Site selection for CO2 storage in aquifers in the complex geological setting of Southeastern France

Abstract : The VASCO project, "Valuation and Storage of CO2", aims at studying the CO2 emissions reduction and valuation opportunities on the area of Fos-Berre-Beaucaire-Gardanne. Geological storage is one of the four studied routes. This study is led on four geographical domains close to Fos-sur-Mer and aims at identifying the favorable areas for CO2 geological storage within the carbonated formations of lower Cretaceous and of upper Jurassic. The geological setting of this region is characterized by a complex and multi-phase geological history which results in a high geological variability. First of all, geometry of target formations has been characterized thanks to the analysis of geological maps, well data, seismic data and gravimetrical data. A synthetic map of pre-rift series structuration has been drawn, reflecting the two target formations' main geometries and showing that horst structures and ramp anticlines structures could be favorable for storage. Combination of selection criteria relative to salinity, layers geometry and cap-rock allowed identifying four favorable sites for CO2 geological storage. First storage capacities have been calculated for each site showing that three sites could present an industrial scale but the calculation process also showed the need for more precise parameters on geological formations and sites in order to provide more reliable assessments.