Aim. The presentation of the latest results on the studying of Frasnian isolated carbonate platforms in the southeast of the Volga-Ural oil and gas province is the purpose of this publication.

Materials and methods. The results of interpretation of 3D seismic data and core study of deep exploration wells served as source materials for the work. Sedimentological studies with facies diagnostics were performed on the core of deep wells in the interval of the Frasnian Stage.

Results. A group of Middle-Late Frasnian isolated carbonate platforms is identified to the north and northwest of the Sol-Iletsk Arch. These platforms are characterized by steep slopes with coarse clastic carbonate deposits, which is explained by the dominance of reef builders such as stromatoporoids and corals in frame limestones.

Conclusions. In the southern part of the Volga-Ural Paleobassin, isolated carbonate platforms were common forms of large carbonate bodies in the Middle and Late Frasnian of the Late Devonian. Subsequent accretion of isolated carbonate platforms resulted in the formation of long, rimmed carbonate platforms. Isolated platforms are complex carbonate reservoirs with a variety of void forms. The use of 3D seismic data can provide excellent detail of the structure of the Frasnian carbonate complex. This will allow us to adjust the directions of geological exploration in the region in order to search for missed hydrocarbon accumulations both in the carbonate reservoirs of the isolated platforms themselves and in siliciclastic deposits of the Kolganian Formation.

The article outlines an algorithm for the joint work of a sedimentologist and a petrophysicist to identify of FC that are identified with facies established during the sedimentological study of core material.

Aim. The goal of this work is to conduct petrofacial modeling for estuarine deposits of one of the deposits of Western Siberia in order to demonstrate the basic stages and algorithms for solving this problem.

Materials and methods. Full-size core from 6 wells in the amount of 457 meters as the basic material for sedimentological analysis and 3.450 samples (cylinders), on which standard core studies were carried out, including the determination of the open porosity coefficient Kp and absolute gas permeability K_pr.

Results. Based on the results of the performed sedimentological study of the core and petrophysical studies a petrofacial model of the absolute permeability coefficient has been obtained, which makes it possible to clarify this parameter in the reservoir volume based on a conceptual understanding of the distribution of facies.

Conclusions. As a result of the conducted studies, facies complexes of sediments are described and the characteristics of core facies that belong to the estuary system of mixed (mainly wave) type are given. In the presence of a conceptual geological model, petrofacial modeling allows to reduce the uncertainty of the forecast of the permeability coefficient according to GIS from two to one order of magnitude of the determination of this parameter and to clarify the effective thicknesses in wells without pronounced direct signs of penetration of drilling mud filtrate into the formation, by using fixed values of the classification parameter S for two petrofacies and the corresponding boundary values porosity coefficient for isolation of collectors.

Background. The Neocomian clinoform deposits of West-Siberian oil and gas province (WS), which state of exploration is uneven, is one of the fulfilment sources of Russian Federation’s hydrocarbon resource base. The most explored areas are in the south and middle parts of WS with the mature history of oil production and related to large regional uplifts. Though, zones of megadepressions and monoclines are poorly explored, mostly prospected with only few wells and   relatively rare seismic grid. These zones can potentially have rich resource base related to lithological objects and reservoirs of Achimov sequence represented by deepwater alluvial cone deposits.

These are geological reasons of poor exploration maturity of Achimov sequence: complexity of internal structure, poor reservoir parameters (porosity and permeability), high spatial heterogeneity that causes heterogeneity of lenses saturation and difficulties in predicting of perspective reservoirs out of large structural uplifts.

All these factors require using a variety of modifications of the density method when evaluating resource potential of objects.

Aim. Evaluation of resource potential of Achimov sequence object and taking into consideration all geological uncertainties and risks when performing economic-geological evaluation.

Materials and methods. The team of Gazprom neft companу group has developed an approach to probabilistic estimation based on density method, which allows correctly consider all major geological uncertainties when resource base evaluating.

Results. Approach design by Gazprom neft companу group has been successfully tested on real case object without any well data, but with 3D seismic grid. Results of this test formed the basis for production profiles estimation, forming program of geologic exploration activities and economic efficiency assessment within economic-geological evaluation.

Conclusions. The  methodology makes it possible to assess the commerciality of zones with partial and complete lack of geological and geophysical data and to justify the expediency of further appraisal of these zones. 

The aim. The lack of a single classifier of geological and technical tasks of sampling and studies of reservoir fluids leads to misconceptions and approaches when performing field, laboratory and analytical work. Solving this problem is a basic task for creating a methodological and technological basis for improving the qualitative knowledge of reservoir fluids.

