Using streamlines for highly-resolved, reactive transport for CO_2 leakage contamination in groundwater

摘要

We present a Lagrangian streamline approach where a large, heterogeneous 3D flow field is reduced to a number of 1D transport simulations. The streamline approach allows the mapping of these 1D reactive transport simulations back onto a 3D flow field, thus accounting for spatial heterogeneity within the aquifer and complex aqueous geochemical processes. A CO_2 leakage scenario from a hypothetical CCS site is used where a resulting plume of CO_2 lowers the groundwater pH and mobilizes metals from an existing mineral host-rock distribution. The plume migration and related metal dissolution and precipitation within the aquifer were simulated using this streamline-geochemical modelling approach under varying hydrological heterogeneity variances (σ~2_1nK). Results showed that heterogeneity significantly influences well contamination and geochemical processes.