Perm Journal of Petroleum and Mining Engineering
Perm National Research Polytechnic University
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The Possibility of Predicting Oil and Gas Potential based on the Geochemical Characteristics of Rocks
The aim of the study is to forecast the oil and gas potential of the sedimentary section in the Perm Region based on a developed geochemical criterion. A key aspect of the predictive assessment is the use of previous work on the differentiation of distribution organic matter (DOM) based on its composition and content of migratory bitumoids of the epigenetic type. The development of this comprehensive criterion involved the use of methods for statistical analysis of geochemical and bitumenological data. Regression analysis methods were used to develop models for predicting oil and gas content, including the presence of epigenetic bitumoids. Initially, individual models were constructed and analyzed. As an example of such a modeling approach, one characteristic of the distribution organic matter in rocks was chosen - the content of the insoluble residue (IR, %). The models obtained for the characteristics of IR, %, and all other indicators used demonstrated a high level of separation between the classes of epigenetic and syngenetic bitumoids, as confirmed by statistical significance criteria. To develop a complex probabilistic geochemical criterion that would consider all significant geochemical characteristics affecting the distribution of epigenetic bitumoids in rock, individual probabilities were used for the studied parameters. By analyzing various combinations of individual probabilities, it was determined that the most statistically valid approach to classifying epibitumoid groups is to utilize all parameters. Based on the developed model, values for the complex criterion (Pepi) were calculated for the entire dataset. The scheme for changing the values of the criterion obtained for the territory of the Perm Krai solves the task and reflects the prospects for oil and gas potential within the main tectonic regions of the region. Thus, the analysis showed a varying degree of intensity of DOM transformation processes within the studied area. The maximum level of epigenetic bitumoid development in the main oil and gas-bearing complexes of the sedimentary cover is typical of the Bashkirian arch, parts of the Babin saddle and the Byim-Kungur monocline, as well as in the southern part of the Upper Kama depression and within the Solikamsk and Yuryuzan-Sylva depressions.
Copyright (c) 2025 Voevodkin V.L., Galkin V.I., Kozlova I.A.
Creation of Basin and Sedimentation Models of the Territory of the Volga-Ural (Perm Krai)and Timan-Pechora Regions
Basin modeling is a reconstruction of geological processes occurring in sedimentary basins using physical and mathematical apparatus, in particular, in the shell of various software. Each sedimentary basin requires an individual approach to the choice of the method for constructing a geological framework and its subsequent filling. This is due to the different tectonic structure of the regions, the stratigraphy of the sedimentary cover, the conditions of sedimentation, the volume and number of oil and gas complexes, the quality of oil and gas source rocks, etc. The choice of initial data and forecasting tools, including additional studies, depends on the level of study and the goals of modeling – sedimentation modeling and palinspastic reconstructions. The limited sample of initial information used in this case significantly affects the final forecast of oil and gas potential both at the qualitative (with a lack of data on new poorly studied territories) and quantitative (in well-studied areas to clarify the resource base within the license area or a new seismic exploration polygon) levels.In the context of the structural features of the Perm Krai, the Komi Republic and the Nenets Autonomous Okrug (Volga-Ural and Timan-Pechora oil and gas provinces), the authors consider the previously obtained experience in creating basin and sedimentation models with the overview of the important characteristics and parameters of three-dimensional models. In addition, the article describes the applied modules and methods for analyzing and processing data arrays using the Python language, which allows optimizing the stage of collecting and analyzing large, regularly updated geological information bases.
Copyright (c) 2025 Koriakin S.I., Lvovskaia I.L., Makiev T.T., Khvorost I.M., Filimonchikova D.D.
