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Date submitted2024-05-15
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Date accepted2025-01-28
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Date published2025-04-30
Study of changes in the void space of core samples under cyclic loading
The subsurface state is explored and analysed by studying the core material. This is the basis for forecasts, construction and improvement of models. The reservoir properties of rocks obtained from the laboratory study of sample are subject to a system error caused by three main factors: rock selection in the zone of altered stress-strain state, rock removal from the thermobaric conditions of natural occurrence, and the measuring equipment error. A change in the natural stress-strain state of rocks occurs as a result of intervention in the formation system and the entire massif by constructing a well, creating overburden and depression. The rise of the core causes unloading from formation pressure to atmospheric one, natural saturation is lost, temperature conditions change. This affects the reservoir properties and rock injectivity. This study is aimed at investigating changes in the void space of the rock in formation conditions under cyclic loading. Based on the data obtained, a regression forecast of properties is made, excluding external influences. The article describes the results of experiments on multiple loading and unloading of water-saturated sandstone samples by geostatic pressure with precise control of the water displaced and returned to the void space. This method enables us to record the change in the internal void volume of the rock and, as a consequence, elastic and plastic deformations, the value of relaxation of elastic deformations. The dynamics of change in the coefficients of porosity and compressibility from the stress state cycle is estimated and the range of predicted porosity values of the rock in formation conditions is determined. For samples of permeable medium- to fine-grained sandstone, the obtained character of porosity change gives a forecast of the initial porosity in formation conditions of 20.19±0.61 %. Thus, the exclusion of human impact on porosity gives values 1.42 % higher than the results of standard laboratory studies.
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Date submitted2023-10-02
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Date accepted2024-11-07
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Date published2025-04-25
Laboratory studies of hydraulic fracturing of intersecting boreholes in a non-uniform stress field
This study focuses on the features of hydraulic fracture propagation in intersecting boreholes in polymethyl methacrylate blocks in a non-uniform stress field. Glycerol aqueous solution and plasticine were used as the working fluids. According to linear fracture mechanics, a stress concentrator at the borehole intersection contributes to the beginning of crack formation, with further crack propagation occurring in the plane containing their axes. The relevance of this study is due to the search for innovative approaches and the development of technological solutions to address the issue of effective longitudinal crack formation and its further propagation in a rock mass under unfavourable stress field conditions. This paper provides a scheme of laboratory stand operation and a general view of the sealing packers used to isolate a specified interval when performing tests. The graphs of glycerol pressure versus injection time are presented, and the breakdown pressure in the blocks is specified. The shape of fractures formed during the indentation of plasticine into the borehole system was investigated. The findings of physical modelling indicate that longitudinal cracks are predominantly formed in the boreholes. The deviation of the crack trajectory from the vertical plane containing the borehole axes is primarily affected by the magnitude of the horizontal compressive stress field rather than the increase in the angle between them. In addition, the angles of inclination of the longitudinal crack plane measured at its intersection with the side face of the block are specified.
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Date submitted2024-03-20
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Date accepted2024-11-07
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Date published2025-04-25
Analysis of the stress state of rocks transformation near a horizontal well during acid treatment based on numerical simulation
The article presents an overview of the assessment and modelling of the stress state of rocks in the near-wellbore zone of horizontal wells during acid stimulation of the formation for improving the efficiency of oil and gas field development. A numerical finite element model of near-wellbore zone of the reservoir drilled by a horizontal section was compiled using one of oil fields in the Perm Territory as an example. The distribution of physical and mechanical properties of the terrigenous reservoir near the well was determined considering transformation under the action of mud acid for different time periods of its injection. Multivariate numerical simulation was performed and the distribution of horizontal and vertical stresses in near-wellbore zone was determined with regard for different values of pressure drawdown and changes in stress-strain properties depending on the area of mud acid infiltration. It was found that a change in elastic modulus and Poisson's ratio under the influence of acid led to a decrease in stresses in near-wellbore zone. Analysis of the stress distribution field based on the Coulomb – Mohr criterion showed that the minimum safety factor of rock even after the effect of mud acid was 1.5; thus, under the considered conditions of horizontal well modelling, the reservoir rock remained stable, and no zones of rock destruction appeared.
