2003 Strategic Environmental Assessment SEA4 Technical report - Sub-seabed geology (north UKCS)

This report is a contribution to the Strategic Environmental Assessment (SEA4) conducted by the Department of Trade and Industry (now Department of Energy and Climate Change). This report summarises the geological history of the SEA4 area from Pre-Cambrian times to the present day, sets the framework in which oil and gas fields have been discovered to the west of Shetland, and discusses the seismicity of the area. A generalised geological map of the area is presented and three approximately NW-SE trending sections across the southern part of the SEA4 area are shown. The petroleum geology of the area is reviewed and the geological settings in which oil has been found at the Clair, Foinaven, Schiehallion and Loyal oilfields is described. Other hydrocarbon fields to the west of Shetland, for which there are no immediate development plans, are briefly touched on. The seismicity of the SEA4 area, which is very low, is discussed.