This article investigates the impact of geothermal water from the Cherkashinskaya No. 36-RG self-injection exploration well on ecosystem watercourses. The well was drilled in 1965 to investigate deposits of iodine-bromine water. This article presents estimations of the acceptable levels of radiation hazard content in the water and near-bottom sediments of gravity-flow hydrogeological wells. The radiation safety of working with these materials for personnel in geological exploration and national economic enterprises is also evaluated. The article provides information on the study of the natural radiation background, as well as results on the natural radioactivity of the bottom sediments and the volumetric radium content of the water. Natural radioactivity in the bottom sediments of potassium (⁴⁰K) and thorium (²³²Th) is analyzed in this study. The relevance of this research originates from over fifty years of pollution by highly mineralised iodine-bromine water within the catchment area of one of Western Siberia's largest transboundary rivers, the Irtysh River. The Aremzyanka River is first-order tributary of the Irtysh River, and it receives water from a stream originating from exploration well No. 36-RG.

During the geological modeling process, it can be problematic to substantiate predicted faults or barriers that are estimated from seismic data and require additional research. However, logging data from horizontal wells (LWD — logging while drilling), whose trajectories intersect predicted seismic faults or hydrodynamic barriers, can be used to validate such barriers.

The aim of this study is to substantiate hydrodynamic barriers in several fields in Western Siberia using data from a complex of geophysical surveys conducted while drilling horizontal wells that pass through such barriers. The main research method is azimuthal gamma-gamma density logging and its interpretation to identify hydrodynamic barriers, including tectonic faults, based on the criteria described in A. V. Chashkov's, S. Z. Mutaev's and other scholars' works.

This study presents the practical application of the azimuthal gamma-gamma density logging method to substantiate predicted seismic faults, estimated from seismic data and require additional research, using the example of the First field. This model has been examined and accepted by the State Reserves Committee.

The investigation of the permafrost zone situated in the Yamal Peninsula pertains to gasand hydrate-saturated intervals. The avoidance of gas discharge frequently met during well drilling is of utmost importance. The allocation of permafrost rocks governs the quest for novel approaches to analyze the geocryological situation of the locale, together with ascertaining the principal regularities of the zone structure, ascertained via geological and geophysical investigations, analysis of well drilling data, and seismic assessments.

The investigation of the permafrost zone plays a crucial role in well drilling to prevent various types of complications. Moreover, the interpretation of geophysical survey data in combination with drilling and seismic data allows us to construct a model of the zone's lateral spread.

Carrying out geophysical methods helps to prevent, to some extent, and also prevent possible emergency situations. A fairly large fund of geophysical material has been reviewed, and a complex of studies in the permafrost zone of the Yamal Peninsula in many fields has been analyzed.

Following these studies, this article presents the primary geophysical survey material interpretation techniques with highlighted criteria for identifying different permafrost conditions in rocks.

Two contact masses were obtained and analyzed for their catalytic properties in the production of hydrophobic coatings. These masses are based on the silicon-copper system and consist of 25%Cu-75%Si and 50%Cu-50%Si compositions. A standard method of copper(I) chloride reduction was optimized to obtain finely dispersed copper particles with high catalytic activity. It is shown that reduction is possible directly in contact with silicon, the resulting average diameter of copper particles is 5-10 microns in both contact masses (25%Cu-75%Si and 50%Cu-50%Si). A metallographic analysis revealed a loose morphology of the silicon-copper phase interfaces, which is necessary to enhance the catalytic activity of the contact masses. Local chemical analysis by scanning electron microscopy has established the ratio of the particle size of the initial polycrystals of copper chloride(I) and the resulting copper particles as a result of reduction on silicon. The process of deep reduction makes it possible to obtain particles up to 5 microns in size. These results provide useful insights into the formulation of coatings containing organosilicon compounds to reduce friction in hydrocarbon transport.

Applying nitride or oxide coatings in the form of thin layers is a method that can enhance steel structures and resilience of oil pipelines against flooding and corrosion. Such coatings have excellent corrosion-resistant properties. The article presents the results of an assessment of the use of both ionic and electronic modifications of nitride coatings (TiN) on stainless steel to enhance its resilience against hydrogenation and degradation processes occurring during the hydrogen accumulation in the surface layer. These processes lead to embrittlement and corrosion of steel. O²⁺ and N²⁺ ions with an energy of 20 keV/charge were chosen as ions for modifying the coatings; the irradiation fluences were in the range of 10¹³-10¹⁵ ion/cm² . Electrons with an energy of 500 keV and radiation doses from 100 to 500 kGy were utilised to carry out the electron modification process. The experimental results indicate that modifying the ionic content contributes to the creation of more dislocation defects in the structure. This accumulation of defects results in improved strength and resistance to cracking. Through electron irradiation, the thermal effect primarily modifies the crystal structure, enhancing both its stability and densification. An analysis of the effect of hydrogenation and corrosion has demonstrated that ionic modification using a fluence of 5 × 10¹³ ion/cm² enhances the stability of the coating structure and elevates corrosion potentials.

