* Chevron shuts Gulf of Mexico platform - regulators
* Alaska pipeline expected to restart this week-source
* Brent premium over U.S. crude widens to 23-month high
* Coming Up: API U.S. oil inventory report; 2130 GMT
(Recasts, updates prices and market activity, changes byline and moves dateline from previous LONDON)
By Robert Gibbons
NEW YORK, Jan 11 (Reuters) - U.S. oil prices rose sharply on Tuesday as a shut production platform in the Gulf of Mexico curbed more supply on top of the shut Alaska crude pipeline still keeping more than half a million barrels per day of output offline.
Chevron <CVX.N> shut in a platform on Eugene Island Block in the U.S. Gulf of Mexico after an upset on the structure on Monday, according to a filing with regulators. [
]The Trans Alaska Pipeline System's main oil pipeline remained closed but was still expected to restart this week after a spill on Saturday forced it to shut down, according to a source familiar with its operations. [
]Forecasts for below normal temperatures and above normal heating oil demand in the United States sent U.S. heating oil futures <HOc1> to a 28-month high. [
]U.S. crude oil for February delivery <CLc1> rose $1.70, or 1.9 percent, to $90.95 a barrel at 11:50 a.m. EST (1650 GMT), having reached $91.20.
In London, ICE Brent crude for February <LCOc1> rose $1.88 to $97.58 a barrel, having traded as high as $97.75.
The premium for London's ICE Brent crude over the U.S. light sweet crude benchmark, West Texas Intermediate, jumped as above $7 a barrel on Tuesday, pushing the spread <CL-LCO1=R> to its widest since February 2009.
Brent has traded above U.S. crude since August last year, supported by a combination of dwindling North Sea crude supplies and disruption of oil grades priced off it.
Traders said if the disruption to the Alaskan pipeline lingers, it could result in shifting crude supplies priced off Brent to the U.S. West Coast.
"There is the possibility the pipeline will resume operations pretty soon, in fact 3-5 days from now, but if it doesn't, it will have a strong impact on the market," said Christophe Barret, global oil analyst at Credit Agricole.
"If the pipeline doesn't restart, the need to find other sources will impact crude oil prices in the Middle East."
Barret said the wide Brent/U.S. crude oil futures spread was due to a combination of high U.S. oil stocks, maintenance work in the North Sea and some speculative trading in Brent. The problems with the Alaskan pipeline had added to the strength.
U.S. OIL INVENTORIES
U.S. crude oil inventories probably rose by 400,000 barrels last week as imports rebounded, in what would be the first gain in six weeks, according to a preliminary Reuters poll before the release of weekly inventory reports. [
]Industry group the American Petroleum Institute will publish inventory statistics at 4:30 p.m. EST (2130 GMT) on Tuesday, while the U.S. Energy Information Administration will follow with government figures on Wednesday at 10:30 a.m. EST (1530 GMT).
Distillate stocks, which include heating oil and diesel fuel, were forecast to have increased 1.3 million barrels for their third straight weekly gain, while gasoline stocks probably rose 2.8 million barrels, the survey showed. (Additional reporting by Gene Ramos in New York, Christopher Johnson and Jessica Donati in London and Alejandro Barbajosa in Singapore; Editing by Marguerita Choy)