Vol 5, No 4 (2023)

Due to the depletion of hydrocarbon reserves in traditional reservoirs with good filtration and reservoir properties, there is currently increasing interest in hard-to-recover reserves, and the main difficulty in developing such reservoirs is the efficiency of reservoir pressure maintenance systems. When developing low-permeability reservoirs, various mechanisms of oil displacement during flooding can be distinguished. For reservoirs with permeability less than 1 mD, there is no need to maintain high wellhead pressure; moreover, with a large accumulated compensation, stopping the maintenance of reservoir pressure for up to six months does not lead to a drop in production, which creates the prerequisites for organizing cyclic flooding. This will solve a number of problems that arise while maintaining reservoir pressure when working in such conditions.

The facies structure of reservoirs sometimes has a decisive influence on the performance of wells and their interinfluence. The transition to the development of fields with a complex geological structure, low filtration characteristics of the formation, the existence of geological bodies with different properties requires not only careful formation of a conceptual understanding of the field, but also the creation of detailed facies digital maps taking into account the existence of zones with different sedimentation, which, as a consequence, creates zones with different filtration and capacitance properties, requiring different approaches to development.

Background: The main problem of the process of field development in the later stages is the limitation of free funds associated with the decline in production and the corresponding decrease in the profitable part of enterprises. At the same time, the accumulated effect of critical production problems is manifested, for the solution of which in practice a significant amount of capital investments is required in different areas of field development.

The late stage of development of fields is associated with a number of problems, the main of which are the deterioration of the structure of the reserves and the slow pace of their replenishment, low withdrawal rates and high water cut, frequent failure of ground equipment, technological limitations of the production infrastructure, the quality of construction and completion of wells, a short turnaround time of production wells affecting the wells’ operation coefficient, and insufficient coverage of production processes with digitalization.

Aim: Considering the large amount of work involved in the oil production process (from geology to onshore infrastructure), an internal benchmarking analytical tool is needed to identify current and most common technological challenges, to focus scientific, technical and production personnel in a certain direction and develop a systematic approach to solving production problems. The purpose of this work is to develop such a tool

Materials and methods: As the input data, historical data on the production, hydrocarbons reserves, the current technological parameters of underground and surface equipment of 12 oil fields of the group of the NK “Kazmunaygaz” JSC companies were used. 17 basic criteria were formed in the areas of geology, development, oil production, drilling and infrastructure, which served as the basis for internal benchmarking of oil fields.

Results: As a result of this work, a tool was developed for the diagnosis of key production problems of KMG oil fields. The diagnostic chart is effective for determining zones of the spread of production problems both in one oil field and in all oil fields of KMG. This approach can be scaled to the level of oil fields and horizons.

Conclusion: The developed internal benchmarking tool serves as the basis for the annual analysis of key problems of the oil fields of the group of the NC “KazMunaygaz” JSC companies and the formation of a long -term plan to solve key production challenges.

Background: The study is devoted to increasing the efficiency of bactericidal treatment of sediments at the oil fields of Ozenmunaigas JSC. Calculations were carried out to assess the capability of heating the formation and the pipeline, hydraulic heat loss when injecting a bactericide, and the efficiency of mixing the reagent with water. The analysis revealed the ineffectiveness of mixing the bactericide with water at low temperatures and rates of inhibitor introduction.

Aim: The purpose of the study was to identify solutions to overcome the problems caused by the increased content of hydrogen sulfide in the fields of Ozenmunaigas JSC. This included addressing the temperature issues during bactericide delivery and increasing the rate of inhibitor injection.

Materials and methods: Heat loss calculations were carried out using the UniSim program for both tank heating and input lines, as well as an analysis of bactericide mixing inside the pipeline using the ANSYS program.

Results: The results of the study led to specific recommendations and measures that could mitigate the problems associated with temperature and rate of injection. These included measures such as heating and insulation, temperature control, regular inspection of thermal insulation, and selection of a new reagent with improved mixing properties at lower temperatures. It is also recommended to install reagent flow and temperature sensors along with power supply control.