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Date submitted2024-03-29
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Date accepted2024-11-07
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Date published2025-04-25
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 accepted2025-01-28
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Date published2025-04-25
Determination of impact hazard potential of rocks in the Norilsk Industrial Region
The deeper the mineral deposits developments are, the worse the mining and geological conditions become. Significant growth of stress level in the rock mass contributes to possible manifestation of rock pressure in dynamic form. The resulting task of assessment of rock impact hazard is closely related to the task of obtaining more accurate results of compression tests of samples in rigid or servohydraulic test presses using graphs of their full deformation. This approach requires special expensive equipment, considerable time resources, and sufficient core material. Therefore, it is important to have an approach that allows to assess the propensity of rocks to brittle fracture with research methods simple enough not to result in the loss of quality and reliability of the obtained results. This paper presents the results of laboratory tests of rocks from the Norilsk Industrial Region to determine their tensile and compressive strengths. Test methods involved both domestic and foreign standards for determining the value of the brittleness coefficient. The impact hazard potential of rocks was determined using the Kaiser criterion. It is found that the tested lithological types (rich sulfide ores, hornblende, disseminated ores, and gabbro-dolerite rocks), with the exception of anhydrite, have a low impact hazard potential.
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Date submitted2023-12-07
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Date accepted2024-11-07
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Date published2025-04-25
Determination of the tangential component of cutting resistance during frozen sedimentary rock cutting using blocked, deeply blocked and cell cutting methods
Due to the insufficient accuracy of existing studies of frozen sedimentary rock cutting process for practical calculations, the article solves the problem of determining the tangential component cutting resistance for blocked, deep blocked and cell cutting, which are currently the most commonly used methods in earthmoving equipment. The cutting tool and rock mass force interaction is considered from the point of view of the emerging stresses, which act on the separated chip element. The analytical dependences for determining the tangential component of cutting resistance were obtained. The numerical explanation of the choice of cell cutting in relation to blocked and deeply blocked cutting is given. For all three methods of cutting, under equal geometrical parameters of the cutting tool and the physical and mechanical properties of the frozen rock, the numerical value of the tangential component of cutting resistance is obtained. The comparison of the cutting resistance estimated values has shown that cell cutting requires relatively less energy and is preferred during the process of frozen sedimentary rock excavation. During field and laboratory investigations with the use of a multi-purpose cutting stand, a sufficient convergence of the analytical statements with the physics of frozen sedimentary rock cutting process was established. The results of the research allow a more reasonable approach to the adjustment of existing methods for determining the required tractive force and power for the drive of an excavation machine, and, therefore, to the actual efficiency and profitability of work.
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Date submitted2024-06-04
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Date accepted2025-01-28
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Date published2025-04-04
Impact of dry and wet magnetic separator process parameters on iron oxide removal from Egyptian feldspar ore
The demand for feldspar as a raw material in the ceramic industry is continuously increasing. Feldspar is abundant in the Earth's crust and typically found alongside other silicate minerals, as well as titanium and iron oxides. This study aims to reduce the iron oxide content in feldspar ore from the Wadi Zirib region and achieve an optimal grade of feldspar concentrate for various industrial uses. The research involved dry and wet magnetic separation techniques followed by leaching with oxalic and citric acids to minimize iron impurities and enhance optical properties. The factors affecting the dry magnetic separation, for feldspar size of –250+45 µm, were optimized using the Box – Behnken factorial design and a non-magnetic concentrate with 0.29 % Fe2O3 and an 92.19 % feldspar yield was obtained. The wet magnetic separation for feldspar fines of size –45 µm was optimized and a concentrate with 0.27 % Fe2O3 was achieved. The acid leaching was conducted on the non-magnetic feldspar concentrates using oxalic and citric acid. Oxalic acid was more successful in reducing iron oxide of dry (to 0.19 %) and wet (to 0.12 %) non-magnetic feldspar concentrates. The optical properties of the leached concentrates were improved compared to the original sample, as the whiteness improved up to 90 %.
