Vol 335, No 2 (2024)
Articles
Combustion in a chamber furnace with a tangentially swirling vortex
Abstract
Relevance. The need to analyze the furnace processes in boiler units with vertical vortex when arranging pulverized coal combustion with the enhancement of environmental parameters through the installation of tertiary blast nozzles. Despite the carbon-free policy in modern power engineering coal remains one of the main sources of energy, so the reconstruction of boiler units in order to reduce harmful emissions is very relevant.
Aim. To study aerodynamics and combustion processes of pulverized coal fuel in the furnace chamber of a boiler unit with a tangential arrangement of burner devices using a combustion scheme with tertiary air blowing.
Methods. The Eulerian–Lagrangian approach was applied to numerical study of flow characteristics, heat transfer and combustion in a furnace with a tangential burner arrangement. Also, k-ε model of gas turbulence, particle-turbulence interaction, diffusion model of particle dispersion, P-1 radiation modeling method and pulverized coal particle combustion model based on global particle kinetics and experimental data were used for numerical calculations.
Results. Based on numerical calculations and analysis, the dependences of combustion product concentrations, temperature, hydrodynamics at combustion of Kuznetsky coal grade D in the furnace chamber with tangential arrangement of burners for brown coal, as well as at installation of tertiary blast nozzles have been obtained. Insufficient redistribution of air between burners and tertiary nozzles is revealed, as for maintenance of stable twist of vertical vortex and accordingly presence of high values of velocities at the outlet of burner devices it is not possible to increase the portion of tertiary air without reconstruction of burners. It is also established that the volume of the furnace chamber below the burners is poorly involved in heat exchange.
7-16
Effect of mechanical impurities composition on formation of organic deposits
Abstract
Relevance. The need to study the effect of solid particles in oil stream on formation, composition and structure of deposits. Modern models of formation of asphalt-resin-paraffin deposits, based on correlation dependencies or empirical data, do not take into account the influence of the content of solid particles in oil to the proper extent. Recent studies show that various solid particles in oil can affect both the critical velocity and the structure of the formed deposits, but the effect of various particles on the intensity of formation of asphalt-resin-paraffin deposits remains unexplored.
Aim. To study the effect of various sand fractions on the intensity of formation, composition and structure of asphalt-resin-paraffin deposits.
Methods. Modeling of formation of asphalt-resin-paraffin deposits at the laboratory installation “Cold Finger” when adding various sand fractions to oil; studying composition and structure of deposits after the conducted investigations using a microscope.
Results. According to the research results, there is a significant increase in the intensity of formation of asphalt-resin-paraffin deposits when large fractions of sand are added to oil at a concentration of 5% or higher. It is worth noting that small fractions have almost no effect on the amount of deposits formed. Also, if various fractions are added to oil in equal proportions, there is almost no effect on the intensity of formation of asphalt-resin-paraffin deposits. When analyzing the deposits images from a microscope, it can be concluded that paraffin molecules, when interacting with sand particles of a dimension greater than 0.05 mm, form homols, and with an increase in the fraction, their structural strength grows.
Conclusions. The study of modern models of formation of asphalt-resin-paraffin deposits and current articles made it possible to understand that the issue of studying the factors of formation of asphalt-resin-paraffin deposits, in particular the effect of the presence of solid particles in oil, remains open. The results of this article can be aimed at improving existing technologies in the field of modeling paraffin formation, as well as contribute to the further work of researchers in this direction.
17-24
Effect of preparation method of pyrolysis liquid mixed with coal on its ignition and combustion characteristics
Abstract
Relevance. The need to develop technological solutions to increase the competitiveness of pyrolysis processing of various wastes. Combustion of pyrolysis liquid in a mixture with coal is one of these solutions, which makes it possible to stabilize the properties of the obtained fuel and use in standard energy equipment.
Aim. To determine the influence of the method of preparing a mixture of pyrolysis liquid and low-grade coal on its ignition and combustion characteristics, as well as on composition of the released gas-phase products, depending on the temperature of heating medium and concentration of the additive.
Methods. Pyrolysis and oxidation characteristics were studied using thermogravimetric analysis, and formal kinetic constants were calculated using the Coates–Radfern method. Samples of mixed fuels were prepared by the methods of homogeneous mixing and surface wetting of pyrolysis liquid of rubber processing and low-grade coal. Ignition and combustion characteristics were determined using an experimental stand, and composition of gas-phase combustion products was determined using once-through gas analyzer.
Results. The authors have determined the features of pyrolysis and oxidation of the pyrolysis liquid as well as the values of formal kinetics constants, indicating the physical nature of the factors that defining the rate of these processes. It was found that at 600°C the ignition of the studied mixtures weakly depended on concentration of the additive, while at 700 and 800°C the dependence was linear, and the differences between the samples prepared using different methods were insignificant. For samples obtained by the method of surface wetting, combustion of the additive occurred in the gas phase near the surface of the sample. For the samples obtained by the method of uniform mixing, it occurred predominantly in the bulk of the backfill. This led to more intense and complete coal combustion in these compositions due to more uniform releasing of heat and initiation of coal particles. The concentration curves of the NO, CO and CO2 release demonstrated, that behavior of the fuel mixture components was additive in terms of released gas-phase combustion products, as well as the absence of significant nonlinear effects over the entire studied range of temperatures and additive concentrations.
