Kimmeridgian and Volgian fault-margin sedimentation in the Northern North Sea area

The Upper Jurassic sediments of the East Coast of Sutherland and the South Brae Oilfield were deposited during the late Jurassic taphrogenic episode in which there was rapid subsidence in the grabens and uplift of the adjacent areas. The initiation of coarse-grained sedimentation in the grabens was directly related to an increase in subsidence rates. At Sutherland the most sand-rich sequences were deposited during the cymodoce zone of the Kimmeridgian, immediately after the increase in subsidence rates. Depositional environments varied from a relatively shallow water and sand-rich submarine slope during the early Kimmeridgian to a deeper water sediment starved submarine slope during the early Volgian. The sediments of the South Brae Oilfield were deposited in the channelised part of a submarine fan system which was sourced from a point which lay to the west of the 16/7a-8 well and to the southwest of the 16/7a-12 well. The South Brae sequences are part of a much larger complex which was composed of at least seven different submarine fan systems. Sediment entry points occurred along the western margin of the South Viking Graben from the T-Block in the south to East Brae in the north and each of these fed a submarine fan system. The reservoir sequences will tend to be vertically stacked and spatially restricted in proximal areas and will become less stacked and less restricted distally. Stratigraphically trapped "Brae-like" plays probably exist at the margins of many North Atlantic Continental Shelf grabens. The eastern margins of the Vøring and Træna Basins have especially high prospectivity.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral-pg

Grantor dc:publisher.institution

University of Strathclyde

Year dc:date.issued

1985

Author dc:creator

• MacDonald, Alister C.

DOI

10.48730/zkgq-9f51

Identifier

uk.bl.ethos.381118
T5314

OAI identifier oai:identifier

oai:strathclyde:9306sz313