The investigation of bitumen occurrences confined to zones of hydrothermal alteration developed within volcanic rocks of the Late Permian-Early Triassic age, intersected by a well in the upper part of the pre-Jurassic basement section at the Litvakovskoye oil field, is of critical importance for predicting the petroleum potential of the West Siberian basement. The presence of bitumen in metasomatically altered basalts provides evidence of either a destroyed oil accumulation or the existence of hydrocarbon migration pathways within the pre-Jurassic complex. According to mineralogical and petrographic data, hydrocarbon emplacement occurred after the hydrothermal-metasomatic alteration of the volcanic rocks. Based on V.A.Uspensky's classification, the studied bitumens are identified as pure asphaltites and transitional asphaltite - kerite varieties. Molecular composition and carbon isotope data suggest that the precursor source organic matter of the naphthides was formed under reducing conditions in a shallow basin with elevated water salinity and clay - carbonate sedimentation, which may have received humic material input. The level of thermocatalytic transformation of the bitumens corresponds to the early phase of the oil window. The naphthides have been variably affected by hypergenic and, possibly, migrational processes. In addition to the typical biodegradation markers - C-28-C-34 25-norhopanes - the bitumens reveal, for the first time, their lighter homologs: demethylated tricyclic C-19 and tetracyclic C-23 terpanes, as well as unusual tetracyclic hydrocarbons of the hopanoid type (secohopanes C-27, C-29, C-30). These compounds, along with bicyclic terpanes C-17-C-24, may be considered a distinctive feature of the solid naphthides from the pre-Jurassic complex of the study area. The bitumens are characterized by low sterane content and exhibit specific compositional features similar to those of crude oils from the Kotyg'yeganskoye and Severo-Khokhryakovskoye oil fields. The distribution of tri- and tetracyclic terpanes indicates a similarity between the bitumens and both crude oils and bitumoids of the Tyumen Formation. The observed sterane and terpane signatures in the bitumens may be attributed to the contribution of humic material to the precursor source organic matter and suggest a possible genetic link between the naphthides and the deposits of the Tyumen Formation.
The global volume of natural gas trapped in hydrate deposits far exceeds the conventionally recoverable hydrocarbon reserves. However, the high costs associated with hydrate production, transportation, and storage currently hinder the large-scale implementation of hydrate-based technologies. A promising way to reduce these costs is through phase transition technology, which involves & Scy;& Ncy;(4) hydrate depressurization in the presence of biosurfactants, followed by & Scy;& Ocy;(2) formation. This approach also enables carbon dioxide sequestration, addressing the corresponding environmental concerns. Biosurfactants, which are naturally present in many hydrate reservoirs, enhance hydrate growth and accelerate & Scy;& Ncy;(4)-& Scy;& Ocy;(2) exchange. The newly developed method of producing highly porous ice using biosurfactants, presented in this research, provides higher formation rates, substantially reducing the time required for the process. Most importantly, this technique eliminates the risk of mixed hydrate formation-a major limitation, which hindered the replacement efficiency. As a result, the proposed sequential phase transition method decreases the total time of CO2 hydrate synthesis by two to three orders of magnitude compared to direct & Scy;& Ncy;(4)-& Scy;& Ocy;(2) replacement. The method is particularly effective for permafrost regions and offers a more environmentally friendly approach to developing gas hydrate deposits by minimizing methane emissions while enabling CO2 storage.
The work investigates the influence of seasonal changes in the composition of fresh water on the rheological properties of guar-borate hydraulic fracturing fluids. Between October 2024 and August 2025, monthly samples were taken from three sources in the Republic of Tatarstan, with analysis of pH (7.3-7.9), alkalinity (73-275 mg/l HCO3-), total hardness (180-520 mg/l Ca2++ Mg2+), chlorides (42-284 mg/l), sulphates (61-146 mg/l), and iron ions (0.1-0.3 mg/l). Fracturing fluids were prepared using these waters and tested on a Brookfield PVS high-pressure rheometer at 32 degrees C in accordance with ISO 3219:1993. The target viscosity range was approximately 400-700 mPa.s. We found that in water with high salinity (source N 2, average hardness similar to 419 mg/l, Cl->180 mg/l), gel viscosity decreased by 10-15 %, the time to recover to operating viscosity increased, and breakdown accelerated, which raised the risk of premature proppant settling. Correlation analysis showed strong positive correlations between hardness, chlorides, sulphates, and alkalinity (r = 0.53-0.90) for "soft" sources N 1 and 3, whereas in the mineralized water of source N 2 these correlations are weakened (r = 0.17-0.51). The results demonstrate that the seasonal increase in salinity (winter-spring period) significantly impairs the rheological stability of hydraulic fracturing fluids and emphasize the need for mandatory monitoring of water composition and adaptation of formulations during periods of peak salinity.
