Petrophysical Properties and Capacity of Prospective Structures for Geological Storage of CO2 Onshore and Offshore Baltic

AbstractThis study is focused on the investigation of four prospective structures for geological storage of CO2 in the Baltic region, specifically in the onshore structures South Kandava and Dobele, and offshore structures (E6 and E7) in Latvia. Using detailed petrophysical, mineralogical and geochemical analyses of the Middle Cambrian Deimena Formation sandstones in these structures, their CO2 storage capacity was estimated with different levels of reliability. Different storage efficiency factors and porosities of the reservoir rocks were applied for optimistic and conservative estimates. Offshore structure E6 was estimated as the most prospective for CO2 geological storage in the Baltic Region. Its optimistic CO2 storage capacity was 264-631 Mt, and its average conservative capacity (158 Mt) is the largest among all the studied until now in Latvia onshore and offshore structures. Total capacity of four studied structures estimated using an optimistic approach was on average 630 Mt and using a conservative approach 210 Mt. Earlier capacity estimates made during the EU Geocapacity project of the Dobele and South Kandava onshore structures are in the range of our optimistic capacities