The U.S. Minerals Management Service said on Saturday that 10,300 barrels per day out of 1.3 million barrels in Gulf of Mexico oil production was shut in due to the threat of Hurricane Dean.
About 16 million cubic feet out of 7.7 billion cubic feet of daily natural gas output in the Gulf of Mexico has been shut, said the agency, which oversees offshore energy production.
So far, one production platform and two drilling rigs have been evacuated due to the storm.
Oil majors Exxon Mobil, Shell Oiland ConocoPhillipssaid they were evacuating workers on Saturday.
Exxon said production was not cut on Saturday as it pulled non-essential workers from the Gulf.
Shell said 300 more support workers were being taken from the Gulf Saturday.
"Since the beginning of the week, Shell has evacuated approximately 460 people," the company said in a statement. "Evacuations are expected to continue through the weekend."
Shell has shut in daily production of 10,000 barrels of oil and 15 million cubic feet of natural gas, the company said.
ConocoPhillips was evacuating non-essential workers from the Magnolia platform on Saturday ahead of a possible shutdown on Monday, the company said in a statement.
Offshore production and well operations were unaffected by the evacuations, Conoco said.
Conoco did not expect Dean to affect onshore production in southeast Louisiana. The Magnolia platform is about 165 miles south of the central Louisiana coast and can handle 50,000 barrels per day in oil and 150,000 cubic feet of daily natural gas output.
Leading driller Transoceansaid staff on its drilling rigs had been reduced by about 360 people in the last two days.
Two of the company's rigs in the western Gulf were to be evacuated by Monday, Transocean said.
BPplanned to take workers from offshore platforms throughout the weekend, the company said on Friday.
Murphy Oilalso said on Friday workers were being evacuated.
Non-essential workers are taken first to ensure there is room for workers essential to production aboard helicopters flying from the U.S. coast when it becomes necessary to close to valves so the wells stop producing.