HYDRODYNAMIC MODELING OF CO2 INJECTION AND STORAGE IN THE AQUIFER OF THE PRIIRTYSH BASIN

The injection and geological storage of carbon dioxide (CO2) is one of the key strategies for reducing greenhouse gas emissions. This study presents a hydrodynamic simulation of CO2 injection into an aquifer within the Yertis (Irtysh) sedimentary basin using the tNavigator software. The primary objective is to evaluate the behavior of CO2 in the water-saturated formation, including its migration, solubility, and long-term storage stability. A 3D geological model with dimensions of 200×200 m was constructed based on data from a single well. The model incorporated porosity, permeability, and pore-fluid properties. During simulation, CO2 was injected into the formation for one year at a bottomhole pressure of 500 bar, followed by 100 years of post-injection modeling to assess retention mechanisms. The results show that approximately 87% of the injected CO2 dissolves in formation water, while the remaining 13% is trapped in pore spaces due to capillary forces. This indicates limited CO2 mobility and a stable storage system. Overlying low-permeability strata further restrict vertical migration, contributing to structural trapping. However, the study is subject to certain uncertainties due to the lack of detailed laboratory data, including PVT properties, geochemistry, and capillary pressure measurements. Additional studies are recommended to enhance model accuracy. The results confirm that the Yertis Basin has potential for safe, long-term geological CO2 storage. Nevertheless, due to its limited exploration, depleted hydrocarbon fields may be more suitable candidates for immediate implementation. Keywords: CO2, injection, storage, hydrodynamic modeling, tNavigator, Yertis Basin, porosity, solubility, residual saturation.