Materials and methods. The methods of expert questioning and thought experiment were used in the formation of the terminological system.

Results. A consistent terminological system is presented, which makes it possible to describe modern concepts of the hydrodynamics of multiphase flows

Conclusion. It is recommended to use the proposals in the formation of normative and methodological documentation and training materials in the field of sampling and hydrodynamics of multiphase flows. 

Aim. The paper presents the results of testing new approaches to the sampling of downhole samples of reservoir oil in a stratified oil-water stream.  

Materials and methods. The influence of two factors of success in capturing reservoir oil was evaluated:

• The position of the inlet channel (top / bottom) relative to the piston of the sample chamber of the downhole sampler. For this purpose, autonomous and cable samplers were used, which were lowered into the well in various configurations.
• The position of the inlet valve relative to the lower forming tubing. To do this, two geophysical centralizers were lowered in combination with samplers.

Results. It is shown that the piston intake chamber can act as an effective trap for oil extraction in a watered stream, even in the case of a narrow winding inlet channel; for samplers with the position of the inlet channel from the bottom of the receiving chamber, no positive effect of geophysical centralizers was revealed; the use of geophysical centralizers in combination with samplers with the position of the inlet channel on top of the sample chamber can lead to the capture of a certain amount of oil sufficient for subsequent laboratory preparation and sample studies.

Conclusion. It is recommended to take the results of the work into account when planning sampling with a possible risk of well flooding.

Background. This paper discusses the determination of optimal development system parameters for earlystage gas projects in Eastern Siberia using analytical models. It explores the relationship between these optimal parameters, geological characteristics, and economic conditions. Based on the test data of actual wells, the filtration resistance coefficients a and b, which depend on many factors, including the filtration-capacitance properties of the reservoir, were determined.

The purpose of the work is to determine the optimal number of the design well stock, to assess the influence of geological and economic parameters on the optimal parameters of the gas field development system.

Materials and methods. Calculations were conducted using an analytical technical and economic model that describes the gas field development system. This model is built upon the standard inflow equation for gas wells and material balance equations.

Results. Calculations based on the methodology showed stability of optimal design solutions of  Talakh horizon at field A to technical and economic conditions and well elevator design, as well as unprofitable development of Talakh horizon at field B under current technical and economic conditions, which is due to relatively high contribution of nonlinear effects of gas filtration in the bottomhole zone of the well on productivity and relatively low ratio of well productivity to the cost of well construction.

Conclusion. The results and recommendations presented in this paper are valuable for optimizing gas and oil extraction processes in Eastern Siberian fields.

Introduction. The article raises the topic of complications that arise during the recording of pressure buildup curves at some flooded wells of the Prirazlomnoye field. The complication is a sharp increase in pressure, which can occur at any time during a well test. This anomaly leads to a distortion of the pressure build-up and, accordingly, to errors in interpretation.

Goal. The purpose of this work is to analyze the mechanism and causes of anomalous pressure growth in water-flooded horizontal wells, to propose a method for restoring the true appearance of distorted pressure build-up with identifying problematic reservoir intervals.

Materials and methods. The work is based on the analysis of real readings from pressure and temperature sensors installed at various depths in the wellbore during periods of abnormal pressure growth.

Results. It is concluded that during the anomaly there is a decrease in the level of the oil-water phase interface below the pressure sensors. Reasoning about the reasons and mechanisms for reducing the phase separation level is given. A mathematical tool is also proposed for calculating the depth of phase separation reduction in the wellbore, which allows you to correctly recalculate pressures from the measurement depth to the target depth and obtain smooth pressure recovery curves without anomalies.

Conclusion. In conclusion, the conditions under which it is possible to observe similar anomalies in other wells are highlighted. It is concluded that it is important to pay attention to such effects.

Introduction. In order to reduce operating costs during the transportation of ballast produced water at the X field located in the Ural-Volga region, the oil company conducted pilot field tests of a sump well that performs preliminary cold discharge of produced water directly at the well pad of this field. The commissioning of the «sump well» was carried out by changing and regulating the operating mode of the pumping equipment using a frequency-controlled drive, as well as by limiting the flow of liquid to the reception of the sump well. However, during these pilot field tests at the «sump well», the quality of the discharged water in terms of the residual content of petroleum products according to Industrial Russian standard OST 39-225-88 was not achieved in order to further implement the reservoir pressure maintenance system.