25-36
Possibility of reclamation of ash dumps
Abstract
Relevance. The need to dispose ash and slag waste from CHPP-1 and CHPP-2 in Ulan-Ude, which have a negative impact on the environment. A promising way to eliminate environmental damage is the biological reclamation of ash dumps. Its result is manifested in greening dumps and reducing ash deflation.
Aim. To study ash and slag wastes from thermal power plants in Ulan-Ude and establish the possibility of reclamation of ash dumps to reduce the negative impact on the environment.
Objects. Ash and slag wastes from the ash dumps of CHPP-1 (ASW-1) and CHPP-2 (ASW-2) in Ulan-Ude.
Methods. Chemical, X-ray phase, granulometric, microscopic methods of analysis.
Results. The authors have determined chemical, mineralogical and grain compositions of ash and slag wastes from thermal power plants. It was established that they have a high content of silicon, aluminum and a low content of calcium and magnesium. Ash and slag contain vitreous, crystalline and organic components. In the waste, to a greater extent, there is a crystalline phase containing silica, mullite, hematite, magnetite and, to a lesser extent, a glass phase, represented mainly by minerals of the orthoclase group. In terms of granulometric composition, the waste from CHPP-1 is dominated by a finer fraction compared to CHPP-2. Laboratory studies of soil mixtures based on ash and slag waste and local ameliorants (sewage sludge, lignin and chicken manure) were carried out. The optimal ratio of soil components was determined, equal to 4:1:1:1. A beneficial effect of sewage sludge was revealed, as well as a negative effect of high doses of bird droppings on growth and development of plants. Pure ash and slag from CHPP-1 and CHPP-2 without introduction of ameliorants can act as an independent substrate for perennial grasses.
37-47
Impact of steam flow into a combustion chamber of a contact gas-steam installation on its energy characteristics
Abstract
Relevance. Reduction of natural gas consumption and emissions of harmful substances into the environment based on introduction of water vapor into a combustion chamber of a contact gas-steam installation.
Aim. To carry out numerical studies on the influence of relative steam flow into the combustion chamber of the contact gas-steam installation on its energy characteristics.
Objects. Contact gas-steam installations based on gas turbines with steam injection into the combustion chamber.
Methods. Numerical methods based on material and energy balances of systems and elements of gas-steam installations.
Results. Based on the calculation of the thermal circuit of the contact gas-steam installation, the authors have studied the influence of the relative steam flow into the combustion chamber on its energy characteristics. It was determined that the absolute electrical efficiency of the contact gas-steam installation increases linearly with growth of relative steam flow into the combustion chamber. The range of changes in the relative steam flow into the combustion chamber strongly depends on the temperature of the gases behind the combustion chamber and the compression ratio in the air compressor; the smaller these parameters, the greater the range of changes. The maximum efficiency of 56% for all options is achieved at the maximum relative steam flow into the combustion chamber. It was established that the excess air coefficient, depending on the relative steam flow rate, decreases linearly, and the higher the temperature of the gases behind the combustion chamber and the compression ratio in the air compressor, the greater the rate of decline and the smaller the range of changes in the relative steam flow rate. It was revealed that the efficiency coefficient strongly depends on the relative steam flow into the combustion chamber, the temperature of the gases behind it and the degree of compression in the air compressor; with increasing these parameters, it increases linearly. It was determined that the temperature of the gases at the outlet of the gas turbine also strongly depends on the relative flow of steam into the combustion chamber, the temperature of the gases at its outlet and the compression ratio in the compressor. With an increase in the relative flow of steam into the combustion chamber, this temperature increases linearly from 600 to 700°C, while the higher the temperature of the gases at the outlet of the combustion chamber and the compression ratio in the compressor, the higher the temperature of the gases at the outlet of the gas turbine. The authors revealed the dependence of useful work on a gas turbine shaft on the relative steam flow into the combustion chamber. With an increase in the relative steam flow, the useful work on the gas turbine shaft increases along the branch of the parabola. The higher the temperature of the gases behind the combustion chamber and the compression ratio in the compressor, the steeper the branch of the parabola, but the smaller the range of changes in the relative steam flow. It was established that with an increase in the relative steam flow, the gas flow to the gas turbine decreases according to a hyperbola. Moreover, the lower the temperature of the gases behind the combustion chamber and the compression ratio in the compressor, the more the gas flow to the gas turbine drops.
