External Vibration-Assisted Carbon Dioxide Sequestration in Heavy Oil Reservoirs: The Influences of Frequency and Cavity Distribution

This study investigates the effect of external vibration stimulation on CO2 dissolution behavior in heavy oil reservoirs, focusing on the influence of vibration frequency and cavity distribution within porous media. Experiments reveal that 5 Hz vibration significantly enhances CO2 dissolution, while higher frequencies (10 Hz and 20 Hz) hinder the process. A more homogeneous and extensive distribution of oil-depleted cavities further improves dissolution rates, particularly in post-gas flooding scenarios. The dissolution process, observed under constant pressure conditions, is categorized into three stages: cavity filling, fast dissolution, and slow dissolution. Vibration stimulation effectively enhances the fast dissolution stage but has a minimal impact on the slow dissolution stage. Intermittent vibration shows mixed effects, improving dissolution at 100% oil saturation but reducing rates at 90% saturation due to cavity-induced flow disruptions. These findings demonstrate the potential of vibration-stimulated CO2 dissolution (VS-CO2 dissolution) as a novel technique for enhancing CO2 storage and heavy oil recovery in reservoirs. This study provides critical insights for optimizing vibration frequency and cavity distribution, paving the way for improved field applications of this innovative technology.