Tyumen State Oil and Gas University

Providing the extractive industry with new technologies to maintain the levels of oil and gas production planned in the strategy of the Russian Federation is the most important task. First of all, an increase in profitable reserves must be ensured; this goal can be achieved both through geological exploration and through the capabilities of “digital transformation” and the formatting of decision-making systems. A field controlled by artificial intelligence is a new reality. At the same time, the main task of AI is not to reduce jobs or completely replace humans in the field, but to provide a systematic, objective approach to decision-making based on physics and mathematics, and not on the personal experience of an individual. Currently, the main planning tool in the oil and gas industry is a geological and hydrodynamic model. Recently, thanks to an increase in design capacity, the industry has made an evolutionary leap in this direction and is transitioning to integrated modeling that combines both the underground and surface parts of the field. The future is neural network technologies, combined with classical methods into a single digital environment for optimizing all processes, from reservoir to processing and sales of products. In the new paradigm, the process of development management at different stages of field development requires a radical transformation of both the tools used for this and changes in governing documents. To meet the ever-accelerating pace of progress, timely updating of the legislative framework is required, development of regulations for integrated modeling, including all elements of research and production, from seismic exploration to field development; in addition, each stage of field development requires its own requirements for the quality and volume of initial information, in accordance with the new production paradigm.

Shale is a typical sedimentary rock that exhibits anisotropic strength characteristics owing to the presence of planes of weakness, such as bedding planes and joints. However, conventional quantitative risk assessment (QRA) models for wellbore stability often assume that shale is isotropic, leading to inaccurate predictions of the risk of wellbore collapse. This study proposes a novel QRA model of the wellbore collapse risk in inclined wells that considers the combined effects of anisotropic rock strength and parameter uncertainty. First, the semi-analytical model of wellbore collapse was revisited using various coordinate system transformations, the classical Bradley’s solution, and a single plane of the weakness criterion. Second, based on the reliability theory, a QRA method of wellbore collapse was established for inclined wells in formations with anisotropic rock strengths. Third, the K–S test and normal information diffusion (NID) method were used to determine the uncertainty of the logging interpretation results. The key parameters with significant uncertainty were obtained through sensitivity analysis. Finally, Monte Carlo simulation was conducted to quantitatively evaluate the risk of wellbore collapse. The results show that when the anisotropic rock strength is considered, the assessment of the equivalent mud weight (EMW) of the collapse pressure is more accurate. The failure of vertical wells primarily occurred within the rock matrix, whereas that of inclined and horizontal wells predominantly occurred along the planes of weakness. The pore pressure, Biot coefficient, and in-situ stress are the parameters with the greatest influence on wellbore stability. When considering the uncertainty of the weak plane occurrence, the collapse pressure EMW for inclined and horizontal wells significantly increased. The NID method yielded a more precise quantification of the parameter uncertainty compared with the normal distribution. The novel model proposed in this study incorporates the anisotropic rock strength and parameter uncertainty, resulting in more consistent predictions under actual conditions. This model and analysis provide a crucial theoretical foundation for drilling trajectory and drilling mud weight optimization to maintain wellbore stability of horizontal wells in shale formations.

The aim of the work was to analyze the relationship between carbon dynamics and changes in the states of natural territorial complexes in two key areas of the carbon polygon in the Chechen Republic from the standpoint of landscape and landscape‐geophysical approaches. The work was carried out at two sites of the carbon polygon in the Chechen Republic: in Chernorechye (the Chechen plain under water‐protective broad‐leaved forests, about 169 m above sea level) and Roshni‐Chu (low‐ mountain broad‐leaved forests, about 450 m above sea level).Methods: landscape‐geophysical description of geomasses, geohorizons and vertical structures in key areas, detailed microclimatic studies using installed loggers with temperature and humidity sensors, observations of the state of the vegetation cover, biomass dynamics, determination of mortmass fractions on the soil surface, as well as humus and basic nutrients.The relationship between carbon dynamics and changes in seasonal states of natural‐territorial complexes is expressed in changes in landscape‐ geophysical parameters: the ratio of geomasses, geohorizons and vertical structures. Seven seasonal states of natural‐territorial complexes with different carbon dynamics have been identified. Two of them are key to understanding the long‐term carbon balance. These states are determined by the dynamics of accumulation and decomposition of mortmass. The ways of changing the intensity of carbon deposition based on the creation of new phytocenoses, increasing soil fertility, including by optimising the carbon and nitrogen ratio have been identified. A more radical way – mortmass utilisation – requires detailed research and consideration of environmental consequences.