48-59
Visual inspection results and evaluation of Akhtala tailing safety based on tailing management facility safety methodology
Abstract
Relevance. Mining sector is one of the leading branches of the industry in Armenia. Therefore, effective government regulation of the sector based on a sound legal basis is a necessity. Accidents at tailing management facilities are posing a high risk to people and environment especially in their near vicinity and often have a transboundary impact. The tailing management facility safety methodology elaborated under the auspices of the German Environmental Agency is an efficient tool for quick assessment of the technical condition of the tailing management facilities.
Aim. To present the results of application of the tailing management facility methodology in Armenia, which was applied to the operated Nahatak tailing management facility of the Akhtala Ore Dressing Combine (Lori region, Armenia).
Objects. Tailing management facility methodology was applied to the operated tailing management facility Nahatak of the Akhtala Ore Dressing Combine, for which all documentation was checked. Enrichment wastes were stored at the tailing management facility during processing copper ore from the Shamlug mine and polymetals from the Akhtala mine. The main visual inspection was carried out in three parts of the tailing management facility: main dam, drainage canal and secondary dam. Special attention was drawn to the main dam conditions. The video recorded by a drone was used to explore the dam bottom-line.
Methods. The tailing management facility methodology includes the following elements: the method of evaluation of Tailings Hazard Index; the tailing management facility checklists including the questionnaire for visual and documentation inspection, the evaluation matrix for the tailing management facility safety level; the measures catalogue for taking actions to improve tailing management facility safety. The questions of each tailing management facility checklist are stated in a way to encompass the minimum set of the requirements, critical for tailing management facility safety, which allows evaluating the tailing management facility conditions. Questions in all groups of the checklist are sorted by the tailing management facility lifecycle and each subsection contains relevant questions applied to a specific stage (design, construction, operation, re-cultivation, closure). Application of the tailing management facility checklist is supported by a measures catalogue with short-, medium- and long-term safety measures.
Results. The tailing management facility methodology was used/tested for the operated tailing management facility in Armenia for the first time. Тhe main problems of the Nahatak tailing management facility were identified and analyzed, and appropriate recommendations were provided based on them. Based on the obtained results it can be concluded that the main problems are related to the drainage system and the management of water flows, some parts of the primary dam that require restoration, as well as the improvement of monitoring systems. At the same time the experience of application of the tailing management facility methodology in Armenia, allowed improving this methodology and making it the most effective working tool for quick and efficient visual inspection of tailing management facilities and for thorough inspection of relevant documentations. The user-friendly tailing management facility safety methodology (with questionnaires of visual and documentation checking) is an efficient tool for quick assessment of the technical condition of the tailing management facilities, as well as for training staff both in the governance bodies and in mining enterprises.
60-68
Evaluation of the effect of acid additives on rheological properties and technological efficiency of zwitterionic and anionic surfactant mixtures
Abstract
Relevance. Various acid additives, such as corrosion inhibitors, iron stabilizers, demulsifiers, anti-precipitation agents, are usually used to provide necessary technological properties to acid compositions. Adding them into the acid composition based on viscoelastic surfactants can have a significant impact on the efficiency of their subsequent use, since micelle formation and, consequently, rheology of their solutions are particularly sensitive to the presence of additional components in the system. Accordingly, determination of the acid additives influence on rheological properties and technological efficiency of acid compositions with surfactants is a vital task.
Aim. To evaluate the effect of acid additives on rheological behavior of viscoelastic surfactants-based acid compositions (mixture of cocamidopropyl betaine and ethoxylated fatty alcohol sulfosuccinate).
Object. Acidic composition based on viscoelastic surfactants (a mixture of anionic and zwitterionic surfactants) and a package of acidic additives – corrosion inhibitor, iron stabilizer, demulsifier and antisludge agent.
Methods. Investigation of rheological properties using an MCR52 rheometer (Anton Paar GmBH) in the shear rate range from 1 to 100 s–1 at temperatures from 20 to 90°C, standard tests for selecting acid additives.
Results. The authors have determined the effect of acid additives on rheological properties of the developed self-diverting acid solution based on the viscoelastic surfactant (a mixture of anionic and zwitterionic surfactants). The obtained results confirmed that adding the acid additives into solutions leads to a decrease in partially neutralized solution viscosity. However, it expands the range of manifestation of viscoelastic properties. This will increase the efficiency of the developed composition during acid treatment. Also, the addition of acid additives reduces the initial viscosity, which facilitates acid injection into formation. A viscoelastic gel is not formed with hydrocarbons, which indicates that the treatment is effective in cleaning up the area after acidizing. The temperature test showed that the additives do not affect the temperature range of acid solution application.