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Date submitted2024-05-03
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Date accepted2024-11-07
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Date published2025-04-02
Assessment of ancylite ore dressability by flotation method
For more than 50 years, most rare earth elements were extracted from carbonatite deposits, which can contain different rare earth phases, but the main extracted minerals are bastnaesite, monazite and xenotime. Many studies focused on the improvement and development of dressing circuits for ores of these minerals. However, in some carbonatite complexes, rare earth deposits are composed partly or mainly of ancylite ores. This type of rare earth ores was very poorly studied in terms of dressability – previous experiments with ancylite ores are rare and not productive enough. Ancylite is the main concentrator of rare earth elements in most carbonatite complexes of the Devonian Kola Alkaline Province (northwest Russia). Dressability of ancylite ore from the Petyayan-Vara carbonatite field in the Vuorijärvi alkaline-ultramafic complex was assessed using the flotation method. The complex is one of the most potential rare earth deposits associated with carbonatites in the Kola Region. Petrographic and mineralogical studies demonstrated the occurrence of abundant iron and barite oxide inclusions in ancylite, which imposes restrictions on physical separation of these three minerals. The study of petrogeochemical and mineralogical composition of fractions formed during mechanical grinding of ores to a size less than 2.0 mm showed that even at this stage of sample preparation, the finest-grained fractions (less than 0.071 mm) were enriched in ancylite (to 19 vol.% or more with a content of 15 vol.% in ore). Three classes of reagents were considered as collectors in flotation experiments: fatty acids, alkyl hydroxamic acids, and amino acid derivatives. The reagent from the amino acid derivative class was highly efficient. The use of such a collector in combination with sodium hexametaphosphate depressant made it possible to obtain a flotation concentrate in an open circuit with total rare earth oxides content 33.4 wt.% at 64.7 % extraction.
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Date submitted2024-04-27
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Date accepted2024-11-07
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Date published2025-03-05
Comprehensive studies of the snow-firn layer in the area of the Russian Antarctic Vostok Station
The article presents the findings from research conducted at Vostok Station during the 69th Russian Antarctic expedition. The primary goal of the research is to perform a thorough investigation of the snow-firn layer using both direct (drilling and core analysis) and indirect (georadiolocation and seismic exploration) methods. As part of the research, fundamental tasks related to the study of the structure and dynamics of the upper part of the ice sheet were addressed, as well as applied tasks aimed at justifying the depth of explosive charge placement for seismic work with the goal of conducting a detailed study of Lake Vostok and selecting the point for drilling access to the lake. Data on the microstructure and physical properties of the snow-firn layer were collected. The findings will allow for future improvements to the firn densification model, which is required to understand the evolution of ice grains during the early stages of metamorphism. The study's findings aided in the understanding of the structural features of the ice sheet's surface layer, allowing for more precise determination of the structural and physical characteristics of the snow-firn layer and ice, potentially leading to a better understanding of climatic and geological processes in Antarctica.
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Date submitted2023-04-10
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Date accepted2024-11-07
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Date published2025-02-25
Consideration of the geomechanical state of a fractured porous reservoir in reservoir simulation modelling
This paper presents reservoir simulation modeling of a hydrocarbon accumulation with a fractured porous reservoir, incorporating the geomechanical effects of fracture closure during variations in formation pressure. The fracture permeability parameter is derived from the impact of stress on fracture walls. The fracturing parameter is determined based on 3D seismic data analysis. A permeability reduction model is implemented in the tNavigator reservoir simulation platform. The proposed approach improves the convergence of formation pressure dynamics in well data while maintaining flow rate and water cut adaptation accuracy. This results in enhanced formation pressure prediction and optimization of the pressure maintenance system.
