Sept. 19 (Bloomberg) -- The Energy Department's Sept. 24 inventory report may show that U.S. gasoline supplies fell 8.5 million barrels from a four-decade low as Texas refineries assess damage from Hurricane Ike, a department official said.

``Probably the max is an 8.5 million draw in gasoline because demand is down, and it could be as low as 6.5 million'' barrels, John Duff, survey manager for the Energy Department's weekly petroleum status report, said in an interview. The report will show ``the real impact of the hurricane on the refining sector,'' he said. Supplies will fall ``substantially.''

Gasoline stockpiles dropped 3.31 million barrels to 184.6 million in the week ended Sept. 12 as the storm forced refineries with about 20 percent of the nation's fuel-processing capacity to shut, the department's weekly inventory report on Sept. 17 showed. Supplies were the lowest since November 1967, according to Jonathan Cogan, a department spokesman.

``That reporting period closed before Hurricane Ike hit and shortly after the refineries starting shutting down, so refineries only lost one-seventh of their operations during the week of Sept. 12,'' Duff said.

A decline of 8.5 million barrels of gasoline in next week's report, covering the week ended today, would be 4.6 percent of the total.

Inventories fell 6.5 million barrels in the week ended Sept. 5, and four of those seven days were affected by refinery shutdowns from Hurricane Gustav, which made landfall on the Louisiana coast on Sept. 1.

Reduced Demand

Demand for gasoline in the U.S. dropped 2 percent to 8.91 million barrels a day last week, the lowest since January 2006, the Sept. 17 report showed. Duff expects next week's report to show demand of about 8.8 million to 9 million barrels a day.

``How much inventories fall will depend on the demand and on imports,'' Duff said. ``This is going to be temporary and fortunately it's happening when the demand is temporarily low, both because it's seasonal and because of the weakness in the economy.''

U.S. crude-oil stockpiles fell 6.33 million barrels to 291.7 million barrels last week, according to the Energy Department. It was the fourth-straight inventory decline.

Crude oil inventories may be little changed in next week's report because refineries were shut and not using their crude, Duff said.

``I suspect the following week you'll see things slowly returning to normal,'' he said.

The Energy Department said yesterday that 12 Gulf Coast refineries with a total operable capacity of 3 million barrels of crude oil daily were shut in Louisiana and Texas, four plants were restarting and eight were running at reduced rates.

To contact the reporter on this story: Barbara Powell in Dallas at Bpowell4@bloomberg.net.

Last Updated: September 19, 2008 09:35 EDT