This article focuses on the problems associated with shaping the civic identity among students in Russia as they study the history of the North Caucasian peoples. One of the powerful tools to overcome them is to develop a sense of historical consciousness in the younger generation of Russians. However, while the collective memory of the past can serve as a unifying force through shared national values, it can also ignite historical grievances, claims, and conflicts in the present. Here, the debates revolving around the conflicting interpretations of the events that took place in the North Caucasus during the 19th and early 20th centuries (the Caucasian War, the tactics and warfare methods of the Russian military commanders and mountain leaders, the Muhajir movement, and the actions of the imperial power structures) are considered. The questions are raised about how to effectively convey the history of the North Caucasus to the youth, as well as what approaches should be employed to explain the complex, contradictory, and sometimes tragic events of the region’s past so that it would contribute to the development of an all-Russian civic identity instead of fueling confrontations and divisions. Several approaches (recommendations) for teaching the history of the North Caucasus are outlined. They highlight the integrative tendencies in the history of the region, emphasizing the factors that unite its diverse peoples, cultures, and worldviews and define their common pathways for historical development.

The article presents the results of comparative analysis of the main geourbanistic processes in the North-Eastern Caucasus. Modern concepts and approaches in the works of Russian and foreign researchers to the functional zoning of urban areas as the most important tool for their regulation and management are revealed. The period 1986–2023 reveals a significant increase in the area of built-up territories in large cities. The most active rates of construction occurred in Makhachkala and Grozny. In the larger cities considered in the article, the last decade has seen an increase in the area of residential and public-business zones. The current structure of land funds in Makhachkala and Nazran is dominated by agricultural land, while Grozny also has a high share of residential area. It is shown that the areas of recreational zones in the cities under study are insufficient both to meet the recreational needs of residents and for the development of tourism. It is proved that it is necessary to increase the area of recreational zones at the expense of agricultural land, and in Grozny also by reducing the industrial-engineering zone. Assessment of the areas of urban forested territories and their cartographic visualization revealed an insufficient level of greening and uneven distribution of forest areas. Very low level of greening was found in Nazran (less than 1%) and Makhachkala (6%). Taking into account the identified features and trends in the ratio of functional zones in large cities of the North-Eastern Caucasus, recommendations are given to optimize functional zoning by regulating the ratio of functional zones, green spaces, including vertical landscaping, introduction of elements of creative linguistic landscapes. Special attention is paid to providing a diversity of recreational areas.

The processes of oil production and its further transportation are accompanied by the discharge of large amounts of waste contaminated water into reservoirs, which pollutes the environment, increases the acidity of water resources, kills the ecosystem of reservoirs, and the process of waterlogging occurs. The purpose of the study is to study methods for purifying water bodies from pollution using gabion filtration purification of water bodies. The authors hypothesize that gabion treatment filtration structures can be used to successfully clean water bodies of contaminants and impurities. The research methods were the study of scientific literature and scientific research in the field of sanitary treatment of the aquatic natural environment, based on the experience learned, the creation of an experimental model of gabion structures. Based on the results of tests of gabion structures in the Khanty-Mansiysk Autonomous Okrug of Yugra, it was experimentally proven that wastewater is effectively purified from impurities of artificial and natural origin through gabion treatment filtration structures.

In this paper, we examine the appearance of high-order terms in the continuity equation for an incompressible fluid obtained by L. Euler in 1752 from the linear Cauchy–Helmholtz equations. Solution of the inhomogeneous wave equation allows one calculate or estimate the intensity of vibrations and self-oscillations, which are sometimes considered spontaneous.

The article analyzes modern concepts and approaches in the works of Russian and foreign researchers to the formation of ecological tourism as a form of nature-oriented tourism. The peculiarities of mountain ecotourism consist in taking into account the specific conditions inherent in mountain ecosystems (ecological vulnerability to anthropogenic impact, dynamism of landscape-forming processes, etc.). In the mountainous regions of Russia, favorable prerequisites have been identified for the development of various areas of ecotourism (apitourism, agritourism, geological tourism, scientific tourism, etc.) both within specially protected natural areas and outside their borders. SWOT analysis on the example of mountain regions of the Northeast Caucasus showed that there are many strengths and opportunities for the development of ecotourism within the boundaries of specially protected natural areas (unique natural complexes and objects, attractive natural landscapes, high biological diversity, the presence of endemics and relics in the structure of biodiversity, favorable climate, transport accessibility, significant labor resources, etc.). Also, weaknesses were identified that impede the development of ecotourism, and possible threats (poor development of tourist infrastructure, organized tourist routes, equipped ecological trails, a shortage of qualified personnel in the field of ecotourism, etc.).

