Abstract A core repository is a physical record of a country's or commercial organization's subsurface wealth. Some of the largest core repositories hold thousands of kilometres of core material and it is a challenge to turn this physical archive into an accessible digital resource for all. Non-destructive multi-sensor core logger, hyperspectral and X-ray imaging techniques offer a unique chance to rescue valuable data trapped within core samples, improving the way that a core repository delivers data to academic or industrial end users. Here we present a case study of an archived petroleum core acquired in 1985 at the Osprey Field, UK Continental Shelf. Data from the UK National Data Repository are augmented by a multi-sensor core logger, hyperspectral and X-ray dataset that is uploaded into a cloud-based digital repository. The data were analysed using a multi-variant analysis to reclassify the original lithological interpretations, uncovering a greater proportion of clay and cemented horizons than was previously interpreted. A workflow is established to optimize the use of legacy cores and exploit the abundance of data trapped within the core repository using continuous multi-sensor core scanning and imaging data, which are stored within the virtual environment for visualization and access to all.

Abstract The Clair Field is a giant oilfield containing in the region of 6–7 Bbbl of stock tank oil initially in place, located approximately 75 km west of the Shetland Islands. As such, it represents the single biggest hydrocarbon accumulation on the UK Continental Shelf. Clair was discovered in 1977, but first production did not occur from Phase 1 until 2005, after a lengthy appraisal period. The major appraisal milestone occurred in 1991 after well 206/8-8 proved up fractured clastic red beds of the Devonian Lower Clair Group. This was followed up with an extended well test on 206/8-10Z, which demonstrated the longer-term performance of the reservoir. Further appraisal on Clair Ridge led to the sanction of the Clair Ridge, which came on stream in November 2018. Following the Greater Clair appraisal programme in 2013–15, development options are currently being worked for Clair South, which will develop the Lower Clair Group reservoirs together with overlying shallow-marine reservoirs of the Cretaceous and Jurassic.

Abstract The Edradour Field, located in Licence P1453 on Block 206/4a of the Faroe–Shetland Basin, was put on production in August 2017. It lies c. 50 km NW of the Shetland Islands in a water depth of c. 300 m, and consists of one subsea well that produces gas condensate from the Albian Black Sail Member of the Commodore Formation. It is part of a joint development scheme along with the Glenlivet Field that sees the commingled multiphase production transported to the Shetland Gas Plant via tieback to the pre-existing Laggan–Tormore flowlines. The Edradour single well development has reserves of 21 MMboe from a gas initially-in-place of 142 bcf. It is operated by Total E&P UK Ltd under the P1453 licence with Ineos E&P (UK) Ltd and SSE E&P UK Ltd as partners.

Abstract The Glenlivet Field, located in Block 214/30a within the Faroe–Shetland Basin, was put on production in August 2017. It lies approximately 70 km NW of the Shetland Islands, in a water depth of c. 440 m. The development consists of two subsea wells that produce gas condensate from the Paleocene Vaila Formation, which comprises deep-water turbidite deposits with excellent petrophysical properties. It is part of a joint development scheme along with the Edradour Field that sees the commingled multiphase production transported to the Shetland Gas Plant via tie-back to the pre-existing Laggan–Tormore flowlines. Glenlivet is operated by Total E&P UK Ltd under the P1195 licence since September 2014 with Ineos E&P (UK) Ltd and SSE E&P UK Ltd as partners.

Abstract The Laggan and Tormore fields are found within the Flett sub-basin of the Faroe–Shetland Basin. Situated 120 km west of the Shetland Islands in 600 m water depth, they are part of the deepest subsea development in the UK to date with a 143 km subsea tie-back to onshore facilities. The reservoirs are found within the T35 biostratigraphic sequence of the Paleocene Vaila Formation and comprise sand-rich turbiditic channelized lobes with good reservoir properties, separated by metric to decimetric shale packages. Laggan is a gas-condensate field, whereas Tormore fluid is a richer gas with a saturated oil rim. Seismic reservoir characterization is a key to the field development where differentiation of fluid type proved challenging. Both fields came on stream in 2016 as part of the Greater Laggan area development scheme.

Abstract The Rosebank Field is located primarily in Block 213/27a in the Faroe–Shetland Basin, c. 130 km west of the Shetland Islands in water depths of c. 1100 m (3600 ft). Hydrocarbons are trapped within an elongate, SW–NE-trending four-way anticlinal structure. The principal Colsay Sandstone Member reservoir consists of several vertically stacked, Late Paleocene to Early Eocene fluvial and deltaic reservoirs separated by volcanic sequences. Well log and core data indicate that reservoir quality is high, with porosities in the range of 19–23% and average permeability of c. 3 D. Oil quality is also high, with average oil gravity of 37°API and in-situ viscosity of c. 1 cP at a mean reservoir temperature of 175°F. The field holds a substantial resource and is currently under evaluation for development.

Abstract The Schiehallion subsea development comprises two fields, Schiehallion and Loyal, which are located approximately 200 km to the west of the Shetland Islands in the UK Continental Shelf. The Schiehallion and Loyal fields were discovered in late 1993 and 1994, respectively, with a combined oil-in-place of more than 2.3 Bbbl. The fields are developed under waterflood and were on production from 1998 to 2013. After an extended shut-in, the fields were brought back on line in 2017, through new floating production facilities. Most of the production to date has been from the Paleocene Vaila Formation deep-water turbidite, in the T31 and T34 reservoir intervals. The ongoing Quad 204 redevelopment drilling programme commenced in April 2015, has drilled and completed 21 wells to date, and is expected to continue for several more years. The campaign includes new producer–injector pairs and stand-alone wells to support existing well stock, targeting stacked turbidite reservoir intervals, including the youngest T35–T34 interval, the main T31 interval and the previously under-developed T28–T25 fairway. In addition to an active drilling programme, a 4D seismic survey was acquired and processed in 2018, and its interpretation is key to unlocking further potential sources of value in this mature field.