This paper presents methodological approaches to study the influence of temperature and gas content on pressure variations within a well, with the goal of identifying the depth at which oil degassing occurs. The study also examines the accuracy of accounting for variable inflow under non-steady filtration conditions during well testing.

The goal is to develop a decision-making model for evaluating pressure changes along the wellbore relative to either wellhead or bottomhole drawdown.

Additionally, the model aims to estimate the role of natural thermogaslift in facilitating flow during natural well production and to accurately determine the volume of fluid withdrawn from the wellbore or accumulated within it over time under non-steady flow conditions.

We identified the lag time of gas liberation from the reservoir fluid. We identified the lag time of gas liberation from the reservoir fluid. Based on field data, this gas release delay in Bashkirian fields ranges from 4 to 15 minutes. In contrast, similar studies are generally not done in Western Siberia, and this affects the accuracy of reservoir and production modelling. When the wellhead pressure drops below the oil saturation pressure, dissolved gas starts to separate and transitions into the free gas phase from a specific depth upward along the wellbore. The volume of free gas increases continuously as it moves toward the wellhead, reaching its maximum at the surface. At the same time, since the mass flow rate remains constant regardless of gas release, temperature changes occur further along the wellbore due to gas throttling, adiabatic expansion, and the absorption of latent heat of vaporization as gas evolves from the gas-liquid mixture in thermal exchange with the surrounding reservoir.

Technique for exploring fresh groundwater in cryolithic zone as a water supply remains limited and underdeveloped. Securing reliable water resources in regions underlain by continuous permafrost presents significant challenges. This is because of the fact that an area is located within an ice macro-zone. An ice macro-zone is the first water-bearing complex of Quaternary sediments from the surface, whose aquifer system consists of isolated, vertically oriented narrow troughs of underflow taliks of rivers, bowl-shaped subzero and rare interfrost taliks. All of which possess very limited fresh water reserves.

To enhance the identification of promising areas for fresh groundwater during the exploration stage, the technology of complexation of research methods is proposed. This technology involves the interpretation of earth remote sensing with lineament analysis of the search area, electrospecting geophysical method (electromagnetic sounding in the near-field zone) with nuclear magnetic resonance (NMR) sounding.

As a result of this study, several promising sites for fresh groundwater were identified. Exploratory drilling was conducted, uncovering fresh groundwater reserves within the upper 110–120 meters of the geological section. These reserves are part of the Quaternary water-bearing complex located within the boundary of the custody transfer station at the Zapolyarnoye oil and gas condensate field.

Numerous researchers have extensively studied the material composition of pre-Jurassic deposits. Over the years, various authors have created geological structure maps of the pre-Jurassic basement of Western Siberia, covering both the entire region and specific areas.

The most recent version of such a map was produced in 2016, through collaboration among several research institutions. The geological structure depicted in the 2016 map is primarily based on interpretations of potential field data and results from deep drilling.

It is important to note that the vertical profile of the pre-Jurassic section remains poorly understood. In many wells, core samples were only collected from either the preroofed part or the bottom-hole parts of the section, leading to generally low core recovery rates. Descriptions of preJurassic cores found in well reports, particularly when lacking laboratory analysis, often fail to provide reliable information about the material composition. This study analyses core descriptions and thin-section examinations of pre-Jurassic deposits conducted by the authors at the core storage facility in Khanty-Mansiysk. It incorporates seismic survey reports from research teams that have worked in the area, along with published data from various researchers who have investigated the geological structure of the Yugansk Depression and its surrounding regions.

Authors studied core samples from several fields including Travyanaya, Larlomkinskaya, Novoyutymskaya, Merkulskaya, Severo-Yutymskaya, and Koimlykhskaya.

The results of this study suggest that revisions may be necessary in the mapped distribution of material and age complexes within the pre-Jurassic geological framework of the KhantyMansi Autonomous Area —Yugra.

Developing oil rims presents a complex engineering challenge that requires careful consideration of various factors. One of the primary difficulties in oil rim development is selecting appropriate well completion methods and reservoir pressure maintenance technologies to ensure effective production of reserves.

Drilling multilateral wells in oil rims can help limit the rising gas factor at early operating steps. However, multilateral well architecture can significantly affect development efficiency and remains an area of further studies.

While water injection into the reservoir for maintaining reservoir pressure is a wellestablished and widely used technology, gas re-injection into the gas cap of an oil rim is a promising approach with effect requiring further validation through estimates and practical results.