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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 submitted2023-07-31
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Date accepted2024-11-07
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Date published2025-02-25
Environmental assessment of biochar application for remediation of oil-contaminated soils under various economic uses
- Authors:
- Tatiana V. Minnikova
- Sergey I. Kolesnikov
Remediation is an important area of oil-contaminated soil restoration in Russia, since oil refining industry is the major one for Russia and neighbouring countries, and the issues of environmentally effective and economically profitable remediation of oil contamination have not yet been solved. Soils under various economic uses have different surface areas and degrees of soil particles envelopment with oil due to the presence or absence of cultivation, the amount of precipitation and plant litter. The introduction of various substances for remediation into oil-contaminated soils of steppes (arable land), forests, and semi-deserts, considering their differences, gives different results. Biochar is coal obtained by pyrolysis at high temperatures and in the absence of oxygen. The uniqueness of this coal lies in the combination of biostimulating and adsorbing properties. The purpose of the study is to conduct an environmental assessment of biochar application for remediation of oil-contaminated soils under various economic uses. The article compares the environmental assessments of biochar application in oil-contaminated soils with different particle size fraction. The following indicators of soil bioactivity were determined: enzymes, indicators of initial growth and development intensity of radish, microbiological indicators. We found that the most informative bioindicator correlating with residual oil content is the total bacteria count, and the most sensitive ones are the roots length (ordinary chernozem and brown forest soil) and the shoots length (brown semi-desert soil). The use of biochar on arable land and in forest soil (ordinary chernozem and brown forest soil) is less environmentally efficient than in semi-desert soil (brown semi-desert soil). The study results can serve to develop measures and managerial and technical solutions for remediation of oil-contaminated soils under various economic uses.
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Date submitted2023-10-03
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Date accepted2024-11-07
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Date published2025-02-25
Investigation of the effectiveness of the use of various substances for dust suppression during the transshipment of granular sulfur
The article is devoted to the problem of dusting during the transshipment of granular sulfur and existing methods of dust suppression. The analysis of various methods for reducing dust emission at granulated sulfur storage and transportation facilities is presented. The necessity of using special reagents to increase the efficiency of dust suppression and re-granulation of sulfur crushed by abrasion is noted. The sulfur dust obtained from the port terminal during the transshipment of technical sulfur was analyzed for granulometric composition. The results of experimental studies of the effectiveness of the use of various substances for sulfur dust suppression (alkyl polyglycosides, sodium silicate, starch) are presented. The laboratory installation was a hopper, inside which a test sample of dusty material was placed. The sample was subjected to an aerodynamic effect by an air flow at a given speed. The concentrations of suspended solids were measured with a dust meter-nephelometer with a sampling tube placed in the geometric center of the hopper. The effectiveness of dust suppression agents was determined based on a comparison of the concentration values obtained on dry and treated samples. For dust suppression at granulated sulfur treatment facilities, it is proposed to use a composition based on nonionic surfactants represented by a mixture of C12-14-alkylglycosides oligomers (1-1.5 %), additionally containing a mixture of amylose and amylopectin polysaccharides in the form of soluble starch (1-2.5 %) and water. The dust suppressor showed consistently high dust suppression efficiency both when measured immediately after irrigation (98.3 %) and after the expected time (99.7 %). The developed composition provides an increase in the dust-suppressing ability of the solution and the elimination of the possibility of repeated dusting due to the formation of a polymer film on the surface, as well as the regranulation of the product crushed by abrasion.
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Date submitted2023-10-04
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Date accepted2024-09-24
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Date published2025-02-25
Crustal movement model in the ITRF2020 – a case study in Northern Vietnam
- Authors:
- Bui Thi Hong Tham
- Phi Truong Thanh
In the North area of Vietnam, the crustal movement velocity of 38 GNSS points belonging to different international Earth reference frames (ITRF2000, ITRF2005, ITRF2008) is adjusted to the international Earth reference frame ITRF2020. This is the latest frame up to now. Since then, the picture of crustal movement in the North area of Vietnam has been unified in a dynamic coordinate system. In the study area, the rate of crustal movement is about 35 mm/year, and the direction of displacement is from northwest to southeast. To build a model of the crustal movement of the Earth in the northern area of Vietnam, the movement velocity data of 38 stations in ITRF2020 is evaluated with high accuracy. All points are also satisfactory. And then, the crustal movement velocity model is built by using the collocation method in the form of the 3-order Markov function. Within 38 stations, 34 stations are used to build the model and 4 remaining stations are used as checked stations. The obtained results show that the Earth's crust movement velocity model has an accuracy of about 2 mm/year for movement velocity and 2 deg for movement direction. This is the first model of Earth's crust movement in the North of Vietnam that has been built in the latest dynamic coordinate system ITRF2020. These results have important significance in the research and practical application of the movement of the Earth's crust. The steps of building the movement velocity model in this study can be applied to other experimental areas in the territory of Vietnam.
