Monitoring CO2 Injection in Sandstone by Laboratory Resistivity Measurements

CO2 sequestration in a deep aquifer is considered to one of the most effective method to solve Global warming. We must understand the behavior of injected CO2 to examine long-term stability of CO2 sequestration. We tried to monitor the behavior of supercritical CO2 injection in water- saturated sandstone by measuring the resistivity of core samples. The infiltration of CO2 into the core is expected to be detected sharply ,because CO2 is an insulator while the pore water is a conductor We made experimental apparatus that can reproduce the high pressure of the_@underground. A cylindrical sample of Berea sandstone(50 mm in diameter and 120 mm in length)was used in this study. It was coated with silicone, and current electrodes in both ends of the core. The end electrodes were a circular mesh made of copper. Point electrodes to measure potential were installed along the side of the core. CO2 as both gas, liquid, and supercritical phases was flushed through the sample. Consequentially we could monitor the time-lapse behavior of CO2 in water- saturated sandstone. This study will serve as a reference to the CO2 monitoring on the site.