Midwest oil refineries are planning a heavy load of maintenance this autumn that could keep fuel supplies in the heartland tight through the rest of the year, according to a Reuters survey released Thursday.
Other regions of the United States, however, could see a lighter-then-normal fall maintenance season after many plants completed their overhauls earlier in the year -- taking some of the pressure off thin fuel stocks in the world's biggest energy consumer.
U.S. gasoline supplies are running about 8 percent below last year's levels due to the persistent refinery outages, with Midwest stocks 9 percent below a year ago, according to the most recent government data.
Experts said the focus of refinery maintenance in the Midwest region comes after plants in the area kept running to take advantage of sterling profit margins while other refineries continued a prolonged recovery from coastal hurricanes in 2005.
"The Midwest has hung on for so long after Katrina that there is a lot there that never went down," said Mark Routt, an analyst with consultancy group ESAI in Massachusetts.
September is expected to be the heaviest month for Midwest refinery maintenance, with 351,000 barrels per day of the region's 8.27 million bpd of crude distillation capacity scheduled to shut.
Supplies of gasoline and diesel in the northern tier of the Magellan Pipeline, which runs from Houston to Minnesota are expected to be extremely constrained as two of top refineries are seen going out concurrently.