The aim of the study is to identify the influence of some parameters of the geological environment on the formation of the current hydrogeochemical profile in the Middle Jurassic hydrogeological complex (layers YU2-4) of the Lyaminsky oil and gas field in Western Siberia.The factors controlling the changes in the chemical composition of the groundwater (geotemperatures, influence of neotectonics, etc.) after the process of sedimentation and water accumulation were analysed on the basis of the lithogenetic theory of the transformation of the composition of groundwater during geological evolution. In the course of the research, correlation coefficients were obtained for the value of groundwater mineralisation in the complex with the modern and paleotemperatures of the Tyumen suite, the porosity coefficient and the depth of the foundation. The obtained results allowed assuming that the current hydrogeochemical profile of the Middle Jurassic hydrogeological complex is the result of the consistent action of the whole complex of factors. The results of the analysis showed that the influence of neotectonic processes on the current hydrogeochemical profile is quite probable. The reasons for the heterogeneity of mineralisation, apart from neotectonic processes, may be different, but in any case, the identification of relationships such as "Mineralisation - a parameter of the state of the geological environment" indicates a change in the concentration of salts in groundwater after their accumulation together with sediment.

The modern idea of the geological structure of oil deposits of the Nizhnechutinskoye field is presented. The uniqueness of the field lies in the shallow depths of productive deposits. The oil-saturated layer is 100 m. The shallow depths of productive formations led to low formation temperature and pressure. Under such conditions, oil is inactive, characterized by high viscosity, and dissolved gas is practically absent. The features of the formation of the sedimentary cover in the area of the field predetermined the block structure, while the rocks of the productive horizon are characterized by a complex system of vertical fractures, which greatly complicates the process of oil recovery. A distinctive feature of the studied section of the field is the presence of effusive rocks underlying the main productive stratum and overlapping the lower productive layer. The article systematizes the results of field trial operation, which revealed a number of complicating factors, which is associated primarily with the uniqueness of the geological structure of the studied deposits. Despite the solid history of studying the Nizhnechutinskoye field, which has almost 300 years, given the negligible depth of productive deposits, oil production at this field still remains a difficult task.

Evaluation of the impact of energy efficiency on the activities of the oil and gas sector enterprise Gazprom, PJSC has been given. By using the tools of correlation and regression analysis it was proved that investing in resource-saving and environmental technologies can improve the energy efficiency of an enterprise, reduce the negative impact on the environment, increase the amount of profit to be distributed among shareholders and improve profitability by reducing costs. As a result of building an economic and mathematical model for Gazprom, PJSC it was found that investments aimed at protecting the environment and rational use of natural resources in the amount of 1 billion rubles lead to savings in fuel and energy resources aimed at own needs in the amount of 0.1 million tons of standard fuel annually. The savings achieved are reflected in the return on sales, which increases by 0.429%. Energy efficiency is improved as a result of technical changes that allow the company to provide the same services with less energy consumption. For this reason, investments in energy-saving technologies are key to improving the energy efficiency of oil and gas companies, as they reduce operating costs and improve operating performance by reducing energy consumption. The matrix of Pearson’s correlation coefficients is illustrated. Analysis of scientific sources was carried out confirming the importance of studying the impact of energy efficiency on the activities of enterprises. Conclusions are drawn about the need for research in the field of energy efficiency of the oil and gas industry of the economy and its parameters. It is noted that the achievement of energy efficiency remains an important task of the economy and its industries.

The present study aimed to identify the formation factors of the current hydrogeochemical character of the Middle-Jurassic aquifer groundwaters (beds YU 2–4) in the Lyaminsky petroleum district of West Siberia in Russia. We hypothesized that the scales of the impact of post-sedimentation processes at the current stage have largely predetermined the character of the Middle-Jurassic aquifer system. To check if the hypothesis is valid, two research problems have been addressed using the lithogenesis theory of the transformation of the groundwater composition during the geologic evolution: we have evaluated factors that governed the genetic type and composition of initial waters (lithologic, paleogeographic), and factors that control subsequent changes in the chemical composition of groundwaters (geotemperatures, neotectonics effect, etc.). To solve the first problem, the formation conditions of groundwaters under study in the continental setting were investigated. To settle the second problem, we obtained the coefficients of correlation between the Middle-Jurassic aquifer groundwater salinity and the current temperature and paleotemperature of the Tyumenian suite, and between the porosity coefficient and the basement depth. We have concluded that the current hydrogeochemical character of the Middle-Jurassic aquifer system is the resultant of the consecutive effects of the whole set of factors.

The relevance of this research is necessitated by the need to advance geochemical prospecting methods for raw hydrocarbon deposits. The study aimed to design new migration models by the interpretation of surface geochemical survey data. In particular, the relationship behavior needs to be identified between the hydrocarbon migration intensity and the presence of oil-bearing reservoirs within the section. To reveal quantitative relationships between the oil show and the oil-bearing capacity of the section, a substantial body of geochemical data across different fields in West Siberia was processed herein. Field-type and in-office operations were being performed by the snow survey procedure. The СН4–С6Н14 saturated hydrocarbons were employed as the major measured parameter. No direct quantitative connection was found between the intensity of surface hydrocarbon anomalies and the section productivity. Nonetheless, the two basic factors were found to affect the structure of the surface geochemical field: first, oil-bearing reservoirs present in the section and, second, fluid-resistant properties of the above-productive strata. Despite a direct quantitative relationship between the oil-bearing capacity of the section and the intensity of surface hydrocarbon anomalies being absent, the large sample made it possible to determine quantitative measures of the surface geochemical field that credibly characterize territories whose sections hold oil-bearing horizons.