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Date submitted2023-12-15
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Date accepted2024-06-13
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Date published2025-02-25
Development of equipment and improvement of technology for inertial thickening of backfill hydraulic mixtures at the final stages of transportation
The results of the study of the functioning of the developed thickening equipment as part of the stowing complex for the formation of a flow of high-concentration hydromixture are presented. To explain the operation of the hydrotransport system of the stowing complex, equipped with a thickener of the developed design, its basic diagram is presented. A mathematical model has been created that describes the mechanism of inertial sedimentation of a solid component of a hydraulic mixture in a working chamber equipped with hydrodynamic profiles. Interaction with the profile leads to flow stratification due to a change in the trajectory of movement and a decrease in speed. The interval of rational velocity of primary pulp entering the input of the working chamber of the inertial thickener is substantiated. The synthesis of solutions of the thickening process model is performed in the COMSOL Multiphysics and Ansys Fluent programs. This made it possible to eliminate physical contradictions in the operation of the equipment and justify the overall dimensions of its main elements, ensuring the implementation of the mechanism of inertial sedimentation of the slurry. It was found that the concentration of the thickened flow at the outlet branch pipe of the thickener working chamber is determined by the level of the primary hydraulic fluid velocity, the characteristic length of the section of interaction with the deflecting profile, and the ratio of the flow and attack angles. A nomogram of the dynamics of the change in the hydraulic fluid concentration in the section of the outlet branch pipe depending on the ratios of the overall dimensions of the deflecting profile of the working chamber was compiled. The results of the study allowed formulating recommendations for selecting the dimensions of the thickener's deflecting hydrodynamic profile to form a flow of hydraulic mixture with a concentration of about 50 % by weight. The developed equipment can be used in a stowage complex and will increase the range of supply of the stowage mixture. This is due to the fact that a flow of primary slurry with a low concentration, due to lower pressure losses, can be moved in a pipeline system over a greater distance than a flow with a high filler content. The use of a thickener at the final stage of transportation is intended to increase the concentration of the hydraulic mixture immediately before production.
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Date submitted2024-03-22
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Date accepted2024-09-24
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Date published2025-02-25
Behaviour of cerium (III) phosphate in a carbonate-alkaline medium
- Authors:
- Tatyana E. Litvinova
- Stepan A. Gerasev
The article investigates the behaviour of rare earth metals in carbonate-alkaline systems. The results of experimental studies on rare earth element extraction from phosphogypsum, a large-tonnage industrial waste forming in production of phosphoric acid are presented. Using the liquid phase leaching method, it was possible to extract more than 53 % of rare earth elements from old phosphogypsum and more than 69 % from fresh phosphogypsum due to solid phase treatment with a 4 mol/l potassium carbonate solution at temperature 90 °C. The behaviour of model cerium (III) phosphate in a carbonate-alkaline medium is characterized: a solubility isotherm is obtained as well as the dependences of the degree of cerium extraction into solution on temperature, carbonate ion concentration, interphase ratio, stirring intensity, and pH. The ability of soluble rare earth element complexes to precipitate over time was established, which was confirmed using cerium and neodymium as an example. Within 240 h after the end of the experiment, approximately 25 % of cerium and 17 % of neodymium were precipitated from the liquid phase. A similar property was recorded in representatives of the light group and was not noted in elements of the heavy group. The ability to self-precipitate in future can serve as a basis for developing an alternative approach to separating rare earth metals into groups after extraction in a carbonate ion medium. Also, based on the analysis of experimental data, the mechanism of cerium (III) phosphate dissolution in a carbonate-alkaline medium was characterized. An assumption was made that rare earth metal phosphates dissolve sequentially passing into an insoluble carbonate and then into a soluble carbonate complex.
