The potential leakage of CO2 from a geological storage site through existing wells represents a major concern. An analysis of well distribution in the Viking Formation in the Alberta basin, a mature sedimentary basin representative for North American basins, shows that a CO2 plume and/or acidified brine may encounter up to several hundred wells. If carbon dioxide is geologically stored in regions, such as this, that have experienced intensive exploration for petroleum products, the acidified brine will come into contact with numerous abandoned wells. Corrosion of the cement that seals the well could lead to rapid leakage, so it is essential to determine the duration and intensity of exposure to the acid. Detailed numerical simulations with Dynaflow, incorporating a flash calculation to find the phase distribution and speciation in the brine, indicate that the carbonated brine may spend years in contact with the cement in abandoned wells. Preliminary results from an ongoing experimental study of cement corrosion indicate that the rate of attack is rapid, when the pH of the solution is low, so the risk of leakage will be high if the acidic brine can flow through an annulus and bring fresh acid into contact with the cement.
|Original language||English (US)|
|Title of host publication||Carbon Dioxide Capture for Storage in Deep Geologic Formations - Results from the CO2 Capture Project|
|Subtitle of host publication||Vol 1 - Capture and Separation of Carbon Dioxide from Combustion, Vol 2 - Geologic Storage of Carbon Dioxide with Monitoring and Verification|
|Number of pages||22|
|State||Published - Feb 22 2005|
All Science Journal Classification (ASJC) codes