0.7 % mass, H 2 O – 4% mass).
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Date submitted2015-12-08
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Date accepted2016-02-02
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Date published2016-12-23
Effect of chemical composition and quality of heavy Yarega oil on selection of appropriate processing technology
- Authors:
- N. K. Kondrasheva
- Anchita Khorkhe
The paper explores physical and chemical properties and composition of heavy oil from Yarega field and its vacuum residue, i.e. the tar. The capillary chromatography and gas chromatography-mass spectrometry were used to identify specific group hydrocarbon composition of heavy Yarega oil and components extracted therefrom, which has proven its belonging to highly resinous sulfurous naphthenic and aromatic oils. Based on the comparative analysis of composition and quality of feedstock a possibility has been assessed to produce a high-quality needle coke with low content of sulphur and metals from the heavy oil of Yarega field and its vacuum residue. An integrated process flow diagram for heavy Yarega oil refinement has been proposed, including preliminary deasphalting and demetallization, hydrotreatment, delayed coking and thermodestructive processes or gasification.