Background. The article presents an approach to assessing the geological data density, the main indicators are the quantity and quality of investigations.
Aim. Developing a numerical metric for assessing the geological data density in 1D and 2D.
Materials and methods. The methodology considers data from six areas: seismic exploration, well logging, core analysis, production tests, fluid sampling, well test. The data density for each of them is unified and varies from 0 (minimum data density) to 1 (maximum data density). In addition to the quantitative metric, the authors proposed a method for representing data density in the form of a map (2D view).
Results. A methodology of quantitative assessment of geological data density has been developed for 1D and 2D.
Conclusion. Visualization of data density in 2D allows evaluate the areas with the maximum and minimum amount of information of the object. A comprehensive assessment of the data density, together with the geological complexity of the field, makes it possible to evaluate and plan measures to reduce geological, technological, and economic uncertainties.

Background. Flowback period to achieve well productivity succeeds to the hydraulic fracturing operation and the period of braking of the cross-linked fluid. The well control during flowback is often not regulated or determined by external factors. At the same time, in the process of fracture cleaning, a number of hydromechanical and geomechanical effects build-up, which can reduce the long-term fracture conductivity and thereby reduce the final well productivity. Increasing the efficiency of the flowback process is associated with an increase in oil recovery of low-permeability oil reservoirs and is topical for the oil industry.
Aim of this work is to assess the contribution of the geomechanical and hydromechanical group of effects to the degradation of fracture conductivity and based on their balance propose a method for calculating the optimal flowback scenario where production is maximized.
Materials and methods. To assess the contribution for each group of effects, a comprehensive method for numerical simulations of the well clean-up process was developed using a suspension filtration model taking into account non-Newtonian rheology, particle transfer, reservoir inflow and geomechanical factors.
Results. An integrated approach for finding the optimal well dynamics during clean-up period based on the balance of competing groups of effects was implemented using the well with a hydraulic fracture model history-matched to the field experiment data. The well drawdown optimum was obtained, minimizing the effect of fracture degradation on production. Conclusions. The obtained results confirm that the developed approach to assessing the contribution for each group of effects is a reliable basis for optimizing the flowback process. As a result of the proposed method application, a recommendation for target bottomhole pressure corresponding to the optimal scenario is issued for the flowback period.

Purpose. Identification of the main errors in determining the coefficient of displacement of oil by water and estimating the relative phase permeability for oil and water in the laboratory. Method. Analysis of the results of laboratory studies to determine the coefficient of displacement of oil by water and the assessment of relative phase permeability for oil and water in laboratory conditions. Results. Estimation of the oil displacement coefficient by water and the relative phase permeability of productive rocks for oil and water is an obligatory step in substantiating the initial data for the design of oil field development. Recently, very often began to appear the results of experiments that differsignificantly from the results of experiments conducted earlier in various research institutes of the Soviet Union, and later in Russia for several decades. The main reason for these differences is related to the violation of the fundamental requirements for conducting experiments to determine the coefficient of displacement of oil by water, which leads to errors in assessing the potential of reservoirs during flooding. Errors in the calculation of the dependencies of relative phase permeability for reservoir fluids on the water saturation of the porous medium are often associated with a lack of understanding of the physical foundations of the two-phase filtration process. Conclusion. The article analyzes the methods for estimating the parameters used in calculating the coefficient of displacement of oil by water and shows the whole range of errors allowed in its determination. Recommendations are given to increase the objectivity of the assessment of the fundamental characteristics of reservoir formations used in substantiating the forecast of production in conditions of natural or artificial flooding of oil deposits.

Background. The article analyzes the causes of high corrosive aggressiveness of associated petroleum gas from Western Siberia fields, causing premature wear of the internal surfaces of technological pipelines, walls and elements of separation equipment and offers recommendations (technical solutions) for their elimination. Aim. In order to improve the reliability of pipelines and equipment of compressor stations, gas treatment plants that receive crude associated petroleum gas, it is necessary to identify the causes of gas corrosion aggressiveness and develop recommendations (technical solutions) to eliminate them. Materials and methods. Field and laboratory studies are required to analyze, evaluate and determine the causes of high corrosive aggressiveness of associated petroleum gas: 1) analysis of associated petroleum gas and separated liquid at the inlet/outlet of each vessel and apparatus included in the technological process; 2) analysis of gas flow in separators and its effect on the walls of apparatuses and pipelines; 3) studies of pipeline sections with corrosion damage. Results. It has been revealed that corrosion of pipelines and equipment of compressor stations, gas treatment plants, to which crude associated petroleum gas enters, occurs in places of condensation of the produced water and the formation of water films on the metal surface, as well as in the drainage lines of gas separators and other places of accumulations of precipitated water and proceeds by the mechanism of carbon dioxide and hydrogen sulfide corrosion. Conclusions. In order to reduce the intensity of corrosion processes and prevent subsequent gusts of technological pipelines, it is recommended to use corrosion protection methods and organize a corrosion rate monitoring system.

