The major Forties pipeline system in the North Sea is expected to restart early next year as work to repair a hairline crack continues.
Ineos, the owner of the pipeline, shut down the pipeline system on 11 December after discovering a cracked pipe. The Forties pipeline transports around 450,000 barrels of oil a day, or about 40 per cent of UK production.
The chemicals giant today said the work on the crack was "progressing well" and based on current estimates would be completed around Christmas.
Initially, only a handful of customers will be able to send oil and gas through the pipeline so that Ineos can control the flow of the system.
"Ineos will complete this work as quickly as possible but safety is the highest priority," it said.
The firm expects to bring the pipeline "progressively" back to normal rates early in the new year.
"We apologise to our customers and the local community for the issues that this creates and we are working hard to minimise the impact of the pipeline closure as far as possible," Ineos said.