69-77
Development of a system for controlling a diamond drilling mode in terms of rock fault resistance
Abstract
Relevance. Resistance to rock-cutting elements in rock destruction largely determines the effectiveness of drilling results. Information about the drag coefficient allows you to correctly and timely adjust the intensity of a drilling tool impact on the bottom of the well. To control the force contact of the drilling tool cutters with the bottom of the well, it is necessary to have a methodological apparatus that allows determining the rock destruction mechanism, taking into account the resistance forces. The existing methods for selecting combinations of diamond drilling mode parameters according to the known RPI index or according to the criterion of energy intensity of rock destruction N/vm, where N is the bottomhole power to overcome the resistance during rock destruction at the bottom hole; vm – mechanical drilling speed, have a number of disadvantages. They consist, for example, in occurrence of tool wear or the need to obtain a bottomhole power value in the current time mode, which is difficult under modern drilling conditions. Therefore, the study of rock resistance to destruction by a diamond cutter, based on application of the full factorial experiment method with obtaining mathematical models of factors and their graphical interpretation in combination with process control systems using computer technology in the current time mode, is a relevant topic. The disclosure of this topic will determine the direction of increasing technical and economic indicators of drilling.
Aim. To develop a methodological apparatus that allows determining the mechanism of rock destruction taking into account the resistance forces to ensure optimal control of diamond drilling.
Objects. Mechanism of rock resistance to destruction by a diamond cutter.
Methods. Analysis, analytical research, full factorial experiment.
Results. The paper presents an analytical analysis of the possibility of controlling drilling modes in order to achieve the greatest effect from drilling by estimating the drag coefficient as a function of the intensity of destruction or deepening per one revolution. Based on the analytical studies and the mode of drilling control by a computer in the real time mode, the authors have proposed a method for selecting the parameters of the drilling mode according to a given optimal value of the resistance index during drilling, and a way for its automatic implementation.
78-87
Comparative estimation of a random error component of automatic well level gauges based on processing measurements of earth-tidal level of groundwater
Abstract
Relevance. Introduction of autonomous digital level gauges allows significantly expanding the range of tasks solved in various fields of geology and ecology, by increasing the frequency of measurements and applying mathematical processing methods to avoid distortions of different nature. The expansion of the field of application of downhole level meters makes it a topical issue to choose a particular type of device to ensure the required measurement accuracy.
Aim. To consider the approaches to comparative estimation of random error of several types of automatic level gauges based on their recording of earth-tidal variations of groundwater level.
Methods. Methods of compensating the influence of variations in atmospheric pressure on groundwater levels; methods of calculating tidal level variations; methods of correlation and frequency analysis of the calculated and experimental data.
Results. The authors have carried out a comparative assessment of the accuracy in readings of several digital level gauges, installed in one well, by comparing the measured values of earth-tidal variations of the groundwater level with the calculated ones. Based on the experimental data, tidal variations of the groundwater level were obtained by eliminating distortions from variations in atmospheric pressure and then filtering with the moving mean. From correlation and amplitude-frequency analysis of the calculated and experimental data, indicators were determined for making a comparative assessment of a random component of the error of the tested level gauges.
Conclusions. The approach suggested allows choosing independent digital level gauges with a minimum random error component using the totality of calculated parameters. The most promising way to eliminate the distorting effects of tidal variation of groundwater level is the method based on the cutter frequency filtering of the level signal measured by the level gauge.
88-104
Geological and hydrogeological structure of the Sheshma terrigenous complex of the Belsky uplift
Abstract
Relevance. The importance of industrial and technical water supply to an oil field in the north-east of Perm region. The requirements to subsoil use and environment protection demand a sanitary restriction zone of the water supply source in the northern part of the field. The current study of a geological structure and groundwater conditions and circulation of Sheshma aquifer complex will assess its resources and elaborate on organization of water supply to the oil field.
Aim. To study geological structure and groundwater conditions of Sheshma aquifer complex.
Objects. Formations rocks and groundwater conditions of Sheshma terrigenous complex.
Methods. Studying the archival records, conducting a hydro-geological survey of the territory, drilling groundwater exploration wells, conducting pilot-filtration works on groundwater exploration wells in the flooding and low-water period.
Results. The authors have discovered Sheshma formation thickness, which ranges from 100–150 to 300 m, and lithological composition of rocks and groundwater conditions of Sheshma aquifer complex. It was established that groundwater is deposited as a system of separate isolated water-bearing interlayers and blocks within the Durinsky trough. The most water-bearing zones were identified. Two aquifers of fine-grained and coarse-grained sandstones were detected in low-permeability thickness of Sheshma formation. The aquifers are not hydraulically connected and are separated from each other by a 40 m thick layer of water-resistant mudstones. Groundwater is deposited as strata with Neumann's boundary conditions, orientated sublatitudinally, from west to east. The obtained data can be further used to solve the issues of water supply within the area under study and the rational use of these waters.
105-119
Basin-analogy for calculating spring flood volumes at insufficiency of meteorological data (Tuba river as a case study)
Abstract
Relevance. The necessity in provision of insufficient data on streamflow formation factors when predicting floods in the poorly explored and unstudied basins. For this purpose, in hydrological calculations and forecasts the method of hydrological analogy is applicable.
