(New throughout, adds details and updates storm damage and outages)
By Laura Sanicola
Sept 14 (Reuters) - The largest U.S. fuel line shut down on Tuesday due to power outages caused by Nicholas, which made landfall as a hurricane before weakening on Tuesday, the second U.S. Gulf storm in as many weeks.
Rains, flooding and power outages were affecting Texas and Louisiana, which were still trying to recover from Hurricane Ida, which knocked most U.S. Gulf offshore oil and gas production offline. Power outages in the Houston area caused Colonial to pre-emptively shut down its main gasoline and distillate fuel lines, the company said in a notice to shippers.
Nicholas was about 10 miles (15 km) southeast of Houston by 10 a.m. Central Time (1400 GMT), heading northeast with maximum sustained winds of 45 miles per hour (75 km per hour), the National Hurricane Center (NHC) said in a bulletin.
The storm caused widespread power outages as it crossed over the Houston metropolitan area late Monday night and early Tuesday morning. About 485,000 customers were without power in Texas.
Colonial supplies roughly 2.5 million barrels a day of refined products to some of the busiest U.S. fuel markets, mostly in the Southeast and East Coast. The line also shut during Ida, but was restarted without incident a few days after the storm landed.
More than 40% of the U.S. Gulf of Mexico's oil and gas output remained offline on Monday, two weeks after Hurricane Ida slammed into the Louisiana coast, according to offshore regulator Bureau of Safety and Environmental Enforcement (BSEE).
Shell, which saw significant damage to facilities in Louisiana, said it shut production at its Perdido oil platform on Monday night due to heavy winds, and was ready to restart once a downstream facility operated by a third party restored power. The company had no plans to return staff to the facility on Tuesday.
Some 14 inches of rain fell in Galveston while Houston got almost six inches overnight and into the morning, the National Weather Service reported. Nicholas, which landed in Texas, had a much less pronounced effect than Ida on Gulf Coast refining capacity.
Most Texas refiners were operating on Tuesday. Motiva Enterprises' 607,000 barrel-per-day (bpd) Port Arthur, Texas refinery - the largest in the United States - was operating normally as Nicholas was passing over the area on Tuesday morning, said sources familiar with plant operations.
Royal Dutch Shell Plc's 302,800 bpd joint-venture Deer Park, Texas refinery was also operating normally on Tuesday, as was Exxon's Baytown and Beaumont refineries.
Texas energy company CenterPoint Energy Inc said on Tuesday that about 400,000 homes and businesses in its Houston-area service territory were without power.
Vessel traffic was idled on Tuesday morning at the Houston Ship Channel and the Calcasieu Ship Channel. The ports of Houston, Freeport, Galveston and Texas City were open with restrictions, however, according to the U.S. Coast Guard.
Some shippers expect the restrictions set by Texas and Louisiana ports while Nicholas passes through will add to ongoing import and export delays from Ida. (Reporting by Laura Sanicola; additional reporting by Erwin Seba and Arpan Varghese; Editing by Steve Orlofsky and David Gregorio)
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