Abstract The Endurance, four-way, dip-closed structure in UK Blocks 42/25 and 43/21 occurs over a salt swell diapir and within Triassic and younger strata. The Lower Triassic Bunter Sandstone Formation reservoir within the structure was tested twice for natural gas (in 1970 and 1990) but both wells were dry. The reservoir is both thick and high quality and, as such, an excellent candidate site for subsurface CO 2 storage. In 2013 a consortium led by National Grid Carbon drilled an appraisal well on the structure and undertook an injection test ahead of a planned development of Endurance as the first bespoke storage site on the UK Continental Shelf with an expected injection rate of 2.68 × 10 6 t of dense phase CO 2 each year for 20 years. The site was not developed following the UK Government's removal of financial support for carbon capture and storage (CCS) demonstration projects, but it is hoped with the recent March 2020 Budget that government support for CCS may now be back on track.

Abstract The Blake Field is subdivided into two discrete parts, the ‘Channel’ and the ‘Flank’ areas. The two areas are geologically different but also reflect the different levels of maturity in terms of their development. Blake Channel was discovered in 1998, with first production commencing in 2001. Blake Flank was discovered in 1974 and developed in 2003. The field contains saturated light oil, with a field-wide oil–water contact and two significant gas caps. The reservoir comprises deep-water turbidite sands of Lower Cretaceous age. The combination of complex depositional environment and dynamic data resulted in the decision in 2016, to create a new model incorporating a fully integrated approach to subsurface evaluation and modelling. The latest work summarized in this paper incorporates a new geological interpretation along with the addition of aquifer extensions to capture depletion from offset fields, and a palaeo-oil leg, to help limit aquifer influx and improve history match. 4D seismic has also been incorporated to support the evaluation. Blake Channel and Flank have oil-in-place of 230 MMbbl and 300 MMbbl and have produced 94 MMbl and 15 MMbbl, respectively, to date.