Waking a Sleeping Giant: Extending the West of Shetland Fractured Basement Play

Abstract

Summary Fractured basement exploration has resulted in multiple discoveries along the Rona Ridge. Ahead of the UK's future licencing rounds, it is possible to establish exploration criteria and a regional screening approach to quickly assess the extension of the West of Shetland fractured basement play. Criterion necessary for successful exploration includes heavily fractured Lewisian basement fault blocks onlapped or capped by Late Jurassic Kimmeridge Clay mudstones and draped by Cretaceous-Paleocene/Late Jurassic mudstones. Regional screening in the West of Shetland revealed that the fractured basement play is most likely to be successful on the Rona Ridge, Westray High, parts of the Corona High, and the Sjurdir, Heri, Trondur, and East Faroes highs, and identified critical risks associated with timing of charge, migration distance and reservoir effectiveness. A similar screening methodology can be used to evaluate similar fractured basement plays elsewhere on the UK Continental Shelf and North Atlantic Margin by evaluating criteria common to fractured basement fields across the globe: pervasively fractured, uplifted basement blocks adjacent to prolific, or potential, source kitchens. These include the unproven More and Faroe-Shetland (Faeroese side), Lofoten, Vestfjorden, and Rockall basins and the proven South Viking and Witch Ground grabens.