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Date submitted2024-05-17
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Date accepted2025-03-27
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Date published2025-03-27
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 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 submitted2024-03-20
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Date accepted2024-11-07
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Date published2025-02-27
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 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 submitted2023-09-05
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Date accepted2024-11-07
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Date published2025-02-25
Investigation of the accuracy of constructing digital elevation models of technogenic massifs based on satellite coordinate determinations
At all stages of the life cycle of buildings and structures, geodetic support is provided by electronic measuring instruments – a laser scanning system, unmanned aerial vehicles, and satellite equipment. In this context, a set of geospatial data is obtained that can be presented as a digital model. The relevance of this work is practical recommendations for constructing a local quasigeoid model and a digital elevation model (DEM) of a certain accuracy. A local quasigeoid model and a DEM were selected as the study objects. It is noted that a DEM is often produced for vast areas, and, therefore, it is necessary to build a local quasigeoid model for such models. The task of assessing the accuracy of constructing such models is considered; its solution will allow obtaining a better approximation to real data on preassigned sets of field materials. A general algorithm for creating both DEM and local quasigeoid models in the Golden Software Surfer is presented. The constructions were accomplished using spatial interpolation methods. When building a local quasigeoid model for an area project, the following methods were used: triangulation with linear interpolation (the least value of the root mean square error (RMSE) of interpolation was 0.003 m) and kriging (0.003 m). The least RMSE value for determining the heights by control points for an area project was obtained using the natural neighbour (0.004 m) and kriging (0.004 m) methods. To construct a local quasigeoid model for a linear project, the following methods were applied: kriging (0.006 m) and triangulation with linear interpolation (0.006 m). Construction of the digital elevation model resulted in the least aggregate value of the estimated parameters: on a flat plot of the earth’s surface – the natural neighbour method, for a mountainous plot with anthropogenic topography – the quadric kriging method, for a mountainous plot – quadric kriging.
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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 submitted2024-04-24
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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 submitted2024-05-03
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Date accepted2024-10-14
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Date published2024-11-12
Genetic geological model of diamond-bearing fluid magmatic system
The article proposes a genetic geological model of diamond deposit formation associated with kimberlites and lamproites. It is based on the synthesis of published data on diamond-bearing kimberlite systems and an original study of the ontogenetic features of diamond crystals. Deep diamond crystallization, its upward transportation and subsequent concentration in near-surface kimberlite-lamproite bodies and other rocks, including those brought to the surface by high-amplitude uplifts of crystalline basement rocks, are combined in a single system. An assumption is made about the primary sources of the Anabar placer diamonds. The possibility of hydrocarbon generation at mantle levels corresponding to diamond formation areas and their transportation to the upper crustal zones by a mechanism similar to the mantle-crust migration of diamond-bearing fluidized magmas is shown. The high rate of their upward movement allows transportation to the surface without significant loss as a result of dissolution in melts and sorption on the surface of mineral phases. The significant role of fluid dynamics at all stages of this system is noted.
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Date submitted2022-03-01
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Date accepted2024-06-03
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Date published2024-12-25
Study of the possibility of using high mineralization water for hydraulic fracturing
The results of laboratory studies aimed at developing hydraulic fracturing fluid based on alternative sources of high mineralization water are presented. It is shown that Cenomanian sources have the most stable mineralization parameters, while bottom water and mixed waters collected from pressure maintenance systems differ significantly in their properties, with iron content varying several times, and hardness and mineralization undergoing substantial changes. The quality of the examined hydraulic fracturing fluids based on alternative water sources is confirmed by their impact on residual permeability, as well as residual proppant pack conductivity and permeability. The experimental results show similar values for these parameters. The comprehensive laboratory studies confirm the potential for industrial use of high mineralization water in hydraulic fracturing operations.
