Aug. 27--What a difference a storm makes.

Oil and natural gas markets shrugged off tropical storms Edouard and Fay, as the first formed too close to shore to affect much production and the second inundated parts of Florida and Georgia without threatening energy infrastructure in the Gulf of Mexico.

But the National Hurricane Center projected that Tropical Storm Gustav would pass Cuba as a growing hurricane on Saturday and be in the Gulf by Sunday morning, possibly headed for the bulk of the basin's oil and gas infrastructure. It would be the first major storm to hit the central and east-central Gulf since Katrina and Rita roared ashore three years ago.

"That'll get their attention fast," said Rick Mueller, an analyst with Energy Security Analysis in Wakefield, Mass.

Crude for October delivery closed up $1.16, or 1 percent, at $116.27 a barrel, while natural gas for September delivery rose 45.3 cents, or nearly 6 percent, to $8.278 per million British thermal units on the New York Mercantile Exchange.

"Still a long way from oil and gas infrastructure, but gas traders will be keenly focused on direction/magnitude of this summer's first storm to potentially impact energy markets," securities firm Tudor, Pickering, Holt & Co. said in a note to investors.

Gulf producers and drillers were monitoring the storm and were ready to start evacuating workers as early as today.

"We're watching it very closely," Shell Oil Co. President Marvin Odum said in an interview.

If evacuations prove necessary, the company will start transporting out workers who are not essential to drilling or production operations.

"We know how to do this," Odum said. "We have enough experience with storms coming through."

Mickey Driver, spokesman for Chevron Corp., the Gulf's largest leaseholder, also said the company will be watching Gustav closely.

"The next 48 hours will say a whole lot about where this storm might be going," Driver said.

Facilities that could be affected include some fairly new infrastructure, such as BHP Billiton's Neptune platform about 120 miles south of the Louisiana coast.

The platform, with a capacity of 50,000 barrels of oil per day, began production in early July. Neptune is just northeast of BP's 200,000-barrel-a-day Atlantis platform, which began production late last year.

Other platforms in the potential path of the storm include BP's Thunder Horse, 150 miles southeast of New Orleans. It started pumping from a single well in June after nearly three years of delays.

The platform, with the largest capacity of any Gulf installation at 250,000 barrels a day, struggled with design troubles as well as the repair of critical seabed equipment.

Also, Enterprise Products Partners' Independence Hub, operated by Anadarko Petroleum, finished its first year of production last month. The platform can produce up to 1 billion cubic feet per day of natural gas, 2 percent of all U.S. gas production.

"Obviously we've been watching it for a little while, and we'll continue to do that," Anadarko spokesman John Christiansen said of the storm.

The Gulf provides about 15 percent of U.S. natural gas production and about 27 percent of its oil production, according to the Interior Department's Minerals Management Service.

In 2005, Katrina and Rita destroyed more than 100 platforms and forced shut-ins of 92 percent of oil output and 83 percent of natural gas production.

kristen.hays@chron.com

David Ivanovich contributed to this story from Washington

-----

To see more of the Houston Chronicle, or to subscribe to the newspaper, go to http://www.HoustonChronicle.com.

Copyright (c) 2008, Houston Chronicle

Distributed by McClatchy-Tribune Information Services.

For reprints, email tmsreprints@permissionsgroup.com, call 800-374-7985 or 847-635-6550, send a fax to 847-635-6968, or write to The Permissions Group Inc., 1247 Milwaukee Ave., Suite 303, Glenview, IL 60025, USA.

NYSE:CVX, NYSE:EPD, NYSE:APC,