Aim. To study probable application of the hydrological analogy method in calculations of spring flood volumes of a mountain river. The analysis was carried out by the example of the basins of the Tuba river and its tributaries (rivers Amyl, Kazyr and Kizir), as well as neighboring catchments (rivers Abakan and Syda).
Methods. Integrated geographical-hydrometeorological analysis, correlation and regression analysis, and the hydrological analogy method.
Results. We calculated total winter precipitation in the Amyl basin by means of (traditionally used in hydrology) elevation dependences, estimated average annual precipitation in the Tuba basin using modern glaciation data, and built a stochastic predictive model of flood runoff volume on the Amyl river (settl. Kachulka) based on the relationship between precipitation for the previous winter and flood periods. The influence of liquid (flood) precipitation on the forecast quality was analyzed. A comparative analysis of other Tuba tributaries (Kazyr, Kizir), including neighboring basins (rivers Abakan and Syda), in terms of their application as basins-analogies was performed. For instance, a feasible use of the Amyl basin as an analogy for forecasting flood runoff depth of the Tuba river (vill. Bugurtak) was analyzed.
Conclusions. The correlation analysis of flood volumes of the Tuba, its main tributaries and neighboring rivers suggests that as an analogy the application of basins with similar conditions for precipitation formation (slope orientation relative to the direction of the prevailing moisture-bearing air masses) and average catchment elevation is currently favored. The Amyl basin use as the Tuba analogy is expedient for a medium-term forecast of melt runoff volumes (excluding liquid (flood) precipitation).
120-132
Adjustment of a reservoir model by the material balance method in the MBAL program. Setting up the integrated model in GAP
Abstract
Relevance. Modern approach to development of oil and gas fields. Digitalization and automation of hydrocarbon production allow not only reducing the response time to possible deviations from the operating level of production, but also quickly making decisions on its further normalization. The use of modern software to create a reservoir model applying the material balance method allows you to calculate current and predicted reservoir pressures depending on the amount of selected and injected fluid. With high-quality adaptation, the integration of the reservoir model, wells and collection system, in its turn, allows you to correctly approach the choice of a field development system, as well as correctly assess the possible potential of the field. Forecast calculations performed on an integrated model can form the basis for budget planning, as well as the basis for carrying out geological and technical activities on wells, commissioning new wells, and modernizing equipment and infrastructure. Moreover, group optimization calculation allows us to maximize additional oil production, taking into account all geological and technical constraints.
Aim. Formation and analysis of an approach to setting up a reservoir model by adapting parameters using the material balance method; formation of a solution for adapting the integrated model, reconciliation of the results with actual data; carrying out an optimization calculation and obtaining additional oil production.
Methods. Adjustment and adaptation of reservoir models using the material balance method; adjustment and adaptation of the integrated model of a field/group of fields; calculation of the forecast for a period of 30/90 days; optimization calculations.
Results. The obtained results make it possible to adapt the components of the integrated model with an accuracy of more than 95%, which makes it possible to simulate the operating mode of the field. As a result of the analysis, tuning criteria were identified, and the minimum required set of parameters for a qualitative adaptation of the reservoir model and the collection system was presented. The effectiveness and accuracy of the tool are also proven by comparing actual data on operating modes with synthetic ones. Based on the work done, it can be concluded that the use of the integrated model shows us a high convergence with real data, which allows us to optimally approach the field development mode. Moreover, an optimization calculation was carried out to obtain additional oil production using the proposed solution, and a forecast for oil production for a period of 90 days was calculated, which was later confirmed when compared with actual data.
133-140
Features of determining organometallic compounds in organic matters of black shale using diffuse reflectance infrared Fourier transform spectroscopy
Abstract
Relevance. The problem of studying organometallic compounds in carbonized and carbonaceous substances is a part of the global problem of the structure of natural materials from plant remains and manifestation of ore genesis in organic sedimentary deposits. This problem covers a number of issues. The most pressing one among them is the form of occurrence of finely dispersed gold in the form of organometallic compounds in metal-bearing coals and shales. This is especially true for large gold deposits of black shale strata.
Aim. To study the relationship between sedimentation of organic formations and ore genesis in black shale deposits using the example of the Verninskoe deposit (Patom Highlands, Yakutia). Using the SKAUFV hardware and software complex together with ICP-MS and INAA methods, which allow one to assess the degree of Au concentration in organic matter, to substantiate the possibility of determining organometallic compounds of gold that are significant in the processes of sedimentogenesis, lithogenesis and epigenesis.
Methods. IR spectroscopy, instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS).