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Date submitted2023-11-01
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Date accepted2024-05-02
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Date published2024-12-25
Improving the procedure for group expert assessment in the analysis of professional risks in fuel and energy companies
The lack of a unified approach to the assessment of professional risks in fuel and energy companies (FEC) in the national regulatory environment and a high degree of subjectivity of the results of hazard identification and risk assessment makes mathematically sound recruitment of an expert group urgent and necessary. The article presents the results of a comprehensive study on hazard identification and risk assessment at 6,105 workplaces in 24 branches of a FEC company based on the application of the expert assessment method and a scientifically sound qualitative and quantitative selection of experts. The priority vectors of factors are determined, global priorities are calculated, the size of the expert group (15 persons) is determined and mathematically substantiated for carrying out hazard identification and risk assessment at workplaces with sufficient reliability of results. For the first time, a set of factors characterizing the FEC companies that influence the determination of professional competence of experts is proposed. The formed expert group presented more precise, objective and consistent results of risk assessment. Standards for free distribution of personal protective equipment (PPE) and wash-off agents to 7,234 company employees for implementation and trial use were developed. A fragment of the results obtained for a driller's workplace is presented. This approach allows a significant increase in objectivity and efficiency of the professional risk management system and provision of the PPE to employees in the concept of a risk-oriented approach helping to prevent industrial injuries and improve the level of occupational safety culture in fuel and energy companies taking into account global practice.
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Date submitted2023-07-07
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Date accepted2023-12-27
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Date published2024-08-26
Landslide hazard assessment in Tinh Tuc town, Cao Bang province, Vietnam using Frequency ratio method and the combined Fractal-frequency ratio method
Landslides are one of the most frequent natural disasters that cause significant damage to property in Vietnam, which is characterized by mountainous terrain covering three-quarters of the territory. In 17 northern mountainous provinces of the country, over 500 communes are at a high to very high landslide hazard. The main goal of this study was to establish landslide hazard maps and conduct a comparative evaluation of the efficiency of the methods employed in Tinh Tuc town, Cao Bang province. The landslide hazard assessment was carried out in this study using the combined Fractal-frequency ratio (FFR) and the Frequency ratio (FR) methods. The FR method is based on the actualist principle, which assumes that future landslides may be caused by the same factors that contributed to slope failure in the past and present. The FFR method is based on the determination of the fractal dimension, which serves as a measure of the landslide filling density in the study area. Eight landslide-related factors were considered and presented in cartographic format: elevation, distance to roads, slope, geology, distance to faults, land use, slope aspect, and distance to drainage. Determining the area under the receiver operating characteristic curve (ROC-AUC) and verification index (LRclass) was performed to assess the performance of prediction models and the accuracy of the obtained maps. As a result, five zones were identified for the study area, characterized by very low, low, moderate, high, and very high landslide hazards. The analysis of the reliability of the obtained landslide hazard maps using the AUC and LRclass indices revealed that the FFR model has a higher degree of reliability (AUC = 86 %, LRclass = 86 %) compared to the FR model (AUC = 72 %, LRclass = 73 %); therefore, its use is more effective.
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Date submitted2022-11-21
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Date accepted2024-05-02
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Date published2024-08-26
M1 formation tectono-structural features and gas-oil potential within Archinskaya area Paleozoic basement (Western Siberia)
- Authors:
- Vladimir B. Belozerov
- Mikhail O. Korovin
Western Siberian Plate basement oil and gas potential evaluation largely depends on structural and stratigraphic complex architecture representation. New modern procedures for seismic data processing, detailed Paleozoic deposits stratigraphic studies and expanded geophysical well logging significantly change the representation of the basement rocks fold-block structure and previously developed hydrocarbon reservoirs models. Detailed studies conducted within the Archinskii uplift showed that Paleozoic sediments form a contrasting folded structure complicated by block tectonics. The significant block displacements amplitude determines the lithological and stratigraphic basement rocks erosional-tectonic surface, while the identified stratigraphic blocks control the oil productivity distribution within the Archinskaya area. The filtration-capacity heterogeneity folded structure of the Paleozoic sediments is reflected in the distribution of hydrocarbon saturation in the well section, forming independent gas, oil, and oil-water zones for the development process. The relationship between anticlinal structural forms of basement rocks to lowered, and synclinal to elevated blocks, determines the necessity to conduct exploration prospecting within younger stratigraphic blocks when assessing the deep Paleozoic oil and gas potential.
