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6581885 
Book/Book Chapter 
Chapter 8: Reactive transport modeling of cap-rock integrity during natural and engineered CO2 storage 
Johnson, JW; Nitao, JJ; Morris, JP 
2005 
Elsevier Science 
Amsterdam, Netherlands 
Carbon dioxide capture for storage in deep geologic formations: Results from the CO2 capture project: Volume 2 
787-813 
English 
is a chapter of 10328052 Carbon dioxide capture for storage in deep geologic formations: Results from the CO2 capture project: Volume 2
Long-term cap rock integrity represents the single most important constraint on the long-term isolation performance of natural and engineered CO2 storage sites. CO2 influx that forms natural accumulations and CO2 injection for EOR/storage or saline-aquifer disposal both lead to geochemical alteration and geomechanical deformation of the cap rock, enhancing or degrading its seal integrity depending on the relative effectiveness of these interdependent processes. Using the reactive transport simulator (NUFT), supporting geochemical databases and software (GEMBOCHS, SUPCRT92), and distinct-element geomechanical model (LDEC), the influx-triggered mineral dissolution/precipitation reactions within typical shale cap rocks continuously reduce microfracture apertures, while pressure and effective-stress evolution first rapidly increase then slowly constrict them. For a given shale composition, the extent of geochemical integrity enhancement in the cap rock is nearly independent of key reservoir properties that distinguish EOR/sequestration and saline formation settings and of CO2 influx parameters that distinguish engineered disposal sites and natural accumulations, because these characteristics and parameter have negligible impact on mineral dissolution/precipitation rates. In contrast, the extent of geomechanical integrity degradation is highly dependent on these reservoir properties and influx parameters. 
Thomas, DC 
9780080445700