Introduction. Recently geological prospecting works become aimed at more complicated perspective objects in terms of their exploration, that leads to higher costs of works. From first stages of exploration, it is necessary to apply integrated approaches while geological analysis & reserves assessment as well as for further works planning considering economic attractiveness of project.
Aim. Main aim is an integrated technical approach development for reserves probabilistic assessment accounting geological risks for Achimov deposits with low exploration maturity.
Materials and methods. This article describes an approach allowing subsequent uncertainties evaluation at three main stages: during structural framework construction, effective thickness estimation and saturation forecast considering possible geological risks.
Results. More than 800 groups of maps were obtained upon the workflow calculation. In each group general, effective and productive volume maps were evaluated as well as fill factor maps. These maps being geologically realistic were used for development strategy planning.
Conclusion. Geologically justified maps at all stages in terms of submarine fans’ conceptual model are obtained upon the workflow calculation. Analyzing the fill factor distribution, application of such approach allows avoiding additional reserves decrease due to the similarity of such distributions estimated by data from analogues. Finally, output maps seem to be suitable for development wells placement and production profiles construction during further reservoir simulation.

Background. Vibrating sources of seismic waves have a number of advantages over explosive ones: the ability to work in difficult surface conditions, a greater number of source parameters that allow you to control the shape of the seismic signal, high-performance technologies for vibroseismic work can reduce the time of data acquisition. But data quality is o` eninferior to explosive sources. The loss of quality is associated with technical problems in generating low and high frequencies and nonlinear distortions. Also, during high-performance work, an additional source of interference arises in the form of a signal from neighboring sources.
Aim. The article discusses several methods aimed at improving the quality of the transition stage from raw vibrograms to correlograms.
Materials and methods. The article discusses several methods aimed at improving the quality of the transition stage from raw vibrograms to correlograms. Testing of the methods includes the use of non-stationary filtering of vibrograms, the use of records from vibrator plates (Ground Force) for correlation and deconvolution of vibrograms, and the suppression of harmonic noise from secondary sources.
Results. There are two types of noise for attenuation: correlation noise and harmonic noise. The first type of noise is caused by a mismatch between the actual vibration signal and the pilot sweep. Therefore, suppression methods are aimed at searching for a signal close to the actual one, or using the Ground Force signal. Harmonic interference suppression is relevant for high-performance applications in which a harmonic signal from a secondary source interferes with the fundamental mode of the signal from the main source.
The effectiveness of the methods was evaluated by applying the methods to real data. It has been shown that standard correlation of vibrograms with a pilot sweep has filtering properties similar to time-variable bandpass filtering of vibrograms. Deconvolution of vibrograms with the Ground Force signal makes it possible to reduce the amplitudes of correlation noise, but increases the amplitude of random noise at short distances. Harmonic noise is effectively suppressed by a method that does not use a Ground Force signal, due to which the delay between excitations (slip-time) in high-performance methods can be signifiantly reduced.
Conclusions. A qualitative and quantitative assessment of the efficiency of vibration data processing methods was carried out. Recommendations for the application of the considered methods were formulated.

Introduction. The technique of color mixing or chromatic interpretation is a widespread analysis tool, especially for geological complexes of complex structure. The implementation implies the use of either frequency slices obtained within the framework of spectral decomposition, or amplitude slices spaced apart in time.
Aim. The purpose of this research is to study the process of occurrence of anomalies within the framework of color mixing of amplitude slices. An additional task is to develop metrics for comparing chromatic interpretation tools with each other.
Materials and methods. The python programming language and open libraries were used to implement the research. At the initial stage of the study, the selected algorithms were studied on simple model data, which allows us to form key hypotheses, which were later tested on a real seismic data.
Results. The key factor leading to the appearance of anomalies in the color mixing of amplitude slices is the shape of reflection. This factor works for both frequency slices and amplitude ones. However, there are differences in the detail of the results. Thus, mixing the amplitude slices allows geophysicist to get a more information about the internal structure of the studied complex due to a local character of the anomaly, as well as the preservation of information about the reflection sign.
Conclusion. The developed algorithm for evaluating the informativeness of chromatic maps allows us to conclude that the results of color mixing of amplitudes are more informative. This thesis was confirmed both on model data and on a real example.

