Monitoring Underground Migration of Sequestered CO2 using Self-potential Methods☆

Abstract To appraise the utility of the self-potential (SP) method for monitoring CO 2 injected into saline aquifers, we carried out numerical simulations based upon a hypothetical aquifer system and calculated the temporal changes in SP caused by changing underground conditions as computed by the reservoir simulation. In addition to electrokinetic coupling, we considered the geobattery mechanism operating near metallic well casings. The results show that SP measurements in the neighborhoods of wellheads offer quite promising and effective methods for sensing the approach of CO 2 to the well casings deep within the subsurface.