Deposits of unconventional hydrocarbons are reserve sources of replenishment of the raw material base of Russia. A significant part of unconventional gas is associated with gas hydrates, the search and exploration of which today remains a complex task for geologists. The extraction technology has not been developed yet, and the search criteria are still unclear for many objects. Western Siberia permafrost plays the key role in the existence of gas hydrates, creating conditions for their formation and ensuring their stability. Geophysical studies using the shallow near-field transient electro-magnetic sounding method together with the analysis of the hydrogeological and cryogenic structure, as well as the results of drilling and laboratory experiments contribute to the study of permafrost and gas hydrate formation. The purpose of the study is to assess the possibilities and prospects for studying gas hydrates using surface electrical exploration in the Arctic permafrost zone. The paper considers the physical and geological characteristics of gas hydrate accumulations and their manifestation in geophysical study results. Examples of gas hydrate manifestation in sandy deposits of the Tibeysalinskaya formation are given based on the materials of electrical exploration using the method of shallow near-field transient electro-magnetic sounding. The intervals of possible presence of gas hydrates are characterized by increased values of specific electrical resistance up to 30 Ohm∙m. The application prospects of using geophysical studies for gas hydrates mapping in Arctic are outlined.

The article considers the possibilities of reducing the starting depth of studies using the near-field transient electromagnetic method by determining the effective transmitter-receiver offset. The solution of this problem is relevant due to the need to apply inductive electromagnetic exploration using ungrounded multi-offset templates in the climatic conditions of the Arctic. Optimization of the transient electromagnetic method technology in the far and near-field zones will expand the range of explored depths, which is extremely important for studying the accumulations of difficult to recover hydrocarbons located at depths from the first tens of meters to 3–4 km. To solve this problem for a half-space model, mathematical modeling of the transient electromagnetic signals was carried out taking into account the geometric spacing of soundings, which allowed to determine the effective signal offset by solving the inverse problem. On the basis of the mathematical modeling performed, a nomogram of the effective offset dependence on the transmitter loop size and template geometric spacing has been built. The use of the results obtained makes it possible to provide the actual starting depth of electromagnetic soundings from 7–10 m, which significantly increases the range of the studied depths due to the interpretation of the far-field sounding zone.

The purpose of the work is to demonstrate the possibility to clarify and correct medium-scale geological maps of precursors (scale 1:200000–1:50000) using low-altitude unmanned aerial geophysical survey which is the fastest and low cost method of obtaining geological and geophysical data. A quantitative assessment is given to the more accurate identification of the location of geological boundaries and potential ore-bearing structures of the Sukhoi Log type. The first stage of geological study of the area involved obtaining the data from low-altitude unmanned gamma and aeromagnetic surveys. The survey results were prepared, interpolated, visualized, and, finally, subjected to geological and geophysical interpretation. Lineaments of the highest and lowest values, as well as the maximum gradients were identified in the magnetic field while the areas with the least variability at the lowest values and positive anomalies were identified in the gamma field. Interpretation and cross-comparison of the specified data allowed to compile new geological maps of the day surface and pre-Quaternary formations without any ground geological survey but based on the ideas about the geology of the region and characteristic differences in the physical properties of rocks. Taking into account regional stratigraphic and structural search criteria, two sites promising for gold mineralization were identi-fied in the studied area. It is shown that the known geological boundaries in these areas are shifted relative to the real ones by 100–1400 m (on average by 300 m), which is a significant error both in terms of mining and drilling operation planning and general correct understanding of the geological situation. The results obtained are typical for the projects aimed at gold exploration in the Bodaibo District of the Irkutsk region. The results of the study allow to conclude that the express and inexpensive method is useful for the specification of the position of geological and promising ore-bearing structures in the area under investigation, as well as for similar areas in nearby licensed areas and other sites of the Bodaibo synclinorium.

Growing current demand for new water supply sources determines the need to search for new sources of groundwater. Since well drilling is expensive and environmentally risky, it is becoming relevant to use geophysical methods, in particular electrical exploration. Electrical resistivity tomography allows a detailed study of geological structure and properties of aquifers, but there are no clear recommendations for conducting electrical resistivity tomography studies when searching for groundwater in various geological conditions. To improve the accuracy and efficiency of geophysical works, it is proposed to perform mathematical modeling of electrical resistivity tomography data, which allows to assess the method sensitivity and possible measurement errors as well as to ensure the most accurate results. The purpose of the conducted study is to develop an optimal technique for groundwater exploration using electrical resistivity tomography in the conditions of permafrost distribution in the Bodaibo district. The technique takes into consideration possible groundwater occurrence conditions and includes mathematical modeling to assess the impact of permafrost on the data obtained. Numerical modeling has proved the efficiency of the method in permafrost areas. Water-flooded fractured areas characterized by low values of specific electrical resistance have been reliably identified in all obtained modeling data. The results of solving direct and inverse problems of electrical exploration compared with the data of production works performed in 2020 in the Republic of Buryatia and in 2022 in the Irkutsk region have shown that electrical tomographic studies, which were successfully confirmed by drilling, make it possible to identify a productive water-flooded horizon with a very high degree of confidence.