The hazard of rock bursts at the Khibiny deposits is largely due to their block structure and the natural gravitational-tectonic stress field in the rock mass. A detailed analysis of documented cases of rock bursts in the fields of the Kola Peninsula allowed to develop a classification of geodynamic events by the mechanism of their occurrence. During the analysis, it was found that in the period 1980-2024, 40 % of all rock bursts were associated with geological disturbances with high strength of the aggregate material. Such geodynamic events occur as a result of activation of a combined mechanism. The cause of the geodynamic event in this case is a combination of structural disturbances of the rock mass with a high level of tectonic stresses. An important criterion of rock burst hazard in the area of geological disturbances in highly stressed rock masses is their relative rigidity, and consequently, the degree of fracturing in relation to the natural conditions of the rock mass. The mechanism of this class of rock bursts can be described within the framework of the theory of rigid-platen theory. Based on the research results, the need to pay serious attention to the development of special measures to prevent or minimize the risk of geodynamic events when approaching tectonic disturbances with high strength of the aggregate material of the stoping and development workings is justified.
Wastes from mining and ore processing have a negative impact not only on surface- and groundwater, soils, but also on the state of the ground-level atmosphere. In highly permeable deposits of waste storage facilities, as a result of weathering of ores and rocks hosting mineralization, highly mineralized waters containing metals are formed. Under their influence, liquid aerosol flows are formed above the storage facilities. Their conditions of formation and chemical composition are still poorly studied. The objective of the work is to determine the qualitative and quantitative composition of toxic metals entering the ground-level atmosphere as part of aerosols from the storage facility of oxidized ores and overburden rocks stockpiled during the development of the Ozernoye polymetallic deposit. The tasks set are to identify the mechanism of aerosol flow formation from the aeration zone of storage facilities, to develop a methodology for sampling aerosols by condensing them, and to collect the amount of condensate required for analysis. The collected condensate samples were analysed by inductively coupled plasma mass spectrometry using Agilent 7500ce quadrupole mass spectrometer according to a certified procedure. We found that the total mineralization of condensation waters reaches 110-130 mg/dm3. The content of toxic elements (mercury, lead, zinc, copper) is several times higher than the concentration in surface waters of the area. In the snow cover in the area adjacent to the Mining and Processing Plant, manganese, zinc, copper, and mercury were found in abnormally high concentrations exceeding the MPC for fishery purposes. Their input into the snow cover is associated with evaporation from the surface of stockpiled wastes and transport of pollutants by air currents. The work shows that liquid aerosols containing high concentrations of toxic chemical elements are released into the atmosphere from the stockpile of oxidized ores and overburden rocks. To protect the natural environment, the enterprise needs measures to isolate stockpiled mining wastes from weathering agents and prevent aerosol input into the atmosphere, as well as to use personal protective equipment for personnel working with mining and processing wastes.
The paper presents the results of modeling stress fields and analyzing the strength of the rock mass at the Yeniseiskiy site (Krasnoyarsk Region), selected for the construction of an underground research laboratory. Variants of boundary loading conditions along the model boundaries are substantiated, and the results of modeling the distribution of stress tensor components for four loading scenarios are presented, along with an assessment of rock mass stability using well-known strength criteria, including Hoek-Brown, Mohr-Coulomb, von Mises, and others. Regularities in the distribution of stress fields within the rock mass and differences associated with the tectonic conditions of the area are identified. It is established that the localization of zones of stress intensity concentration depends on the ratio of the principal stress components. Orientation of compression in the submeridional direction leads to an increase in stress intensity by 10-15 % relative to other modeling variants. Zones of anomalous stress intensity values are located within blocks as well as in the footwalls of tectonic faults. The models are characterized by high values of the potential energy of distortion in fault zones (as parts of the rock mass most susceptible to deformation) and at their intersections. Three-dimensional modeling makes it possible to identify effects that are weakly expressed in plane strain models. The results of geomechanical modeling are required for planning experiments in the underground research laboratory in order to refine the isolation properties of the rock mass during the disposal of highlevel radioactive waste. Methodological approaches of three-dimensional modeling are applied by geomechanical and geotechnical services of industrial enterprises and other hazardous facilities (underground gas storage facilities, mineral deposits, etc.).
