A shutdown of the UK North Sea’s main pipeline system for emergency repairs has helped to send the oil price above $65 a barrel for the first time in more than two years.

The Forties Pipeline System (FPS), which billionaire Jim Ratcliffe’s Ineos bought from BP just six weeks ago, delivers almost 40% of UK North Sea oil and gas production. Its shutdown for several weeks, announced on Dec. 11, will have an immediate knock-on effect on operators in the region that rely on its capacity.

Brent crude, the international crude oil benchmark, rose on Dec. 12—reaching a day-high of $65.70 a barrel, up 1.6%—before slipping back to $65.33, a rally of 0.9% leaving it at a peak not seen since the summer of 2015.

Wholesale natural gas prices for same-day delivery in the UK surged almost 30% on Dec. 11 to the highest since 2013, with traders scrambling to secure imports at a time that much of the country is experiencing snow and sub-zero temperatures.

The jump in wholesale oil and gas prices, which may filter through to consumers over the winter, is likely to reignite questions about the UK’s aging energy infrastructure, with the country increasingly dependent on fuel imports to meet its needs.

Falling storage capacity for natural gas has left UK supplies increasingly susceptible to short-term outages, with Centrica shutting the Rough storage site, the country’s largest facility, making imports from Norway increasingly important.

“A shutdown of the Forties Pipeline System, even temporary, will have wide-reaching implications for the UK oil and gas industry,” said Wood Mackenzie analyst Fiona Legate. “Companies with fields utilizing the FPS export route will suffer from reduced cash flows during the shutdown period.”

Richard Longden, a spokesman for privately held Ineos, said the company’s decision to shut FPS followed the worsening of a hairline crack in an onshore section of the 450,000 barrel a day (bbl/d) line in Aberdeenshire, which had first seen the company reduce pressure on the line last week.

While a “precise timeframe” for repairs was still being worked out, the shutdown was likely to last for “several weeks rather than days,” Longden said, emphasizing that safety was the company’s first priority.

Last winter, 6% of gas supplies came from storage, with 42% coming from Norway and 38% from the North Sea, according to National Grid, which operates the UK’s electricity and gas networks.

A further 10% was sourced via pipelines from continental Europe and 4% was met by LNG, which is shipped to the UK from locations such as Qatar.

Apache, the owner of the Forties field after which the pipeline was named, said it had been forced to shut down production at the asset on Dec. 11, affecting its own output of 35,800 bbl/d. The total Forties stream, including production from nearby fields that also utilize the FPS, was set to be about 400,000 bbl/d in December.

Chrysaor, one of the biggest independent operators in the North Sea after buying a large number of Royal Dutch Shell’s fields in the region, confirmed its output that would normally pass through the line was currently shut in, affecting three of its platforms: Everest, Lomond and Armada.

Ineos’s Grangemouth refinery, which supplies the majority of gasoline and diesel in Scotland and parts of the north-east of England, was likely to keep operating despite normally relying on FPS for around half of its crude supplies, Longden said.

The plant, which was previously operated by BP, has oil in storage tanks and can bring in alternative supplies of crude by tanker.

Ineos founder and Chairman Ratcliffe, who moved the company headquarters to Switzerland in 2010 to save on tax before returning in 2016, has been a vocal proponent of fracking in the UK to help reverse its growing dependence on gas imports.

Ineos became one of the 10 biggest producers in the North Sea this year after spending more than $1 billion to acquire the oil and gas business of Danish renewable energy group, Ørsted, previously known as Dong Energy.

A UK government spokesperson said: “There is no security of supply issue for fuel or gas supplies as a result of the repairs needed to the Forties pipeline. The government will continue to liaise with industry operators to monitor the situation to ensure repairs are undertaken as quickly as possible.”