Shell has spudded its hotly tipped Edinburgh exploration well near the UK-Norwegian border – potentially one of the largest remaining undrilled structures in the central North Sea.
Edinburgh lies on Licence P255, around 175 miles off the north-east coast and near the UK/Norwegian median line, in water depth of approximately 71 metres.
Volumes at the prospect have been estimated at between 100-675 million barrels of oil equivalent (boe), making it potentially one of the most high-impact wells drilled in the UK North Sea in recent years.
Shell holds a 40% operated stake in the licence, alongside Norwegian firm DNO – who acquired 45% via its acquisition of former operator Faroe Petroleum – while Spirit Energy holds 15%.
Drilling at well 30/14a- 5 began on March 15, according to records held by the North Sea Transition Authority, using the Valaris 122 jack-up rig. A filing with regulator OPRED suggests drilling could take up to 136 days to complete.
The well will be drilled in five sections, filings add, using water-based mud (WBM) for the top two sections, with mud and associated cuttings discharged to sea.
Commenting on the well spud, Welligence vice president of North Sea research, David Moseley noted that whilst the structure presents “significant risk”, the extent of potential volumes “arguably make the prospect too large to leave untested.”
“The maturity of the North Sea means there are very few large, robust prospects remaining in mature areas. However, as TotalEnergies’ recent Isabella well proves, large discoveries in this region remain possible,” Mr Mosely added.
Mr Mosely pointed to several tieback options for Edinburgh in the event of a successful discovery, including J-Block 12 miles to the northwest if a standalone development is not feasible.
However, a discovery in line with pre-drill volumes would require multiple appraisal wells to refine resources. This process, in combination with the complexity of the high pressure, high temperature (HPHT) reservoir means monetisation in the success case “will likely be years away.”
“A further complication relates to environmental issues – Shell’s development plan for the nearby Jackdaw project in the same HPHT play was rejected by the regulator (OPRED), in 2021, reportedly due to its choice of tieback host,” Mr Mosely added.
“In the success case at Edinburgh, this is likely to be a key consideration and will impact development plans.”
Despite this setback, last week Energy Voice reported Shell has prepared new plans for Jackdaw in a bid to get field development back on track.
Edinburgh prospect is the latest of several exploration and appraisal wells to be drilled in the HPHT Central Graben region, following appraisal drilling at Glengorm and exploration at Jade South, Dunnottar and Isabella.
It also follows closely behind drilling at Shell’s Jaws prospect, also using the Valaris 122 rig, though this proved unsuccessful.
