Introduction. Nanotechnology has received a lot of attention in the oil and gas industry as an effective means of improving properties and increasing production rates, especially in harsh environments such as ultra-deep and shallow gas fields, deviated and horizontal wells, geothermal zones, and high pressure/high temperature (HPHT) areas. These environments present numerous economic, technical, operational, and HSE challenges that need to be addressed.Cementing operations play a critical role in these environments, as the cement sheath serves as a barrier to meet the different well conditions, including pressure, temperature, and the flow of liquids or gases. The use of nanomaterials as additives to cement has been credited with improving its properties and performance under these complicated conditions. Methods and materials. The study presents an analysis of the effect of pressure and temperature on the behavior and complexity of cementing operations in high-pressure wells. Analytical performance of the main characteristics of nanoclay (structural and mechanical) and evaluation of its effect on the durability and strength of cement slurry during well construction are presented. Results and Discussion. The results of the study allow us to conclude that nanoclay can be widely used as an additive to improve the durability and properties of cement-based materials under difficult conditions. Conclusions. The results of this study provide valuable information to researchers, engineers and practitioners in the field of cementing oil and gas wells, especially in solving problems related to providing the most favorable conditions for well operation with the long-term use of more durable cement slurry

Introduction. Cement microstructure imaging is an emerging field of non-destructive compositional investigation. Some data may be available via one method but not the other due to various physical and chemical mechanisms that could cause cement decay. In order to quantitatively and qualitatively evaluate cement stone, it is necessary to investigate it as a complex multi-phase composite material, identify its crystalline phases, and estimate the precise size of its nanoparticles. Materials and methods. This work presents the results of a microscopic study of the effect of Nanozeolites (particle size <= 100 nm) on cements for cementing wells. To study the surface properties (chemical bonds between molecules, analysis of mineral composition, and surface topography and morphology) of class G cement stone, three types of microscopes - IR spectrum, X-ray diffraction (XRD), and atomic force microscopy (AFM) - were used. Zeolite nanoparticle additives were introduced at varying concentrations (0.5%, 1%, 1.5% by weight of cement) after 8 hours of curing in a water bath at atmospheric pressure and a heating temperature of 60(& ocy;)C (140(& ocy;)F). Results and discussion. The infrared spectra revealed changes in surface properties, indicating a decrease in free water and an increase in the strength of the system with the addition of nano zeolite. X-ray diffraction method (XRD) allowed for the identification of the main phases of crystalline hydration. The highest peak intensity is due to calcium hydroxide CH, which decreases with the addition of nano zeolite. This phenomenon elucidates the pozzolanic behavior of nano zeolite, which reacts with precipitated calcium hydroxide upon hydration to form C-S-H, reduces the calcium hydroxide content of the layered structure and increases C-S-H. The topography and surface morphology of the samples were studied at the nanoscale using atomic force microscopy. The images show the nanoparticles propagate along the cracks and appear to increase the surface layer's resistance to deformation and stress relaxation in cement-based materials. In addition, they promote viscoelastic C-S-H behavior. Conclusion. Adding nano zeolite to Portland cement affects the process of early hydration of cement stone and increases its early strength. Additionally, the introduction of 1.5% nano zeolite into cement results in the formation of irregular peaks and valleys of low porosity filler, ultimately enhancing the cement's strength

Effective fluid-loss control in oil wells is a critical concern for the oil industry, particularly given the substantial reserves situated in carbonate reservoirs globally. The prevalence of such reservoirs is expected to rise with the slow depletion of hydrocarbons, intensifying the need to address challenges related to deteriorating reservoir properties post well-killing operations. This deterioration results in significant annual losses in hydrocarbon production at major oil enterprises, impacting key performance indicators. To tackle this issue, this study focuses on enhancing well-killing technology efficiency in carbonate reservoirs with abnormally low formation pressures. To address this issue, the authors propose the development of new blocking compositions that prevent the fluid loss of treatment fluids by the productive reservoir. The research tasks include a comprehensive analysis of global experience in well-killing technology; the development of blocking compositions; an investigation of their physico-chemical, rheological, and filtration properties; and an evaluation of their effectiveness in complicated conditions. The technology’s application in the oil and gas condensate fields of the Volga-Ural province showcases its practical implementation. This study provides valuable insights and solutions for improved fluid-loss control in carbonate reservoirs, ultimately enhancing well performance and hydrocarbon recovery.

