Plans by the operator of the UK's largest oil supply pipeline, Forties, for a major maintenance overhaul starting May 27, 2021, mean around 10% of both oil and gas production from the UK is likely to be shut off for a month, according to industry sources.
Switzerland-based Ineos, which took over Forties from BP in 2017, was obliged in April to abandon plans for a three-week shutdown of the pipeline intended to ensure its reliability out to 2040, after pressure for a postponement from upstream oil companies worried about the risks of COVID-19 infection and keen to avoid an interruption in output.
The Forties pipeline handles around a third of the UK's oil output, making Forties the country's largest crude export stream, as well as a feedstock for Scotland's Grangemouth refinery.
The Forties shutdown has now been rescheduled for May 27 next year, with the core Forties route to be closed for the three weeks to June 16, reducing oil output by as much as 350,000 b/d, but with an additional 11 days of shutdown, until June 27, for an interlinked section known as the Graben Area Export Line (GAEL), according to the Ineos website.
The GAEL route is responsible for about 100,000 b/d, or over a quarter of typical Forties volumes, including liquids from so-called 'wet' gas fields such as the Elgin-Franklin complex, operated by Total, and Shell's Shearwater.
Elgin-Franklin and Shearwater rely on GAEL being available for liquids export in order to maintain uninterrupted gas supply to a terminal at Bacton on England's Norfolk coast.
Such is the inter-dependence of oil and gas supply that Elgin-Franklin amounts to one of the largest sources of UK oil production, with combined liquids output of around 62,000 b/d last year.
A Total spokesman confirmed to S&P Global Platts it plans a shutdown of Elgin-Franklin for maintenance, to coincide with the Forties shutdown and to last "circa one month."
A source close to the Shearwater operation confirmed that gas production from that facility would also cease during the GAEL shutdown.
GAEL serves some 14 fields in all, also including BP's ETAP hub, a cluster of six oil fields. Combined production from the 14 fields last year amounted to around 100,000 b/d of oil and almost 600 MMcf/d of gas, with most of the gas being sent to Bacton.
The Forties pipeline system as a whole serves some 90 fields, including a few in Norwegian waters, with combined production of around 350,000 b/d.