Assessment of Geotemperature Conditions for the Use of Supercritical Carbon Dioxide to Enhance Oil Recovery in Oil and Gas Complexes of the Perm Region
The article is devoted to the assessment of geothermal conditions for the application of supercritical carbon dioxide (SC-CO2) to increase oil recovery in the oil-and-gas-bearing complexes of the Perm Territory. In the context of the depletion of the region's fields, CO2-based technologies are of particular interest due to their effectiveness and compliance with the trends of decarbonization. The main focus is on analyzing the reservoir temperatures that determine the possibility of CO2 transitioning to a supercritical state.The assessment takes into account the thermodynamic features of CO2 and the reservoir characteristics of the main oil and gas-bearing complexes. It has been established that temperature parameters are critical for the effective application of the technology, and they vary depending on the depth of the reservoir and the geological structure of the area.The geothermal conditions within the Devonian and Visean terrigenous and Tournaisian-Famennian carbonate oil and gas-bearing complexes have been examined. Areas with favorable conditions for the use of SC-CO2 have been identified, where reservoir temperatures exceed the minimum values required for the transition to the supercritical phase. It has been noted that complex effects, including changes in the filtration properties of rocks, are possible in carbonate reservoirs.The results of this study can be used to plan measures for increasing oil recovery, taking into account regional characteristics.It has been stated that further research on reservoir parameters and the mechanisms of CO2 interaction with fluids and rocks is required for the successful implementation of this technology.
Copyright (c) 2025 Bashkov A.N., Kozhevnikova E.E., Bashkova S.E.
Development of Probabilistic-Statistical Models for Predicting the the Trajectory of Horizontal Wells in a Reservoir
At present, when planning horizontal wells, there are a number of uncertainties associated with the accuracy of the forecast of reservoir propagation along the wellbore of a horizontal section, which largely determines the feasibility of drilling horizontal wells. The problem is particularly relevant in the context of the constant deterioration of the structure of residual oil reserves. Ultimately, the technical and economic success of drilling depends on the accuracy of this forecast.Forecasting the distribution of reservoirs along the length of a horizontal section, based only on geological modeling, does not always allow to reliably determine this value.Improving the accuracy of the forecast of trajectory in the reservoir is possible through the use of additional geological information characterizing the presence of a reservoir in the horizontal wellbore. To solve this problem, it is most appropriate to use probabilistic statistical methods. In this paper, it is proposed to use the probability of the presence of a reservoir in a horizontal wellbore (Pres), which is defined as the ratio of the penetration along the reservoir (Lres, m) to the total length of the horizontal wellbore (Lhor, m). Geological indicators that determine the presence of a reservoir in a horizontal wellbore are the coefficients of sandiness (Ks), dissection (Kdis) and effective oil-saturated formation thickness (HEff). Based on actual data, multivariate statistical models for predicting the values of Lres. were constructed.The models were developed based on data from 471 horizontal wells drilled in the Volga-Ural and Timan-Pechora oil and gas provinces.This approach makes it possible to more accurately predict the value of Pres, which can be used in planning production drilling of horizontal wells and reduces the risks of drilling inefficient wells, improves the quality of design solutions, and, consequently, increases the technical and economic indicators of the asset.
Copyright (c) 2025 Galkin V.I., Chernykh I.A., Ushakhin A.N., Eremeev N.S.
The Method of Choosing Optimal Implementations for Multivariate Digital 3D Modeling of Oil Deposits
Multivariate geological 3D modeling allows the most reliable consideration of the degree of uncertainty in the structure of oil deposits. At the same time, the task of selecting optimal settings for multivariate 3D modeling seems relevant, which involves the selection of criteria that limit the most probable implementations of the geological structure in the interwell space based on the uncertainty and existing heterogeneity of the geological environment. As a result, a model of reservoir distribution at each point in 3D space should be built that best matches the actual data. To study the heterogeneity of the geological structure of deposits, the work uses mathematical analysis methods based on experiment planning. A methodology for generating a set of lithological cubes with different variogram ranks is implemented. The problem of optimizing the selection of geological 3D models is reduced to probabilistic ranking based on the criteria of their convergence with the results of well drilling, interpretation data of 3D seismic exploration, actual well operation and lithological continuity of reservoirs. A comprehensive accounting of these criteria based on the additive formula allows calculating the extremum (Ores) with maximization of the ratio between the useful signal of the optimal response and interference.The possibilities of practical use of the developed methodology of geological multivariate 3D modeling are shown on the example of estimating the reserves of a real oil deposit. The step and ranges of change in the variogram ranks are consistently substantiated, after which 289 realizations of the geological 3D model are obtained by the kriging method. After calculating the complex criterion Ores, 49 3D models are characterized by a value of more than 0.9, which allows narrowing the sample of realizations.To obtain the final optimal version of 3D modeling, all realizations with Ores > 0.9 at each point of the three-dimensional lithology cubes are averaged. Analysis of the generated realizations shows that due to the low density of the well grid over the area of the deposit, the 3D models do not correlate well enough with the actual drilling results. In such conditions, the model quality is largely determined by the reliability of 3D seismic data, which is much better implemented for 3D models with Ores > 0.9. Models with low Ores values do not reflect the lithological consistency of the reservoir and, as a consequence, the dynamics of oil production at the site. The practical result of the studies performed was the selection of the most realistic geological 3D model based on multiple implementations.
