Energy Transition and Evaporitic Formations Utilization as Potential Subsurface Storage for H2 and CO2

Until recently, the role of evaporitic formations in H2 and CO2 storage has not been given much attention and it was described as less important in most publications assessing various types of geological storage. Last decade a few countries begun to investigate scenarios of old salt mines as potential store-sites. Although relevant experiments have been made in these countries, this type of geo-subsurface-storage has not been studied in Greece yet. Despite the absence of salt mines in Greece, a lot of evaporitic formations occur, located mostly in the western and southern part of the country. A few of them show adequate salt bed thicknesses and could be used, given the appropriate requirements, as either, a very good seal or as a potential reservoir. Some of them outcropping due to diapirism, some others due to the Hellenides Fold and Thrust Belt (FTB) tectonic framework. Two types of evaporites are documented; the Triassic ones and the Messinian, both well-known all over the Mediterranean Sea. Among the commonly reported structures are included, well-layered-anhydrites with salt beds, saltintrusions, diapirs, deformed, thrusted, and collapse breccia bearing peculiar porosities. Each of them may present various risks and a variety of potentiality in commercial-scale which is the question. In this presentation geologic, and technical data of the various Greek evaporitic formations from onshore and offshore wells are provided, complimented by 2D seismic-lines. The technical challenges and commercial viability are discussed, in order to demonstrate the sustainable potentiality for H2 and CO2 geo-storage in terms of Energy Transition.