The Impact of Capillary Heterogeneity on CO2 plume migration at the
Endurance CO2 storage Site in the UK
Abstract
Predictive modelling of subsurface CO2 flow is used for optimising the
design of geological CO2 storage projects e.g. with respect to mass
stored and long term security. However several field scale projects have
reported plume dynamics that do not match numerical predictions.
Previous work has indicated that upscaling capillary heterogeneity
results in different plume dynamics in synthetic 2D cross-sections and
at early times (<0.2PV injected). Here we extend the workflow to
3D and analyse the impacts of longer term flow behaviour in an
industrial scale geological carbon storage site with multi-point CO2
injection, structural relief and realistic flow rates. The models reveal
that capillary heterogeneity in horizontally layered lithologies enhance
channel formation, increases reservoir sweep, and reduces vertical
migration speed near the injectors, all of which improve storage
efficiency. At distances far from the injectors, the plume travels
faster as a result of the heterogeneity. The results also show that
simulations in 3D have qualitatively distinct results from those in 2D
due to the increase in flow pathways.