Oil and gas operators, including BHP Billiton, evacuated personnel and shut-in output from operations ahead of hurricane Gustav entering the Gulf of Mexico earlier this week.
ExxonMobil Corp, the world's biggest oil company, said it was returning crews to facilities that were not in the direct path of the storm, with some production restored.
The company had shut-in gross production of about 37 thousand barrels a day of oil and 600 million cubic feet a day of natural gas in preparation for hurricane Gustav.
A BHP Billiton spokesperson said on Thursday that production at the the 50,000 barrel-a-day Neptune facility, located about 200 kilometres off the Louisiana coast, remained shut-in.
"We're continuing to monitor the storm," BHP spokesperson Emma Meade said.
The are about 717 manned platforms located in the Gulf of Mexico, producing around 1.3 million barrels of oil and 7 billion cubic feet of gas per day.
The Minerals Management Service in the US said on September 3 that about 95.8 per cent of the oil production and about about 91.6 per cent of the natural gas production in the Gulf had been shut-in, according to reports from operators.
Sydney-based Petsec Energy was another company forced to shut-in production and evacuate all personnel from its offshore gas fields - with the exception of the Mobile Bay 900 series wells.
Petsec company secretary Craig Jones said the company would update the market by the "end of the week" but that some of the fields were still "no fly zones".
"By the end of the week we should have some people out and we'll able to update everyone," he said.
Three years ago hurricane Katrina caused extensive damage to the Typhoon rig jointly owned by BHP Billiton and Chervon after it was torn from its moorings.
Katrina hit the US coast in August 2005, killing about 1,800 people in Louisiana and Mississippi and causing billion of dollars in damage.