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Date submitted2023-10-29
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Date accepted2024-04-08
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Date published2025-02-25
Evaluation of the impact of the distance determination function on the results of optimization of the geographical placement of renewable energy sources-based generation using a metaheuristic algorithm
- Authors:
- Andrei M. Bramm
- Stanislav A. Eroshenko
Since the United Power System was created electrical supply of remote and hard-to-reach areas remains one of the topical issues for the power industry of Russia. Nowadays, usage of various renewable energy sources to supply electricity at remote areas has become feasible alternative to usage of diesel-based generation. It becomes more suitable with world decarbonization trends, the doctrine of energy security of Russia directives, and equipment cost decreasing for renewable energy sources-based power plants construction. Geological exploration is usually conducted at remote territories, where the centralized electrical supply can not be realized. Placement of large capacity renewable energy sources-based generation at the areas of geological expeditions looks perspective due to development of industrial clusters and residential consumers of electrical energy at those territories later on. Various metaheuristic methods are used to solve the task of optimal renewable energy sources-based generation geographical placement. The efficiency of metaheuristics depends on proper tuning of that methods hyperparameters, and high quality of big amount of meteorological and climatic data. The research of the effects of the calculation methods defining distance between agents of the algorithm on the optimization of renewable generation placement results is presented in this article. Two methods were studied: Euclidean distance and haversine distance. There were two cases considered to evaluate the effects of distance calculation method change. The first one was for a photovoltaic power plant with installed capacity of 45 MW placement at the Vagaiskii district of the Tyumen region. The second one was for a wind power plant with installed capacity of 25 MW at the Tungokochenskii district of the Trans-Baikal territory. The obtained results show low effects of distance calculation method change at average but the importance of its proper choose in case of wind power optimal placement, especially for local optima’s identification.
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Date submitted2023-10-31
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Date accepted2024-11-07
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Date published2025-01-24
Specifics of magnetotelluric studies in Antarctica
One of the priority areas of scientific research in Antarctica is the study of its deep structure. Most of the continent is covered with a thick ice sheet, so the main geoscientific data are acquired using geophysical methods, among which magnetotelluric (MT) ones have the greatest penetration depth and insignificant environmental impact. The possibility of acquiring high-quality MT data in the conditions of the sixth continent has long been questioned. The work is aimed at studying the specifics of magnetotelluric survey in Antarctica. The following tasks were set: to summarize the world experience of studying Antarctica using MT sounding methods; to identify factors that negatively affect the high-quality data acquisition; to determine methods for minimizing the influence of these factors. The article analyses geophysical studies conducted by the magnetotelluric sounding method in the Antarctic region from 1964 to the present. The application of the method is complicated by the following: extremely low temperature affects the drop in the batteries capacity, freezing of the non-polarizing electrodes solution, and changes in the strength properties of materials. Electromagnetic noise occurs during strong winds; proximity to the magnetotelluric field source can violate the plane wave principle on which the method is based. The ice sheet covering most of Antarctica does not allow acquiring optimal values of the contact resistance of the electrode grounding; the extended coastline distorts the acquired data. Studies of the influence of factors complicating the MT sounding method in the coastal and central parts of Antarctica made it possible to formulate recommendations for preparing equipment and adapting the work procedure, modifying the processing flow and a set of measures to ensure safety, the implementation of which will both allow safe performance of geophysical investigations and high-quality data acquisition.
