The work perpetuates the names of scientists and discoverers of hydrocarbon deposits who have contributed to the development of the oil and gas industry. These figures are the finest examples of service to the Motherland, Society, and Science. The article is based on the results of a report at the plenary section of the international scientific conference entitled “Formation and development of the oil and gas industry — the contribution of Russian and Azerbaijani scientists and specialists”.

Background. Due to the complex tectonic structure of the Sea of Okhotsk shelf and intense geodynamic activity in this area, specialized technologies are required to study reservoir properties. In this work, we implement the technology of secondary permeability estimation using the Kirinskoye and Ayashskoye license blocks as an example. The research objects included structural and lithologic traps of different complexes. It was found that the Prisakhalin shelf, including the Kirinsky and Ayashsky license areas, is subject to the modern shear stress field with the sublatitude-oriented axis of maximum compression. This initiates the formation of a local stress field, launches changes in the degree of fracture openness, and determines the secondary porosity and permeability of rocks. 3D modeling allowed us to calculate predicted permeability for each stratigraphic horizon. A significant difference of secondary permeability in the upper and lower stratigraphic horizons is noted.

Aim. To evaluate secondary filtration and capacitance properties of reservoirs by geomechanical modeling.

Materials and methods. Geomechanical modeling to assess the filtration and capacitance properties of Sakhalin shelf reservoirs was carried out using the ROXAR software package.

Results. This work allowed not only the filtration efficiency to be predicted, but also the processes occurring in the geological section of the shelf of the Sea of Okhotsk to be elucidated.

Background. Although the recent years have seen a significant increase in the amount of geological and geophysical data on the oil and gas potential of the Yenisei-Khatanga trough, no notable hydrocarbon discoveries have been made within its northeastern part. This is primarily related to a lack of understanding of the development of sedimentary basins, along with the processes of oil and gas generation, migration, and accumulation. This determines the need to generalize and analyze the accumulated geological, geophysical, and geochemical data within the framework of a comprehensive basin analysis and revision of the existing geological models.

Aim. Elucidation of the evolution of sedimentary basins in the northeastern part of the Yenisei-Khatanga trough and the adjoining Anabar-Khatanga saddle; updating the geological model of the sedimentary cover for further assessment of hydrocarbon systems.

Materials and methods. Development of a numerical geologic model of the Yenisei-Khatanga trough and the adjoining Anabar-Khatanga saddle based on available publications and engineering reports. A basin analysis and paleogeographic reconstructions for the main time steps of sedimentary cover evolution.

Results. The evolution of the sedimentary basins under study has been reconstructed, and the main stratigraphic units in the development of hydrocarbon systems have been identified. Depositional environments supporting the development of the essential hydrocarbon system elements have been delineated for further hydrocarbon system modeling and geological risk assessment.

Background. The sedimentary cover of the Leno-Anabar trough and the adjacent Anabar-Khatanga saddle show signs of oil and gas bearing capacity, which indicates the presence of generation and accumulation hydrocarbon systems. In addition, the offshore area of the Laptev plate and the adjacent Siberian platform is promising in terms of oil and gas potential, since the sedimentary basins, including hydrocarbon systems, are characterized by a transboundary (onshore/offshore) position. Until now, the offshore and onshore parts of this area have been investigated separately. Such an approach significantly reduces the estimation accuracy of hydrocarbon potential. This determines the relevance of developing a unified regional geological model of the junction zone, which may serve as the basis for further oil and gas geological studies.

Aim. Construction of a geological model to trace the development of sedimentary basins within the junction area of the Laptev plate and the Siberian platform.

Materials and methods. Collection and analysis of published materials, as well as data from geological repositories related to geological, geophysical, and geochemical investigations of the sedimentary cover in the construction of a geoinformation database; development of a numerical geological model of the studied area; carrying out paleogeographic reconstructions with identification of the main depocenters and domains of consistent subsidence delineation; assessment of sedimentation rates of the main sedimentary complexes.