Conclusion: The implementation of the proposed measures will effectively solve the problems associated with high levels of hydrogen sulfide. This approach will ensure a smooth and safe flow of bactericide and help maintain the operating efficiency of the affected facilities.

The problem of treatment and neutralization of wastewater from chemical, petrochemical and oil refining industries is associated with the removing from them of suspended solid and plastic particles of pollution of various chemical natures, oil and petroleum products, heavy metals, surfactants, acids, alkalis, phenols and other harmful substances. To effectively treat water, various filters are used, which differ in parameters and characteristics. The purpose of this work is to determine the possibility of replacing cartridge filters used at PetroKazakhstan Oil Products LLP with easily regenerable bag filters. In the course of the research, it was found that the use of cartridge and bag filters contributes to more effective water treatment, in particular, from suspended sub- stances. When comparing them, we can say that the latter is advantageous in that it does not need to be changed when clogged, like a cartridge filter, but simply rinsed and used again in the technological chain. The bag element is quite simply washed in water, but if it is heavily clogged, it can be washed either in a solution of citric acid (20 g/l) or in an alkali solution (10 g/l).

Background: The study of the interaction of hydrochloric acid with carbonate materialsis important in the oil and gas industry. Carbonate rocks are common rock types, and half of all petroleum reserves worldwide are found in carbonate deposits. Understanding the mechanisms and characteristics of dissolution of carbonate rocks is of great practical importance in the production of hydrocarbons and the injection of carbon dioxide into formations.

Aim: The purpose of this article is to study the dissolution processes of carbonate samples in laboratory conditions using X-ray microcomputer-based tomography.

Materials and methods: The study used 5 cylindrical carbonate samples, which were tested during the injection of hydrochloric acid solutions. Additional experimental and digital data from 8 samples are also used. The three-dimensional pore space of the samples was obtained using specialized software based on tomographic images.

Results: The results obtained demonstrate the significance of the use of X-ray computed tomography for a deeper understanding of dissolution processes in geological and engineering studies. The study highlighted the complexity of the rock dissolution process, which depends on many factors. The created three-dimensional models of the samples allowed us to visualize wormholes, including branched and dominant wormholes. 3D imaging provided valuable information about changes in the pore structure of the samples before and after acid exposure.

Conclusion: The results of this study highlight the importance of considering physical and structural properties when analyzing dissolution processes in carbonate samples. These data can have practical applications in the oil and gas industry, contributing to a more accurate understanding and optimization of the processes of interaction of acid solutions with carbonate samples.

Rationale: A characteristic feature of the modern stage of oil field development is the increase in the share of hard-to-recover oils, which mainly include heavy, highly viscous oils. This is due to changes in the structure of oil, an increase in the water cut of produced oil, geological and geophysical characteristics and conditions of oil occurrence that are unfavorable for extraction. The reserves of such oil significantly exceed the reserves of light and low-viscosity oil and, according to experts, they amount to at least 1 trillion tons. In industrialized countries they are considered not so much as a reserve for oil production, but as the main basis for its development in the coming years. The peculiarity of heavy oil is explained by its composition and PVT properties, which have a fairly serious impact on production.

Target: Application of an integrated approach to substantiating the properties of high-viscosity oil and tools for mathematical modeling of the phase state of fluids in order to increase the reliability of reserve calculations and the efficiency of the oil field development.

Materials and methods: The scientific work was based on the results of geochemical studies (fingerprinting and biomarker analysis), experimental data from rheological studies and the results of modeling the phase state of fluids.

Results: It is proposed to use an integrated approach to data interpretation and compositional calculations, which make it possible to narrow the range of uncertainty and explain the huge variation in the values of physicochemical parameters across samples.

Conclusion: An integrated approach to analyzing the results of PVT experiments, together with geological and field data and the results of geochemical studies, provides high-quality data that allows you to make strategic decisions on the oil field development, conduct accurate resource assessments and predict hydrocarbon production.