Introduction. Vertical permeability is an important characteristic of an oil-bearing reservoir, the knowledge of which allows solving many problems of scientific in oilfield practice. This parameter significantly affects the distribution of fluid flows in the formation, and therefore, understanding the specifics of its changes during the development of a production object is highly relevant. One of the most accessible sources of information on vertical permeability can be hydrodynamic well testing methods under unsteady filtration conditions.
Objective. To evaluate the peculiarities of changes in vertical permeability of the formation during the life cycle of horizontal wells under specific geological conditions of a particular oil fi eld by analyzing pressure restoration curves.
Materials and methods. The materials of geophysical, production hydrodynamic research conducted under steady-state and unsteady filtration conditions, as well as the results of their interpretation, were used. Data processing methods using mathematical statistics and graphical analysis applied.
Results. Shown that within a certain range of wellbore depressurization during well operation before shutting them down for testing, vertical permeability linearly depends on pressure drop. The equation of the approximating straight line has different characteristics for different wells. The obtained data served as the basis for developing a method that allows for a prompt assessment of horizontal permeability under the condition of well operation under such regimes.
Conclusions. The conducted research provides that the movement of reservoir flid in the vertical direction within numerically established depression intervals is complicated by nonlinear effects and does not follow Darcy’s law. Nonlinear effects are absent at higher pressure differentials. In the horizontal plane, the flow of reservoir fluid is not anomalous, so, it corresponds to the law of linear filtration.

Introduction. During analyzation the results of calculating integrated asset models, it is possible to obtain results that are inconsistent with the history of field development. Detecting incorrect results can cause difficulties related to the human factor and lack of experience in the field of IAM. While determining the causes of oil production losses and determining the necessary measures to optimize production require high awareness of the development processes.
Aim. For specialists in geology and mining, as well as production control centers, the creation of intelligent assistant algorithms for working with IAM is a crucial task. Using this approach it is possible to identify problems promptly and find the potential of an asset based on an IAM.
Materials and methods. Applying machine learning (ML) models based on the historical data of field development and deposits of analogues, obtained from field data of the technological regime of the well, as well as on the basis of synthetic models built in specialized simulators, for further reuse in predictive and optimization calculations.
Results. Recommendation algorithms for making optimal decisions by an engineer during the development of an oil and gas field.
Conclusion. This tool allows engineers to make more informed decisions when choosing a strategy for the development of oil and gas fields, even with limited computing resources. It helps to explore different options, take into account uncertainties and work with constraints, which significantly increases the efficiency of work in the fields.

Introduction. Achimov deposits are characterized by low filtration properties, that require special tools development to obtain an economically attractive result. In particular, such tools include drilling horizontal wells with multistage hydraulic fracturing.
Aim. The aim is to develop a modified water cut map considering the fractional flow model as a tool for analyzing and development strategy modification of Achimov deposits in order to reduce uncertainties associated with runin water cut and reservoir saturation.
Materials and methods. Water cut map construction technique based on Leverett J-function within simulation model is presented. History matching of model to 89 wells as well as filter usage considering hydraulic fractures’ spreading is a center point of described method. Water cut map is assumed to be appeared into the economic efficiency matrix based on finance & economic model with actual macroparameters.
Results. The estimated water content of new wells according to the water content map at the proper level and dynamic model history match showed a high percentage of convergence with the actual launch indicators, which makes the use of the technique as a perspective tool for appropriate development strategy application for object associated with reservoir saturation assessment uncertainties.
Conclusion. The use of a water cut map is a perspective useful tool for analyzing development, which reduces the uncertainties associated with water cut beginning and reservoir saturation in general within the area new wells planning. The use of the economic efficiency matrix allows ranking of the project wells, optimizing the process of evaluating by time costs.

