Saudi Aramco officials are growing less optimistic about a rapid recovery in oil production after an attack on the giant Abqaiq processing plant on Saturday, a person with knowledge of the matter said.
The plant, where more than half of Saudi production is processed, may take longer than previously thought to resume operations, the person said, asking not be named before an official announcement.
The company is scheduled to provide an update later today.
Saudi Aramco is firing up idle offshore oil fields -- part of their cushion of spare capacity -- to replace some of the lost production, they said.
The loss of Abqaiq, which handles 5.7 million barrels of oil a day, is the single worst sudden disruption to the oil market.
Crude prices posted their biggest intraday jump on record.
Aramco customers are being supplied using stockpiles, though some buyers are being asked to accept different grades of crude oil.