Inducing a CO2 Leak into a Shallow Aquifer (CO2FieldLab Eurogia+ Project): Monitoring the CO2 Plume in Groundwaters

Abstract

The CO2 Field Lab project consisted in an injection of 1.7 tons of CO2 at a 20 m depth within a shallow aquifer located in fluvio-glacial deposits. Baseline acquisitions, leakage monitoring and post-injection monitoring were performed in the water phase at different depths (5, 10 and 15 m). Strong deviations of pH, specific conductance or alkalinity were observed and monitored at the horizons affected by the CO2 intrusion. The complex distribution of waters in the ridge deposits not only induced water/rock interactions but also mixing of saline and fresh waters. This points out the complexity of natural environments and the challenge in identifying CO2 leakage from deeper-seated reservoirs.