CO2 Underground Storage and Wellbore Integrity

Abstract

Geologic storage is the component of Carbon Capture and Storage (CCS) in which the carbon dioxide (CO2) is disposed in the appropriate underground formation. To successfully inject CO2 into the subsurface to mitigate greenhouse gases in the atmosphere, the CO2 must to be trapped in the subsurface and must not be allowed to leak to the surface or to potable water sources above the injection zone. For the purposes of risk assessment, a priority is to evaluate what would happen if CO2 migrated unexpectedly through the confining unit(s), potentially resulting in undesirable impacts on a variety of potential receptors. One of the main risks identified in geological CO2 storage is the potential for CO2 leakage through or along wells. To avoid leakage from the injection wells, the integrity of the wells must be maintained during the injection period and for as long as free CO2 exists in the injection zone.