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Date submitted2023-11-10
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Date accepted2024-05-02
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Date published2024-08-26
Paleoproterozoic Saltakh Pluton, Anabar Shield: mineralogical composition, age and a geodynamic setting
- Authors:
- Nikolai I. Gusev
- Lyudmila Yu. Romanova
The Saltakh Massif is located in the northern Anabar Shield, in the Saltakh shear-zone. It consists of two-pyroxene schists and plagiogneisses metamorphosed under granulite-facies conditions. Their chemical composition is consistent with that of a differentiated series of rocks ranging from gabbro to tonalites with abundant alaskitic gneissose granite veins and bodies. The rocks are mainly high-potassium (K2O/Na2O > 0.50), high-magnesium (mg# 50-70), low-titanium (TiO2 0.35-1.31 wt.%) with low TiO2 concentration in clino- and orthopyroxene. Normative olivine makes up 6-9 % of metagabbroic rocks. The rocks display well-defined negative Ti, Nb, Ta, and P anomalies typical of subduction magmatism. The two-pyroxene gneisses show high Sr/Y ratios of 67.6-88 and (La/Yb)N of 24.8-25.6. Saltakh rocks are part of a shoshonite series, as indicated by Nb/La, La/Yb, Th/Nb and Ce/Yb ratios. All the rocks display positive εNd(T) values of 1.9-4.1 and εSr(T) of 0.77-17.8 indicative of a mantle source of magma and T(Nd)DM of 2,20-2,26 Ga. U-Pb zircon dating (SHRIMP II) has shown that the protoliths of Saltakh melanocratic rocks were dated at 2100-2086 Ma, and those of two-pyroxene plagiogneisses of tonalite composition were dated at 2025±7 Ma. Alaskitic gneissose granites were dated at 1969±7 Ma. The study of the trace element composition of zircon has revealed general enrichment in LREE. High LREE concentrations are due to secondary zircon alterations and the shoshonitic pattern of the melt, the high-temperature conditions of crystallization, and an anomalous fluid regime. The geodynamic setting in which the Saltakh Massif was formed was consistent with a pericontinental magmatic arc. The formation of alaskitic gneissose granites was due to anatexis provoked by later collision processes. Saltakh magmatic rocks were formed simultaneously with magmatic rocks from the Khapchan prospect which occur farther south, and were studied earlier (2095±10 Ma tholeiitic metadiorites and 2030±17 Ma calc-alkaline metatonalites). We interpret them as part of a metamorphosed juvenile Paleoproterozoic suprasubduction complex.
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Date submitted2024-04-11
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Date accepted2024-06-03
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Date published2024-07-04
Assessment of the efficiency of acid mine drainage purification (using the example of copper-pyrite mines in the Middle Urals)
According to the results of the anti-rating of regions with extreme pollution of watercourses in the Sverdlovsk region, the largest number of polluted rivers has been recorded in recent years – more than a quarter of all high and extremely high pollution. One of the sources of pollution of natural water bodies in the Middle Urals are closed and flooded copper-pyrite mines, where acidic mine drainage continue to form and unload to the surface. Several of them have organized collection and a two-stage acidic drainage purification system, including neutralization with lime milk and settling in a clarifier pond. Despite the identical schemes, different indicators of pollutants are recorded during discharge into water bodies. The aim of the work is to evaluate the effectiveness of the applied acid mine drainage purification system and identify the parameters affecting the quality of treated mine water. Laboratory studies were performed using methods of flame emission spectrometry, flame atomic absorption, atomic absorption spectrometry, mass spectrometry with ionization in inductively coupled plasma, potentiometric, etc. It has been established that the existing mine drainage purification system at the Degtyarskii mine makes it possible to significantly reduce the concentrations of most toxic components of mine waters to almost standard values. At the Levikhinskii mine, the multiplicity of exceeding the maximum permissible concentrations reaches hundreds and thousands of times. To achieve a higher degree of purification, it is necessary that the duration of passive purification is sufficient for the reactant to interact with acidic waters. However, to ensure this possibility, it will require the creation of a cascade of ponds with an area of several thousand hectares. If the current two-stage system is quite effective for the Degtyarskii mine, then for Levikhinskii it is necessary to switch to the use of more modern systems, including three stages of purification.
