Challenges and Opportunities for Underground Storage in Salt Caverns of the Norwegian North Sea

Summary Halite beds in the Permian Zechstein Group represent an opportunity for the future development of salt caverns in the Norwegian North Sea. Although the Zechstein Group has been studied in this area, previous works have mainly focused on salt tectonics evolution. Therefore, a proper characterization of the Zechstein rocks to discern their potential for underground storage in salt caverns is necessary. The main objective of this study is to characterize the Zechstein Group in the Norwegian North Sea to evaluate opportunities for geological storage. We divide the area into four main structures: 1) Thin beds, which lack halite and therefore do not have potential for the development of salt caverns. 2 and 3) Bedded salt units and gentle diapirs, where halite beds with a thickness of more than 300 m are present, but they are usually deeper than 2000 m. 4) Shallow diapirs, where halite beds of more than 300 m and shallower than 2000 m are present. Additionally, lithological heterogeneities and internal deformation within the Zechstein Group, and their implications for cavern construction and drilling operations are discussed.