Sedimentological and structural features in the Zechstein Supergroup in the SE-Northern Salt Basin, North Sea
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The focus area lies in the south-east Northern Salt Basin, and comprises the proximity of the Mandal High, a crystalline elongated horst in the southern North Sea. The Mandal High is considered as a possible analogue to the Utsira High, a crystalline horst in the southern Viking Graben, associated with several major recent hydrocarbon discoveries. In the Feda Graben, west of the The Mandal High, a source rock kitchen is proven. Hydrocarbons appear to have migrated eastward towards the Mandal High area. Contrary to the Utsira High, the Mandal High is located in a salt basin, where salt structures may act as migration barriers or form diapiric and/or structural traps. Considerable amount of work has been undertaken on salt tectonics in recent years, and several works have been published. However, main focus has usually been in the Southern Salt Basin, while on the interest for the Northern Salt Basin has been low. In this thesis, seismic interpretation of the Base-Zechstein Supergroup horizon has been conducted on 43 2D seismic lines in The Kindom Software. The further detailed study of Zechstein Supergroup features was continued in Petrel E\&P Software. Here the seismic lines were tied and gridded to make the time structural contour map, and maps showing observations and well positions were made. After studying the public accessible Norwegian Petroleum Directorate FactPages database, 74 wells located within the SE-Northern Salt Basin were chosen for further investigation, and relevant data for the Zechstein Supergroup interval was summarized. Structural contour for the Base-Zechstein Supergroup, sedimentological and structural features, and multiple flooding events within the Zechstein Supergroup have been interpreted. Observations are subsequently supported through a literature review. The work has brought attention to which elements need further investigation in order achieve a thorough understanding for the mechanisms of salt tectonics and Zechstein Supergroup sedimentology in the SE-Northern Salt Basin. It turns out that the Zechstein Supergroup is more complex than earlier presumed. The knowledge achieved with this thesis has a direct application to hydrocarbon exploration, and was a contribution to licence work.