Results. A unified geological model of the junction area of the Laptev plate and the Siberian Platform was created, enabling investigation of the sedimentary basins and delineation of the essential hydrocarbon system elements.

Background. The construction of a nuclear power plant inevitably requires excavation of a deep pit. This task may be impeded by high groundwater levels. The groundwater inflow into the pit can be limited by erecting a cut-off wall. As a rule, the cut-off wall is deepened to the aquitard elevation; however, the presence of hydrogeological windows therein may reduce the efficiency of such a solution.

Aim. To determine the nature of clay layer deformation along the regional dislocation area of the Paks II NPP construction site.

Materials and methods. A comprehensive geological and hydrogeological study was carried out to identify the continuity of the clay layer. This included an analysis of core samples from more than 1000 engineering and geological boreholes, surface and borehole geophysical surveys, a multi-level borehole network for groundwater level monitoring, as well as numerical hydrogeological modelling.

Results. It was found that extensive borehole data does not always guarantee the sufficiency of information for mapping the hydrogeological settings. The continuity of the clay layer with a vertical displacement amplitude of 100 meters was established through a probabilistic analysis using a numerical model and a set of hydrogeological surveys aimed at confirming or refuting the modeling results.

Conclusion. Assessment of hydrogeological conditions when implementing high-risk projects, such as nuclear power plants, underground excavations, and open-pit quarries, determines their safety and economic feasibility. In the absence or inconsistency of geological structure knowledge, hydrogeological surveys can serve as an independent source of missing information.

Background. During the first 10—20 years after the creation of large reservoirs, the process of processing of coastal territories is activated, which leads to the loss of land resources, has a negative impact on the existing coastal infrastructure and changes in the depth of the reservoir as a result of activation of the process of rock accumulation, destruction of coastal slopes. Shoreline retreat is 10—15 meters per year. The paper considers the process of recycling of reservoir banks on the example of the Volgograd reservoir.

Aim. Development of a methodology for studying and forecasting the process of reshaping of reservoir banks using remote sensing.

Materials and methods. The data of 1980—1990 on the actual magnitude of bank reprocessing of the Volgograd reservoir were collected, processed and analyzed, and the coastal territory was typified. It is proposed to use remote sensing materials to obtain the values of coastal overbanking for the period from the 1990s to the present time. Forecasting of the process of reformation of reservoir banks is carried out on the basis of application of mathematical statistics methods.

Results. On the basis of solving the set tasks, a universal new methodology for studying and forecasting reservoir bank reformation was proposed. The methodology was tested on the materials of the Volgograd reservoir.

Conclusion. The proposed new methodology makes it possible to obtain data on the dynamics of the Volgograd reservoir bank reformation process and to make a forecast for the next 10 years. This methodology can be used to study the process of bank reformation of large reservoirs.

Background. The main aspects of the influence of suction pressure on slope stability are considered; an example of calculations in the Plaxis software is presented. Specific features in the behavior of unsaturated and saturated soils are described. A model for describing the behavior of saturated soil under the influence of suction pressure is proposed.

Aim. Soviet hydrophysic and soil scientists actively explored the relationship between capillary-sorption (structural or matrix) water pressure in the soil and humidity. However, the introduction of foreign methods and software based thereon into the engineering and geological practice of calculating the stability of slopes has raised the question about the influence of suction pressure of clay soils on the stability of slopes.

Materials and methods. The main research material was loams of the Moscow glaciation. Simulation was carried out based on the Muallem — van Genuchten model.

Results. The simulation results showed that suction pressure and capillarity directly affect the slope stability coefficient, provided that the similarity of other model parameters.

Background. The lower-middle course of the Selennyakh River in the Momsky and Abyisky districts of the Republic of Sakha, Yakutia, is characterized by a wide distribution of alluvial gold placers. The absence of obvious potential primary sources of these placers raises the question of their identification. Aim. To identify sources of gold placers found in interfluve area of the Selennyakh and Indigirka rivers, as well as to assess the gold-bearing potential of this area.