Copyright (c) 2025 Potekhin D.V., Lei W., Galkin S.V., Ashikhmin S.G., Cherny K.A.
RefInement of Structural Lithofacies of Pirallahi Island and Darwin Banks Based on Comparative Analysis
Currently, an increased interest in the discovery of previously laid down productive horizons in oil and gas fields with a long development period and in the extraction of residual oil leads to deep and thorough investigation, assessment of the mineralogical composition of rocks and lithofacies characteristic based on geological, geophysical, hydrogeological and other data.The deposits of Darwin Bank and Pirallahi Island are located in the eastward of the Absheron Peninsula, in the northwestern part of the Apsheron Archipelago, on the anticline zone of the Absheron Bank, Darwin Bank, Pirallahi Island, "Gurgandeniz".The southeastern periclinal of the Darwin Bank field borders the northern part of the Pirallahi Island field, and these two fields are separated from each other by fracture.Two fields are considered in the research work. These fields considered in the study belong to the class of long-term development fields that are in the final stages of development.These fields from a tectonic point of view belong to complicated (complex) structures. Even though it has been processed since the last century, it contains a large amount of oil reserves. For this reason, the structural and tectonic field structure, lithofacial composition, in-place and recoverable reФserves, development parameters are important. The issue we are considering is the distribution and clarification of lithofacies characteristics of the fields. The neighboring fields of the Darwin Bank and Pirallahi Islands are poorly studied and researched from the lithofacial point of view. We investigated the types of facies for the QD, QA and QaLD series of strata in the fields and compared them by compiling 3D models. As a result, changes were observed both in the areal and vertical directions.
Copyright (c) 2025 Gurbanov V.S., Mustafayev Y.R., HeydarlI S.O., Abbasova G.G.
Assessment of the Impact of Solid Waste on the Environment, Ground and Surface Water
The article presents the results of a study of the impact of a waste disposal facility with filtration and protective dams made of natural materials on the state of the surrounding natural environment. For a detailed assessment of the impact, studies of the state of ground and surface waters at the location of the facility were conducted. Field engineering and geological work was carried out. Areas located near the storage ponds of the solid municipal waste landfill were considered. Engineering and geological testing was carried out in order to study the physical and mechanical properties of soils and identify the main patterns of spatial variability of their properties. Wells were drilled, and during their drilling, a layer-by-layer description of all encountered soil types was carried out, with a description of their structural features. Soil samples were taken along the predominant directions of groundwater movement. The chemical composition of the facility's wastewater and the chemical composition of the soils that make up the filtration dams of the storage ponds are given. Based on the analysis of the data obtained, a conclusion was made about the possibility of using filter dams to significantly reduce pollutant concentrations and minimize the spread of pollutants in the environment. The filtering capacity of the dam protecting the environment from the penetration of solid municipal waste landfill filtrate was assessed. According to the results of the conducted studies, no excess concentrations of pollutants were detected. The possibility of using the filtration and sorption characteristics of dams made of natural materials at old solid municipal waste disposal sites to prevent or minimize their impact on the environment was confirmed. These studies can be used in the construction of enclosing structures for waste disposal facilities to reduce the concentrations of pollutants in filtration waters and prevent them from spreading beyond the facility.