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Date submitted2023-11-02
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Date accepted2024-03-05
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Date published2024-08-26
The polyphase Belokurikhinsky granite massif, Gorny Altai: isotope-geochemical study of zircon
Based on the isotopic-geochemical analyses of zircons from granites of the Belokurikhinsky massif in the Gorny Altai using the U-Pb method, the ages of three intrusion phases have been determined for the first time: the age of the first phase refers to the time interval of 255-250 Ma, the second and the third phases have similar ages of about 250 Ma. The formation time of the Belokurikhinsky massif is estimated as not exceeding 5-8 Ma. The δ18O values for zircons from granites of the second and the third intrusion phases average around 11.5-12.0 ‰, indicating a significant contribution of a crustal component in the formation of the parent melts for granites of these phases. The crystallization temperature values of the zircons by the Ti-in-zircon thermometer for three phases range from 820 to 800 °C. The P-T crystallization parameters of titanite from the first phase, determined using a titanite thermobarometer, average around 770 °C and 2.7 kbar. The zircons from the first phase mostly exhibits geochemical characteristics of typical magmatic zircons. The zircons from the second and the third intrusion phases either may be unaltered magmatic zircons or enriched in incompatible elements (LREE, Th, U, Ti, Ca, etc.) due to fluid influence, resembling hydrothermal-metasomatic type zircons in terms of their geochemical characteristics. A number of zircon grains from the second and the third phases of granites demonstrate anomalous geochemical characteristics – the REE distribution spectra atypical for zircons (including “bird's wing” type spectra with oppositely tilted of light and heavy REE distribution profiles), as well as significantly higher contents of certain trace elements compared to other varieties. Such an enriched zircon composition and wide variations in the incompatible element content are due to non-equilibrium conditions of zircon crystallization and evolution of the fluid-saturated melt composition during the final stages of the massif formation.
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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 submitted2023-03-16
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Date accepted2023-12-27
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Date published2024-04-25
Comprehensive assessment of deformation of rigid reinforcing system during convergence of mine shaft lining in unstable rocks
Operation of vertical mine shafts in complex mining and geological conditions is associated with a number of features. One of them is a radial displacement of the concrete shaft lining, caused by the influence of mining pressure on the stress-strain state of the mine workings. A rigid reinforcing system with shaft buntons fixed in the concrete lining thus experiences elastoplastic deformations, their value increases with time. It results in deviation of conductors from design parameters, weakening of bolt connections, worsening of dynamic properties of geotechnical system “vehicle – reinforcing”, increase of wear rate of reinforcing system elements, increase of risks for creating an emergency situation. The article offers a comprehensive assessment of displacements of characteristic points of the bunton system based on approximate engineering relations, numerical modeling of the deformation process of the bunton system and laser measurements of the convergence of the inner surface of the concrete shaft lining. The method was tested on the example of the reinforcing system of the skip-cage shaft of the potash mine. Displacement of the characteristic points of the reinforcing system is determined by the value of radial displacements of the surface of the concrete shaft lining. Evaluation of the radial displacements was made using monitoring measurements and profiling data. The results obtained make it possible to justify the need and timing of repair works. It is shown that the deterioration of the reinforcing system at different levels occurs at different rates, defined, among other things, by mechanical properties of the rock mass layers located at a given depth.
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Date submitted2022-07-10
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Date accepted2023-06-20
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Date published2024-02-29
Mathematical modeling of the electric field of an in-line diagnostic probe of a cathode-polarized pipeline
A mathematical model of the in-line control of the insulation resistance state for cathodically polarized main pipelines according to electrometry data is considered. The relevance of the work is caused by the opportunity to create in-line internal isolation defects indicators of the main pipelines for transported liquids that are good conductors and expand the functionality of monitoring and controlling cathodic protection systems of the main pipelines. Features of the mathematical model are: consideration of the electric conductivity of transported liquid influence on electric field distribution; consideration of the influence of external and internal insulating coating resistance; use of the electric field of an in-line diagnostic probe for quality control of internal insulation. Practical significance consists in the development of modeling methods for control subsystems of main pipeline protection against corrosion and the development of special mathematical and algorithmic support systems for monitoring and controlling the operating modes of the cathodic protection station of main pipelines.
