Introduction and review

Abstract

As we are reminded in the opening paper (Cordey) of the Jurassic session, over 50% of the proven hydrocarbon reserves of the UKCS Northern and Central North Sea occur within the Jurassic. More importantly with a view to future exploration, the Jurassic probably contains the majority of the undiscovered reserves in the North Sea basin in subtle structural and stratigraphic traps, many of which may only be denned using novel interpretation techniques, such as sequence stratigraphy and detailed 3D seismic. The Jurassic also provides us with an excellent opportunity to study the evolution and fill of an ancient rift system from both sub-surface and outcrop data. The Jurassic session was therefore specifically targeted at developing new insights into Jurassic stratigraphy at both basin and field scales by utilizing seismic stratigraphy (Vail and Mitchum 1977; Galloway 1989), tectono-stratigraphy (Hubbard et al. 1985), sequence stratigraphy (Van Wagoner et al. 1988, 1990) and some novel techniques such as the application of ichnofabrics as an environmental indicator (Taylor and Gawthorpe). The development of sequence stratigraphy over the past 15 years has contributed greatly to our understanding of basin fill processes but little has been published on its application to the North Sea Jurassic. Sequence stratigraphic models have mainly evolved from the analysis of sedimentary basins with relatively simple subsidence histories, such as post-rift successions of passive continental margins and intra-cratonic basins (Vail and Mitchum 1977; Galloway 1989). These models have proven applicable to the prediction of reservoir, source and seal facies on a field and basin. . .