Background. To optimize the development of heterogeneous reservoirs, a number of previously developed methodologies are used, including the methodology for constructing a volumetric fracture grid model by V.D. Viktorin (MOST). Summarize of previously works results showed the absence of a formalized area of MOST application and, as a result, the possibility of recommending its application in production for actually development objects. In order to form such an area, a generalization of geological and industrial information and previously conducted studies was performed. An assessment of a new unique object in the Republic of Iraq Mishrif was carried out.
Aim. The purpose of the research was to determine the boundary conditions for the application of the volumetric fracture grid model method as a way of taking into account the complex heterogeneous structure of carbonate reservoirs, as well as to determine the possibility of using this method for the highly productive Mishrif object of the Republic of Iraq.
Materials and methods. The research methods were the analysis of the results of previously works, determination of the researching objects parameters intervals, MOST by V.D. Viktorin. The initial data were the reports of previously completed R&D for the Perm Territory objects, geological and industrial information on the results of the Mishrif object studies (Republic of Iraq).
Results. The work considers widely used approaches to accounting for fracturing, characterizes the capabilities of the proposed method, builds a model using the MOST methodology (Viktorina V.D.) for a previously unexplored object Mishrif of the Republic of Iraq, forms (without Mishrif) and expands (supplemented with the Mishrif) the scope of the method. The research results shows possibility to recommend the creation of methodological approaches to the use of a volumetric fracture mesh model (MOST) for geological and hydrodynamic models of objects included in the scope of the method.
Conclusions. Based on the research results, the boundary conditions for the application of MOST are determined taking into account previously completed work, the possibility of using MOST for the highly productive Mishrif object of the Republic of Iraq is confirmedthe scope of this method is expanded.

Aim. The aim of this work is to describe approaches to managing annular pressure at various stages of the well lifecycle. Throughout a well’s lifecycle, sustained casing pressure (SCP) may occur. Global practices in hydrocarbon well production show that approaches to managing annular pressure will differ at various stages of the well lifecycle.
Materials and methods. This article comprehensively utilizes case studies illustrating existing approaches to managing annular pressure at various stages of the well lifecycle. In the absence of a unified database on wells with SCP, disparate information sources have been collected and summarized, providing an overview of global practices in managing wells with SCP.
Results. The analysis results demonstrated the importance of a comprehensive, conscious approach to operating wells with SCP and managing annular pressure at various stages of the well lifecycle. The article highlights the vast experience accumulated in global HC well production practices, allowing for the development of a comprehensive approach to ensuring well integrity and reliability, considering the specifics of working with SCP at various stages of the well lifecycle.
Conclusion. The article presents real examples of industry regulatory and methodological documents (RMD) and approaches developed by oil and gas companies for managing annular pressure, ensuring that well construction, operation, and abandonment are carried out in accordance with established RMD requirements, project approaches, and changing operational conditions. Effective management of SCP throughout the entire well lifecycle is a necessary condition for rational field development and ensuring safe well operations. The accumulated experience and scientific-methodological base create good prerequisites for preventing and eliminating SCP. The challenge lies in the widespread implementation of best practices and their adaptation to specific conditions.

Objective. It looks like a MWD static survey takes so short time just few minutes, however, when you calculate total time for taking all surveys during drilling one well you will get considerable number. The objective of the article is to analyze how MWD telemetry speed affects the total well construction cost.
Materials and methods. The article contains calculation of time spent on such operation like taking MWD static surveys and relogging, how it affects total well construction time and cost. It also describes some methods for increasing the telemetry rate.
Results. According to the given analyses results, the telemetry rate can be increased twice with minimum cost. The increase doesn’t affect the MWD signal quality. Due to double telemetry rate the time spent for taking MWD surveys and reclogging will be twice shorter. That leads to the lowering the total well construction time by 0,57%, the total well construction cost will be decreased accordingly.

Aim. Assessment of the possibility of using foam and gas generating compounds for the development of oil and gas wells after repairs.
Materials and methods. The classification of chemical reagents that can potentially be used to create a foam gas generating system is based on patent research and analysis of domestic and foreign open sources. The hypothesis of the possibility of developing oil wells after repairs by removing part of the jamming fluid using foam gas generating checkers was tested by modeling the main parameters of the well start in the OLGA software package.
Results. The results of patent and analytical studies show that foam gas generating systems are most often used in gas, gas condensate wells and oil wells operating in the gushing mode. Application in oil wells operated by pumping is limited primarily by the energy of the reservoir and the amount of liquid that must be removed from the bottom of the well. Modeling of the oil well development process has shown that the volume of gas released by the checkers is not enough to promptly trigger an inflow from the reservoir.
Conclusion. The current characteristics of foam gas generating checkers, such as the volume and intensity of gas release, do not allow them to be used in oil wells muffled by mineralized aqueous solutions of salts. The technology can gain development prospects provided that new chemical reagents are selected to increase the volume of gas released. Also, one of the possible improvements may be the development of a technology for dissolving gas in the volume of process fluid filling the well and initiating the process of intensive gas release in a short period of time.

