A spokesman for Chevron Nigeria, said the bodies of the three Nigerian workers were found after the barge they were working on exploded on Sunday near the company's Opuekeba oil field.
The men were working for an as yet un-named contractor. The cause of the explosion has not yet been established.
Other workers suffered minor injuries in the blast and were treated at a Chevron hospital at the nearby Escravos export terminal, a company spokesman said.
The Opuekeba field produces up to 22,000 barrels per day, making up less than five percent of Chevron's daily Nigerian output of 450,000 barrels per day.