Results. The authors have determined that the SKAUFV hardware and software complex, together with the ICP-MS and INAA methods, makes it possible to establish the role of organic matter in metasomatism and to identify temperature zonality and the associated gold concentration in the ore zone. To determine the organometallic compounds of Au, structural and genetic indicators (Pm, Ko, PVt+L, PI) were selected. These indicators reflect the significance of sedimentation, diagenesis, catagenesis and epigenesis on Au concentration in organic matter. These indicators made it possible to assess the level of temperature impact on sedimentary deposits of regional metamorphism and near-ore metasomatism. In this regard, subzones of Au concentration were established in the ore zone, determined by temperature zoning in the form of a manifestation of local metasomatism. The latter was influenced by the protein-fat composition of plants that form organic matter.
141-156
Distribution of stable Н, О and С isotopes in natural waters in the area of the Taz oil and gas condensate field (Yamalo-Nenets Autonomous Region)
Abstract
Relevance. The study of isotopic composition of water and dissolved substances makes it possible to determine not only their genesis, but also the fractionation processes occurring in the “water–rock–gas–organic matter” system over time, i. e. as different stages of the evolution of water composition pass through. Interest in the groundwater of the Arctic regions of Western Siberia is additionally associated with the widespread occurrence of oil deposits at the depths of formation waters and the possible influence of cryogenic metamorphization processes on composition of near-surface waters.
Aim. To study and compare the isotopic composition of oxygen, hydrogen and carbon in natural waters of the Yamalo-Nenets autonomous region to identify conditional isotopic markers, as well as to be able to trace the evolution of the isotopic composition of waters along a vertical section in the area of the Taz oil and gas condensate field.
Objects. Surface (river, soil and lake), underground waters of the active water exchange zone of the Yamalo-Nenets autonomous region and formation waters of oil and gas deposits of the Taz field.
Methods. The study of the isotopic composition of oxygen, hydrogen, and carbon of water-dissolved carbon dioxide was carried out in the Research Equipment Sharing Center at the Institute of Geology and Mineralogy SB RAS using Isotope Ratio Mass Spectrometer FinniganTM MAT 253 equipped with H/Device and GasBench II for sample preparation.
Results and conclusions. The paper introduces the data on isotopic composition of O, H and C for natural waters of the Yamalo-Nenets autonomous region. The authors have determined the characteristic trends in changes in the isotopic composition of water and dissolved carbon dioxide for various water bodies. Surface and underground waters with active water exchange in terms of isotopic composition (δD and δ18О) are infiltration. As water moves down the section, with an increase in the time of interaction of the “water–rock” system and increase in temperatures, the isotopic composition becomes significantly heavier with a slope from the GMWL to the right. The authors compiled the diagram of the evolution of water-dissolved carbon isotopic composition in the region according to the obtained and some literature data. Despite the wide range of δ13C values from –30.4 to 23.6 ‰, there are, obviously, only two sources of carbon dioxide in the region: biogenic and atmospheric, with biogenic being predominant for groundwater.
157-169
Changes in conditions of interaction of ground, river and swamp water during swamping of the West Siberian plain in the Holocene
Abstract
Relevance. The need to understand and long-term forecast the conditions of interaction between groundwater, river and swamp waters in the Ob River basin.
Aim. To identify patterns of changes in the conditions of interaction of groundwater, river and swamp waters during swamping of the flat part of the Ob River basin in the Holocene.
Methods. Mathematical modeling methods, statistical methods, geographical-hydrological method.
Results and conclusions. The author has carried out an analysis of materials from long-term hydrogeological and hydrological observations in the wetlands of the Ob basin and studied the hydrodynamic and geochemical conditions for interaction of groundwater, river and swamp waters. It is shown that the emergence and evolution of swamp ecosystems in the territory under consideration is a complex of erosion-accumulation processes, the development of which until the modern period took place in three stages: 1) from the beginning of intense degradation of glaciation to 4...6 thousand years ago is the formation of a primary hydrographic network approximately modern appearance, distribution of peat bogs; the groundwater regime is close to the groundwater regime of the permafrost zone in the north of modern Western Siberia; 2) from 4...6 thousand years ago to 1.5...3 thousand years ago is large-scale distribution of lowland swamps and degradation of part of the primary river network; groundwater levels in river watersheds are generally lower than at present, but the amplitude of their fluctuations is high; a significant part of the watersheds are flooded during high water and floods, and underflooded during low water periods; 3) from 1.5...3 thousand years ago is degradation of a significant part of the primary river network, wide distribution of raised swamps, formation of a secondary hydrographic network in the swamps; at watersheds, groundwater levels rise, but the amplitude of their fluctuations decreases, and water exchange with swamps is significantly reduced; in the valleys of medium and large rivers, water exchange between surface and groundwater is most intense, which causes the flow of significant amounts of organic substances and products of their transformation into river and groundwater from swamps. Scenarios of possible changes in the conditions of interaction between surface and groundwater were assessed.
170-186
Features of chemical elements migration in natural waters and their deposition in the form of neocrystallisations in living organisms (physico-chemical modeling with animal testing)
Abstract
Relevance. An original modeling method is presented, which allows obtaining qualitatively new results in practice of ecological-geochemical and biomedical research.