Materials and methods. The data on the studied area obtained in previous works was analyzed. Microprobe analysis (CSRF IGEM RAS) was used to study the composition of alluvial gold grains sampled during field works in the Vetvisty Creek, the right tributary of the Selennyakh River, conducted in 2020–2021. The mineral composition of heavy concentrate was also studied.

Results. The source of the gold placer under study was established to be an intermediate reservoir, i.e., Neogene coarse sand and gravel. Possible paths of gold transit within the placer were revealed. Theoretically, this allows enriched layers in the sediments feeding the placer to be localized.

Conclusion. In order to replenish the gold mineral base of the country, including in such hard-toreach regions as the Arctic zone of the Russian Federation, regional research projects should be resumed. In addition, new models should be developed for forecasting and prospecting of atypical placer deposits, with gold sources from Tertiary sediments filling large Cenozoic depressions in the western rim of the Yano-Indigirskaya lowland).

Background. Disperse megaspores from the Givetian deposits of the Mikhailovsky mine, Kursk Oblast, were studied for the first time. Following chemical maceration of the samples, their selection and identification, 12 species belonging to 8 genera of disperse megaspores were identified. The conducted analysis of the layer-by-layer distribution of disperse megaspores in the studied outcrop, two megaspore assemblages were established, describing the lower (M1) and upper (M2) parts of the section. Both assemblages are dominated by small-sized azonate megaspores of the Hystricosporites McGregor genus, although belonging to different species. The upper assemblage (M2) is more diverse in terms of taxonomic composition. Along with the Givetian deposits of the Mikhailovsky mine, the identified disperse megaspores were previously found in coeval deposits of Canada and Libya.

Aim. To study of disperse megaspores from the Givetian deposits of the Mikhailovsky mine (Kursk Oblast) and to establish megaspore assemblages for this section.

Materials and methods. Samples of the clay deposits of the Givetian stage of the Middle Devonian from the Mikhailovsky mine (Kursk Oblast, Zheleznogorsk) were collected by employees of the Paleontological Institute of the Russian Academy of Sciences (PIN RAS) in the summer of 2017. The samples were macerated at the Department of Paleontology using concentrated (55%) hydrogen peroxide. The samples heavily contaminated with megaspores were additionally treated with hydrofluoric acid and further purified in hot drops of denaturated alcohol. Selection, counting, and determination of macerated samples of disperse megaspores were carried out using an Olympus CZ65 stereomicroscope at a 20x magnification or greater. Microphotographs were taken using a TESCAN Vega-3 scanning electron microscope (PIN RAS).

Results. A total of 12 species belonging to 8 genera were identified. These included Hystricosporites McGregor, Verrucisporites Chi et Hills, Nikitinsporites Chaloner, Biharisporites Potonié, emend. Glasspool, Ancyrospora Richardson, Contagisporites Owens, Grandispora Hoffmeister, Staplin et Malloy, emend. McGregor, and Lagenicula (Bennie et Kidston) Dybova-Jachowicz et al. On the basis of disperse megaspore distribution along the section, two megaspore assemblages were established: M1 (lower, layers 7–12) and M2 (upper, layers 18–21).

Conclusion. The disperse megaspores established in the Givetian deposits of the Mikhailovsky mine were early described in the Arctic Canada. The majority of the studied megaspores were most likely produced by lycopsids. This conclusion is based on their comparison with identical in-situ megaspores, as well as on the ultrathin structure of the sporoderm, previously established for some species. Consequently, the Givetian forests of the studied region were populated with numerous lycopsids, including tree-like ones, among heterosporous plants, with an insignificant role of archaeopteridalean tree-like species.

Background. A rare morphological variety of magnesian serpentine, described in 1939 in the veins of the Lesnaya Varaka alkaline ultrabasic massif (Kola Peninsula) under the name “kolskite” is studied. For a long time, this variety has been considered an antigorite.

Aim. Identification of the polymorphic modification of “worm-like” serpentine; determination of its crystal chemical features and possible genesis.