Aim. The purpose of this work was to determine the root cause for which it is impossible to achieve the required quality of discharged ballast produced water according to Industrial Russian standard OST 39-225-88 with the established design technological parameters.

Materials and methods. The thermochemical method of gravitational sedimentation called Bottle test was used as a research method to determine the residual content of petroleum products in water over time of gravitational sedimentation. In addition, the stalagmometric method (using the stalagmometer called Rubin-02A) was also used to simulate the reduction of interfacial tension at the oil-water interface using a demulsifier and a corrosion inhibitor, which were used at the object of the study. The identification of the critical concentration of mycelium formation and confirmation of the solubilization effect was carried out using a stalagmometer called the Rubin-02A trademark.

Results. During the analysis of field data, lab and pilot works, it was revealed that one-time well treatments with a corrosion inhibitor and a demulsifier lead to a significant decrease in interfacial tension at the oil-water interface, and as a result, a solubilization effect occurs. With the resulting solubilization effect, it is impossible to achieve standard water quality values for the content of residual petroleum products in water, even taking into account a significant increase in the time of gravitational sedimentation.

Conclusion. The obtained results of the work will make it possible to adapt the application of cold discharge technology of associated produced water using a «sump well» at the late stages of oil field development. 

Background. The article describes the experience of using one of the directions of hydrojet perforation technology with acid fracturing in wells, the design of which is a non-cemented horizontal section in a fractured carbonate object. The technology is considered from the point of view of the method for refracturing into zones which were not previously stimulated (or where stimulation was only in the form of acidizing). A complicating factor is the presence of hydrogen sulfide in borehole products with a content of up to 6 %, which limits the pool of technologies and methods that are applicable to this type of facility.

Materials and methods. In the work, using the example of well, is given the logic of evaluating reservoir stimulation during primary acidizing. The result made it possible to choose a method of stimulation and zones of interest for further work. The most suitable solution was to apply the hydrojet perforation technology with acid fracturing for two formation intervals at once. The isolation of annular space from hydrogen sulfide was performed by packer setting. Also, were used bottom hole pressure and temperature gauge for evaluation quality of the job and prove the result of intervals separation.

Results. The authors show the company’s internal experience, industrial tests, methods and schemes of technology adaptation. The results presented in the article allow us to conclude that the solution applied at the facility, with a high-quality selection of candidates for fracturing, can have an effect in the form of additional production and, thereby, prolong the life of existing wells.

Conclusion. This article shows the successful experience of implementation of the hydrojet perforation technology with fracturing in terms of preparation and execution of jobs, analysis of available information, risks and limitations. A qualitative approach made it possible to successfully complete all planned activities at the well, starting from the running down hole tubing with equipment, two-stages of fracturing and ending with its running out. The authors believe that with the correct assessment of candidate wells, their potential and previously performed work, the solution can be widely used in similar geological and completion conditions.

Introduction. Field experience in the field’s development with wells with hydraulic fracture shows that after oil production, these wells are often transferred to water injection. The accompanying increase in bottom-hole pressure can lead to fracture growth, which reduce the sweep efficiency. Classical models for predicting fracture
growth do not consider the difference in the characteristic scale of the processes.

The aim of the article is to calculate the dynamics of the fracture growth near injector using a quasi-stationary
model.

Materials and methods. A quasi-stationary concept of the fracture near injector growth is proposed. Based on
this approach, a new model of such fracture growth has been formulated, which makes it possible to predict
the change in the flow rate of wells depending on the volume of water injected. It describes the establishment of
pressure in the fracture based on the model of deep-bed suspension migration. The suspension flow through the
fracture is calculated based on the laws of conservation of mass and momentum. Exceeding the flow rate of the
injected suspension above its outflow causes the fracture growth.

Results. The dynamics of fractures growth and the corresponding relative increase in flow rate for 2 wells of one
of the Russian fields are calculated. The correlation dependence of the damage factor on the permeability of the
reservoir is determined.

Conclusion. The calculated forecasts based on the proposed model make it possible to determine the dynamics
of fractures growth, depending on the filtration and capacitance properties of the rock.

Aim. This review article discusses the methods of calculating the economic effect in integrated asset modeling. The main objective of the paper is to develop a software module capable of performing economic calculations and forecasts efficiently. During the research process, factor analysis has also been conducted in order to optimize the economic module and reduce time and resource costs. This paper provides an overview of various methods aimed at improving asset management through the application of more accurate and efficient economic calculations.