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Date submitted2022-05-11
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Date accepted2023-02-20
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Date published2023-08-28
Application of the support vector machine for processing the results of tin ores enrichment by the centrifugal concentration method
The relevance of the research is due to the acquisition of new knowledge about the features of the applicability of the support vector machine, related to machine learning tools, for solving problems of mathematical modeling of mining and processing equipment. The purpose of the research is a statistical analysis of the results of semi-industrial tests of the Knelson CVD technology on tin raw materials using the support vector machine method and the development of mathematical models suitable for further optimization of the technological parameters of the equipment. The objects of research were the products obtained as a result of the operation of hydro-cyclones, as well as the technological parameters of the operation of centrifugal concentrators. The work uses classical methods of mathematical statistics, the least squares method for constructing a linear regression model, the support vector machine implemented on the basis of the Scikit-learn library, as well as the method of verifying the resulting models based on the ShuffleSplit library. A general description of the process of testing the Knelson concentrator with continuous controlled unloading in relation to the enrichment of tin ores is presented. The results obtained were processed using the support vector machine. Regression models are obtained in the form of polynomials of the second degree and in the form of radial basis functions. A significant non-linearity is shown in the dependence between the content of the valuable component in the tailings and the values of the technological parameters of the apparatus.
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Date submitted2022-05-03
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Date accepted2022-11-22
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Date published2023-02-27
Development of methodology for scenario analysis of investment projects of enterprises of the mineral resource complex
Theoretical and applied aspects of scenario analysis of investment projects of enterprises in the mineral resource sector of the economy are considered, its advantages and disadvantages are analyzed. Taking into account the organizational and economic features of mineral resources management, a number of new modifications of the scenario analysis method, aimed at solving an urgent problem - reducing the information uncertainty in assessing the expected efficiency and risk of investment projects, are proposed. The peculiarity of the proposed new modifications is the use of the interval-probabilistic approach in the implementation of the scenario analysis procedure. This approach is based on a moderately pessimistic system of preferences in obtaining point values of the investment project initial parameters. Fishburn estimates and the hierarchy analysis method were used to reduce subjective uncertainty. The maximum likelihood values in the sense of the maximum a priori probability are used as expected estimates. An additional indicator of risk assessment, which characterizes the probability of the event that the net present value of the project will take a value less than the specified one, is proposed. When analyzing one project, this indicator is more informative than the standard deviation. A statistical hypothesis was tested on the improvement of the validity of investment decisions developed using the modified scenario analysis method compared to the standard method.
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Date submitted2022-08-01
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Date accepted2022-11-17
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Date published2023-02-27
Use of machine learning technology to model the distribution of lithotypes in the Permo-Carboniferous oil deposit of the Usinskoye field
- Authors:
- Denis V. Potekhin
- Sergei V. Galkin
Permo-Carboniferous oil deposit of the Usinskoye field is characterized by an extremely complex type of the void space with intense cross-sectional distribution of cavernous and fractured rock. In this study, for this production site, the process of 3D geological modeling has been implemented. At the first stage, it provided for automated identification of reservoir volumes by comparing the data of core and well logging surveys; at the second stage, identification of rock lithotypes according to Dunham classification is performed on the basis of comparison of thin sections examination and well logging data. A large array of factual information enables the use of machine learning technology on the basis of Levenberg – Marquardt neural network apparatus toward achievement of our research goals. The prediction algorithms of reservoir and rock lithotype identification using well logging methods obtained on the basis of the training samples are applied to the wells without core sampling. The implemented approach enabled complementing the 3D geological model with information about rock permeability and porosity, taking into account the structural features of the identified lithotypes. For the Permo-Carboniferous oil deposit of the Usinskoye field, the volumetric zoning of the distribution of different rock lithotypes has been established. Taking into account the lithotypes identified based on machine learning algorithms, density and openness of fractures were determined, and fracture permeability in the deposit volume was calculated. In general, during the implementation, the machine learning errors remained within 3-5 %, which suggests reliability of the obtained predictive solutions. The results of the research are incorporated in the existing 3D digital geological and process model of the deposit under study.
