The Effect of Water Flushing on CO2 Concentration Around Injection Well as Identified through Laboratory Study

Abstract

A clear understanding of dynamic water flushing on laboratory scale is useful for the effectiveness and safety of CO2 geological storage. The objective of this study was to investigate the effect of water flushing on CO2 concentration including displacement and the dissolution. The high-resolution Magnetic Resonance Imaging (MRI) technique was used to visualize the process. The core sample was packed with glass beads under the temperature and pressure of 40 and 8 MPa, corroding to the depth of 800 m. The CO2 unsaturated brine was injected upward into the supercritical CO2 saturated sample with flow rate of 0.03 mL /min, to imitate the water flushing. The transient intensity in MRI image during the water flushing was observed, reflecting the transition from displacement to dissolution in the porous media. The concentration distribution along the porous media was inhomogeneous. The CO2 concentration declined along the porous media with injected pore volume.