Copyright (c) 2025 Viskov M.V., Parshakova I.N., Kushnir E.D., Margina I.M.
Development of a Comprehensive Model of Zonal Oil and Gas Content based on the Criteria of Migration, Accumulation and Conservation of Hydrocarbons (using the Example of the Northern Part of the Bashkir Arch)
Using the northern part of the Bashkir Arch (BA) in Perm Krai as an example, a zonal oil and gas potential forecast was developed based on a combination of generation, migration, accumulation, and conservation indicators. The relevance of the study is due to the declining efficiency of geological exploration in the highly studied area.The study aims to develop a probabilistic model for assessing zonal oil and gas potential by combining probabilistic estimates of the generation and migration of dispersed organic matter, as well as the accumulation and conservation zones of hydrocarbon deposits.It has previously been established that the generation and migration of dispersed organic matter are primarily determined by the bitumen coefficient (β, in %) and the insoluble residue (IR, in %). The accumulation of hydrocarbon deposits directly depends on the absolute elevations and thicknesses between the main reflecting horizons of the BA. The preservation of hydrocarbon deposits is controlled by the hydrogeochemical properties of formation waters, among which the mineralization and metamorphism coefficient of formation waters are of key importance.Within the framework of this work, a complex probability was developed based on the criteria characterizing the processes of generation and migration (Pgcom), accumulation (Pacom) and conservation (preservation) (Pccom) of hydrocarbon (HC) deposits. Analysis of the Pcom values for territories within the contours of HC fields (class “in contour”) and territories outside the contours of oil and gas bearing capacity (class “outside contour”) showed that this criterion is characterized by statistically different average Pcom values in the classes (0.536 – “in contour” and 0.424 – “outside contour”).A comparison of Pcom with the criteria determining the processes of generation and migration (Pgcom), accumulation (Pacom), and conservation (Pccom) of hydrocarbon deposits revealed that the accumulation criterion Pacom has the greatest influence on the Pcom (r = 0.864), followed by the generation and migration criterion Pgcom (r = 0.355). The preservation criterion Pccom has a lesser influence (r = –0.146). An analysis of the distribution of Pcom values across the study area revealed that zonal oil and gas potential probabilities Pcom greater than 0.7 units are characteristic of the southwestern part of the BA region, where large oil and gas fields are concentrated.The developed model demonstrates a relatively high predictive ability for assessing the zonal oil and gas potential of the BA territory. Characteristics associated with hydrocarbon accumulation processes (Pacom) have the greatest impact on oil and gas potential, confirming the traditional concept of hydrocarbon deposits confined to anticlinal (uplifted) structures. The study's results are applicable to predicting oil and gas accumulation zones and ranking prepared structures based on the priority of deep drilling to optimize geological exploration in the Perm Krai.
Experimental studies of changes in the filtration and capacity properties of the Astrakhan field carbonate reservoirs under acid exposure
One of the most frequently used methods of increasing oil and gas recovery of carbonate reservoirs is the treatment of wells with hydrochloric acid reagent. The acid solution interacts with the mineral skeleton of the rock, resulting in the formation of a network of wormhole channels, which significantly increases the permeability of the near-wellbore zone. In this regard, it is necessary to develop scientific and methodological foundations for predicting changes in the natural properties of the reservoir during acid treatments. In this article, we use core samples from the Bashkir deposits of the Astrakhan gas condensate field to demonstrate the methodology for conducting laboratory experiments to study the transformation of porosity, permeability, and bulk density in reservoir rocks. A special feature of the developed method is the injection of an acid solution even after the reagent breaks through from the opposite end of the sample. The results of experiments conducted using the developed method are presented. Typical graphs of injection and the dynamics of pressure drop and permeability are shown, which have a number of features, including sections that characterize the breakthrough of the acid. The dependencies that link the values of the studied characteristics before and after exposure to the acid reagent are identified. It is noted that these dependencies have a relatively high correlation coefficient. It has been shown that after the appearance of wormhole channels, the permeability of the core images increases by several thousand times. Statistical dependencies of porosity-permeability before and after exposure to hydrochloric acid have been constructed, and it has been shown that after exposure to the reagent, the graph lies much higher than the initial graph. The relationship between bulk density and porosity has a high correlation coefficient, both before and after exposure to an acid solution, and both graphs follow a single trend, with the difference that after acid filtration, the values shift downward and to the right, indicating an increase in porosity and a decrease in rock density. The relationships between the studied characteristics and the amount of acid реагента прокачанного в поровом объеме определены. The scientific and methodological approaches developed in this work can be used to predict changes in the natural properties of a carbonate reservoir in the near-wellbore zone and for further numerical modeling.