Introduction. Drilling and reconstruction of oil and gas wells are key stages in the development of hydrocarbon fields. One of the most significant technological elements that greatly influences the efficiency of the process is the drilling fluid (DF). It performs many functions, including cooling and lubrication of rock-cutting and special tools, bottomhole cleaning from drilled rock, maintaining well wall stability and many others. In recent years, special attention has been paid to the use of nanomaterials in the DF drilling fluid composition. Nanoscale additives can significantly improve technological properties of water-based muds, increase their efficiency and reduce drilling costs. Methods and Materials. The influence of additives on general technological parameters of Clay-Free Drilling Mud (CFDM) was evaluated. Special attention was paid to revealing the influence of the developed experimental additives on the friction coefficient and antifriction properties of (CFDM), which were determined using modified friction machine AI5018. Results and discussion. This study focuses on the investigation of the impact of nano-additives on the technical properties of water-based mud (WBs) and their effectiveness for drilling and well reconstruction. In the course of the work, comprehensive laboratory studies have been carried out to evaluate the effect of nano-additives of different nature, such as nano-graphite and nano-carbon materials, on the lubricating properties of water-based mud (WBs), which helps to reduce the wear of drilling equipment, increase the mechanical speed of drilling and, as a consequence, reduce the time and financial costs of well construction and re-construction. Conclusion. The introduction of nano-additives allowed significantly in improving the technological properties of drilling fluid DF. The obtained results can be used to improve the compositions of solutions based on the use of nanomaterials, which will increase the efficiency and reliability of well drilling processes

А riser, which is an offshore water separation column is the main difference between offshore drilling and onshore drilling. The idea of the research is to calculate the stressed-deformed state of a riser made of various materials to identify technological advantages during drilling on the shelf and at sea in the Arctic. The article is the result of research conducted in the Mathematica application program to determine the operating stresses that depend on the drilling process conditions and the external environment. Modern drilling technologies are designed to increase the capacity of the equipment or to use alternative materials. Given the pace of development of the fields of the Northern Shelf of Russia, there is a need to explore the use of alternative materials for such marine equipment as risers.

Most of the main types of complications in the process of drilling wells, such as collapses, taluses, collapses of the walls, the formation of caverns, etc., are associated with external mechanical and hydrodynamic effects on the walls of the wellbore. Therefore, ensuring the stability of the borehole walls is one of the urgent and difficult technological formation fluid pressure on mechanical processes in rocks when they are opened with a directional well, especially of horizontal wells. This article provides solutions to problems associated with hydraulic fracturing of a well and the condition of its prevention, calculation of generalized stresses in the rock formation for inclined well. As a result of this calculations, the necessary data are obtained for making a decision on the density of the drilling fluid to drilling the considered interval of rocks, as well as for making other technological decisions. The given calculation formulas make it possible to fully evaluate the effect of the formation fluid pressure on the mechanical processes in the rocks when they are opened by a horizontal well. Keywords: hydraulic fracturing; blade bit; steel ball-shaped toothed bit; polycrystalline diamond bit; laser drilling; impact rope drilling; rotary drilling.

Ensuring the completeness of oil and gas production from the subsoil by using modern techniques and technologies for controlling the inflow into the well is an urgent task, especially for wells with long horizontal ends. Inflow control devices (ICD), used in conjunction with packers and downhole measurement devices, are part of such systems, covered by the concept of «smart well». In general, such systems make it possible to control the inflow (flow rate) in individual intervals of horizontal wells or in vertical wells of multilayer fields while operating simultaneously in order to optimize production without additional downhole operations in real time. Keywords: inflow control device; horizontal well; intelligent well.

One of the complex technological tasks in the process of drilling is to ensure the stability of the wellbore walls, as well as their modeling for further forecasting the state of the wellbore and the likelihood of hydraulic fracturing. This is due to the fact that most of the complications and factors affecting the equilibrium state of the wall are associated with external influences. The article discusses the mechanical and partially hydraulic aspects of solving the described problems associated with modeling the stability of the wellbore walls and predicting hydraulic fracturing. As a result of calculations, the necessary data are obtained for making a decision on the density of the drilling fluid for drilling the considered interval of rocks. The assumed model of the porous rock and the given calculation formulas make it possible to fully evaluate the influence of the formation fluid pressure on the mechanical processes in the rocks when they are opened by a well. Keywords: hydraulic fracturing; blade bit; steel ball-shaped toothed bit; polycrystalline diamond bit; laser drilling; impact rope drilling; rotary drilling.

The article is about problem of drilling deepwater oil and gas wells that consists in complicating and increasing cost of their well design due to narrowing mud window at different depths. The authors analyse drilling technology developed and applied in practice of offshore drilling with a dual gradient drilling, which allows drilling significant intervals without overlapping an intermediate casing string. Based on analysis of these technologies and taking into account their disadvantages the authors proposed and tested a new drilling technology of dual gradient drilling with placement of all necessary innovative equipment on drilling platform. Keywords: managed pressure drilling; deepwater drilling; offshore drilling; dual gradient drilling; riser; oil and gas exploration in sea.

