Oil prices have continued to rise as a main Alaskan pipeline¹ remained all but closed for a fourth day, and Norway's Statoil was forced to shut two fields in the North Sea.

阿拉斯加一条主要输油管已经关闭四天，挪威国家石油公司被迫关闭北海两处油田，美国油价因此持续上涨。

Alaska contains some of the largest US oilfields

The Trans-Alaska Pipeline has now been closed since Saturday, after a spillage（溢出，泄露） at one of its pump stations. It is expected to reopen later this week.

Statoil halted output at Snorre and Vigdis after a gas leak on Tuesday.

US light crude oil ended Tuesday up $1.86, or 2%, at $91.11 per barrel.

London's Brent added $1.91 to settle at $97.61.

It is not yet known when Norway's 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 is important because it carries almost 12% of US crude output, typically 630,000 barrels per day.