Materials and methods. Samples were studied using electron probe analysis and scanning electron microscopy by a Jeol JSM-IT500 scanning electron microscope equipped with an INCA X-Max energy dispersion spectrometer; powder X-ray diffraction; infrared spectroscopy using a FSM-1201 IR Fourier spectrometer; and Raman spectroscopy using a EnSpectr R532 spectrometer.

Results. Serpentine “kolskite” is represented by lizardite with the empirical formula (Mg_2.79Al_0.04Fe³⁺_0.01)_∑2.84[Si_2.06O₅](OH)₄. The calculated parameters of the trigonal unit cell are as follows: a = 5.32(1) Å, c = 7.88(2) Å, V = 193.0(1) ų. An increase in parameter c compared to that of apoolivine lizardite typical of ultrabasic objects indicates an expansion of the interlayer distance and is associated with serpentine hydration.

Conclusion. The formation of “worm-like” lizardite aggregates could occur either by replacing vermiculite under the action of low-temperature alkaline hydrothermal solutions, or as a result of hypergenic alteration in the earlier apoolivine serpentine.

Background. The Stazh-2 deposit of blue corundum is a representative object in the post- Soviet territory with prospects for mining of jewelry crystal raw materials. In terms of its geological position, the deposit can be classified as a contact-reaction (bimetasomatic) deposit formed in the contacts of granite veins and magnesites, being comparable to the world-famous Kashmir Sumjam deposit. During its study at the end of the last century, no mineralogical studies of blue corundum were conducted using precision methods, such as IR, Raman and absorption spectra, DiamindView luminescence, in order to establish patterns in color distribution, solid and gas-liquid inclusions, deformations and chemical composition. Determination of these parameters could serve as a basis for the involvement of crystal from this deposit in the jewelry industry.

Aim. Examination of blue corundum from the Stazh-2 deposit located in Archean magnesite marbles of the Goran metamorphic series of the South-West Pamir using IR, Raman spectra, absorption spectra, and DiamondView luminescence to establish color distribution within crystals, solid and gas-liquid inclusions, deformations, and their chemical composition.

Materials and methods. Four polished plates weighing from 0.48 to 0.76 carats with an area of about 1 cm² and a thickness of 1.5—2 mm, as well as two faceted inserts — “Oval” 2.86 carats, 9.5x7.5 mm, and “Circle” 1.35 carats, 9 mm. The inserts were prepared from samples from the collection of the Department of Mineralogy and Gemology, Russian State Geological Prospecting University (MGRI). The research methodology comprised (1) optical microscopy using a Leica S9D stereomicroscope; (2) infrared spectroscopy in the mid-IR range from 400 cm^-1 to 4500 cm^-1 with a Nicolet iS50 FT-IR Thermo Scientific FT-IR spectrometer, detector DTGS KBr, aperture 200, resolution 4 cm^-1 , PIKE DRIFTS attachment; (3) Raman spectroscopy using a confocal Renishaw InVia Qontor Raman-microspectrometer with an excitation solid-state laser 532 nm, nominal power 100 mW and diffraction grating 1800 lines/mm; (4) UV-Vis-NIR absorption spectroscopy by a PerkinElmer Lambda 1050WB spectrometer in the range of 270—1200 nm, a spectral resolution of 0.5 nm, a scanning speed of 56.7 nm/min; (5) micro-X-ray fluorescence analysis using a Bruker TORNADO M4 micro-XRF spectrometer with an X-ray tube power 20 W and a vacuum mode of 20 mbar, an X-ray beam diameter of 50 μm; (6) luminescence imaging in short-wave radiation 225 nm, recorded using a Diamond View device. Instrumental studies were carried out at the Gemstone Research Laboratory of Gokhran of Russia.

