Sammendrag
The Draupne Formation is dominated by deep marine shales and forms an important sealing unit for future CCS operation in the North Sea. Meanwhile, seismic mapping has clearly shown the unit to be heterogeneous in lithology, showing variation in thickness and composition. The aim of this thesis is to map the depositional heterogeneity and assess depositional environments and from this ascertain regional variation in sealing capacity within the Stord Basin and across the Horda Platform. The primary target will be a prograding clinoform succession in the Stord Basin with lateral analysis of the inter-fingering successions towards the deeper marine deposits towards the North. Geometric analysis of the clinoforms, which are covered by 2D seismic data, will allow for assessment of scale, dip and dimensions of these units which will lead to some tentative inferences on composition, classification, and depositional processes. Such insight can be linked to the successive prograding units above and provide important information on the spatio-temporal influx into the North Sea. Our comprehensive study of the clinoforms within the Draupne Formation, particularly its calculated and measured parameters, has revealed crucial insights about the feasibility and risks associated with CO2 storage and potential migration within this geological framework. The Draupne Formation benefits from a consistent sediment supply from the Hardangerfjord deltaic system, contributing to its dimensions and potential volume for CO2 storage. Compared to other formations, the larger size of clinoforms in the Draupne Formation enhances its capacity to withstand CO2 injection pressures, improving storage prospects. The surface map data suggests an eastward migration of CO2 along the steepest surface gradient, with the Øygarden Fault Complex potentially acting as a barrier against CO2 leakage. The heterogeneous deposition of the Draupne Formation indicates the presence of diverse potential storage sites for CCS, cyclical patterns and regional variations in thickness and lithology warrant further investigation with integrity assessment of overlying Cromer Knoll Group playing role as a thick caprock.