Introduction and review

Abstract

In reviewing the Jurassic papers in the Proceedings of the 4th Conference on the ‘Petroleum Geology of Northwest Europe’ Fraser (1993) drew attention to the fact that over 50% of the reserves in the UK sector of the Northern and Central North Sea were contained in the Jurassic (Cordey 1993). Fraser went on to state that ‘. . . 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 defined using novel interpretation techniques, such as sequence stratigraphy, in concert with 3D seismic interpretation’. The regional and field specific use of detailed lithostratigraphy, biostratigraphy and chronostratigraphy was demonstrated by a variety of workers, in particular from BP and Exxon, to provide a basis for a rigorous and systematic approach to understanding the stratigraphic evolution of North Sea Jurassic basin fill processes. The 1992, 4th Barbican Conference dedicated several sessions to the Jurassic alone, entitled ‘The Jurassic: from regional models to field development; the impact of sequence stratigraphy on hydrocarbon geology,’ and the purpose of the Jurassic session at the 5th Conference was to review our current thinking on these concepts and their application to successful hydrocarbon exploration. The underlying assumption is that virtually all of the economic Jurassic four-way dip and up-thrown fault closures in the North Sea have been drilled. The search for additional reserves in the Jurassic must therefore target more subtle features such as: 1. downthrown fault closures; 2. stratigraphic traps 3. untested sequences identified . . .