Results. (1) For the first time, spectrometric data of blue corundum from the Stazh-2 deposit were obtained by IR-, Raman, and UV-Vis-NIR spectroscopy methods, as well as micro-XRF. (2) In blue corundum, a local (focal) content of chromium, an element alien to granites, was established. Here, metasomatites with corundum were formed. Areas with chromium exhibit sharp rectilinear boundaries. (3) Zircon, diaspore, boehmite, muscovite, calcite, as well as gas-liquid inclusions with CO₂, were determined in the composition of blue corundum. (4) Two color generations due to newly formed fractures and minerals were identified. (5) The inclusions of diaspore, boehmite, muscovite, and calcite are the result of the hydration and carbonation reactions that occurred between corundum and anorthite at later development stages. (6) The blue corundum samples contained Ti and Fe with a predominance of Ti over Fe, which is a distinctive feature of the Stazh-2 deposit from other deposits of blue corundum and sapphires.

Conclusion. The obtained materials can be used by Gokhran of Russia for identifying sapphires of the contact-reaction (bimetasomatic) genesis, which include Kashmir sapphires of the highest quality, as well as for educational purposes.

Background. The current state and pressures associated with the anthropogenic impact on the Caspian region environment are examined. Surrounded by five coastal countries, including the Republic of Azerbaijan, the Russian Federation, the Republic of Kazakhstan, Turkmenistan, and the Islamic Republic of Iran, the Caspian Sea is the world’s largest endorheic water body. The isolation of the Caspian Sea, which is characterized by special climatic conditions and salinity gradients, has led to the formation of a unique ecosystem.

Aim. Environmental impact assessment of the Caspian region and the associated anthropogenetic load.

Materials and methods. The anthropogenic processes affecting the environment of the Caspian Sea and the surrounding area were assessed using the DPSIR concept. This concept includes the components of driving forces, pressures, state, impacts, and response in order to inclusively determine the connections between human activities and the environment. This concept was used as by the European Environmental Agency as the basis for integrated environmental analysis.

Results. The conducted study determined the scale and geography of greenhouse gas degassing, the volume of pollutant emissions into the atmosphere by components, the structure of greenhouse gas emissions, and the dynamics of emissions of carbon dioxide, methane, and nitrogen oxide generated from stationary sources in the Caspian region. Anthropogenic emissions of greenhouse gases that pollute the atmosphere and sea waters, generated from stationary sources, are formed as a result of the production activities of a number of industries: mining; electricity, gas, and steam generation; air conditioning; manufacturing; water supply; wastewater treatment; construction industry; agriculture and forestry; transport storage and communications; repair of vehicles and motorcycles; as well as other activities.

Conclusion. The share of enterprises in the fuel and energy complex that emit greenhouse gases is about 60%. The structure of greenhouse gas emissions and the dynamics of CO₂, CH₄, and N₂O emissions generated from stationary sources in the Caspian region are shown. The Caspian Sea is one of the most important endorheic basins in the world. Being surrounded by land on all sides, the Caspian Sea lacks flows that would maintain its self-purification. Pollutants that enter the Sea remain there due to the lack of mechanisms for their removal. Complete information about the level of pollutant inputs is crucial for selecting the most effective means of environmental compensation or pollution reduction. The largest polluting sectors are agriculture, industry, including oil and gas, and urbanization.

Background. The system of environmental monitoring in the Republic of Ecuador and its history is considered using the Galapagos Islands as an example. The need for its modification with the purpose of preventing the negative consequences of human activity is substantiated.

Aim. To assess the environmental consequences of anthropogenic activity in the Galapagos Islands and to propose a unified environmental monitoring system for two protected natural areas of the Galapagos Islands.

Materials and methods. The current laws and legislative acts related to the activity of the Republic of Ecuador state institutions in the field of environmental monitoring were analyzed. Statistical data and reports on monitoring programs in the Galapagos Islands were reviewed.

Results. A unique environmental monitoring program for two protected natural areas of the Galapagos Islands was developed. It is recommended to complement the program with a system of stationary observations. This system is aimed at collecting data for assessing the impact of socioeconomic activity on the nature of the islands, monitoring the state of ecosystems, rare, endemic and invasive species, as well as for conducting scientific research to restore populations.