Feb 27 (Reuters) - The U.S. Coast Guard was responding to a report that a crewboat struck an inactive wellhead off the Louisiana coast, and that the platform was discharging an unknown quantity of an oily-water mixture, the agency said on Wednesday.
It said reports indicated a 42-foot (13-metre) crewboat, the Sea Raider, had struck a wellhead owned by Swift Energy on Tuesday evening, and that the energy company had said the wellhead was shut down in 2007.
A small sheen had developed, Ensign Tanner Stiehl said.
"We don't know the specific oil content," said Stiehl.
The Coast Guard was working with federal, state and local agencies plus Swift Energy on the response.
Swift Energy had no immediate comment but said it would issue a statement soon.
The incident occurred about nine miles (15 km) southwest of Port Sulphur, a small town along the lower Mississippi River some 50 miles (80 km) south of New Orleans.
There has been a heightened awareness of spills of any magnitude since the Deepwater Horizon disaster that killed 11 rig workers and spilled millions of barrels of oil into the Gulf of Mexico in 2010.
Oil giant BP is currently on trial in a civil case in New Orleans over the spill.
Potential liabilities stretch into the tens of billions of dollars if the judge determines BP or the other defendants were grossly negligent. Oil came ashore from Texas to Florida, threatening livelihoods and state economies dependent on seafood and tourism.