The National Hurricane Center in Miami reports that Hurricane Isaac, a Category 1 storm, was moving slowly toward the northwest after making landfall late Tuesday in southern Louisiana.
Sustained winds of 80 mph were expected from the storm, which was expected to weaken at it moves inland toward Arkansas.
Oil companies in the Gulf of Mexico evacuated staff from offshore installations well ahead of the storm.
Cinnamon Odell, a rig analyst for consultant company IHS, said operators and rig contractors working in the gulf were braced for Isaac long before the storm approached the region.
"Once the storm passes, people will be sent out to determine the extent of any possible damage," she said in a briefing note. "Once it is deemed safe to return, personnel will begin returning in a phased fashion and operations will gradually start back up."
The U.S. government reported that around 65 percent of the offshore drilling rigs in the U.S. waters of the Gulf of Mexico were shut down ahead of Isaac. Onshore refinery production was curbed as a result of the storm.
The U.S. Bureau of Safety and Environmental Enforcement estimates that around 1.3 million barrels of U.S. oil production and 3 billion cubic feet of natural gas were missing from daily production because of the storm.