RE: Thistle update last Friday29 Oct 2019 09:05
Yes that's probably correct then - BP were one of the original producers - presumably the tank dated from this era - this is from Wikipedia -
"Production commenced for partners BNOC, Britoil and BP on the site in 1978. Ownership of the operations licence for the site was subsequently transferred to DNO in 2003, followed by Lundin in 2004 before the demerging of Lundin's UK assets in 2010, when EnQuest became the operator. The site is currently operated in partnership between EnQuest and BP, with EnQuest holding over 99% of the total ownership of the site."