Abstract Fractured crystalline basement reservoirs (basement) on the UK Continental Shelf (UKCS) and the Norwegian Continental Shelf (NCS) have been underexplored. Over the last 12 years, Hurricane Energy has deliberately set out to explore basement potential by exploring and appraising the Rona Ridge, West of Shetland; and the Rona Ridge Lancaster Field is now being progressed towards being the first UK basement field development. The Norwegian basement play is also recognized as a potentially material resource through serendipitous oil discoveries, with the 16/1-15 well, drilled in 2011, being the first successful full-scale basement test on the NCS. Building on this success, the 2018 Rolvsnes appraisal well (16/1-28 S) has demonstrated the significant basement potential of the extensive Utsira High and confirmed the materiality of a Norwegian basement play. The Rona Ridge and Utsira basement discoveries are used as a comparison with two other, yet to be evaluated, prospective basement plays on the NCS, with the objective of establishing technical subject areas where future UKCS and NCS collaboration would aid in accelerating understanding of the UKCS–NCS basement play.

Abstract The NE Atlantic volcanic rifted margins include vast underexplored basin areas neighbouring mature petroleum-producing regions. We appraise the cross-border prospectivity of the outer and central Faroe–Shetland, Møre and southern Vøring basins and present insights from extensive new 3D seismic surveys. Regional seismic surfaces are used to compile a cross-border seismic profile highlighting key discoveries from the UK Rosebank field in the SW to the Norwegian Ormen Lange field in the NE. Cretaceous to Paleocene reservoirs remain the main exploration focus seaward of the platform areas, and the presence of several large untested structures presents important exploration targets in the mid-Norway region. Improved imaging of the areas affected by Paleogene igneous rocks reveals major untested sub-basalt structures including some regions on the marginal highs where the basalt cover has been entirely removed by erosion, revealing sub-basalt stratigraphy and structures with pre-Cretaceous potential prospectivity. The influence of igneous rocks on both discovered and prospective hydrocarbon systems is discussed. Neogene sand injectite fields and Quaternary glacial sand bodies are extremely well imaged in the Møre Basin, documenting shallow prospectivity supported by the presence of successful regional analogue plays. New 3D seismic data are revealing previously unseen prospectivity in frontier and underexplored regions.

Abstract Deep-marine gravity-driven deposits represent one of the more investigated depositional systems owing to their potential interest as targets for exploration and carbon capture and storage activities, as well as an important record of the depositional history of a basin through time. Although the Halten Terrace (Norwegian Sea) is one of the main successful exploration areas, we still have poor understanding of the post-rift Cretaceous interval. Here, 3D seismic reflection and borehole data are integrated to investigate the stratigraphic distribution and sedimentological characteristics of the Cenomanian–Turonian intra Lange Sandstones in the Gimsan Basin and Grinda Graben. The Lange Fm records the deposition in a deep-marine environment of a 1000 m-thick shale unit punctuated by gravity-driven coarse-grained sandstone intervals that are tens of metres-thick and sourced from the Norwegian mainland. The presence of gravity-driven deposits and the deep-marine setting are supported by seismic interpretation, architectural elements and the facies analysis of cored material acquired within the studied stratigraphic interval. Borehole data indicate the presence of both turbidites and hybrid-event beds rich in mud content. The results of this study have implications for understanding the distribution and reservoir potentiality of the Late Cretaceous Lange Fm in the Halten Terrace.

Abstract A dataset with pore pressures from more than 1000 exploration wells has been used to investigate the dynamics of aquifer systems in the Norwegian Continental Shelf (NCS). Variations in aquifer pressures reflect flow of porewater through permeable rocks over geological time. Strongly overpressured regimes are formed within confined aquifers in subsiding areas, where fluid flow out of the aquifer is controlled by vertical seepage. In transitional pressure regimes, fluid flows within permeable beds towards areas with hydrostatic pressures. In the hydrostatic regime, pressure differences result from density differences due to varying formation water salinity and by hydrocarbon columns. An underpressured regime has been encountered in confined aquifers in the platform areas of the Barents Sea, and is related to net uplift and erosion. In the case studies, pressure differences are interpreted in the context of the relevant pressure regime, and with a dynamic approach where segment boundaries and cap rocks are regarded as low-permeability restrictions rather than barriers. The present distribution of pressure regimes was developed over the last few million years due to rapid Pleistocene sedimentation and erosion processes.