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Date submitted2024-05-28
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Date accepted2024-11-07
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Date published2024-12-25
Methods of intensification of pipeline transportation of hydraulic mixtures when backfilling mined-out spaces
The paper presents an analysis of the advantages and limitations of additional measures to intensify the transportation of the backfill hydraulic mixture flow. The results of the analysis of the conditions for using pumping equipment to move flows with different rheological properties are shown. Generalizations of the methods for influencing the internal resistance of backfill hydraulic mixtures by means of mechanical activation, as well as increasing fluidity due to the use of chemical additives are given. The article presents the results of studies confirming the feasibility of using pipes with polymer lining, which has proven its efficiency in pumping flows of hydraulic mixtures with different filler concentrations. An analytical model of hydraulic mixture movement in the pipeline of the stowage complex has been developed. The trends in pressure change required to ensure the movement of hydraulic mixture in pipelines of different diameters are exponential, provided that the flow properties are constant. The effect of particle size on the motion mode of the formed heterogeneous flow, as well as on the distribution of flow density over the cross-section, characterizing the stratification and change in the rheological properties of the backfill hydraulic mixture, is assessed. An analytical model of centralized migration of the dispersed phase of the hydraulic mixture flow is formulated, describing the effect of turbulent mixing of the flow on the behavior of solid particles. An assessment of the secondary dispersion of the solid fraction of the hydraulic mixture, which causes a change in the consistency of the flow, was performed. The studies of the influence of the coefficient of consistency of the flow revealed that overgrinding of the fractions of the filler of the hydraulic mixture contributes to an increase in the required pressure in the pipeline system.
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Date submitted2024-07-28
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Date accepted2024-11-26
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Date published2024-12-12
From import substitution to technological leadership: how local content policy accelerates the development of the oil and gas industry
- Authors:
- Oleg V. Zhdaneev
- Ivan R. Ovsyannikov
Achieving technological sovereignty implies accelerating innovation and reducing import dependence. An effective tool for addressing these challenges is local content policy (LCP). The purpose of this study is to assess the impact of LCP on innovation activity in oil and gas companies and to provide recommendations for enhancing the effectiveness of this policy in Russia. The paper analyzes the influence of LCP on innovation levels in the oil and gas sector, drawing on examples from 10 countries. A positive short-term impact of LCP on innovation was identified in Brazil, Malaysia, and Saudi Arabia, with long-term effects observed in China and South Africa. Recommendations for improving the effectiveness of LCP in Russia are supplemented with a methodology for calculating the level of technological sovereignty. A refinement of the method for solving the «responsiveness» problem, incorporating the level of localization, has been proposed.
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Date submitted2024-04-10
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Date accepted2024-10-14
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Date published2024-11-12
The influence of ocean anoxia on conditions for the Domanik deposits formation
The article considers one of conditions for the Domanik facies formation on the example of Tatarstan and Bashkortostan. The main emphasis is on the influence of anoxic paleobasin conditions on the high-carbon strata formation. A detailed study of the hydrocarbon composition of Domanik deposits made it possible to find characteristic biomarkers in their composition. They are based on the composition and structure of diagenetic products of biological compounds composing the sulphur bacteria living in anoxic/euxinic paleobasin conditions. Such compounds include C40 diaryl isoprenoids – isorenieratane and paleorenieratane. C10 tetramethylbenzenes also occupy a special place in the Domanik deposits study. Their appearance in the composition of organic matter of these deposits results from the transformation of sulphur bacteria compounds. Diaryl isoprenoids and tetramethylbenzenes are a reliable indicator of anoxic conditions of the Domanik deposits formation. The thermodynamic state of the hydrocarbon environment can be determined from the ratio of tetramethylbenzene isomers.
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Date submitted2024-04-12
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Date accepted2024-09-05
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Date published2024-11-12
Promising reagents for the extraction of strategic metals from difficult-to-enrich mineral raw materials
The need of the mining and processing industry for new types of directional reagents is due to the deterioration of the material composition of the processed ores. Low Au content (less than 0.5-1.0 g/t), finely dispersed Au inclusions (0.1-10.0 microns) in the ore, similar properties of the separated minerals have an extremely negative effect on flotation performance when using traditional reagents, which leads to significant losses of valuable metal with enrichment tailings. Expanding the range of domestic flotation reagents based on the latest achievements of fundamental research and their targeted application at mining and processing companies will compensate for the negative impact of the mineral composition of raw materials and ensure maximum extraction of strategic metals from difficult-to-enrich ores. The use of modern research methods (scanning electron and laser microscopy, UV spectrophotometry, XRF and chemical analysis) made it possible to visualize the adsorption layer of new reagents-collectors of a number of dithiocarbamates with different structures of a hydrocarbon radical and an organic modifier on the surface of gold-containing sulfides. The amount of adsorbed reagents on the surface of minerals has been experimentally determined. The specific features of the fixation of reagents on minerals of various compositions led to optimal correlations of their consumption in the flotation process. Scientifically based reagent regimes ensured an increase in the gold content in the concentrate and a decrease in the loss of gold with tailings by 5-6 % during flotation enrichment of the refractory ore of the Malinovskoe deposit.