Copyright (c) 2025 Muminov S.A., Chernyshov S.E., Popov S.N., Wang X., Derendyaev V.V.
Study of the Influence of Deformation Heterogeneity on Core Permeability Under Cyclic Loading
The study of sensitivity of filtration-capacitive properties to pressure is an urgent task in the planning and operation of natural reservoirs, in which cyclic changes in pore pressure inevitably occur. Among the existing laboratory methods for studying the sensitivity of rocks to pressure, there are a number of shortcomings that lead to a decrease in the accuracy of permeability prediction, especially when creating a comprehensive confining pressure. The paper presents the results of experimental studies of the effect of cyclic loads on the filtration parameters of 3D analogs of rocks manufactured by the SLA printing method with specified conductivity parameters. The mechanism of the influence of the composite structure of the model on the deformation of the filtration channel is revealed. The resulting effect of slippage of parts of 3D analogs of rocks leads to a greater narrowing of the filtration channel in the central part of the sample under cyclic application of the load. It was found that the channel located in the central part is compressed on average by 60% more than those located on the sides. The dependence of the degree of deformation of the sample on the number of loading cycles was found. It was found that during one loading cycle, the channel located in the central part of the sample narrows on average by 30% less than in the lateral part. During unloading, the channels in the central part open less, since the stored internal elastic energy is insufficient to overcome friction and shear of the halves. The results of the study show that the composite type of the design of 3D rock analogues leads to an excess of deformations parallel to the contact area over perpendicular ones. This type of design imitates the presence of relaxation cracks inherent in rock samples extracted from great depths and subject to significant stresses in natural conditions of occurrence.
Copyright (c) 2025 Riabokon E.P., Guzev M.A., Qi C.
Experimental assessment of the influence of colloid migration on the filtration characteristics of carbonate rocks under cyclic loading
The influence of natural colloidal particle migration on changes in the permeability of carbonate reservoirs under transient and cyclic loading is considered. To exclude chemical and plastic factors, an experimental technique was developed based on the saturation and drying of cores with isopropyl alcohol as an inert fluid. The studies were conducted on carbonate cores with different porosity and initial permeability. It was shown that after saturation and drying cycles, the permeability of individual samples either decreases or increases depending on the nature of colloid migration: blocking or clearing of pore channels. It was determined that the maximum permeability values in the loading cycle reflect the true permeability of the rock, at which the effect of colloidal migration is minimal. Based on the obtained data, power-law dependences of relative permeability on effective pressure with high correlation coefficients (R² > 0.99) were constructed, which allows us to isolate the elastic component of changes in filtration properties. A comparison of water-saturated experiments revealed a significant effect of mineral dissolution (calcite, halite, etc.) on the increase in apparent permeability. Microscopic and tomographic analysis confirmed the preservation of the overall structure, but also revealed localized colloid redistribution, similar to the "coffee ring" effect. The developed methodology provides a quantitative assessment of the contribution of colloid migration to permeability hysteresis and can be used to refine reservoir flow-mechanical models, improving the accuracy of reservoir performance predictions.
Copyright (c) 2025 Riabokon E.P., Farid Bin Abu Bakar A., Azlan Mu t.K., Katunin D.E., Savitsky Y.V., Liyuan Y., Parshakov A.G.
