The US Coast Guard rescued 28 oil workers from an offshore platform in the Gulf Of Mexico on today after a fire broke out.
No one was reported hurt in the incident, but pilots noted a 1.4 nautical mile (2.6 kilometer) "rainbow sheen" on the water.
"The well was shut in and production has ceased," a Coast Guard statement said.
"The platform has an estimated 4,000 barrels of crude oil on board in storage tanks.
"Initial response vessels are on scene with additional vessels en route."
The rig is in the Breton Sound, southeast of New Orleans, near a bank of islands that form the Breton National Wildlife Refuge.
It was not immediately clear if Friday's incident would cause large-scale pollution.
In 2010 an explosion on the Deepwater Horizon rig further off the Louisiana coast caused millions of barrels of oil to pour into the Gulf.
