Oil prices continue to rise as a main Alaskan pipeline remains all but closed for a fourth day and Statoil of Norway was forced to shut two fields in the North Sea.
The Trans-Alaska Pipeline has now been closed since Saturday, after a spillage at one of its pump stations. The BBC reports it is expected to reopen later this week.
Statoil halted output at Snorre and Vigdis after a gas leak on Tuesday.
US crude oil was up $US1.56 or 1.8% per barrel to $US90.81. This followed a rise of $US1.22 or 1.4% on Monday.
Meanwhile, London Brent crude was up $US1.79 to $US97.49 per barrel.
It is not yet known when Statoil will be able to resume production at the two oil and gas fields.
Since Saturday, only 5% of typical output has flowed through the Trans-Alaska Pipeline.
The pipeline carries almost 12% of US crude output, typically 630,000 barrels per day.