This paper discusses topical problems of further effective development of depleted oil fields (DOF) to increase their final oil recovery on the example of the oil field in Western Kazakhstan. Further exploitation of fields using waterflooding becomes unprofitable. At the same time, on average at these facilities, at least 50% of the reserves will remain unrecovered. Most of the oil fields in the Republic of Kazakhstan are at the late and final stages of development, which is characterised by an increase in the share of hard-to-recover oil reserves, a decrease in annual oil withdrawals, and a high water cut of the produced oil. Therefore, the problems of improving the technology aimed at reducing the volume of associated water production and increasing oil recovery from partially flooded deposits is very urgent. With an increase in the well density, the degree of field drilling and aging of the well stock, the work with the current declining well stock remains a very topical issue. Improving the efficiency of diagnostics and the systematic selection of wells for repair and isolation works is an important element for rationalising field development in the current conditions of profit variance in the oil and gas industry. The methods of bottomhole zone treatment also implement a deflecting effect on filtration flows. Therefore, this method includes a wide range of geological and technical measures: down-spacing; water production restraining; conformance control of injectivity profiles; forced production; all types of mechanical, thermochemical and thermal technologies. Consider a number of geological and technical measures that perform the tasks of occupational safety rules. Geological and statistical models are proposed for diagnosing wells for a premature increase of water production using factor analysis calculations for base production and Hall plots. Results. The degree of temperature influence of the primary components of the compounds on the rheology, filtration characteristics, and stability of inverted emulsions was determined. The classification of oil loss factors was carried out based on the results of downhole analysis and oil production losses were determined. Geological and statistical models for well diagnostics for premature increase in water production were built using factor analysis calculations for base production and Hall plots.

Purpose. Establishment of regularities of variability of pressure dynamics in the reservoir and development on this basis of methods of control and regulation of hydrocarbon production. Methodology. To achieve this goal, experimental studies were conducted, and the results of the experiments were summarized. Findings. Pressure distribution functions for stationary fluid inflow in two planes have been established, which allow monitoring and management of mining operations, especially at late stages of development. Originality. Based on the established regularities, a model of pressure distribution in the reservoir in a two-dimensional plane has been created. An experimental study of the pressure distribution in the reservoir was carried out, which allowed us to remove the characteristics of the pressure distribution along the axis of the segment of the oil reservoir under varying boundary conditions. Practical value. A mathematical model of pressure distribution processes along the angle of inclination is proposed, which allows determining the effectiveness of flooding. The influence of the deformability of the formation, the location of the well relative to its impenetrable roof and sole, the length of the horizontal trunk and the power of the opened formation on the magnitude and intensity of the inflow to the horizontal well is estimated.

Purpose. To develop a technology to increase the oil recovery of formations using injection of polymer compositions. Methodology. For this study, practical methods were used such as enhanced oil recovery using stimulating technologies, technology using polymer systems based on a water-soluble polymer acrylamide, and emulsion-polymer technology. To achieve the conformance control, which was a prerequisite for testing, a thorough selection of wells was carried out, as well as an analysis of their hydrodynamic connection. Findings. As a result of using the method for limiting water inflows in the development of oil-bearing formations, redistribution of filtration channels, and a decrease in the production of fossil water as well as stabilisation of water cut were achieved. Originality. The scientific novelty of the study is the withdrawal of wells that are able to redistribute the volume of water injection at perforation intervals. Increased sweep efficiency and pressure at the wellhead at the beginning and at the end of the conformance control indicate a decrease in the conductivity of high-permeability formation intervals. Practical value. Application of the proposed technology for limiting water inflows will make it possible to develop low-permeability interlayers with filtration flows. The wells brought to a stable production rate during the study will ensure a decrease in formation water production and the water cut of the produced products, as well as stabilisation of the water cut over a certain period.

One of the chemical methods of stimulating the reservoir to increase the efficiency of the oil field development process is polymer flooding. This article conducted a feasibility study of the effectiveness of the application of polymer flooding technology in one field in Western Kazakhstan. This field is characterized by high viscosity of reservoir oil, water cut, and dynamic heterogeneity of the reservoir. World experience in the application of polymer flooding in analogous fields shows high technological efficiency. Presented results of the analysis of the experience of applying technology in analogous fields, physicochemical studies of polymers, filtration studies on bulk models, hydrodynamic modeling of polymer flooding and the expected cost-effectiveness of introducing the technology, as applied to the conditions of the Karazhanbas oil field with high viscosity of reservoir oil. The analysis based on the experience of applying polymer flooding in high-viscosity oil fields, laboratory studies and estimated calculations of the expected production in the sector geological and hydrodynamic model shows a decrease in water cut, an increase in oil production, and an increase in current and final oil recovery.

Ultrasonic technology is a cost-effective and environmentally friendly non-traditional method of enhancing oil recovery, which is of great interest to researchers and field production engineers. The integration of ultrasound with surfactants has been proven to be effective in increasing oil recovery by reducing salt adsorption in the fluid. Many studies focused on the water-oil phase behavior to determine whether ultrasound can actually reduce oil viscosity (fluidity). However, the phase behavior alone cannot answer this question. Therefore, the present study investigated the role of reducing oil viscosity with the use of ultrasound at different intense frequencies. For this purpose, ultrasonic processing of an unconsolidated model with sand placed in an ultrasonic bath was applied. As a result of a laboratory experiment, the viscosity during ultrasonic processing showed a significant decrease to 30% from the initial value of 138 MPa*s. The change effect was discovered in the physical properties of the studied oil-water compositions in electromechanical field variables of different nature. Based on the results of experimental work, a method was developed and tested for reducing the viscosity of high-paraffin oils. However, in the course of research, several manifestation features of these effects were revealed, suggesting their applicability in the processes of synthesis and destruction of heavy hydrocarbons. In this regard, the relevance of the study consists in the dependence of changes in oil viscosity on the type and parameters of electrophysical effects. The authors conducted a laboratory experiment to reduce viscosity, built a hydrodynamic model to determine its effectiveness for processing a single well, and built a model using COMSOL Multiphysics software. The technology of stimulating oil wells with high-power ultrasound has been applied in various onshore and offshore fields. The developer of this technology takes good care of their customers and maintains confidentiality in relation to linking their performance indicators to a specific field. However, extensive ultrasonic tests have been provided showing that oil production rises from 38% to 380% based on average barrel/day flow rates.