Laboratory Studies of the Process of Injection of CO2 Mixed with Methane Into Productive Terrigenous Oil-Saturated Rocks of One of the Fields in the Perm Krai
The technological and economic efficiency of carbon dioxide (CO2) injection depends on many factors, such as the CO2 source, the method of gas delivery to the field, the method of injection into the reservoir, the characteristics of the reservoir and oil, etc. Therefore, before implementing the method at oil production facilities, it is necessary to conduct special laboratory tests for the conditions of oil and gas facilities, determine the technological feasibility of CO2 injection and economic feasibility. The paper presents the results of experimental studies carried out in the laboratory of modeling filtration processes and enhanced oil recovery of the Department of Oil and Gas Technologies. Using core material on the example of one of the fields in the Perm Krai, filtration tests were performed to displace oil with gas (a mixture of CO2 and methane) and joint stationary filtration of oil and gas through the porous medium of the reservoir rock. As part of the study, core and fluids were prepared, filtration tests were carried out using modern scientific equipment. Modeling of CO2 injection into oil-saturated rocks was performed on three differently permeable composite core samples. As a result, it was found that when using gas, high values of the oil displacement coefficient are achieved, due to the almost complete mutual solubility of gas and oil. Potentially, this can significantly increase the share of recoverable reserves at new objects that are just entering industrial development when CO2 injection is organized. The ratio of gas and oil in the flow at which complete miscibility occurs was determined. Cases of imbalance of the "oil - gas" system were recorded, in which heavy components of oil form resinous sediments that clog the pore space. The content of oil and gas in the flow at which colmatants were formed was determined.
Copyright (c) 2025 Gladkikh E.A., Shcherbakova I.S., Jing H., Yu L.
Application of Algorithms for Filtering and Processing the Initial Signal in the Technology of Distributed Acoustic Sensing
In recent years, fiber optic technologies have been increasingly used in the oil and gas industry, the advantage of which is the ability to continuously monitor events in real time along the entire length of the well. Analysis of modern production experience shows that abroad in the oil and gas industry the direction of using fiber-optic distributed acoustic sensor systems (DAS technology) is actively developing. The domestic complex "Gorizont" allows, unlike most foreign analogues, to synchronize DAS field studies with the fiber-optic well temperature logging (Distributed Temperature Sensing - DTS) method, which is widely used in industrial geophysics. The main problem with the introduction of the DAS method into production is its insufficiently high sensitivity, i.e. a low ratio of the useful signal to interference waves. Research aimed at testing software algorithms to improve the signal-to-noise ratio (SNR) is presented. When developing a signal filtering algorithm for the hardware complex "Gorizont", a program was developed that sequentially displays signals in the form of wave patterns, performs frequency filtering and constructs a signal spectrum. Then the extended time series is decomposed to obtain the components of symplectic geometry (SGMD method), the useful signal is separated from the noise based on the calculation of the Pearson correlation coefficient. The developed algorithm shows high efficiency in isolating long-term periodic oscillations at SNR > 1. The tested method is applied to DAS production data from an oil production well, where distributed temperature monitoring (DTS) is recorded in parallel. It is found that the DTS and DAS methods synchronously record the pump operation in the well. At the same time, a number of anomalies observed by the DAS and DTS methods do not coincide, which shows the potential of combining the results of fiber-optic methods.
Copyright (c) 2025 Chistyakov N.Y., Belov S.V., Budnik D.A., Kolychev I.Y., Shiryaev E.O.
Proppant Transport in the Low-Flow Oil Wells
The efficiency of low-flow oil wells after hydraulic fracturing is frequently compromised by residual proppant and early-phase proppant production, which can penetrate pumps and severely diminish their lifespan. Proppant management in such wells remains a persistent challenge, particularly due to the inadequate understanding of how proppant travels from the wellbore bottom to the pump intake. This study bridges that critical knowledge gap by introducing pioneering experimental findings on proppant behavior in low-flow conditions—the first to clarify the primary mechanisms at play. Using advanced laboratory simulations replicating post-fracturing environments, we observe that proppant consistently reaches the pump intake via an unnoticed process: immiscible hydrocarbon fluid droplets encapsulate and transport proppant particles upward. Key results include the revelation that the viscosity of the immiscible phase (e.g., oil or kerosene) does not significantly affect droplet transport capacity. Furthermore, proppant concentration during transport shows no correlation with well flow rates, overturning conventional assumptions. A groundbreaking insight is the role of free gas bubbles: they increase the likelihood of proppant being captured by hydrocarbon droplets, with higher gas volumes directly linked to elevated proppant levels in the flow. These conclusions are substantiated by field data from wells exhibiting high free gas content near the bottomhole, where shorter pump operational periods coincided with the proposed mechanism. By identifying this transport process, the research lays the groundwork for tailored proppant management solutions, paving the way for improved pump durability and operational performance in low-flow oil wells.
