Aquifer-CO2 leak project: Physicochemical characterization of the CO2 leakage impact on a carbonate shallow freshwater aquifer

This work is part of the Aquifer CO2-Leak project and aims to understand, quantify model environmental impact a CO2 leak on water quality in carbonate freshwater aquifer as well CO2-water-carbonate interactions. The experiment has been performed within an Oligocene underground quarry located Saint-Emilion (France). A charged with dissolved was injected through borehole. Downstream, seven wells were fitted in-situ probes which automatically measured physicochemical parameters. Periodic samplings all have undertaken determine elemental concentrations by ion chromatography. spread groundwater monitored function time observed influence various Five parameters seem be excellent indicators for monitoring gas plume during geological storage regard our results: electrical conductivity pH, Ca2+, HCO3−, CO2(aq) concentrations. interaction between limestone highlighted saturation index (SI) calculated PhreeqC software. It shows (i) slight trend dissolution calcite injection (SI < 0) linked reaction process CO2-H2O-CaCO3 (ii) transport via diffusion observation SI≃0. evolution physicogeochemical signatures allows us understand reactive processes that occur migration gasified context leakage from reservoir. Our results will make possible complex natural