Experimental Investigation of Salinity and Pressure Impact on CO2 Solubility in Saline Aquifers

Abstract Addressing global climate change necessitates innovative solutions for carbon capture and storage (CCS). With their vast capacities, saline aquifers emerge as promising repositories for CO2 sequestration. While solubility is the primary trapping mechanism for CO2 in saline aquifers, a significant knowledge gap exists regarding the role of salinity level and operation pressure on the CO2 solubility in saline. This study delves into the experimental investigation of CO2 solubility in different saline aquifers, focusing on phase behavior analysis through the use of a Pressure-Volume-Temperature (PVT) cell. The research aims to enhance our understanding of the fundamental interactions between CO2 and brine under reservoir conditions, critical for optimizing CCS strategies. Experiments were conducted to observe CO2 solubility in five different brines with different salinity levels at various pressures. The experiments were designed to measure the equilibrium phase behavior of the CO2-brine system, providing valuable data on CO2 dissolution rates and phase transitions under a range of pressure settings. The experimental data revealed that pressure and salinity significantly influence CO2 solubility in saline aquifers. Higher pressures were found to increase CO2 solubility, while the effect of salinity presented a more complex interaction; lower brine salinity showed higher storage and CO2 dissolution. These findings contribute to a deeper understanding of the thermodynamic principles governing CO2 sequestration in saline aquifers and highlight the importance of tailoring CCS operations to specific reservoir conditions. sIn conclusion, the results of this experimental investigation illuminate the critical role of phase behavior analysis in understanding CO2 solubility in saline aquifers, marking a significant step forward in CCS technology. Integrating the presented empirical data with analytical modeling is the way to develop a new pathway for enhancing the efficiency and reliability of CO2 storage in saline formations. The results of this research efforts contribute to the broader effort of mitigating atmospheric CO2 levels and combating climate change. This model serves as a powerful tool for CCS project planning and optimization, enabling more accurate estimations of CO2 storage capacities in saline aquifers. The implications of this research extend beyond theoretical advancements, providing practical guidelines for the design and implementation of effective and safe CO2 sequestration projects.