The Sedimentological Distribution of Upper Brent, Oseberg field, North Sea

Abstract: The Oseberg hydrocarbon field is located in the northern North Sea sedimentary basin (61-62° N) on the eastern flank of the Viking Graben and is bounded to the east by the Horda Platform and the Øygarden Fault Complex (ØFC). The field is covering up most parts of block 30/6 and 30/9 on the Norwegian Continental Shelf (NOCS) but also minor parts of blocks 30/5, 30/8 and 30/12. The North Sea has developed through a very complex structural setting thus a great effect on the Oseberg hydrocarbon field where good quality sandstone reservoir rocks have been able to deposit very successively. The structural event of the Mid North Sea dome that occurred in the Middle Jurassic (Bajocian-Bathonian) is considered to be a main source of the successive sedimentary formations that the Oseberg field is buildup on. These formations are mainly a part of the Brent Group which consists of five lithological formations; Brent, Rannoch, Etive, Ness and Tarbert, where the Ness and Tarbert formation are representing great sandstone reservoir rocks. The study of structural and stratigraphic frameworks of the Oseberg field and its formations will help predict depositional environments thus evaluate reservoir systems. Fairly good results of lithology interpretation will be provided through analyzing well log-, and core-data and with seismic supplies, even stronger results. Keywords: Sedimentology, Middle Jurassic, Brent Group, paleoenvironment, petroleum geology