Goal. Development and development of interpretive criteria for the method of spectral acoustic noise metry.
Methods. Experimental laboratory studies were carried out on the spectral characteristics of acoustic noise generated by flows of liquid and gas-liquid mixture in overflow channels. Based on the results of laboratory studies, changes in the spectral characteristics of acoustic noise observed by downhole equipment in the wellbore were determined depending on the composition of the fluid and the speed characteristics of the flow in the crossflow channel. Interpretive criteria and directions for the development of downhole equipment are proposed to ensure operational monitoring of the current state of the well.
Results. The frequency range of acoustic noise generated by flows of various compositions in the annular space has been established, and interpretive criteria have been determined.
Conclusion. The possibility of increasing the reliability of the conclusion based on the characteristics of behind-the-casing flows by combining the spectral noise metry method with traditional flow metric studies of existing production and injection wells has been shown.

Purpose. Search for optimal formulations for chemical water shut-off based on polycarylamide and emulsifier.
Materials and methods. Review of existing water shut-off methods. Conducting laboratory studies in bottle tests of formulations differing in rheological properties to determine the optimal ratios of chemical reagents.
Results. The review of existing water shut-off methods was carried out, and possible template designs for water shut-off at wells of the T oil and gas condensate field were shown. Laboratory studies were carried out in bottle tests of various emulsion formulations (based on the Isoplast B reagent) and polymer compositions (based on polyacrylamide AK-642).
Conclusion. The most applicable technology for the conditions of the T field is chemical water shut-off. Optimal formulations 2 and 3 of the Isoplast-D composition, which have selective properties, have been identified. Recipes 1, 2, 3 of cross-linked polyacrylamide brand AK-642 are capable of forming stable gels. The completed studies make it possible to conduct field tests of the formulations of the proposed reagents in the T field.

Aim. The development of oil zones of oil and gas fields located in remote, hard-to-reach areas with no infrastructure is complicated by the problem of utilization of associated petroleum gas (APG). This problem arises most acutely during the development of narrow oil rim in oil and gas condensate fields with a massive gas cap. In such a case, there is a possibility of an abrupt increase in the gas-oil ratio due to gas breakthroughs to oil wells from the gas cap. A possible way to solve the problem of rational use of APG in such conditions is to form a field development system using the technology of gas injection into temporary underground storage facilities. For this purpose, it is required to justify facilities used for the APG injection to temporary reservoirs, which is the main goal of the study.
Materials and methods. Analysis of geological and geophysical information of the oil field and study of world experience [3] of gas injection to underground reservoirs. Forming of requirements and parameters of a reservoir influencing efficiency of the process of gas injection.
Results. A methodology for a comprehensive assessment of the reservoir geological parameters for gas injection has been developed. It allows to characterize all reservoirs of the field in terms of the possibility of their use for gas injection and to identify the most acceptable.
Conclusion. As a result of the analysis, it was found that the most promising reservoir at this field for temporary storing of a gas are the layers NP_2-3, NP₄ and YU_2-6.

Introduction. Gas production from fields in the northern region faces with some of challenges related with climatic and geocryological restrictions during of drilling, building and operating of wells. One of the most crucial factors complicating process of gas manning is the process of thawing of permafrost soils, it is possible in the result of thermal impact from fluid produced from the bottom of well to wellhead through the well casing. This process occurs at the depths of up to several hundred meters. As the temperature of the rock around of the well casing, the icy soils lose their strength properties and this may lead to a reduction in the strength of the wellbore support and casing deformation. In the result of permafrost thawing is formation of wellhead subsidence, appearing of non-project excessive loads on well supports. Movement of soils can lead to accidents caused by wellhead equipment and li` pipes depressurisation with outflow of hydrocarbon fractions from the wellhead releases of hydrocarbon fractions into the atmosphere. During construction of gas wells in areas of ice spreading, special thermal stabilization technologies are used to provide the required thermal protection while at the same time imposing additional costs on the total well construction cost. Goal. The purpose of this work is to search, test and implement a set of technical solutions and heat-insulating materials that provide thermal stabilization of wells in permafrost conditions and have maximum technical and economic indicators, which will increase the technical security of wells and reduce the total costs of their construction.
Materials and methods. The Gazprom ne` company group has carried out research to select technologically effective and technically feasible ways of conserving permafrost soils and preventing damage to the integrity of gas well structures, provided the technology implementation costs are reasonable. In the paper presents the results of modeling of thawing permafrost soils with regard to the application of the considered thermal insulating materials and well casing designs laboratory tests of various thermal insulating materials as well as the possibilities for optimization of the existing technologies by using alternative thermal insulating solutions which have not been considered before in perimeter of vertically integrated oil companies.
Results. Based on laboratory tests, confirmation of the presence of more effective heat-insulating materials (relative to basic solutions) was obtained, which can be used to ensure thermal stabilization of permafrost soils during well construction and allow increasing the technical and economic indicators of well construction.
Conclusion. Based on the presented data, it is recommended to carry out bench and pilot tests of new thermal insulating materials as part of a thermally insulated casing pipe and the use of thermal cement with microspheres during well construction.

