A tectonostratigraphic framework for the Statfjord Field, northern North Sea

Based on detailed analyses of seismic and well data, the Statfjord Field, northern North Sea, can be separated into a relatively undeformed main field area and an east flank heavily deformed by rotational block slides. The main tectonic event is related to the opening of the Viking Graben which started in the middle Jurassic and which increasingly affected deposition of the Bathonian-Oxfordian Heather Formation. This rift phase peaked before the deposition of the Draupne Formation causing gravitational instabilities along the crest of the field and subsequent rotational block slides in the Upper Triassic and Jurassic sections. Compared to fields closer to the graben centre only limited erosion affected the Statfjord Field reservoirs during the Oxfordian-Ryazanian. Here, the Draupne Formation still drapes a partly degraded Jurassic sequence and is thickest on the west flank and within topographic depressions on the east flank. Minor tectonic activity occurred during the Cretaceous and Tertiary.