Understanding risk for the long term storage of co2 in geologic formations

King coal: restoring the monarchy by underground gasification coupled to CCS

“…The reason for this is the lack of available data at this stage. Consequently, some studies have been performed using a deterministic analysis based on well proven numerical simulation tools and examining different scenarios (Espie et al 2005). There have been various projects around the world to perform the ERA of CO 2 geological storage using several methodologies to characterize risk (Damen et al 2006).…”

On CO2 Behavior in the Subsurface, Following Leakage from aGeologic Storage Reservoir

“…Additional concerns arise from environmental impacts of leaking CO 2 and the associated potential for adverse effects to health and safety. General probabilistic and systems-analysis approaches based on identifying FEP-scenarios (features, events, processes) are being used to evaluate risks associated with geologic storage of CO 2 (Maul et al, 2004, Espie, 2004Wildenborg et al, 2004). This approach is similar to what has been used for nuclear waste repositories.…”

“…Upward migration of CO 2 will occur whenever appropriate (sub-) vertical permeability is available, and/or when the capillary entry pressure of the caprock is exceeded (Krooss et al, 2004;Zweigel et al, 2004;Gibson-Poole et al, 2004;Moreno et al, 2004). Three main potential pathways for CO 2 release have been recognized (Zweigel et al, 2004;Espie, 2004), (1) leakage through the caprock (Lindeberg and Bergmo, 2003;Krooss et al, 2004), (2) migration along sub-vertical faults or fracture zones (Pruess and García, 2002;Rutqvist and Tsang, 2002;Hillis, 2003, 2004), and (3) escape through boreholes Bachu et al, 2004;Duguid et al, 2004).…”

“…This requires an understanding of the risks and hazards associated with geologic storage, and a demonstration that the risks are acceptably small or can be mitigated. Much work is currently underway to develop comprehensive approaches towards risk assessment from a systems analysis perspective, which in general requires a simplified description of physical and chemical processes (Maul et al, 2004, Espie, 2004Wildenborg et al, 2004;Walton et al, 2004). This type of approach is very important, but needs to be complemented with development of an understanding of the physical and chemical processes associated with CO 2 storage and leakage .…”

Monitoring Subsurface CO2Storage

“…Features, events and processes (FEP analysis) have been described that may affect the future integrity of the seal (e.g. Espie, 2004;Maul et al, 2004;Wildenborg et al, 2004). Some examples of relevant identified FEP's are (Arts and Winthaegen, 2005): -formation damage due to drilling of a well; -operational failure of a well; -casing or cementation defects due to improper design or construction; -fracturing or fault activation due to increased CO 2 pressure; -dissolution or dehydration of the seal due to the presence of CO 2 ; -unrecognised features in the seal like faults, joints or fractures; -corrosion of casing due to CO 2 ; -deterioration of cement plug after abandonment due to CO 2 .…”