Background. The digital twin of the field is a modern and powerful tool for linking various components of the integrated model and field data on the operation of wells. Thanks to deep integration and access to up-to-date online data, this tool allows you not only to automate standard processes for interpreting research data, but also to implement your own for a better understanding of the energy state of the reservoir.

Aim. The purpose of the work is to describe a methodology for predicting the behavior of the pressure recovery curve (CVD) and estimating reservoir pressure in the case of a short-term well shutdown, the duration of which is insufficient for the formation of a full-fledged CVD and its subsequent full-fledged interpretation.

Materials and methods. The initial materials for the work were the measurement data and the results of the interpretation of hydrodynamic studies of wells, data on the operating mode of the well and the geological and physical characteristics of the productive layers of the studied field. To optimize the calculation of regression coefficients, a script has been written in the C# programming language. Testing and implementation of the methodology was carried out at the wells of the field of Gazprom neft companу group.

Results. The technique used in the work does not solve the problem of determining the entire spectrum of filtration parameters and characteristics of reservoir opening perfection, and also does not exclude the conduct of full-fledged CVD. However, it makes it possible to eliminate ambiguity in the interpretation of long-term pressure stabilization curves (CSD) recorded during stable well operation, control reservoir production, increase the coverage of the well fund by research without additional long-term studies, and, accordingly, production losses.

Conclusions. The advantages of the technology include: 1. the ability to operationalize the process of assessing the energy state of a deposit and, as a result, improve the quality of decisions made during field development, 2. the ability to implement digital Oil Field monitoring tools, 3. ease of soft ware implementation and implementation into existing soft ware tools. It was found that the accuracy of forecasting depends on the quality of the initial data describing the filtration and capacitance properties (FEZ) of an operational facility or regions with similar development conditions. The results of the algorithm allow us to conclude about the effectiveness of the proposed solution and show the importance of these technical stops in understanding the dynamics of reservoir pressure.

Aim. Study of the use of genetic algorithms to solve the problem of finding the optimal version of the drilling/ sidetracking carpet.
Materials and methods. To justify the profitability of drilling, a python algorithm has been developed to assess and reduce the risks of financial losses when deciding to drill new wells by choosing the optimal drilling option from all possible ones. To optimize the drilling decision-making process, a genetic algorithm is proposed, based on a combination of production profiles in such a way as to simultaneously maintain a production plateau at the stage of stabilization of production levels and minimize capital costs for commissioning new wells/laterals in conditions of geological uncertainties.
Results. The use of the proposed algorithm made it possible to significantly simplify the decision-making process on drilling new wells due to the absence of manual enumeration of all possible options, as well as to create a well-founded methodology for selecting a drilling carpet. To make a competent decision on drilling new wells in an existing field, it is necessary to take into account several parameters simultaneously. This approach is called multidimensional optimization, and its result is the selection of one or more best options. The most interesting are the wells that have the highest planned flow rate (that is, ultimately the greatest profit) and entail the least amount of costs.
Conclusion. The idea of multidimensional optimization is implemented using a genetic algorithm, which is based on the theory of probability and the law of large numbers and allows you to make the optimal choice in favor of a particular strategy for drilling a pool of new wells. The proposed approach can be successfully applied to solve optimization problems of various types.