Aim. To obtain new data on the forms of element migration in the conditions of animal and human organism parameters by means of physicochemical modeling (PC "Selector") with verification of calculated data with the results obtained for real natural objects and animal organisms.
Objects. Samples of natural waters and tissues of wild animals.
Methods. Computer modeling (PC "Selector"); inductively coupled plasma mass spectrometry (ICP-MS, Agilent 7700x spectrometer) – 55 elements; atomic emission spectrometry (AES, spectrometer iCAP 7600 Duo) – 5 macrocations; ion chromatography (IC, ion-liquid chromatograph LC-20) – 6 anions; inductively coupled plasma mass spectrometry (ICP-MS, mass spectrometer NexION 300D; scanning electron microscopes Hitachi S-3400N with Bruker X@Flash 5010 energy dispersive spectrometer).
Results. By means of modeling, the authors have determined the qualitative and quantitative composition of the system "solution – crystalline substance". They took into account environmental conditions and physiological parameters of animal and human organism. Natural drinking water, gastric juice, mixture of drinking water and gastric juice were used as a solution, and crystalline substance was used as newly formed mineral phases in equilibrium with the solution. The work allowed establishing that the complexes assumed in the model experiment can be the cause of appearance of nanomineral phases of chemical elements in separate tissues of a living organism.
187-201
Improvement of the methods for determining ore losses when designing cement raw material deposit mining by surface miner combines
Abstract
Relevance. The need to optimize production of cement raw materials and reduce the cost of processing raw materials. Surface miner combines allow high selective mining of a deposit, which helps to reduce moisture content of cement raw materials and reduce energy costs in a cement plant. In open-cast mining of cement raw materials deposits with the use of the surface miner combines, the increase in economic efficiency of mining operations can be achieved by determining the rational values of ore losses and dilution.
Aim. To determine rational level of cement raw material losses during field development by surface miners.
Objects. Cement industry quarries excavated with of the surface miner combines.
Methods. Technical and economic analysis of the cement plant Beočin (Serbia), summation and synthesis of materials, sources and data available in the public domain, as well as calculations to determine the amount of loss and dilution of mineral resources at ore–rock contact for mining conditions of the quarry for extracting cement raw materials.
Results. The main problems that arise during mining quarries for extracting cement raw materials have been identified. It concerns the determination of the volume of losses and dilution of mineral resources at the ore–rock contact for mining conditions of the quarry for extraction of cement raw materials. The authors present and substantiate conclusions about further effective application of optimal mining technology, with the use of the surface miner combines, which allows reducing the cost of production of minerals and specific operating costs of transporting carbonate rocks compared to the traditional technology of mining works at 50–60%.
202-208
Characteristics of water supply network zoning
Abstract
Relevance. The original studies of water supply network and network exploitation data, as well as international experience, applied in similar conditions, and the data of existing literature, data of works on water supply zoning, which were carried out in the networks of various settlements in the Republic of Armenia, have been improved and are now being implemented effectively through the clear procedure developed by us. In our case, zoning is carried out under the conditions of the existing system, therefore the methods developed during design and reconstruction work consider the features of the existing system.
Aim. To develop a technique to enhance the efficiency of water supply systems by implementing network zoning. It involves transforming the network into hydraulically separated zones isolated from each other. Within each zone, water supply can be regulated based on consumption requirements.
Objects. The article discusses issues related to design and reconstruction procedures of existing water supply network zones. It defines the priority of zoning implementation for the current stage and proposes a method for assessing the permissible level of losses, taking into account the technical condition of the water supply network.
Methods. The calculations for this study were performed using well-known hydraulic principles and laws. Experimental studies were conducted directly on the water supply network under production conditions.
Results. The actual implementation of these measures in various urban locations revealed that reduction in water usage in a service zone was only 8–10%. However, analysis of the functioning of the reconstructed zones led to the conclusion that the already constructed zones now offer suitable conditions for productive work on leak detection and elimination. In the given example, during the operation of the study zone, 4300 m (about 25%) of the existing 17400 m pipelines in the reconstruction zone were decommissioned, along with 13 of 22 pumping stations. Over two years of work, the cost of electricity at the existing yard pumping stations was reduced by more than six times, the total cost of electricity in the zone was reduced by more than twelve times, and the amount of water entering the zone was reduced by 44% as a result of the water supply system reconstruction presented in the example.
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Assessment of radiation environmental risks for fish fauna of the cooling pools of a number of operating nuclear power plants
Abstract
Relevance. The need to assess radiation risks for the main types of fish in pools that are under the constant influence of the nuclear power plants.
Aim. To assess the radiation environmental risks for the ichthyofauna of cooling pools of the operating nuclear power plants, to analyze the sources and features of formation of the radiation risks at different stages of their operation.
Objects. monitoring studies of radiation environmental risks for reference fish species in cooling reservoirs of the Leningrad, Beloyarsk and Novovoronezh NPP.
