The database compiles all geochemical data produced in task 2.5 for the French site by the BRGM. The data are organised with spreadsheets in a single Excel file, differentiating data produced for/within the: 1. Geochemical characterisation of the reservoir and caprock 2. Batch experiments 3. Flow through experiments The “geochemical characterisation” subfiles compile (i) the XRD-Rietveld and (ii) the bulk chemistry composition from samples collected at multiple depths in wells VULAINES-1 (VUS-1), CHARMOTTES-4 (CHM-4) and SEIF-1. These datasets improve the mineralogical and geochemical heterogeneity within the reservoir platform (Oolithe Blanche, Comblachian limestone and Dalle nacrée), the transitional caprock and the caprock. The “batch experiments” subfiles compile the evolution of both the XRD-Rietveld (semi quantitative mineral assemblage) and the chemical composition of the synthetic brine monitored over the experimental time (3 – 35 days) for various pCO2 (1 bar, 5 bar and 180 bar), applied at a total pressure 180 bar and a temperature of 70°C with the BioREP platform (ECCSEL platform). The experiments aimed to assess the reactivity of the reservoir platform and caprock to injection of CO2 under different states – CO2(g) or supercritical CO2. The “Flow through experiments” subfiles compile the evolution of the chemical composition of the synthetic brine injected within the porosity of the reservoir and caprock core plug over time (1 month), applied for a pCO2 of 50bar (total pressure 180 bar; temperature 70°C) with the BioREP platform. The mineralogical characterization (XRD-Rietveld and bulk chemistry composition) before and after the flow through experiments is also reported. The experiments aimed to assess the reactivity of the reservoir platform and caprock to injection of CO2 under dynamic conditions.