| dc.description.abstract | Smeaheia is a proposed site for long-term storage of CO2. The site is located on the Horda Platform off the western coast of Norway, situated between the Vette and Øygarden Faults. The burial and uplift history of a basin has significant implications for reservoir and overburden properties. The uplift history of Norway is complex and consists of several phases, and the offshore basins have been linked to this development along with undergoing anomalous subsidence. This study aims to understand the depositional infill of the Smeaheia area with particular emphasis on the Cretaceous development, and how the uplift and subsidence history has affected the deposits with implications for CO2 storage. The study involves a detailed sedimentary analysis based primarily on seismic data (2D/3D) of the depositional successions on the Horda Platform, with a detailed focus on the Cretaceous sedimentary succession. The site-specific development of the area, based on the variations in sedimentary influx and the tilt and erosion of successions, is used to discuss the overburden properties of the storage site and influence on migration and secondary storage of CO2. In this study, Petrel (Schlumberger Ltd.) was used for the seismic interpretation of a 3D seismic cube and three 2D lines. 17 seismic horizons were mapped out, followed by the creation of RMS amplitude and time-thickness maps, which were used to evaluate depositional environments and sediment partitioning within the succession. The study is divided with respect to the Cretaceous, including an analysis of the Pre-Cretaceous, Cretaceous, and Post-Cretaceous development. The primary focus is on the Cretaceous Period, which consists of primarily fine-grained or clay-fraction sediments with some coarse-grained sediments near fault boundaries due to erosion on the edges of rotated fault blocks. The Cretaceous units represent the secondary reservoir of the potential CO2 storage site, Smeaheia, and are composed of shallow to deep marine mudstones with small amounts of sand. Units above the Alpha Structure of the primary Jurassic reservoir display homogeneity with more lithologic variation between the Vette and Øygarden Faults, while units above the Beta Structure are more varied and display more coarse-grained sediments. The Cretaceous units are in close contact with loosely compacted Quaternary sediments due to erosion along the Base Pleistocene Unconformity, which may be a potential leakage site should CO2 enter the secondary storage unit. | eng |