This paper discusses the experience of constructing complex injection wells and implementing the gas re-injection of associated petroleum gas at the Novoportovskoye field. The authors describe the approach to the definition of strategy aimed at asset development. Also, the authors present results from the injection of associated petroleum gas, which aimed to maintain reservoir pressure and removal of risks of failure to meet the 95% standard for rational utilization of associated petroleum gas.

Colmatation is a well-known phenomenon in both natural and industrial processes, particularly in the construction and operation of wells. During drilling, natural colmatation occurs when solid particles from the drilling fluid and cuttings create a weakly permeable internal pore layer and a loose filter cake on the wellbore wall. These formations complicate subsequent casing operations and reduce the quality of cementing. Moreover, they do not prevent interlayer flows, leading to losses of drilling and cementing fluids, as well as contamination of the reservoir with filtrate and solid particles, sometimes extending considerable distances from the well. Consequently, the costs, timeframes, and complexity of well completion, development, and commissioning can increase significantly. Well-construction experience has demonstrated that certain types of forced colmatation during drilling can effectively address these issues. Two methods have emerged as the most widely utilized in the oil and gas industry: Hydrodynamic jet colmatation Wave-induced cavitation-vortex colmatation, which is based on advancements in nonlinear wave mechanics of multiphase media.

The primary goal of this laboratory and field research is to determine which of these two colmatation methods is more effective. This comparison will facilitate the development of more efficient techniques and technologies for well construction. This paper presents mathematical models that have been developed based on laboratory bench-scale experiments. These models describe the effects of key parameters on the wave- and jet-induced forced commutation in permeable rock.

The study revealed a positive effect of these treatments on the properties of clay-based drilling fluids. In particular, the fluids demonstrated enhanced resistance to sedimentation of the solid phase, due to simultaneous dispersion during treatment. Extensive field trials of wave and jet colmatation technologies were also conducted, which confirmed the laboratory results and validated initial expectations. Among the two methods, wave-induced colmatation proved to be more effective.

This paper analyzes the impact of gas on the properties of reservoir water from various reservoir horizons in oil fields in the Republic of Tatarstan. The study utilized both original reservoir water samples and treated water samples that were prepared with a gas agent. Authors employed pressure-volume-temperature (PVT) analysis methods throughout the research. Authors collected subsurface samples of reservoir fluid from the water-bearing horizon A1 of the Devonian system and horizon B of the Carboniferous system.

The experimental results showed that the gas agent has a relatively high solubility in the reservoir water, which increases with reservoir pressure until a certain limit is reached. Additionally, it was confirmed that the solubility of the gas agent in reservoir water is also affected by the salinity of the water.

The author presents a forecast of the stress-strain state of the rock mass during hydrocarbon production at the Salmanov (Utrenneye) gas condensate field, which serves as a resource base for Arctic LNG 2 LLC. The calculations are based on core testing data and geophysical well logs that extend the physical and mechanical properties throughout the rock mass. Geomechanical modelling has been conducted using the "tent model" to simulate the deformation of productive objects.

Authors established correlations established between elastic modulus and Poisson's ratio with longitudinal wave velocity. These correlations allowed for the distribution of elastic properties across the reservoir based on geophysical well data. We identified that the compression index was linked to longitudinal wave velocity. We needed this to support the calculations in the tent model. The modelling results predict surface subsidence of up to 2 meters following the complete depletion of the field. This subsidence may lead to flooding due to the rising groundwater levels. Therefore, it is recommended to use higher sand fill levels in construction projects to mitigate this risk.

Horizontal deformations may approach the permissible limits for infrastructure and pipelines, potentially resulting in operational disruptions over time. These findings emphasise the importance of establishing a deformation monitoring system for the entire field, as well as implementing geotechnical monitoring for critical infrastructure facilities.

Companies actively engaged in geological exploration typically adhere to an established internal standard for ranking license areas during project planning. This ranking process involves a probabilistic evaluation of geological parameters, reserves, and risks — factors that influence the formation and preservation of hydrocarbon accumulations. However, the success of field development also depends on the reliability of resource estimates, reservoir characteristics, and reservoir fluid properties.

This necessitates an additional ranking specifically aimed at selecting the most suitable areas and fields for pilot production. Such selection ensures that exploration is completed on time to plan and initiate pilot operations, meet project deadlines, maximize efficiency, and achieve the company's targets to put into commercial development.

