Large quantities of North Sea oil are processed on the rigs and exported directly to other countries without coming ashore. Prior to December 2016 oil that was shipped directly from the rigs was counted towards the Oil Companies’ Head Offices, rather than being counted as produced in Scotland. Oil imported or exported into or out of the UK was normally associated with the region of the UK where it was produced, but oil exported directly from the rigs was associated with a business, not the country of origin. It was allocated to an “unknown region” and credited to the region where the business’s Head Office was registered (usually not Scotland).
The system has now been updated so that, since 2016, in UK records the value of oil extracted from Scottish waters has been credited to Scotland instead of to an “unknown region”.
This change has resulted in Scotland’s allocation for 2015 rising from £588 million to £6,825 million and the allocation to the “unknown region” falling from £8,826 million to £1,529 million.
(Information taken from a report on the Wings over Scotland website.)