Fluorine-containing wastewater is one of the main problems of the mining and processing industries. Mining, dressing, and sulphuric acid digestion of apatite concentrate-all these processes are accompanied by the generation of vast amounts of wastewater with elevated fluoride content, which pose a serious threat to the environment. Conventional methods do not always allow achieving the required discharge standards, which in turn necessitates the search for alternative reagents. The main objective of this work is to assess the possibility of using waste from the mining and smelting sector (phosphochalk, magnesia scrap, dust from gas cleaning units) as precipitating reagents for the first stage of fluoride ion removal, followed by tertiary treatment with complex titanium-containing coagulants. We conducted experiments to select reagents and their dosages, the use of which will allow achieving the lowest residual fluoride concentrations in water. We found that using calcium/magnesium hydroxides does not allow meeting the standards for residual fluoride anion content. To achieve maximum precipitation efficiency, a 30 % excess of precipitating reagents is required. The study confirms that large-volume mineral waste can serve as precipitating reagents for fluoride ion, with treatment efficiencies of 94 % for phosphochalk, 90 % for magnesia refractory scrap, and 99 % for gas cleaning units. We proved the effectiveness of complex titanium-containing coagulants for water defluorination in comparison with conventional coagulants (aluminium oxychloride/aluminium sulphate). The use of a complex reagent not only significantly reduces coagulant consumption and minimizes residual fluoride anion content, but also substantially intensifies precipitation (by 1.5-1.75 times) and filtration of coagulation sludges (by 1.25-1.5 times). The developed conceptual diagram for wastewater defluorination using large-volume waste and complex titanium-containing reagents allows significantly reducing the level of negative environmental impact and taking a step towards implementing the circular economy concept.
The driving of mine workings in strong dolomites at the “Internatsionalny” mine using the drill-and-blast method is complicated by gas-dynamic phenomena, which manifest as rock and gas outbursts. The presence of fracture zones and significant rock pressure in rock strata at depths exceeding 1000 m has predetermined the occurrence of secondary rock failure from the face of opening workings. The paper presents the results of modeling the stress-strain state of the mine working face in areas hazardous for gas-dynamic phenomena, typical for the geomechanical conditions of the “Internatsionalnaya” kimberlite pipe deposit. The stress-strain state modeling was performed using the finite element method in the domestic software package CAE Fidesys. Eighteen geomechanical scenarios were considered for the position of the mine working face at distances of 2, 4, and 6 m from intensive fracturing zones with thicknesses of 2, 4, and 6 m, both with and without gas present. All computational models were constructed in a three-dimensional formulation at a depth of 1500 m, with vertical stresses equal to 40 MPa, which corresponds to Professor A.N.Dinnik’s theory. Horizontal stresses were applied to the side faces of the computational models via forced displacements under the condition of equicomponent compression, corresponding to a lateral earth pressure coefficient 1. The parameters of an equicomponent or near-equicomponent stress field at the deep horizons of the “Internatsionalnaya” kimberlite pipe are confirmed both by instrumental measurements and by global experience in mining operations at depths exceeding 1000 m. The research results indicate that a safe gas-dynamic state of the rock mass can be achieved by creating a non-reducible advance zone, the width of which is recommended to be determined based on the physical-mechanical and structural characteristics of the mine working drive section.