Traditional geological ranking methods are not entirely suitable for this purpose, as they primarily rely on statistical evaluations of risks, reserves, and resources. To properly assess the potential for pilot production, it is essential to analyze the extent and quality of reservoir characterization and testing while also considering possible operational risks. This paper presents a new approach to the supplementary ranking of license areas for pilot production.

The proposed methodology takes into account the degree of geological and geophysical study as well as the quality of field data obtained during the exploration phase.

Developing a field development strategy is a crucial part of a reservoir’s lifecycle. Key principles of this strategy established during the conceptual design stage. Decisions made during this early phase lay the groundwork for the overall success and economic efficiency of the project. However, this stage is characterized by a high level of uncertainty.

Currently, the new gas production region in Russia — Eastern Siberia — is experiencing active development. This region lacks developed infrastructure and does not have the same resource base as Western Siberia. Additionally, much of the gas potential in Eastern Siberia remains at the selecting, exploration and evaluation stages.

However, many fields in Eastern Siberia are rich in valuable gas components. Given that the current industry trends towards product diversification and improved monetization, there is an increasing need to formulate development strategies at the conceptual stage.

These strategies are based on not only field clustering but also creating of new gas processing facilities, especially in remote areas that are far from existing gas transportation systems.

This paper presents an algorithm for comprehensive input data analysis using the example of the Eastern Siberian cluster, which consists of a group of fields in Krasnoyarsk Krai. This algorithm facilitates the forecasting and comparative assessment of various development options, ranks them according to potential efficiency, and determines the necessary equipment configuration for implementing the selected field development strategies.

This article discusses problems with the design, construction, and operation of oil and petroleum product pipelines in regions characterized by permafrost soils. The best way of solving these problems involves polymer implementation and composite materials in pipeline structures, particularly in arctic desert and tundra zones. The paper presents case studies and research results concerning the performance of pipelines operating in permafrost conditions, along with a complete characterization of the aggressive environments affecting pipe reliability

The aim of this study is to substantiate the feasibility of using polymer and composite materials in oil transportation systems to reduce maintenance and repair costs in permafrost areas. We applied methods of an analysis of the chemical resistance of pipes. The study found that increasing the height of pipeline support s—necessary for aboveground installations in permafrost terrain — can lead to higher stress levels, potentially creating unfavourable operating conditions.

The results also demonstrate the influence of structural elements on the pipeline’s performance in permafrost environments and help to identify the most suitable material for finite element modelling that takes into account seasonal ground deformations. The findings indicate that low-density polyethene (LDPE) pipes exhibit high resistance to the aggressive environments caused by impurities in crude oil. This makes LDPE a strong candidate for pipeline construction in permafrost zones.

The significance of this study lies in demonstrating that the use of polymer and composite materials can reduce the impact of aggressive media on pipeline interiors. Among these materials, LDPE offers an optimal balance of performance and cost-effectiveness for use in such demanding conditions.

Modern pipeline systems for hydrocarbon transportation utilize a diverse array of technologies and equipment. The main oil product pipelines (MOPP) include modular (disassemblable) pipeline systems (MPS). MPS are mobile engineering complexes designed for the temporary transportation of crude oil, light petroleum products, and liquid hydrocarbons. These systems are utilized during the filling and emptying of MOPPs, as well as for scheduled maintenance and emergency response situations within the oil and gas sector.

During the operation of MPS, significant attention is focused on reliability and safety, in accordance with the directives from the President and Government of the Russian Federation aimed at improving the efficiency of oil and petroleum transport through advanced technologies. However, analyzing the experience of deploying the SRT indicate that, over distances of up to 150 km, losses can amount to 5, 5% (approximately 300,000 tons) of the total volume of transported oil products. Additionally, issues related to predictive monitoring and the timely detection of pipeline accident and damages remain largely unresolved.

One of the primary causes of product loss, as classified in MPS incidents, is the loss of pipeline integrity due to mechanical failures or operational accidents. To mitigate these losses, various monitoring systems and techniques are employed across MOPP facilities, relying on different operational principles and physical phenomena.

However, effective solutions for mobile modular pipeline systems are not available. Therefore, the development of advanced automated monitoring systems based on artificial intelligence is an urgent challenge. This paper presents a parameter-based method for detecting oil product leaks in modular pipeline systems and proposes a prototype and architecture of the oil product leakage monitoring system that incorporates a software layer powered by artificial intelligence.