Methods. Calculation of the exposure dose rate and quantitative assessment of the risk of exposure to technogenic radionuclides of the ichthyofauna of the cooling pools of the Beloyarskaya, Leningradskaya and Novovoronezhskaya NPP were carried out using the international computer complex of the updated version of ERICA Tool 2.0.
Results. The paper demonstrates that the radiation ecological risks for the ichthyofauna in the cooling pools of the operating nuclear power plants are caused by the combined effect of radioisotopes of the different origin. The features of the formation of the radiation risks for each pool are specific and depend on the current radiation situation. The cooling pool of the Beloyarskaya NPP is characterized by a pronounced dependence of the radiation load on the types of operating power units. The ichthyofauna experienced the greatest radiation risks during the operation of the first two power units with thermal reactors AMB-100 and AMB-200. The decommissioning of the first power units and the construction of the units with the fast neutron reactors (BN-600 and BN-800) led to a significant reduction in the radiation load on the ichthyofauna of the cooling pool. At present, the radiation risks are caused mainly by the influence of 90Sr, which is almost not discharged from the Beloyarskaya NPP into the cooling pools, but has a predominantly global origin. Therefore, the formation of the risks is more associated with atmospheric fallout of 90Sr, and not with the operation of the nuclear power plant. The radiation risks for the ichthyofauna of the Leningradskaya NPP cooling pool are caused by the combined effect of 137Cs as a result of the radiation accident at the Chernobylskaya NPP and radionuclides with induced activity (14C; 60Co; 3H 54Mn and 65Zn), the origin of which may be associated with the operation of the nuclear reactors of the NPP. The level of radiation risk for the fish fauna of the Novovoronezhskaya NPP cooling pool for 2009–2019 increased 2.2 times due to 60Co content increase in many components of the pool. As a result, 81.7% of the radiation risks in demersal fish species were formed by the affect of 60Co. It cannot be ruled out that 60Co content increase in the cooling pool of the Novovoronezhskaya NPP is a consequence of radioactive contamination of the groundwater as a result of the 1985 accident. The ecological risks for the fish fauna in all cooling pools are two to three orders of magnitude lower than the maximum allowable hazard coefficient. Thus, the normal operation of the nuclear power plants does not create unacceptable radiation risks that pose a real environmental threat to the fish fauna of the cooling pools.
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Clay peptization and clay swelling inhibition in the presence of carbonic acid, bicarbonate and carbonate ions and calcium ions
Abstract
Relevance. The need to ensure the integrity of the wellbore, composed of clay rocks, and the stability of drilling fluid when drilling in conditions of carbon dioxide and bicarbonate aggression.
Aim. To determine experimentally the effect of carbonic acid, bicarbonate and carbonate ions on clay depending on the presence of calcium ions in the dispersion medium.
Objects. Water contaminated with carbonic acid, bicarbonate and carbonate ions with different equivalent concentrations of calcium ions.
Methods. Inhibitory and peptizing properties of the objects of study in relation to the clay rock were studied by the method of clay swelling when it was in the water under study (on the Zhigacha-Yarov device); methods of chemical analysis (complexometric and acid-base titration) and potentiometry were used to control water composition and properties.
Results. The peptizing and inhibiting properties of drilling fluid depend significantly on the form of carbonic acid present in the dispersion medium and the equivalent content of calcium ions (Ca2+). It was found that carbonic acid (H2CO3) contributes to clay inhibition (coagulation), bicarbonate ions (HCO3–) and carbonate ions (CO32–) – clay peptization. Calcium ions (Ca2+) do not have an inhibitory effect in the presence of carbonic acid (H2CO3) – hydrogen ions (H+) displace exchangeable cations from the interlayer space of clays and, due to their small diameter, independently inhibit clay swelling. In the presence of bicarbonate ions (HCO3–), calcium ions (Ca2+) also do not have an inhibitory effect – bicarbonate ions (HCO3–), being in a dispersion medium, draw calcium ions (Ca2+) from the clay surface, increasing the thickness of the electrical double layer. In the presence of carbonate ions (CO32–) the calcium ions (Ca2+) precipitate and effectively prevent clay peptization only in the presence of hydroxide ions (OH–). The authors proved experimentally that calcium ions (Ca2+) in the presence of hydroxide ions (OH–) have a better inhibitory ability than hydrogen ions (H+) of dissociated carbonic acid (H2CO3). A mechanism was proposed for inhibiting the swelling of clays by calcium ions (Ca2+) in the presence of hydroxide ions (OH-), based on the adsorption of the hydrated calcium ion (Ca2+) on a silica tetrahedral sheet due to the preliminary protonation of its oxygen atoms by water molecules. The conditions required for clay effective peptization are formulated: [CO32–]≥0; [OH–]>0, [Ca2+]=0, pH>11.5; for clay swelling inhibition: [CO32–]=0; [OH–]>0, [Ca2+]>0 and pH>11.5.
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