The results of the “Kovdor-2023” experiment on deep electromagnetic sounding of the Earth’s crust within the Archean basement of the southwest of the Kola Region with natural (magnetotelluric sounding, MTS) and artificial (controlled source audio magnetotelluric sounding, CSAMT) sources are presented. The experiment was intended to study the electrical conductivity of the upper Earth’s crust in the area of the Belomorian Block of the Fennoscandian Shield in continuation of the work of 1995, as well as the “Kovdor-2015” experiment, which suggested that the presence of a heterogeneous conductive layer (DD layer) with longitudinal conductivity from tenths to units of siemens in the upper part of the Precambrian crystalline crust at depths of up to ten kilometers is an inherent regional characteristic of the Fennoscandian Shield. During the 2023 experiment, technologically improved versions of field generating and measuring equipment and the new data processing methods were used. The earlier studies have identified the need for the modified measuring equipment with the frequency range expanded towards high frequencies, as well as for better synchronization between the source and receiver. Thus, to carry out the experiment, a new generator group and a new electronic unit combining functions of the control unit for the generator and the source output recorder, as well as a technique for synchronous processing of time series of current in the source and the electromagnetic field component at the observation point, were developed. The “Kovdor-2023” experiment was carried out using a new generator and a new measuring system, which made it possible to obtain additional information about the upper part of the object studied. Synchronous processing of new data was carried out, taking into account the materials and experience of the previous experiment, including static distortions and displacement currents. MTS and CSAMT data were used to construct a geoelectric section using the MARE2DEM program.
The study was conducted on the territory of the Daldyn kimberlite field, within the industrial site of the Udachny Mining and Processing Plant (Yakutia, Russia). The objects of the study were permafrost soils and two types of shrubs - Betula middendorffii T. (Middendorff birch) and Duschekia fruticosa R. (shrubby alder). Soil and plant samples were analyzed using atomic absorption spectrometry for the presence of potentially toxic elements (Pb, Ni, Mn, Cd, Co, Cr, Zn, Cu and As). Bioaccumulation coefficient and potential environmental risk factor were calculated for each element. In the studied plants, the elements of interest were arranged in descending order of content: Mn > Zn > > Cr > Ni > Cu > Pb > As > > Co > Cd, according to the degree of bioaccumulation Betula middendorffii T. characterized by a number of Cr > Zn > Ni > Mn > Pb > Cu > Cd > Co, and Duschekia fruticosa R. - Cr > Zn > Ni > Pb > Cu > Mn > Cd > Co. The research revealed that Betula middendorffiii T. and Duschekia fruticosa R. are resistant to high concentrations of elements, coherent kimberlites - Cr, Ni, Co and dolerites - Cu, Mn and Zn. The consequence of the occurrence of kimberlite magmatism in soils and plants are concentrations of Ni, Cr and Mn that are excessive for plants, which are identified as potential environmental risk factors. Most of the territory of the Daldyn kimberlite field is characterized by low and moderate environmental risk. Impact zones of kimberlite pipe quarries and waste rock dumps are characterized by significant and high potential environmental risk.
The article presents a comprehensive analysis of the mineralogical and geochemical features of xenoliths from the V.Grib kimberlite pipe, represented by lower crustal garnet-clinopyroxene granulites and mantle eclogites. A comparative characterization of the two xenolith types is conducted, as clear criteria for their distinction are currently lacking. The study identifies several distinctive features that unequivocally characterize mantle eclogites: elevated Cr contents (in garnets >300 ppm, in clinopyroxenes >1500 ppm), high pyrope content in garnet (>34 mol.%), and evidence of early metasomatism manifested as metasomatic garnet, spongy clinopyroxene replaced by pargasite, and phlogopite rims at garnet-clinopyroxene contacts. Evaluation of the pressure-temperature parameters of the V.Grib pipe xenoliths confirmed the mantle origin of eclogitic xenoliths formed at T = 800-1200 degrees C and P = 30-50 kbar, and did not refute the initial assumption of a lower crustal origin for granulitic xenoliths characterized by T = 750-800 degrees C and P = 14-15 kbar. To definitively resolve the issue of identifying lower crustal garnet-clinopyroxene granulites and mantle eclogites, a comprehensive comparison of the isotope-geochemical characteristics of "eclogitic" and "granulitic" zircon is proposed for future research.
More complete extraction of minerals from the subsurface by reducing their losses further actualizes the problems of improving mathematical models of mining objects. The purpose of this work is to create geometric models of typical complex-structured blocks (CSB) that can be extended to real CSB. They are based on mining and geological models of virtual (typical) complex-structured ore blocks of the bench, consisting of scattered continuous (the first type) and dispersed ore bodies (the second type). The key parameters of these blocks are coordinates of characteristic points of isolated continuous and dispersed ore bodies, the lengths of segments of the contact lines between the ore bodies and the host rocks, and the areas of the ore bodies on CSB cross-sections. They determine the mining and geological characteristics (ore saturation, complexity of the geological and morphological structure of the block) of these objects. These characteristics are analytically interrelated with geometric parameters of separated ore bodies and the size of the layer of admixed rock or lost ore. They are the basis for the developed methodology of calculation of numerical values of geometric and mining-geological characteristics of ore bodies and the block as a whole and geometric models of the CSB. A computer program for automated determination of mining and geological characteristics of the CSB according to the given initial key parameters of complex-structured blocks was created. An example of calculation of these characteristics for typical complex-structured blocks is considered, and the significance of the research results in CSB development is shown. The proposed methodology of calculation of mining and geological models of CSB is an information basis for making decisions on economical and environmentally friendly development of complex-structured blocks of benches. The research results can be used in the exploitation of real complex-structured deposits to significantly reduce losses and dilution of minerals.
