Storage site analogues and experimental investigations provide quantification of processes occurring during the life of subsurface CO2 capture, and possible escape mechanisms. Analogue investigation provides information at the scale of the storage sites under unique geological conditions and time frames. Experimental investigations under controlled conditions provide detailed data on specific processes observed in analogue sites. St Johns, NM, USA, is a natural laboratory which presents an opportunity to observe measure and model the migration of CO2 through a primary cap-rock and subsequent overburden at geological conditions analogous to the above-seal portions of planned CO2 storage sites. The Fizzy gas reservoir, North Sea, and other reservoirs in the North German Basin (Behrmann et al. 1981) are excellent examples of secure natural CO2 storage sites. By comparing in detail how the cap-rock at St. Johns was breached and the CO2 subsequently migrated to the surface and contrasting how the CO2 has been retained at Fizzy will provide insights on how to avoid for cap-rock failure and how to monitor engineered storage sites. The thermo-tectonic development of the St. Johns and Fizzy analogue sites, i.e. the fluid mobility and compositional variability with time, can be reconstructed on the basis of petrological and fluid inclusion studies, combined with cathodoluminescence (CL) techniques and microstructural analysis (healed microfractures). The changing stress conditions with time are important parameters for the conditions of crack-healing processes and the mechanical stability of the cap rock. Detailed petrological studies allow distinguish carbonate and quartz cement generations, and microstructures related with fluid-rock interaction, like fluid pathways, paleo-porosity, diffusional textures, and healed micro-fractures (Van den Kerkhof and Hein, 2001). Fluid inclusions reflect fluid migration, notably of CO2-H2O-bearing fluids through the cap rock. Fluid inclusions inform about temperatures and pressures during trapping. By comparing past and present gradients, conclusions can be drawn about uplift or subsidence of the area since the time of fluid entrapment. Furthermore, fluid inclusions allow the comparison of paleo-fluids with present pore and circulating fluids, to establish the deformational evolution of the rock (Vollbrecht et al., 1994; Schild et al. 1998). Chronology of paleo-stress directions can be derived from the compiled structural data (Schmidt net).
PANACEA has established a number of valuable connections with organizations that are actually involved in the process of CO2 storage for various purposes (disposal, EOR/EGR and scientific prototyping). It has also created a link with one NER300 project.