The adverse impacts of CO 2 emission on the global warming highlight the importance of carbon capture and storage technology and geological storage of CO 2 under solubility trapping mechanisms. Enhancing the solubility of CO 2 in formation water has always been the focus of research in the area of CO 2 sequestration. Ultrasound techniques are one of the environmentally friendly methods that use high-intensity acoustic waves to improve gas solubility in liquids. Ultrasonic waves can alter the properties of different phases that lead to chemical reactions and provide a means to increase the solubility of CO 2 in connate water. In this study, we investigated the effects of ultrasound on the solubility of CO 2 in connate water under different conditions of pressure, temperature, and salinity. The results showed that the solubility of CO 2 was improved with increasing pressure under ultrasonic effects. However, the solubility of CO 2 was inversely proportional to the increase in brine salinity and temperature. Therefore, it was concluded that the solubility of CO 2 might be enhanced in the presence of ultrasound.