The work addresses the issues of hydrosphere pollution in the Middle Urals resulting from the impact of acid mine drainage from abandoned copper mines. The study examined the concentrations of macro- and trace components in water and bottom sediments in the area of the Levikhinsky copper-pyrite mine, which was abandoned over 20 years ago, as well as changes in their concentrations along the following chain: mine water discharge (acidic environment) - neutralization (alkaline environment) - settling (acidic environment) - middle reach of a small river (slightly acidic environment) - mouth of a small river (neutral environment). Thermodynamic estimations showed that acidic mineralized waters are supersaturated with respect to minerals of the oxides and oxide-hydroxides groups. Strongly alkaline and slightly alkaline waters are supersaturated with respect to minerals of the oxides, oxide-hydroxides, hydroxides, and sulphates groups. Waters from all environments are close to equilibrium or undersaturated with respect to gypsum. The most intensive metal precipitation and sorption by bottom sediments occur in near-neutral environments: the concentration ratio (CR) exceeds n 105 l/kg for Al, Fe, Cu, and Pb. The performed assessment of the degree of equilibrium of anthropogenically impacted waters with respect to minerals allowed us to determine secondary mineral formation, the forms of metal migration in water bodies, and their impact on the environment. The obtained data are essential for justifying measures aimed at improving the state of the hydrosphere.
Soil pollution by oil and petroleum products is a serious environmental problem, especially relevant for industrialized regions. Microbiological remediation based on the use of oil-oxidizing microorganisms is a promising method of restoring polluted soils. The aims of the study are to develop a composition and assess the effectiveness of a specialized bio-based product adapted to the climatic conditions of northwest Russia. Bacterial strains capable of utilizing petroleum products as the only carbon source have been selected and cultivated. Based on laboratory tests, a consortium of microorganisms was selected, including strains of Acinetobacter sp. (VKM B-3202), Rhodococcus erythropolis (VKM Ac-858 T) and Pseudomonas alcaligenes (VKM B-1295), and their growth activity was evaluated. Three biologics compositions have been developed, differing in the proportions of bacterial suspensions by volume, and the technology of their application to oil-contaminated soils has been determined. The effectiveness of cleaning soils contaminated with oil and petroleum products (gasoline, diesel fuel, oil products from a spill at the Tammisuo railway station (Vyborg) at temperatures of 10-20 degrees C, typical for the climate of the region, was studied in laboratory conditions. At a temperature regime of 20 +/- 1 degrees C and natural soil moisture, after 60 days of the experiment, the maximum concentration reduction rates reached 75.59 % for crude oil, 71.97 % for oil products from the spill, 90.53 % for diesel fuel, 75.81 % for gasoline. At a temperature of 10 +/- 1 degrees C-40.62 % for crude oil, 49.58 % for oil products from the spill, 69.06 % for diesel fuel, 68.10 % for gasoline. The results of the study confirm the effectiveness of the developed bio-based product for oil-contaminated soil purification in the climatic conditions of northwestern Russia.
This study investigates unique weathering crust samples from the most altered sections (30-43 m) of the weathering profile within the Souktal Plutonic Complex, Northern Kazakhstan. The samples, obtained from two drill cores, consist of quartz, kaolinite, microcline, muscovite, and plagioclase, as identified through polarized light microscopy and confirmed by X-ray diffraction analysis. Sequential extraction of rare earth elements (REE) was performed using inductively coupled plasma mass spectrometry (ICP-MS) following a two-step leaching procedure with hydroxylamine hydrochloride (0.2 mol NH2OH & centerdot;HCl) and sodium hydroxide (1 mol NaOH) solutions. The extraction process effectively recovered REE, indicating their presence in an ion-exchangeable form, with total extraction rates (REE + Sc + Y) ranging from 4.1 to 7.8 ppm. The total light REE content varies from 3.5 to 5.9 ppm, while heavy REE content ranges from 0.2 to 0.7 ppm across all samples. Petrological and geochemical analyses suggest that the studied area represents an ion-adsorption-type REE weathered deposit. These findings enhance the understanding of ionic-adsorbed REE within weathering crusts and highlight the effectiveness of sequential extraction methods for REE determination. Moreover, the study suggests that this area holds promising potential as a future REE ion-adsorption site, contributing to the development of Kazakhstan's national REE industry.
