In order to establish the formation patterns of the Co–Mg oxide system, samples with different Co:Mg ratios and heat treatment temperatures were synthesized and studied. A study of the samples confirmed the phase transition of Mg_xCo_2–xO₄ spinels into the corresponding solid solutions at 800–900 °C. The similarity of the formation patterns for different compositions is shown. The rocksalt oxide in low-temperature samples is an anion-modified paracrystalline phase that forms a “true” solid solution only upon spinel decomposition. The TPR profiles of the decomposed Co₃O₄ spinel show surface Co₃O₄ peaks and a wide peak corresponding to the well-crystallized CoO, while partial Co₃O₄ TPR up to 380 °C results in dispersed and amorphous CoO. The high-temperature non-stoichiometric samples are poorly reduced, indicating their low oxygen reactivity. Spinel reoxidation after heat treatment to 1100 °C by calcination at 750 °C showed complete regeneration for MgCo₂O₄–Co₃O₄ samples and its absence in case of an excess of MgO relative to stoichiometry.

The purpose of this study is to evaluate the feasibility of different oil fields in Kazakhstan for Carbon Capture, Utilization, and Storage (CCUS) projects using advanced algorithms in Python. Using automated methods, the approach greatly simplifies and accelerates the selection process, allowing efficient analysis of large data sets. Taking into account key geological and operational parameters, with particular emphasis on the importance of the Dykstra-Parsons coefficient, the study presents a comprehensive ranking system for evaluating reservoir suitability. This coefficient is critical to accurately assess the fluid displacement efficiency, which significantly influences the selection of candidates for Enhanced Oil Recovery (EOR). The results show that the inclusion of the Dykstra-Parsons coefficient improves the accuracy of field evaluation by accounting for key reservoir heterogeneity factors along with conventional properties. The comparative analysis shows that this approach provides more reliable field selection compared to the existing methods that do not consider this parameter, thereby improving the efficiency of CO2 storage projects.

The composition of hydrocarbon systems plays an essential role in ensuring reliability in field operation processes, the design of oil onshore facilities, and the availability of reliable information about the PVT properties of systems. In this article, experimental and numerical methods are used to obtain data on the component composition of the extracted oil products and their PVT properties. These methods help obtaining a detailed composition and phase state of the hydrocarbon system. The numerical delumping method is utilized in this article. It is worth noting that all calculations were made on the basis of data on the component composition of Kazakhstani oil samples. The results and comparative evaluation show that the proposed delumping mix-method has excellent consistency with the data obtained with experiments and with the Nichita’s analytical approach. In the future, the results on the detailed composition can improve and link the compositional modeling of the reservoir with the modeling of surface structures.

In order to establish the formation patterns of the Co–Mg oxide system, samples with different Co:Mg ratios and heat treatment temperatures were synthesized and studied. Study of the sam-ples confirmed the phase transition of MgxCo2–xO4 spinels into corresponding solid solutions at 800–900 °C. The similarity of formation patterns for different compositions is shown. The rock-salt oxide in low-temperature samples is an anion-modified paracrystalline phase that forms a “true” solid solution only upon spinel decomposition. TPR profiles of decomposed Co3O4 spinel show surface Co3O4 peaks and a wide peak corresponding to well-crystallized CoO, while par-tial Co3O4 TPR up to 380 °C results in dispersed and amorphous CoO. High-temperature non-stoichiometric samples are poorly reduced, indicating their low oxygen reactivity. Spinel reoxidation after heat treatment to 1100 °C by calcination at 750 °C showed complete regenera-tion for MgCo2O4–Co3O4 samples and its absence in case of an excess of MgO relative to stoi-chiometry. Based on the data obtained, it can be concluded that the processes governing the formation of Co–Mg oxide systems are determined by both Co:Mg ratio and the heat treatment conditions, potentially providing the possibility of fine tuning for specific catalytic processes.

This study follows the preliminary geological screening and construction of a 3D static model (Phase I), which identified promising deep saline aquifers (Upper Jurassic–Cenozoic) in the Priyrtyush Sedimentary Basin for Carbon Capture and Storage (CCS). This paper's primary objective is to transition from a static volumetric assessment to a dynamic hydrodynamic simulation in order to evaluate the technical feasibility and operational constraints of large-scale CO₂ injection. A high-resolution geological model derived from integrated seismic and log data was imported into a commercial reservoir simulator to establish the dynamic framework. The methodology involves simulating a 100-year period of continuous CO₂ injection. A high-resolution hydrodynamic model was developed to assess plume migration and pressure dynamics under a sustained injection rate of 300,000 m³/day, which was identified as a safe operational threshold. The findings quantify a dynamic storage capacity of 13 million tons of CO₂ over the 100-year period and project a maximum average reservoir pressure rise of 340.2 bar. This comprehensive hydrodynamic assessment provides the operational data necessary to progress from resource appraisal to field development planning, offering a robust, data-driven foundation for realizing Kazakhstan’s strategic goal of achieving carbon neutrality by 2060.

The Republic of Kazakhstan has significant amount of heavy oil and natural bitumen reserves. Some of that reserves have high viscous oil more than 1000 mPa*s at shallow depth. The main recovery technique is thermal methods using steam or hot water injection. One of the variants to improve thermal methods is to add liquid or gaseous solvent. In our research we consider hexane as an additive solvent. The purpose of this study is to determine how hexane affects to dead heavy oil of Sarybulak field within the context of dynamic viscosity reduction. Mix of heavy oil and hexane in various proportions are obtained. Also, dependences of heavy oil dynamic viscosity on the hexane content are considered.