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Date submitted2022-07-15
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Date accepted2022-12-13
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Date published2023-02-27
Mathematical modelling of displacement during the potash ores mining by longwall faces
In favourable mining conditions, in particular at the Starobinskoye potash deposit (Belarus), longwall mining systems are used. They cause a high human-induced load on the subsoil, including intense deformation of the ground surface. The presented investigations are aimed at studying the dynamics of the ground surface displacement during the longwall face advance. Mathematical modelling was carried out in an elastic-plastic formulation with numerical implementation by the finite element method. The condition for the roof rocks collapse was opening of the contact between the seams when its boundaries were reached by shear fractures or formation of the tensile stresses area at the outcrop. With the working front advance, an increase in subsidence is observed, followed by its stabilization to a value determined by the process parameters of mining operations and the physical and mechanical properties of collapsed rocks. In this case, each point of the ground surface experiences sign-alternating horizontal deformations: when the front approaches, it causes tension, and when it moves away, compression. The obtained results of mathematical modelling are in good agreement with the data of instrumental measurements of the ground surface displacements, which indicates the adequate description of the rock mass deformation during the slice excavation of sylvinite seams by longwall faces.
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Date submitted2022-05-23
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Date accepted2022-07-21
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Date published2023-02-27
Alluvial tin mining by spray-suction borehole method: a case study on remaining alluvial tin reserves in Bangka Belitung, Indonesia
The area of the Bangka Belitung Islands, which is a potential area for alluvial tin deposits in Indonesia, has been affected by the destruction of tin reserves on the mainland due to rampant artisanal mining, which has left remnants of small-dimensional reserves. The remnants of these reserves can no longer be mined using the hydraulic mining of open pit method due to the small dimensions of the deposits. The hypothesis is that such sedimentary conditions can only be mined by the borehole method. This research aimed to design tools and perform test mining using the borehole method with a spray-suction mechanism. This research produced a novelty, namely, a method and parameters for alluvial tin deposits mining using borehole mining methods, such as the excavation capacity, excavation radius, mining recovery, and dilution factor. The benefit of this research is expected to provide an opportunity to increase the amount of onshore alluvial tin reserves to support tin production.
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Date submitted2021-03-24
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Date accepted2022-12-15
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Date published2023-08-28
Composite model of seismic monitoring data analysis during mining operations on the example of the Kukisvumchorrskoye deposit of AO Apatit
Geomechanical monitoring of the rock mass state is an actively developing branch of geomechanics, in which it is impossible to distinguish a single methodology and approaches for solving problems, collecting and analyzing data when developing seismic monitoring systems. During mining operations, all natural factors are subject to changes. During the mining of a rock mass, changes in the state of structural inhomogeneities are most clearly manifested: the existing natural structural inhomogeneities are revealed; there are movements in discontinuous disturbances (faults); new man-made disturbances (cracks) are formed, which are accompanied by changes in the natural stress state of various blocks of the rock mass. The developed method for evaluating the results of monitoring geomechanical processes in the rock mass on the example of the United Kirovsk mine of the CF AO Apatit allowed to solve one of the main tasks of the geomonitoring system – to predict the location of zones of possible occurrence of dangerous manifestations of rock pressure.
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Date submitted2021-05-13
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Date accepted2022-11-28
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Date published2022-12-29
Reproduction of reservoir pressure by machine learning methods and study of its influence on the cracks formation process in hydraulic fracturing
Hydraulic fracturing is an effective way to stimulate oil production, which is currently widely used in various conditions, including complex carbonate reservoirs. In the conditions of the considered field, hydraulic fracturing leads to a significant differentiation of technological efficiency indicators, which makes it expedient to study in detail the crack formation patterns. For all affected wells, the assessment of the resulting fractures spatial orientation was performed using the developed indirect technique, the reliability of which was confirmed by geophysical methods. In the course of the analysis, it was found that in all cases the fracture is oriented in the direction of the development system element area, which is characterized by the maximum reservoir pressure. At the same time, reservoir pressure values for all wells were determined at one point in time (at the beginning of hydraulic fracturing) using machine learning methods. The reliability of the used machine learning methods is confirmed by high convergence with the actual (historical) reservoir pressures obtained during hydrodynamic studies of wells. The obtained conclusion about the influence of the formation pressure on the patterns of fracturing should be taken into account when planning hydraulic fracturing in the considered conditions.