Study of fracture mechanics in heterogeneous rocks, including crack initiation and propagation, has practical applications for geocontrol and identification of fracture zones in hydrocarbon well extraction. The features of microcrack zone formation depending on the type of rock heterogeneity under triaxial stress state conditions are considered. The research was conducted using an MTS 815 servo-hydraulic testing frame integrated with a Milne DAQ acoustic emission system (Itasca International Company, UK). The paper presents the fracture results of samples of various lithological types manufactured from cores of post-magmatic rocks. Fine-grained samples with gneissic and banded textures, as well as a coarse-grained sample with massive texture, were tested. During the tests, acoustic emission (AE) was recorded using 12 piezoceramic sensors. To describe the geometry of the fracture zone, the coordinates of AE event hypocenters were calculated, then the configuration of hypocenters distribution was analyzed using a tomography procedure (layer-by-layer construction of AE event density maps), and the angles beta between the direction of the macrocrack and the axial stress sigma 1 were determined. To interpret the failure evolution, trends of the b-factor and AE activity were calculated, the intervals of critical behavior of which were correlated with the localization and tomography data. After testing the samples, the types of their deformation and the mechanism of destruction with the phenomenon of dilatation were revealed. It is established that for the considered types of sample inhomogeneities, various microcrack structures are formed under the same volumetric loading conditions. In fine-grained rock of gneissic texture, a linear distribution of AE hypocenters is formed, indicating the formation of microcracks along the direction of layering. For the fine-grained rock with banded texture, the hypocenter distribution is characterized by the formation of distinct clusters, reflecting areas of the most intensive fracturing. In the coarse-grained massive texture sample, a volumetric distribution of hypocenters is observed, manifesting dilatancy properties and the formation of an extensive microcrack network.
With the increasing complexity of electrical equipment in mining enterprises, the development and analysis of methods to enhance the reliability of technical devices within power supply systems are becoming increasingly relevant. This article focuses on assessing the reliability parameters of workshop network circuits in mining enterprises equipped with single-transformer substations operating at 10 and 0.4 kV, considering various redundancy methods. Research objective is to evaluate the reliability parameters of different redundancy methods for power supply circuits in facilities with transformer substations at medium voltage (MV) and low voltage (LV), with respect to low-voltage switchgear consumers in mining operations. Research target is the power supply system of an auxiliary production workshop at a mining enterprise (Kemerovo). The study examines the following network reliability parameters: probability of failure-free (normal) operation, P(t); probability of failure occurrence, Q(t); failure flow rate, omega circuit; time between failures (TBF), & Tcy;TBF. The analysis covers the following circuit configurations: without redundancy; with redundancy at MV; with redundancy at LV; with dual redundancy (at both MV and LV). Estimation results indicate that the TBF for the nonredundant circuit is 2.04 times lower than for the LV redundancy circuit, 2.11 times lower than for the MV redundant circuit, and 2.8 times lower than for the dual redundant circuit. Redundancy proves to be a technically and economically justified method for improving the P(t) parameter of the facility's power supply system. The obtained results can be integrated into power supply system design (to optimize structural circuits and select rational redundancy methods for components), maintenance program development (to develop justified maintenance and repair schedules), reliability monitoring system development (to enable continuous monitoring of equipment status in mining enterprise workshops).
