Deep Geological Conditions and Constraints for CO2 Storage in the Setúbal Peninsula, Portugal

This paper describes the research conducted in order to identify potential CO2 storage reservoirs in the Setúbal Peninsula, Portugal. The studied area is located in the southern sector of the Lusitanian Basin, the largest Portuguese Mesozoic sedimentary basin. Data from deep geological conditions was collected from oil and gas exploration wells and structural maps of the target geological horizons were processed from seismic reflection profiles. A potential reservoir for CO2 storage in the Lower Cretaceous was identified and its volume was calculated based on kriging interpolation methods. Net-to-gross ratio and porosities were determined from geological logs. A total CO2 storage capacity of 42 Mt was estimated. However, the lack of data about the lateral continuity of the seal, the presence of the most important Portuguese groundwater resources at shallower depths and the relatively high earthquake hazard, hinders the studied reservoir from offering the necessary geological conditions for a safe CO2 storage in the studied area.