The CO2 storage potential of the Middle Buntsandstein Subgroup within the Exclusive Economic Zone (EEZ) of the German North Sea was analysed within the framework of the GEOSTOR-Project. A total of 71 potential storage sites were mapped based on existing 3D models, seismic and well data. Static CO2 capacities were calculated for each structure using Monte Carlo simulations with 10,000 iterations to account for uncertainties. All potential reservoirs were evaluated based on their static capacity, burial depth, top seal integrity and trap type. Analysis identified 38 potential storage sites with burial depths between 800 m and 4500 m, reservoir capacities (P50) above 5 Mt CO2 and suitable sealing units. The best storage conditions are expected on the West Schleswig Block where salt-controlled anticlines with moderate burial depths, large reservoir capacities and limited lateral flow barriers are the dominant trap types. Relatively poor storage conditions can be anticipated for small (P50 <5 Mt CO2), deeply buried (> 4500 m) and structurally complex potential storage sites in the Horn and Central Graben. For more detailed information on the methodology and findings, please refer to the full publication: Fuhrmann, A., Knopf, S., Thöle, H., Kästner, F., Ahlrichs, N., Stück, H. L., Schlieder-Kowitz, A. und Kuhlmann, G. (2024) CO2 storage potential of the Middle Buntsandstein Subgroup - German sector of the North Sea. Open Access International Journal of Greenhouse Gas Control, 136 . Art.Nr. 104175. DOI 10.1016/j.ijggc.2024.104175
Within the framework of the GEOSTOR Project, the CO2 storage potential of the Jurassic succession in the German Central Graben was analysed. Twelve potential trap structures were initially mapped along the base of the Kimmeridge Clay Formation, which serves as the primary seal for potential reservoir sandstones within the Central Graben Subgroup. The Kimmeridge Clay Formation is generally continuously distributed across the German Central Graben, with only localized penetrations by rising salt diapirs. In contrast, the Central Graben Subgroup, serving as a potential reservoir unit, exhibits an uneven distribution across the area, limiting the presence and continuity of reservoir rocks within each trap structure. To further delineate the spatial extent of the mapped reservoir structures, the base of the Central Graben Subgroup was used as an additional reference layer. Due to the intermittent nature of Jurassic sandstones within the Central Graben Subgroup, a subsequent analysis classified each structure based on borehole data to confirm the presence of reservoir sands. Structures were categorized as ‘proven,’ ‘not present,’ or ‘uncertain’ depending on sandstone availability and continuity within the trap. All mapped reservoir structures are buried at depths ranging from 2225 to 3043 meters (apex depth) and are considered closed systems, situated within a complex structural network of salt diapirs, faults, and pinch-outs. Capacity calculations were conducted following the method outlined by Fuhrmann et al. (2024), and the horizons used for mapping are based on the work of Müller et al. (2023) and Thöle et al. (2021). Fuhrmann, A., Knopf, S., Thöle, H., Kästner, F., Ahlrichs, N., Stück, H.L., Schlieder-Kowitz, A., Kuhlmann, G., (2024). CO2 storage potential of the Middle Buntsandstein Subgroup-German sector of the North Sea. International Journal of Greenhouse Gas Control 136. Müller, S.M., Jähne-Klingberg, F., Thöle, H., Jakobsen, F.C., Bense, F., Winsemann, J. & Gaedicke, C. (2023). Jurassic to Lower Cretaceous tectonostratigraphy of the German Central Graben, southern North Sea. – Netherlands Journal of Geosciences, 102: e4. DOI:10.1017/njg.2023.4 Thöle, H., Jähne-Klingberg, F., Doornenbal, H., den Dulk, M., Britze, P. & Jakobsen F. (2021). Deliverable 3.8 – Harmonized depth models and structural framework of the NL-GER-DK North Sea. GEOERA 3DGEO-EU; 3D Geomodeling for Europe; project number GeoE.171.005. Report.
The cruise AL278 started on May, 10th 2006 in Kiel and ended in Kiel on May, 19th 2006. The previous BGR-cruises with RV AURELIA in 2003 and 2004 were designed to collect a grid of seismic MCS-data which should enable us to get a high-resolution overview over the upper 1 s TWT of the sediments of the German North Sea sector. During October/November 2005 a subsequent cruises with RV HEINCKE and FK SENCKENBERG was designed to tackle several special aims: - The detailed mapping of glacio-tectonic features North of Heligoland. - The shallow seismic mapping of the Holocene/Pleistocene-Boundary and topography of the Pleistocene sub-glacial valley system offshore of the East Friesian Islands. - High-resolution surveying of two areas designated for offshore wind farms in the southwestern German sector. - Detailed mapping of a wide and deep sub-glacial valley. One additional aim was to acquire a dense grid of seismic line in the area North of Weisse Bank where on several from previous cruises indications for shallow gas accumulations (e.g. “bright spots”) were found. Unfortunately, due to very bad weather conditions this aim could not be reached. Therefore this short cruise with RV ALKOR was used to acquire twelve MCS lines over this area. During the cruise a total ca. 1400 km of high quality MCS lines were surveyed and simultaneously measured by a sediment echosounder system that enabled additional profiles during transits with speeds 5 kn. Together with the previously acquired data these new data should help to extend our knowledge of the Late Tertiary and Quaternary evolution of the German North Sea Sector. The BGR high-resolution multichannel seismic reflection system consisting of a GI-Gun (0.8 l) and a 300 m streamer with 24 channels and a sediment echosounder type SES 2000 standard by Innomar, Rostock. While the BGR-seismic system was used to observe the shallow subsurface down to 2 s TWT penetration depth, the sediment echosounder with a penetration depth of several meters was primarily intended to identify sampling positions for the deployment of the BGR vibration corer during the succeeding Leg 2. Additionally, the echosounder system enables the relationship to the highest-resolution multichannel seismic measurements of the group of the University of Bremen on FK SENCKENBERG. All seismic records were processed onboard for the quality control and for a first interpretation.
Storage of CO2 in deep geological formations is one possibility of reducing CO2 emissions from industry that are difficult to avoid. High-quality geological models and capacity estimates are crucial for the successful planning and implementation of safe storage projects. This study analyses the storage potential of the Middle Buntssandstein (Lower Triassic) and Lower to Middle Jurassic within the Exclusive Economic Zone (EEZ) of the German North Sea. The dataset includes maps of potential storage sites and classifications. Link https://geostor.cdrmare.de/