NEW ORLEANS — Royal Dutch Shell says it is confident a 10-mile oil sheen spotted in the Gulf of Mexico off the Louisiana coast didn’t originate from its operations in the area.

In a statement today, the company says it found no sign of leaks and ruled out any well-control issues associated with its operations. The sheen was spotted late Wednesday.

A Coast Guard helicopter with a pollution officer on board was heading out this morning to the site, about 130 miles southeast of New Orleans, in an effort to determine the source of the oil.

Shell estimates the sheen at six barrels of oil, or about 252 gallons. The company sent a response ship to skim the area as a precaution.

The company has two production platforms in the area.