Materials and methods. Both direct and indirect methodologies were employed to assess free cash flow (FCF) and compute net present value (NPV). The direct approach, drawing from cash flow statements, facilitated the evaluation of operational efficiency in fund utilization. Meanwhile, the indirect method, utilizing data from profit and loss statements and balance sheets, unveiled profit generation sources and areas of potential fund stagnation. NPV computation involved aggregating discounted cash flows. Sensitivity analysis encompassed both local and global techniques. This holistic method yielded a comprehensive understanding of factors influencing financial outcomes, forming the foundation for informed conclusions and recommendations.

Results. The research has achieved the development of a software module implementing an economic component for integrated asset models using the Python programming language. This software enables efficient computation of net present value (NPV) and free cash flow (FCF) for economic analysis within the integrated asset modeling context. By processing input data and visualizing results, the software greatly simplifies the analysis of financial performance. Its introduction facilitates factor analysis for optimizing integrated asset models, leading to more precise and sustainable economic decision-making within this framework.

Conclusions. The developed software module is an effective tool for analyzing the financial performance of an oil and gas asset, which provides the calculation of net present value and free cash flow, which allows you to make informed decisions regarding investments in new fields, equipment modernization and improving the efficiency of production processes at mature assets. This module allows for analysis in various scenarios and is easily integrated into projects, meeting the needs of IMA specialists and providing convenient tools for visualizing results. Using this module contributes to accurate and informed management of oil and gas assets, which is a key factor in achieving successful results in the industry.

Aim. A comprehensive stock quality analysis is the basis for today’s production and its potential.

Materials and methods. The characteristics of tight oil reserves and traditional reserves have been applied to the data listed on the State Balance Sheet, the ratio of different quality reserves has been determined.

Results. The contribution of each component of tight oil reserves to the enterprise’s annual production was determined. The prediction of changes in the quality of reserves up to 2050 has been calculated using the exponential smoothing method.

Conclusion. Tight oil reserves have already exceeded half of total reserves and are gradually replacing traditional reserves Resource degradation is driving the development of new hydrocarbon technologies.

The aim: to present the results of the implementation of the technological project of Gazprom neft company group in cooperation with Nosov Moscow State Technical University on the creation of a module for the flow measurement of the chemical composition of drilling mud by the XFA method.

Matherials and methods. The selection and study of сuttings during drilling is an important, integral part of geological and technological research and the collection of geological information to study the lithological characteristics of the section and signs of oil content in it. At the same time, information on the chemical composition of the drilled rocks can be obtained only after special preparation of the selected samples of cuttings and their laboratory analysis, which excludes the possibility of its operational use during the construction of wells. Therefore, the development of this technological solution is an urgent task that requires an operational solution.

Results. The article provides an analysis of the possibility of stream determination of the qualitative and quantitative content of elements in the drilled sludge by the XRF method on the CON-X 02 spectrometer with indication of the detection limit and relative error. And analysis of the results of determination of the elemental composition of the cuttings at well Gazprom neft company group of Companies in the range from 3673.2 m to 4921.2 m using the module of flow measurement of the chemical composition of drilling mud by the XFA method.

Conclusion. The efficiency of the developed module for the flow measurement of the chemical composition of drilling mud by the XFA method in industrial operating conditions and the potential effectiveness of its application have been proven.

Introduction. The present article deals with the actual topic of polymer composite materials (PCM) implementation in the oil and gas industry. In the conditions of joint work of SPbPU STC “New Technologies and Materials” with VINK the issues of using PCM for existing tasks in cold climate conditions are solved. To date, the main challenge is the lack of standards and regulatory and technical documentation, both in Russia and in the world practice, as well as the lack of comprehensive process re-engineering.

Objective. To highlight the problem of the lack of standards and normative and technical documentation, as well as the lack of complex process reengineering.

Materials and methods. The article presents a review of normative and technical documentation. To solve the identified problem it is proposed to implement a number of steps, including the creation of risk-oriented calculations, typification of basic PCM structures, process re-engineering and creation of PCM knowledge base. The database includes test results of typical structures, as well as information about all Russian suppliers and manufacturers of PCM.

Results. The authors believe that mass introduction of PCM in the oil and gas industry will solve many current problems and will contribute to the efficiency and safety of oil production and transportation processes.

Conclusion. According to the results of the analysis in the main current normative documents there are no requirements preventing the application of products from composite materials at oil and gas objects, but, at the same time, it is noted that the current NTDs describe not all the factors that can affect the possibility of operation of these products. It is necessary to mass introduction of PCM in the oil and gas industry that will contribute to the increase of efficiency and safety of the processes of production and transportation of oil raw materials.