A simulation study of CO2 sequestration in the Arno River Plain (Tuscany, Italy)

We present a geochemical model for the sequestration of anthropogenic CO2 (from hypothetical hydrocarbon-based H-2 production) consequent to the theoretical injection of gas beneath the River Arno plain, near the city of Pisa, Italy. The potential reservoirs for gas disposal are of two different types: dolostones or sandstones. The model predicts the sandstones to be the best reservoirs because CO2 sequestration in these rocks can occur via the deposition of solid carbonates. On the contrary, the injection of gas into the dolostone could generate gas accumulation and high gas pressures (50-100 atm) that could possibly promote rock fracturing and gas leakage in these shallow (500-1000 m depth) reservoirs. The best sites for gas disposal are therefore located west of the town of Pisa, along the coastal plain.