The issue of reducing electricity consumption costs is becoming relevant for industrial enterprises, taking into account the growing demand for electricity every year. The electricity consumption of air coolers at a gas processing plant was considered in the framework of this study. The change in ambient temperature (during the day and depending on the season) is the main disturbing factor affecting the performance of air coolers. With such significant seasonal changes in air temperature, its density changes, which causes fluctuations in the power consumed by the electric motor by up to 30 %. The issues of increasing energy efficiency, forecasting and determining the power consumption rate of air coolers, depending on changing external conditions, therefore become important. A methodology has been developed to determine the standard power consumption of air coolers depending on two factors-the ambient temperature and the load of the gas processing plant. A two-factor power-law approximation of the values was carried out due to nonlinear dependencies on plant loading and ambient temperature. The dependence of power consumption on ambient temperature and the loading of the installation on raw materials for any type of air cooler is determined with high accuracy (the root-mean-square error of the calculated and approximating values does not exceed 1 %). The formula for calculating the standard consumption of electric power of the air cooler at the considered installation was determined based on the results of the study. The methodology can be used by employees of gas processing enterprises to determine the standard electricity consumption of air coolers under changing climatic and technological factors.
The potential of hydroacoustic methods widely used in coastal engineering geophysical survey is limited in the presence of gas-saturated bottom sediments. Under unfavourable conditions it is advisable to use electric prospecting methods. This article analyses the efficiency of modern electric resistivity tomographic (ERT) technologies of the surface and seabed observation systems for studying the geological sections in coastal water areas. Basic geoelectric and electric resistivity tomographic models are synthesized to assess the influence of water salinity and lithological composition of sediments on the results of marine electric prospecting. Petrophysical modelling data showed that, along with the influence of pore water mineralization on the ratio of specific electric resistivity values of dispersed soils, the mineral composition of clay minerals has a significant effect. This effect is manifested as a shift in the position of the inversion point of specific electric resistivity values of sandy-clayey soils with increasing cation exchange capacity typical of different mineralogical types of clays. Results of numerical modelling of electric resistivity tomography sections using surface and seabed observation systems demonstrated that the seabed measurement system provides reliable information on geoelectric structure of sandy-clayey sediment sections, while the sections obtained from the ERT survey on water surface exhibit distortions in the geoelectric section structure and false anomalies. The advantage of seabed ERT for studying the geological structure of coastal marine areas was ascertained. Experimental work in the Luga Bay water area in the Gulf of Finland confirmed the efficiency of the seabed ERT for increasing the reliability of cross-well geological interpolation when constructing composite geological and geophysical sections. The use of seabed ERT ensured a continuous tracking of geoelectric boundaries corresponding to different lithological species in seabed sandy-clayey sediments.
The Arctic shelf zone is an important research target due to its significant hydrocarbon potential. A study of the physical properties (density, elasticity, elastic anisotropy index, specific acoustic impedance, and porosity) was conducted for core samples from six wells in the South Barents Basin: Admiralteyskaya-1, Krestovaya-1, Ludlovskaya-1, Shtokmanskaya-1, Arkticheskaya-1, and Severo-Kildinskaya-82. The sample collection consists of sandstones, siltstones, and limestones. Core analysis revealed that rocks from non-productive wells (Arkticheskaya-1, Admiralteyskaya-1, and Krestovaya-1), located in the central part of the South Barents Basin and within the Admiralty High, differ in their physical and petrographic properties from rocks in gas and gas-condensate wells (Shtokmanskaya-1, Severo-Kildinskaya-82, and Ludlovskaya-1), located near the boundaries of the South Barents Basin. Core samples from productive wells (Shtokmanskaya-1, Severo-Kildinskaya-82, Ludlovskaya-1) exhibit lower average P-wave velocities, lower specific acoustic impedance, and higher open porosity and/or elastic anisotropy index compared to non-productive wells (Arkticheskaya-1, Admiralteyskaya-1, Krestovaya-1). This combination of petrophysical parameters provides the reservoir properties of rocks prospective for hydrocarbons. The petrographic variation of the reservoir properties of the studied rocks from productive to nonproductive wells is associated with a decrease in grain size and a transition from pore-filling cement to thin-film and basal cement. The sandstones from the Shtokmanskaya well have a larger grain size (0.1-0.5 mm), whereas the sandstones from the Arkticheskaya-1 and Krestovaya-1 wells are finer-grained (0.1-0.2 mm). The Shtok-manskaya-1 well is characterized by pore-filling cement, the Arkticheskaya-1 - by thin-film cement, and the Krestovaya-1 - by cement of the basal type. The established physical properties of sedimentary rocks, suitable for the development of productive strata, will allow for the screening out of empty areas at the preliminary stage of analyzing geophysical materials during the search for geological and tectonic structures prospective for hydrocarbon accumulations.