In the development of gas fields, reservoir pressure can be used to estimate gas reserves by means of the material balance methodology and to calculate drained reserves. This provides an indication of the effectiveness of the development system. The authors of the article suggest a methodology for determining drained reserves in wells without reservoir pressure measurements. This approach is useful if the well stock is put into operation concurrently or within a brief period of time. Numerical modelling and analysis of field development data have led the authors to conclude that the current flow rate of wells, the hydrodynamic parameters of the productive formation and the interference of nearby wells are the most significant factors controlling the amount of drained reserves. The use of this technique will improve the understanding of the current processes occurring in the reservoir, clarify the assessment of the energy of the deposit and the value of the initial gas reserves, and also create an additional source of information for timely and more accurate decision-making in field development. Adopting this methodology can improve the understanding of ongoing processes in the reservoir, enhance evaluations of reservoir energy and initial gas reserve sizes, and provide additional information resources for making decisions on field development in a more timely and precise manner.

When leaving the drilling of gas wells at the fields of Western Siberia, various methods and technologies are employed for their development, such as the secondary opening of productive formations. While undertaking the secondary opening, it is essential to maintain the reservoir properties of the bottomhole formation zone. Liquids for perforation work must be employed for this purpose. Simultaneously, it is recommended to use salt-based perforating liquids treated with CMC-700 and sulfacell, on a hydrocarbon basis (diesel fuel and gas condensate) and on acidic compositions with a high permeability recovery coefficient for carrying out perforation work at equilibrium and depression. After conducting laboratory experiments, we have selected perforating liquids with a permeability recovery coefficient of over 96 % and perforating liquids based on acid compositions with a permeability recovery coefficient of over 180 %.

An increase in the share of hard-to-recover oil in the total balance of its reserves, which is particularly important for the Republic of Bashkortostan, inevitably makes it necessary to search for and commercially introduce new ways to extract it. Among the many methods of increasing oil recovery and intensifying the inflow, the method of influencing the bottomhole zone of the formation with a high-frequency electromagnetic field is distinguished, which, despite many years of research, is still considered experimental in Russia and is limited to evaluating the production and technical characteristics of use. At the same time, financial and economic indicators are overlooked, the identification of which will justify the relative low cost and high profitability of the innovative method.

The purpose of the study is to determine the feasibility of introducing methods of oil field development based on the use of electromagnetic field energy. The main research methods are the analysis of scientific literature on the research topic, systematization and generalization of specialized state statistics data. The calculation part uses methods of economic analysis and business analytics.

The existing technologies for oil field development in the Republic of Bashkortostan are considered, a conclusion is made about their obsolescence and the need to replace them with technologies based on new physical principles. The prospects of electromagnetic technologies and the degree of development of this topic in the scientific environment of Russia and the Republic of Bashkortostan are indicated. With the help of modelling, the economic effect of the introduction of technology for influencing the bottomhole zone of the formation with a high-frequency electromagnetic field has been established, the possibilities of covering the deposits of the Republic of Bashkortostan suitable for development have been determined.

The results of the study can be used in the analysis of the prospects of regions with the predominant development of the oil production and oil refining complex, on the territory of which there are large areas of depleted fields that require the use of innovative technologies for additional production. Further research may be devoted to assessing the economic and technological efficiency of using electromagnetic and other innovative technologies for influencing the reservoir directly in fields with different properties of residual oil and geological and geophysical parameters of the host reservoirs.

One of the key tasks in oil and gas well development today is to optimize the cost of various technical processes, including the preparation of drilling muds. The article explores technological remedies to decrease the concentration of potassium chloride, which is the main inhibitor of the hydration of clay rocks, in the composition of drilling mud used for horizontal well drilling. Additionally, it was demonstrated that the drilling mud left after the initial drilling of the productive formation could be reused. Due to the fact that the interval of the horizontal section of wells is represented mainly by sandstone, the composition of the drilling mud must be refined so that the use of inhibitor reagents can be reduced. Reuse of spent drilling muds in the construction of horizontal wells reduces the consumption of multi-tonnage components without impairing the processability of the flushing fluid used. The implementation of this approach will enable the achievement of economic benefits through a reduction in expenses for the preparation of drilling mud and in the amount of drilling waste generated.

Currently, numerous enhanced oil recovery reagents and application technologies have been developed in the domains of flow rejection and injection profile levelling. The choice of stimulation methods is reliant on the geological and physical conditions of the reservoir. Therefore, the accuracy of this choice has a direct impact on the efficiency of implementing enhanced oil recovery technologies.

The current availability of low-volume chemical enhanced oil recovery reagents for high-temperature reservoirs is limited, and their effectiveness varies. This article presents the results of a pilot study from 2018 to 2021 aimed at improving oil recovery in high-temperature reservoirs. The study involves evaluating approved levelling technologies for injection profiles that use thermotropic compositions "Complex 377" and "EOR701R", as well as the polymer composition "EOR909R". The geological and physical conditions of their approbation, as well as the primary injection parameters and resulting findings, are provided.

This information will be valuable to professionals engaged in enhanced oil recovery methods for oil reservoirs, as well as those working on the implementation of physical and chemical methods for the same purpose.