Crude oil processing often requires the extraction of large amounts of water. Crude oil often mixes with water to form water-in-crude oil emulsions as a result of exposure such as high shear at the wellhead and natural surfactants in crude oil. These emulsions are undesirable and require demulsification to remove dispersed water and associated inorganic salts in order to meet production and shipping specifications. In addition, demulsifying these crude oil emulsions reduces corrosion and catalyst and consistently maximizes the overall profitability of crude oil production. The article looks into the results of tests on the selection of a demulsifier for the breakdown of water-in-oil emulsion mixtures at different settling times and temperatures depending on the specific consumption of the chemical agent, the effect of various demulsifiers on emulsions breakdown. The process of oil desalination with and without the addition of demulsifiers is considered. Desalination is carried out stepwise. Research results have shown that proxanol 305/50 is the most effective demulsifier.

Background: At later development stages of oil fields using reservoir pressure maintenance technology, residual recoverable reserves undergo significant transformation, evolving from a mobile to a low-mobile and, eventually, to an immobile state. These reserves are primarily concentrated in formations and reservoir zones that are not affected by water flooding. Identifying, localising, and developing such reserves are critical for maximizing the ultimate oil recovery factor in mature fields. This issue is particularly relevant for the Uzen field, which is characterized by a high depletion level and significant water cut. When combined, these factors necessitate the optimization of geological and technical measures. Aim: To develop and justify an integrated approach to assessing the localisation of residual oil reserves at the late stage of field development. Materials and methods: This approach implements methodology for the construction of depletion maps based on the analytical modelling of drainage radii of production wells, as well as analysis of changes in reservoir fluid mineralization based on laboratory measurement of the composition of produced and injected water. . Results: The results of this study demonstrate that the developed approach is highly informative. It provides a detailed picture of distribution of residual oil reserves, allows for a quantitative assessment of how different zones are involved in development, and helps improve the efficiency of the waterflooding system. Conclusion: The proposed integrated methodological approach is an effective tool for enhanced oil recovery in mature fields, which facilitate rational management of residual oil reserves and allows for systematic implementation of production stimulation measures in conditions of high field depletion.

The study aims to improve the efficiency of oil field development at the Kalamkas field through the implementation of new methods for analyzing hydrodynamic survey data and monitoring well conditions. It is hypothesized that the use of integrated geophysical and hydrodynamic methods will enhance forecasting accuracy, optimize field operations, and increase the hydrocarbon recovery factor. An integrated approach combining pulsed neutron logging (PNL), acoustic cementometry (AC), inflow and injectivity profile evaluation methods, and specialized software for advanced data interpretation was applied, significantly improving the accuracy of well condition analysis. The analysis enabled the identification of oil and gas saturation intervals, zones of increased water cut, and cementing defects in casing, and allowed for a quantitative assessment of reservoir permeability dynamics. Hydraulic fracturing application resulted in a 10–15% increase in permeability in certain zones, with an average oil recovery factor increase of 5%. Analysis of PNL data demonstrated the transition of oil-saturated reservoirs to water saturation during development, confirmed by geophysical and pressure build-up survey results. The study identified the primary causes of increased water cut and key factors leading to production rate decline. Proposed measures for optimizing operating modes and well grid efficiency contribute to improving existing field management practices.

In this article, composite binders based on industrial waste—phosphogypsum, granular phosphoric slag, and burnt barium carbonate tailings––are investigated. It was found that the optimal composition (65% slag, 20% phosphogypsum, 15% tailings) provides compressive strength up to 31.1 MPa after steaming, which corresponds to grade M300 cement. Replacing natural gypsum with phosphogypsum increases strength by 5–10%, and using waste reduces cost by 20–25% compared to traditional binders. This technology eliminates the need for high-temperature firing, reducing energy consumption by 40–50%. Neutralization of harmful impurities of phosphogypsum with oxides of MgO and CaO reduces the ecotoxicity of the material by 70–80%. It is shown that hydrothermal treatment accelerates hardening, providing 90% of brand strength in 28 days. The developed binders are promising for the production of building blocks, road surfaces, and land reclamation.

Cellulose-based materials have been widely investigated as sustainable sorbents for oil spill remediation due to their renewability, biodegradability, low density, and structural diversity. However, reported performance varies substantially across material classes, modification strategies, and testing conditions, making direct comparison difficult. This review summarizes recent progress in cellulose-based sorbents for oil removal, with emphasis on the relationships between processing methods, pore architecture, surface wettability, and sorption behavior. Native cellulose materials, chemically modified cellulose, aerogels, nanocellulose-based systems, and carbonized cellulose are comparatively discussed in terms of oil uptake, selectivity, sorption kinetics, retention stability, reusability, and mechanical performance. The analysis indicates that sorption efficiency is controlled by the combined effects of hierarchical porosity, surface characteristics, and structural integrity. Native materials provide low cost and rapid uptake but limited selectivity, whereas chemically modified systems show improved hydrophobicity and oil retention. Aerogels generally exhibit some of the highest reported absorption capacities but often suffer from low mechanical durability. Nanocellulose-based materials generally offer a balanced combination of sorption capacity and stability, while carbonized materials typically provide enhanced retention at the expense of transport rate. Current limitations, including scalability, durability, and realistic operating conditions, are also discussed to outline future directions for the design of efficient cellulose-based oil sorbents.

Purpose. Research and optimization of the processes of operation of wells equipped with plunger rod pumps in conditions with increased complexity, such as high oil viscosity, high pressure, aggressive geological and physical conditions and significant fluctuations in flow rate, in order to increase the efficiency and reliability of the plunger rod pump (UPSH) installation, increase well productivity and reduce operating costs. Methodology. The authors used the following scientific methods: the method of analysis and synthesis – for a review and systematization of existing scientific publications and experiments on the operation of wells with UPR in conditions of increased complexity; the method of observation and data analysis – for an analysis of the operation of UPR in various conditions, including the study of the effectiveness of their work in difficult geological conditions; experimental methods – for conducting field experiments to evaluate the work of UPSH in conditions of increased complexity. Findings. The use of inhibitors, tubing (tubing and compressor tubes) with protective coating, rod centralizers and special pumps is proposed to combat wiping and deposits in deep pumping equipment. Low-cost options are recommended for use in small and medium-sized wells up to 1,500 m deep, providing an efficiency of 50‒60 % with a viscosity of up to 200 MPaˑs and a sand content of up to 10 %. Originality. The theory of the causes of the failure of the GNR and the downtime of the mechanized fund of production wells equipped with UPSH has been further developed. The influence of complicated conditions on the operational characteristics of plunger rod pumps has been established. The use of OPN in production wells at the Uzen field is justified, taking into account technical and economic factors in comparison with other methods of operation. Practical value. The development and implementation of methods that increase the inter-repair period of wells at the Uzen field make it possible to reduce the cost of repair and preventive maintenance, increase the efficiency of operation and reliability of the mining complex, especially at a late stage of field development. As a result of the pilot tests conducted, the average duration of the inter-repair period of the mechanized fund in 2021 increased by 14 days compared to 2018.