The present study deals with algorithms for the acquisition of a well-core digital model that is used in the Digital Well-Core technology or "Digital Petrophysics." The study involved the initial implementation stage of this technology: identification of geometric dimensions of a sample and spatial scanning resolution, as well as of scanning and reconstruction settings to examine a well core in a SkyScan 1172 X-ray micro-CT system. Well-core samples 30 mm wide (7 µm/ pixel resolution), 10 mm wide (4 µm/pixel resolution) and 5 mm wide (1.5 µm/pixel resolution) were examined by X-ray micro-computed tomography. The porosity coefficient of all samples was measured by the water-saturation and weighing method. The digital models were used to estimate the porosity coefficient compared to the standard method. The results demonstrated that the best convergence of micro-CT and standard method data was achieved with 5-mm samples at a 1.5 µm/pixel scan resolution. A study on digital model optimization through noise reduction in the NRecon standard software was also conducted and discovered that the best convergence of porosity coefficients was attained when smoothing was set at 8. The scanning and reconstruction settings proposed for well-core samples can be used to implement the Digital Well-Core technology. ARTICLE HISTORY

—This study describes a procedure for estimating the distribution of hydrocarbon resources by fields with different sizes of reserves and by the number of pools in each field. Such an evaluation is important in predicting the efficiency of exploration. The procedure first uses a simulation model for generating a population of hydrocarbon pool sizes. Then the spatial distribution of pools over a petroleum basin is modeled as a nonstationary Poisson point field. When we generate a field population in the basin, each field is considered a geometric object consisting of several pools according to the principle of their mutual geometric location. The proposed model was used to estimate a two-dimensional distribution of the number of fields and resources contained in them by resource sizes and the number of pools in each field. The proposed assessment was made for oil resources in the West Siberian petroleum province.

From Middle-Late Triassic continental deposits of the Timezgadiouine Formation (Argana Basin, Morocco), 17 lithofacies are identified, with alluvial fan, fluvial, floodplain and lacustrine associations. Invertebrate traces include Archaeonassa fossulata, Arenicolites isp., cf. Arenituba, Beaconites isp., cf. Camborygma, Cruziana problematica, Diplocraterion isp., Fuersichnus isp., Helminthoidichnites tenuis, Lockeia isp., Palaeophycus striatus, Palaeophycus tubularis, Planolites isp., Rusophycus carbonarius, Scoyenia gracilis, Skolithos isp., Spongeliomorpha carlsbergi, Taenidium isp. and Taenidium barretti. Additionally, rhizoliths were observed. Six ichnoassemblages were distinguished: overbank facies with (1) Rhizolith ichnoassemblage in a low-energy floodplain environment and (2) Scoyenia-Palaeophycus ichnoassemblage in crevasse splay deposits. The fluvial ichnoassociation is of moderate ichnodiversity consisting of the following assemblages: (3) Arenicolites, developed under higher flow velocities of active channels, (4) Taenidium-Scoyenia, formed by the colonisation of inactive channels, (5) Arenicolites-horizontal meniscate burrows, reflecting a rapid transition between active and abandoned channels and (6) Lockeia-vertebrate footprint, formed in littoral lakes. The Aglegal and Irohalene members indicate climatic shifts between arid dry, semiarid and subhumid in a dryland river environment. The sudden onset and the high frequency of lacustrine deposits in the lower Irohalene Member point to a rapid climate change from dry to intermittent wet and dry. This change is discussed in terms of the Carnian Pluvial Event.

In this review we have briefly reviewed the state of the art of “digital core” technology. In particular, we reviewed the main artefacts that can occur in the analysis of rocks by computed X-ray microtomography. Next, we highlighted the existing approaches of direct mathematical modelling of core filtration characteristics using digital model and poroset models. Literature analysis has shown that the most justified in the ratio of required technical resources (computer power) and reliability of results is the integrated approach. Unfortunately, when calculating phase permeabilities using digital core models, it is necessary to calibrate simulation results using standard laboratory methods. We also analysed some approaches to modelling enhanced oil recovery methods such as hydrochloric acid and hydraulic fracturing, as well as thermal stimulation of oil matrix rocks. In conclusion, we noted that the main challenge of today’s “digital core” technology is reliable calculation of phase permeabilities, and further development of the technology should be towards 4D modelling of EOR methods using digital core models.