This paper deals with the process of developing and training a U-Net neural network for image segmentation of lakes and hillocks based on synthetic aperture radar and interferometric synthetic aperture radar data. The main goal of the work is to create an effective deep learning model capable of automatically identifying lakes and heave mounds based on complex radar images. To achieve this goal, several stages were carried out, including data collection and annotation, selection of the neural network architecture, training and validation of the model, as well as evaluation of its performance. At the beginning of the work, the process of creating a training dataset is described, which includes annotating images, highlighting features, and preparing data for training. Next, we consider the U-Net architecture, which was chosen because of its ability to efficiently segment objects in images. The choice of hyperparameters, such as the number of filters, the size of the convolution core and activation functions, is justified, and the Adam optimizer is used to achieve fast and stable convergence of the model. The learning and validation process of the model is described in detail with an emphasis on using the validation subset to monitor performance. Regularization methods, including early stopping, are used to prevent overfitting and improve the generalizing ability of the model. As a result, the importance of using deep learning for synthetic aperture radar and interferometric synthetic aperture radar data analysis is demonstrated, as well as confirmation of the effectiveness of the U-Net model for solving segmentation problems.

Seismic methods are among the most important tools in prospecting, exploration, evaluation and operation of oil and gas fields. The work includes three main stages: seismic data collection, their processing and interpretation. Seismic exploration can be carried out in 2D, 3D or 4D modifications. This study focuses on a 3D offshore seismic survey conducted in the deep shelf of the northern Gulf of Guinea in the Côte d’Ivoire Tano sedimentary basin. The purpose of the work is to assess the commercial prospects for discovering hydrocarbon deposits in the RUS-CIV block, identify the capabilities of seismic exploration, demonstrate effectiveness and sustainability of seismic analysis, which has been developed and improved over the years, achieving improved subsurface visualization results. The data providing reliable information on the seismogeological structure of the area under investigation have been obtained as a result of successive marine seismic operations in 2003–2009. A detailed study allowed to form objective ideas about the internal structure of the block, in particular about the layers of Cretaceous deposits. Also, data were obtained on the presence of a fault network in sedimentary rocks, possible hydrocarbon traps, the nature of pore pressures and the type of fluids. However, the conclusions made remain preliminary, have a qualitative nature and should be confirmed by additional analyses due to the fact that there are no drilled wells in the studied block. Based on the study results, the most promising areas have been identified for detailed interpretation based on the analysis of the dynamic characteristics of seismic waves, seismic exploration data and the choice of the exploration well location.

The purpose of the research is to study and systematize relevant scientific works on monitoring and telemetry systems for operating parameters of borehole core drilling in glaciers and subglacial rocks with electromechanical cable-suspended drills. The study includes a review of monitoring and telemetry systems for operational parameters of core drilling with electromechanical cable-suspended drills, which are used by domestic and foreign specialists when drilling wells in ice and subglacial rocks on islands in the Arctic and Antarctica. Based on the results obtained, a unified concept of the considered systems is defined and their features are outlined. A functional block diagram of a monitoring and telemetry system for operating parameters of core drilling with electromechanical cable-suspended drills is proposed. Taking into account the identified features and applied technical solutions in the monitoring and telemetry systems created by domestic and foreign specialists, the authors of the article formulate the requirements for the monitoring and telemetry system of the core drilling of rocks using a reciprocating rotary method. These requirements will be taken into account when developing a system for monitoring and telemetry of the reciprocating rotary method of drilling boreholes in subglacial rocks, which is one of the stages of the research conducted as a part of development and justification of the technology of subglacial rock core sampling in Antarctica by a dynamically balanced cable-suspended drill.

The purpose of the research is to study the geoecological situation in the urban-type settlement of Vershino-Darasunsky (Transbaikal region, Russia), where a plant producing white arsenic for chemical warfare agents operated from the 1930s until 1973. Reclamation did not follow the shutdown of the plant, which causes a serious environmental threat not eliminated with past decades due to the low priority of this territory in the register of objects of accumulated environ mental damage. The authors consider the current facility assessment, which is based on data on the insignificant area in the boundaries of the former industrial site of the plant, to be critically underestimated. The latter is the main reason for the failure of a number of attempts made by executive authorities for years to launch the development of this site reclamation project. The conducted research is an illustrative case study from real Russian environmental practice and may be of interest to academic and professional communities. The study includes the analysis of the relevant regulatory framework for the assessment and elimination of the objects of accumulated environmental damage as well as the adopted method ology to carry out the assessment. A complex of field and laboratory studies was conducted on the area of 16.5 km², more than 150 soil samples were taken. The article presents the first results of geochemical soil studies, according to which it is not only contaminated industrial site, but also the entire studied territory, which has changed its physico-chemical parameters over many decades are the sources of negative impact on environmental objects. Anomalies of arsenic and heavy metals exceeding the maximum permissible and approximate permissible concentrations by hundreds and thousands of times have been detected, and they are localized not only in the area of the known facility of accumulated environmental damage, but also in several other places without currently visible sources of man-made impacts. The results obtained made it possible to declare the need to expand the reclamation area beyond the immediate territory of the former plant. In accordance with the accepted criteria, the environmental hazard indicator has been recalculated and the need to change the reclamation prioritization of this facility has been justified. Moreover, based on the existing regulatory framework, recommendations are given for further assessment of the impact of objects of accumulated environmental damage on the lives and health of citizens.