Improving the operational properties of lubricants increases the service life of the mechanisms and increase the durability of rubbing joints, which has a positive effect on the indicators of technical and economic efficiency and equipment safety. Therefore, great attention in tribology is paid to the analysis of the state of friction units in technology and the assessment of their resource characteristics, which makes it possible to increase their service life. The research aim is to study the general provisions on lubricants and lubricants, as well as the features of the boundary layers formation on friction surfaces and the observed patterns. Calculations of the boundary layers thickness using lubricating reagents at different energetic loading of the friction pair were carried out as applied to the roller bearing of a roller cone bit in the medium of cylinder oil 52 and DPS grease. The proposed research methodology made it possible to in-crease the efficiency and effectiveness of the means development for improving the tribotech-nical properties of drilling lubricants.

One of the most common hindrances to encounter during the construction of oil and gas wells is lost returns. The methods to select prevention and control measures are based on quantitative criteria that reflect the hydrodynamic capacity and geological structure of the strata. One of the ways to prevent this hindrance during the construction of oil and gas wells is pore-plugging – a sophisticated physicomechanical process to reduce the permeability of a reservoir formation, which takes place over time due to mud filtrates, dispersed particles or specially introduced fillers (plugging additives). For this reason, it seems relevant to use domestic microcalcite, as a component of drilling fluids, from the Minyar field. The paper aims to assess the effect of various microcalcite concentrations on the properties of drilling fluids and to assess as to whether this type of material is effective enough for pore-plugging under the specified drilling conditions.

В статье рассмотрены этапы разработки забойного бурового оборудования и развития технологических приемов для бурения наклонно направленных и горизонтальных скважин (далее ННГС) в период с 20-х годов XX века и до настоящего времени. Цель статьи – обобщение научного и практического опыта, который способствовал зарождению и развитию производственного сектора бурения ННГС. Данная статья является второй из серии публикаций, состоящей из трех частей, посвященных освещению этапов развития ННГС, решению основных технико-технологических проблем возникающих при этом. Современный высокотехнологичный сервис по технико-технологическому сопровождению бурения ННГС прошел долгий эволюционно-революционный путь, в процессе которого примитивные устройства трансформировались в сложные механизмы и комплекс датчиков для отклонения оси скважины в заданном направлении, измерения параметров траектории ствола скважины. Рассмотренные аспекты развития наклонно направленного бурения (ННБ) затрагивают ключевые вопросы, благодаря решению которых данный производственный сектор стал одним из опорных в буровом деле. В качестве результатов исторического исследования приведена пирамида событий по степени важности этапов развития ННБ, в число которых вошли семь событий ключевого характера – с первых упоминаний и до новейшего времени. The article considers the stages of development downhole drilling equipment for for drilling directional technology wells in the period from the 20s of the XX century to the latest time. The purpose of the article is to summarize the scientific and practical experience that contributed to the birth and development of the production sector of drilling in the directed wells. This work is the second part of a series of articles, consisting of three parts, which are devoted to the coverage of the stages of development of drilling directed wells (DDW) and the main technical and technological problems being solved. Under the modern high-tech service for technological support of drilling, a long of evolutionary and revolutionary process is hidden, where primitive devices have been transformed into complex mechanisms and sensors for deflecting the well axis in a given direction and measuring parameters for building a well route. The aspects of DDW development discussed in the article touch on key issues that have made this production sector one of the mainstays in the drilling business. As the results of historical research work, the article presents a pyramid of events by degree of importance at the stage of development of inclined drilling. Among the key historical episodes of the formation of the DDW were seven events from the first mention to the latest time.

The article discusses the development of technology for directional drilling of oil and gas wells in the perspective of modeling downhole operations. The most significant mathematical models developed by Soviet and foreign scientists in the XX century are listed. An example of calculating the reaction on a bit based on the most widely used method of initial parameters is shown. In the process of a typical calculation of the deflecting force on the bit, it was possible to set the boundary conditions on the bottom hole assembly (BHA) supports in a natural form, using a well-known approach for calculating the deflection of the beam. The obtained results of calculations were applied in the construction of a simulation model for computer simulation based on a virtual program-simulator of the drilling directional wells. The simulating software allowed us to evaluate the effect of the Zenith angle of the well and the rigidity of the oriented layout on the deflecting force on the bit, the deflection of the turbo drill along the length from the bit to the nearest lower point of contact of the well wall.

Abnormal drilling conditions are often due to near ultimate loads such as high temperatures, vibrations, and harsh environment. In this context an issue of a need for equipment modification, which not only extends the service life, but ensures safe drilling, is thrown into sharp relief. Development and use of a drill string made of aluminum pipes are of great practical importance to improve drilling efficiency and failure-free operation in different mining and geological conditions. Light-alloy drill pipes have a number of advantages, including the possibility for transportation to remote drilling areas, and development of long vertical wells. During well construction the drill string interacts with aggressive environment, which affects pipe operational performance and drilling process as a whole. Superalkalinity drill fluids with pH more than 10 impact on materials the tubular billets are made of. In order to increase the efficiency of pipe serviceability, not only composition of drilling fluids, but also the pipe material processing methods shall be modified and changed. This article presents the existing methods of light-alloy drill pipe material processing and the ways to increase the corrosion resistance of D16T, the most common alloy, to aggressive environment