Copyright (c) 2025 Kozhevnikov E.V., Ivanov Z.G., Farid Bin Abu Bakar A., Azlan Mustapha K., Kobyakov D.V., Yu L., Belkov F.B., Fedurov D.S., Petrovykh A.P.
Determination of the Operating Mode of a Gas Deposit based on Hydrochemical Monitoring Data
One of the most pressing problems in the development of oil and gas fields is the problem of reservoir flooding. For weakly cemented gas-saturated reservoirs, raising the contour of the gas-water contact leads to such a negative effect as an increase in the intensity of sand removal into the well, which significantly reduces the efficiency of gas reservoir development. An increase in water saturation also results in a change in the operating mode of the gas-saturated reservoir, which requires appropriate technological and design decisions. One of the most effective methods for predicting and controlling the rise in the water level is the use of hydrochemical monitoring (control) based on chemical analysis of liquid samples taken from production and observation wells. This method has shown its effectiveness in summarizing hydrochemical information based on chemical analyses of associated water samples taken from wells in the Senomanian deposits of the Urengoy, Medvezhye, Yamsoveiskoe and Yubileynoe fields. The article presents the results of forecasting changes in the operating mode of a gas reservoir and reservoir water breakthrough based on an analysis of an array of data on the composition of associated waters from producing wells. Criteria such as the sodium-chlorine coefficient, the Larsen-Skold index, changes in the quantitative content of chlorine ions, and the degree of saturation of water with calcium carbonate were used as indicators of the transformation of the initial hydrochemical medium. The forecast was based on data from eight wells developing the Pokursky reservoir of one of the deposits of the Yamalo-Nenets Autonomous Okrug. It is shown that for some wells it is possible to clearly determine the time of the beginning of the breakthrough of reservoir water, while some wells operate in gas mode.
Copyright (c) 2025 Chikirev F.A., Popov S.N.
Integrated Thermodynamic and Kinetic Modeling of Methane Hydrate Formation: Experimental Validation and Predictive Analysis
Gas hydrate formation presents significant flow assurance challenges in oil and gas operations, particularly in subsea pipelines where low temperatures (< 290 K) and high pressures (>5 MPa) create ideal conditions for crystallization. This study integrates experimental and modeling approaches to characterize methane hydrate phase equilibria, the primary component of natural gas hydrates. Controlled stepwise heating experiments (0.3–1 K/hr) in a high-pressure reactor (50–130 bar range) precisely determined dissociation conditions with temperature uncertainty of ±0.1 K and pressure accuracy of ±0.05 MPa. A novel thermodynamic framework combining the PC-SAFT equation of state for chain molecule interactions, the CPA equation for hydrogen bonding effects, and Van der Waals-Platteeuw hydrate theory demonstrated exceptional predictive capability across the 280–290 K and 5.5–13 MPa operating window. The model's robustness was validated against four independent experimental datasets, achieving average absolute deviations of 1.55% for pressure and 0.05 % for temperature with the CPA approach, outperforming PC-SAFT in high-pressure regimes.The study also investigated kinetic behavior using two experimental methods, with Method B (post-cooling gas injection) providing unambiguous induction time measurements. Results revealed critical insights into hydrate nucleation and dissociation dynamics, including the identification of equilibrium points at the intersection of heating-cooling curves. These findings advance fundamental understanding of hydrate thermodynamics while offering practical tools for pipeline design, operational optimization, and emergency response planning in Arctic and deepwater environments. The developed methodology bridges the gap between laboratory-scale data and field-scale applications, ensuring accurate hydrate stability predictions under industrial conditions.
