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.

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.

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.

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.

This study is devoted to a comparative analysis of modern methods for determining the wax crystallization onset temperature (WCOT) of high-paraffin crude oil from the Uzen field. The objects of investigation were crude oil samples from the 13th reservoir horizon with a paraffin mass content ranging from 22.5% to 27.5%. For the first time in the practice of the oil and gas industry of Kazakhstan, a comprehensive comparison of results obtained using two fundamentally different approaches was performed: the light transmittance method using the KING-UNNP-70 apparatus, which simulates reservoir conditions (pressure of 12 MPa), and a dynamic method using a Wax Flow Loop facility, which reproduces crude oil flow in a pipeline. The experimental results showed that the light transmittance method detects the appearance of the first microcrystals at temperatures of 38.0–41.7 °C, whereas the dynamic method yields higher WCOT values, ranging from 41.0 °C to 44.0 °C. It was also found that the temperature of bulk crystallization, characterizing intensive solid phase formation, lies within the range of 33.5–35.0 °C. The results confirm that under flow conditions, paraffin crystallization begins at higher temperatures compared to static conditions, which is of critical importance for the design of crude oil gathering and transportation systems. The obtained data allow more accurate prediction of the risks of asphaltene–resin–paraffin deposits (ARPD) formation and optimization of technological operating conditions of wells at the late stage of field development.

Structural-mechanical properties of heavy oil from Kazakhstan deposits under the heat treatment were studied in this work. The most important and the least studied issues in the technology for the preparation and collection of oil products is the evaluation of the structural and mechanical properties of heavy oils and emulsions and ways to regulate formation them. A feature of the wells operation of fields with high viscosity oils is a sharp increase in water cut at the initial stage of development, which is associated with an excessively large difference in the rheological characteristics of reservoir oil and water. The formation of stable emulsions does not allow for the effective separation of oil from water and leads to a deterioration in product quality. In this regard, in modern conditions of intensification of hydrocarbon production, consideration of the options for the formation and destruction of complex emulsions is a prerequisite for the effective operation of oilfield treatment facilities. Therefore, the research relevance is of reducing the irretrievable losses of hydrocarbons in production systems and study the physical-chemical, structural-mechanical properties of heavy oils emulsions and to develop methods for their regulation, as well as improving oil treatment devices.