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Date submitted2024-04-16
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Date accepted2024-09-24
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Date published2024-11-12
Deep-buried Lower Paleozoic oil and gas systems in eastern Siberian Platform: geological and geophysical characteristics, estimation of hydrocarbon resources
The study of deep-buried oil and gas systems is a promising trend in the preparation of hydrocarbon resources. The study of the factors determining oil and gas potential is extremely important. The Lena-Vilyui sedimentary basin in the eastern Siberian Platform has a potential for the discovery of large oil and gas fields in deep-buried Cambrian deposits. The use of original methodological approaches to the analysis of black shale and overlying deposits, generalization of the results of lithological, biostratigraphic and geochemical studies of Cambrian deposits in territories adjoining the study area, modern interpretation of geophysical data showed that siliceous, carbonate, mixed rocks (kerogen-mixtite) of the Kuonamka complex and clastic clinoform-built Mayan deposits are most interesting in terms of oil and gas potential. Oil and gas producing rocks of the Lower and Middle Cambrian Kuonamka complex subsided to the depths of 14 km. The interpretation of modern seismic surveying data confirms the hypothesis of a limited occurrence of the Upper Devonian Vilyui rift system. Based on generalization of geological, geophysical and geochemical archival and new materials on the Lower Paleozoic deposits of the eastern Siberian Platform, a probabilistic estimation of geological hydrocarbon resources of the Cambrian and younger Paleozoic complexes in the Lena-Vilyui sedimentary basin was performed. Based on basin modelling results it was concluded that the resources were mainly represented by gas. It is presumed that oil resources can be discovered in traps of the barrier reef system as well as on the Anabar and Aldan slopes of the Vilyui Hemisyneclise. With a confidence probability of 0.9, it can be stated that total initial resources of oil and gas (within the boundaries of the Vilyui Hemisyneclise) exceed 5 billion t of conventional hydrocarbons. The recommended extremely cautious estimate of resources of the pre-Permian complexes is 2.2 billion t of conventional hydrocarbons. In the study area, it is necessary to implement a program of deep and super-deep parametric drilling without which it is impossible to determine the oil and gas potential of the Lower Paleozoic.
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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 submitted2024-05-30
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Date accepted2024-10-14
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Date published2024-11-12
Thermodynamic modelling as a basis for forecasting phase states of hydrocarbon fluids at great and super-great depths
The possibility of discovering oil and gas occurrences at great (more than 5 km) and super-great (more than 6 km) depths is considered in two aspects. The first one is the preservation conditions of large hydrocarbon accumulations forming at depths to 4 km and caused by different geological and tectonic processes occurring at great and super-great depths with partial oil-to-gas transformation. It was ascertained that among the factors controlling preservation of liquid and gaseous hydrocarbons are the temperature, pressure, subsidence rate (rate of temperature and pressure increase), time spent under ultrahigh thermobaric conditions, and initial composition of organic matter. The possibility of existence of liquid components of oil at great and super-great depths is characteristic of sedimentary basins of China, the Gulf of Mexico, the Santos and Campos basins on the Brazilian shelf, and in the Russian Federation it is most probable for the Caspian Depression, some submontane troughs and zones of intense accumulation of young sediments. Determination of critical temperatures and pressures of phase transitions and the onset of cracking is possible using the approach considered in the article, based on estimation of organic matter transformation degree, kinetic and thermobaric models taking into account the composition of hydrocarbon fluid. The second aspect is the estimation of composition of hydrocarbons associated with rocks forming at great depths or rocks transformed under conditions of critical temperatures and pressures. This aspect of considerable science intensity can hardly be considered as practically significant. The study focuses on the investigation of the possibilities of thermodynamic modelling and the use of alternative methods for studying the transformation degree of liquid formation fluid into components of the associated gas through the example of two areas with identified oil, condensate and gas accumulations.