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.

Carbon Capture, Utilization, and Storage (CCUS) is globally recognized as a key strategy to mitigate the greenhouse gas emissions and address the climate change. Geological storage in oil and gas fields and saline aquifers offers a promising long-term solution, with growing research focusing on modeling, monitoring, and optimizing the storage performance. This study contributes to Kazakhstan’s national CCUS initiative by presenting the methodology and outcomes of constructing a conceptual geological and hydrodynamic model of the Zaisan sedimentary basin located in East Kazakhstan. By integrating structural, lithological, and petrophysical data from 23 wells, a high-resolution 3D geological framework was developed. This model successfully identified a structurally isolated zone within the Sarybulak field that exhibits highly favorable characteristics for the CO2 storage, including minimal faulting, adequate reservoir thickness, high porosity, and high-water saturation. These features collectively highlight that the Sarybulak field is a highly promising candidate for Carbon Capture and Storage (CCS) deployment and reinforce the potential of the Zaisan basin as a strategic site for future large-scale carbon storage operations in Kazakhstan.

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.

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.

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.

This scientific study presents a comprehensive assessment of the Priirtysh sedimentary basin, focusing on identifying potential reservoirs for carbon dioxide (CO₂) storage. The methodology includes 2D seismic data interpretation, well log analysis, and the construction of a 3D geological model using Petrel software. Seismic surveys conducted between 1992 and 1997, along with data from more than 4,000 hydrogeological wells, were utilized to develop a structural and lithological model of the basin. Kazakhstan currently lacks dedicated infrastructure for CO₂ capture and storage. Notably, potential CO₂ storage formations in the Pavlodar region, which accounts for the highest greenhouse gas emissions in the country, have yet to be systematically evaluated. Thus, investigating the CO₂ storage potential of regional aquifers is of both scientific and strategic importance. By combining geophysical (seismic interpretation) and petrophysical (porosity, permeability, and reservoir quality) analyses with 3D geological modeling, this study offers new insights into the subsurface architecture of the basin. The integration of seismic and well log data significantly enhances the model’s accuracy and enables the identification of structural complexities. Key findings indicate the presence of several promising aquifers at depths between 500 and 2,000 m, particularly within the Upper Jurassic–Cenozoic formations. The study estimates the CO₂ storage capacity of these aquifers and assesses their suitability for long-term containment, laying the groundwork for future hydrodynamic simulations and injection feasibility studies. Ultimately, the identification of viable storage formations in the Pavlodar region aligns with Kazakhstan’s strategic goal of achieving carbon neutrality by 2060.