Background. The article discusses such a technological direction in hydraulic fracturing as working with ultra-light weight propping agents (proppants). These materials deserve special attention in the context of modern trends aimed at optimizing the hydraulic fracturing process, reducing its cost and increasing the efficiency of stimulation. Materials and methods. For a general acquaintance and understanding, the authors cite global trends, experience, practices on the use of ultra-light weight propping agents, and talk about the Russian experience of using such materials. The presented gradation of lightweight propping agents existing in the world and Russian practice makes it possible to get acquainted not only with existing solutions, but also to identify trends in the development of this direction. In the work, special emphasis placed on the conditions for the use of lightweight materials within the framework of traditional collectors, as well as schemes and directions for achieving the best economic effect. A special place in the article given to the inner experience of PJSC Gazprom Neft in estimation the applicability of ultra-light weight proppants presented by Russian manufacturers for conditions of Western Siberia fields. Results. The authors show the inner experience of the company, the results of field tests, methods and schemes of technology adaptation. The results of fieldwork, presented in the article, show the effectiveness of using a lightweight proppant, which expressed in reducing the unit costs. Conclusion. The analysis of the performed operations allows us to conclude that with the right approach in choosing the type of propping agent, its application conditions, geological properties of the object, assessment and adaptation methods, lightweight proppants have the chance to get out of the niche zone, fi nding wide application in the conditions of stimulation of traditional reservoirs.

Background. The extended-reach drilling requires integrated approaches in the construction of wells. Drilling through unstable intervals and the risk of mud loss are the main potential problems in drilling. The length and deviation increase in the intervals of intermediate and production casing complicate the process of well cleaning and construction. Existing methods of wellbore stability monitoring require additional tools. Aim. The set of optimal approaches for a comprehensive assessment of the wellbore has been formed and applied. The main goal is to show the value of the methods used in geomechanics real-time support. Materials and methods. An approach based on control of the annular pressure has been used for the estimation of the wellbore condition in real-time. The logging while drilling (LWD) and measurement while drilling (MWD) data transferred from the telemetry system has been compared with the geomechanical model during the remote operation control. The annular space condition has been assessed by analysis of the equivalent circulation density while drilling, flushing, run in hole (RIH), and pull out of hole (POOH) operations. The calculated method of cleaning efficiency based on actual data allowed us to assess the annular space condition. Results. Comparison of the annular space condition data with the one-dimensional geomechanics model and cave-in mud data on the oil-rig vibrating screen allowed us to avoid possible issues. Recommendations from the remote operation center engineer contained intervals that whether safe or flushing need and duration of the flushing. Preparation for lowering the casing eliminates the requirements for drilling mud parameters change and went without additional lifting operations. Conclusions. Presently, the methods mentioned in the article are successfully used in geomechanical real-time support of drilling. It makes possible to optimize individual operations during the construction of wells.

The main task of well servicing workover units to maintain all active wells fully operable while ensuring compliance with all applicable subsoil protection requirements. The technical equipment of well servicing workover units crews requires automation and robotization, in view of the constant increase in the complexity of well workovers, growing safety barriers and a high proportion of heavy manual labor. Target. In order to automate lifting units for underground workover of wells, a pilot-industrial test project (PIT) «Meh-Brigade» was launched. The purpose of the pilot study is to improve the design of lifting units and equipment, to select the optimal layout for the placement of personnel at the wellhead. Materials and methods. The project involves the improvement and automation of tripping operations by integrating the following main components: cab-transformer, elevator with hydraulic pipe gripper, robot key, mechanized receiving bridge, hydraulic blowout prevention equipment (BOP). Results. A market review was conducted among companies that produce lifting units in the Russian Federation, Europe, China, and the calculation of economic efficiency is being carried out. Conclusion. The pilot test is scheduled for mid-2023.

At the present time, the companies of the oil and gas sector for the purpose of the sustainable development and growth have to expand the portfolio of their assets. The correct cost evaluation of an asset at the initial stage makes a big impact both on the further development of the project and on the long-term development strategy of the company as well as on its economy efficiency. Purpose. The purpose of this work was to solve the issue of forming up the utility line areas with due regard to the local conditions and cost evaluation. Materials and methods. For problem solution, the use of an algorithm was considered based on the search of the best possible coincidence on the graph that finds the lowest cost route from one vertex (initial) to the other (target). This paper presents the use of A-star algorithm for the selection of the right-of-way. In the course of problem solution on the basis of the preliminary pipeline route, the main laying method and obstructions that may be encountered are defined. Then cost increase coefficient is established for pipeline construction in zones that differ from the basic one. Pipeline cost coefficients are selected in accordance with the cost of each method of pipeline construction. Results. The algorithm implementation in the program complex with due regard to the pipeline laying cost in different local conditions allowed to enhance the project evaluation at the initial stage. Conclusion. Thus, using this algorithm to form up the areas of not only minimum length but with due regard to the local conditions, it is possible to enhance the accuracy of the project evaluation and to select the best option of the construction with minimum costs at the initial stage of the project implementation.