| dc.description.abstract | With the continued need to reduce CO2 emissions in the atmosphere, the Carbon Capture and Storage (CCS) project is viewed as a critical part of the solution. The search for and identification of suitable CO2 storage sites has been ongoing for sometime. In the northern North Sea, the Beta prospect located on the Smeahea Fault block, has been considered a possible reservoir to store CO2. The Beta is located in the hanging-wall of the N-S trending Øygarden Fault. The Øygarden has large displacement, and juxtaposes the basement. Therefore, structural risks may arise that are related to along and across fault CO2 migration. As a contribution to the derisking of the Beta prospect as a possible CO2 storage site, a Structural analysis study of Øygarden Fault Complex, starting in Stord Basin, in the South, extending into the Måloy Slope in the North has been carried. The overall study aim is to try and map new CO2 reservoir sites and assess the risks that may be associated with along and across the Øygarden Faults. Using regional 2D seismic lines and well data, mapping of the Øygarden and associated Faults in the hanging-wall have been carried-out to assess geometry, lateral and vertical propagation of the fault using throw-distance and Depth-throw plots respectively. Reservoir and seal units have been mapped to try and screen for new sites, and the surfaces used to create thickness maps. Using thickness maps, identification of Øygarden fault activities has also been possible. Damage zones between relay zones have been assessed to predict risks. In the study, two main rifting phases have been determined; during the Permian-Triassic, as rifting phase one (RP1), and during the Late Jurassic-Early Cretaceous, the second phase (RP2). Two phases of post-rifting have been mapped i.e. post-rift phase 1 in the middle Jurrasic following RP1, and post-rift phase 2 following rifting phase 2 (RP2). The observed approaching tip/linking damage zones between the relay zones are possible fluid/CO2 flow sites. The Øygarden being a large displacement fault, we speculate that it is associated with wide damage zones along and across each of the three curved Øygarden Fault segments (ØFS1-3). These, however may need groundtruthing or advanced seismic attributes to map the damage zones (e.g., Torabi et al., 2017). The Øygarden Fault Complex, therefore posesses additional risks associated with damage and relay zones. These, combined with juxtaposition risks (e.g., Wu et al., 2021) and the fractured basement, the Beta prospect may rank quite low. | eng |