A tectonostratigraphic framework for the Statfjord Field, northern North Sea

Based on detailed analyses of seismic and well data, the Statfjord Field, n orthern North Sea, can be separated into a relatively undeformed main field area and an east flank heavily deformed by rotational block slides. The ma in tectonic event is related to the opening of the Viking Graben which star ted in the middle Jurassic and which increasingly affected deposition of th e Bathonian-Oxfordian Heather Formation. This rift phase peaked before the deposition of the Draupne Formation causing gravitational instabilities alo ng the crest of the field and subsequent rotational block slides in the Upp er 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 top ographic depressions on the east flank. Minor tectonic activity occurred du ring the Cretaceous and Tertiary.