Copyright (c) 2025 Afranejad A., Poplygin V.V., Poplygina I.S., Shi X.
The Role of Zonality of Mining and Geological Parameters of a Mine Field in the Problem of Local Forecasting of Zones Hazardous in Terms of Gas-Dynamic Phenomena
The current pace of mining operations does not always ensure uniformity of operational exploration over the area of the mine field to obtain local mining and geological data, which are very important in tasks sensitive to the modeling of the distribution of these data. Local forecasting of gas-dynamic phenomena based on the linear discriminant analysis of mining and geological data is also sensitive to the adequacy of the representation of the distribution of mining and geological parameters in space. In this study, the authors consider the features of solving the problem of local forecasting of zones hazardous for gas-dynamic phenomena in the conditions of a deep potash mine with an uneven distribution of actual mining and geological observations, in which almost a third of the mine field does not have any data, and all observations are concentrated in the eastern and western parts of the mine field. By checking the mining and geological data using the Mann-Whitney criterion, significant differences in the distributions of these data were established, confirming the importance of zonal distribution features that can be explained by differences in the course of epigenetic processes in the salt rock massif in individual sections of the potash mine field. To test the efficiency of separate modeling based on zonal distribution features of mining and geological data, three models of distribution of zones hazardous for gas-dynamic phenomena were created using linear discriminant analysis using local samples of mining and geological data in the eastern and western parts of the mine field, as well as a common data sample. The model created based on the common data sample showed lower classification efficiency of 76.5% compared to the combined efficiency of the models created using local data samples, which was 82.3%. Comparison of standardized coefficients of discriminant functions of the created classification models revealed significant differences in the importance of model predictors, which also indicates the appropriateness of the presented approach to avoid distortions in local forecasting. As the mine field is further explored and a uniform distribution of actual observations is achieved, adequate dependencies of the distribution of the parameters under consideration can probably be identified, which can be integrated into a single model; however, in large areas without data, a separate analysis of the mine field, taking into account the zonal features of the distribution of mining and geological parameters, allows achieving greater accuracy.
Copyright (c) 2025 Andreiko S.S., Lyadov V.O., Nesterov E.A.
Study of the Gas Factor during the Development of a Carnallite Deposit by the Underground Solution Method in the Territory of the Verkhnekamskoye Potassium-Magnesium Salt Deposit
Underground dissolution technology allows for the development of water-soluble ore deposits in areas with complex geological structures, where mining does not meet safety requirements. In the area of the Verkhnekamskoye potassium-magnesium salt deposit, productive layers are characterized by a shallow depth and increased gas content. This article is devoted to the study of the gas factor at the design stage of pilot industrial tests of the technology of underground dissolution of a carnallite deposit under the conditions of the Verkhnekamskoye salt deposit. At this site, it is planned to test the hydraulic cutting technology using a double dissolution chamber and stepwise development of the deposit. Preliminary assessments of potential gas emissions into the underground dissolution chamber were conducted. The most probable gas composition and phase states at each stage of testing were determined. It was found that the gas fraction will predominantly consist of methane, hydrogen and nitrogen, of which the first two are dangerous, as they have flammable properties. Studies of gas solubility in brine, both in the underground chamber and on the surface, showed that most of the gases will be free, accumulating under the roof of the underground chamber. A significantly smaller portion will be dissolved in the brine. It is possible that they are present in brine and in a blanket (diesel fuel) in a bubbly form. An analysis of the most probable scenarios for gases entering the hydraulic network of a surface brine production complex from an underground chamber was carried out. Dissolved and bubbly gases may enter the brine extraction line and accumulate in receiving tanks. The greatest danger is the entry of free gases into the diesel fuel line during its extraction from the underground chamber in the process of a changeover of the operating stage, followed by accumulation in the separation tank. Sections have been identified where it is advisable to limit the spread of gases along the hydraulic network paths. Technical safety barriers have been developed, which, in combination with organizational measures, will reduce the risk of negative gas factor manifestations and ensure the necessary safety of work.
Copyright (c) 2025 Andreiko S.S., Zaitsev A.V., Pugin A.V., Lyadov V.O., Popovichev D.V.