Government says no leaking oil at Mariner platform

Boats spray water to extinguish a fire on an oil and gas platform operated by Mariner Energy off the Louisiana coast September 2, 2010.

HOUSTON (Reuters) - U.S. government inspectors found no leaking oil at Mariner Energy Inc's burned platform in the Gulf of Mexico, officials said late on Friday, allaying fears about more environmental damage after BP's massive spill.

"Inspectors have reported no sign of pollution," the Interior Department said after government experts checked out the platform for several hours on Friday.

The inspectors confirmed that the safety valves were shut going to the platform's oil and natural wells, pipelines were closed and the platform's tanks and pumps "are secure," the department said.

On Thursday, Mariner's platform burst into flames. The accident follows BP Plc's disastrous Macondo well rupture on April 20 which caused the death of 11 workers and unleashed the world's worst offshore oil spill.

A light oil sheen had been spotted earlier near Mariner's offshore facility, but was thought to be related to Thursday's efforts to extinguish the fire, the U.S. Coast Guard said.

The cause of the fire, which forced the evacuation of the oil and gas production platform's 13-member crew, is not yet known.

Interior Secretary Ken Salazar told reporters in Anchorage on Friday the Mariner fire appeared to be "another industrial accident," and was not comparable to the BP spill.

Even so, the U.S. government promised a vigorous probe.

"We will use all available resources to ensure that we find out what happened, how it happened, and what enforcement action should be taken if any laws or regulations were violated," said Michael Bromwich, director of the department's Bureau of Ocean Energy Management that oversees offshore drilling.

The platform is located about 100 miles south of Vermilion, Louisiana, in shallow water. The facility is not affected by the U.S. government's six-month deepwater drilling moratorium, which only applies to rigs, not production platforms.

Automated shut-off equipment turned off the flow of oil and gas from the platform's seven producing wells, according to the company.

The fire was the fifth reported at offshore sites operated by Mariner since October 2006, according to government data.

None of the earlier fires caused fatalities, although workers were injured in two of the accidents. The company also suffered a blowout while drilling a well about 90 miles off the Louisiana coast in May 2008, but the situation was brought under control within a few hours.

The Vermilion platform was last inspected in January and was found to have three minor compliance violations, government data showed.

Shares of Mariner closed nearly 2 percent higher at $23.16 on the New York Stock Exchange.

(Additional reporting by Kristen Hays in Houston, Yereth Rosen in Anchorage and Tom Doggett in Washington, D.C.; Writing by Anna Driver; Editing by Sofina Mirza-Reid and Lincoln Feast)