Reuters) - The U.S. Coast Guard was investigating a 13,000-gallon spill from an oil rig leased to Shell, operating about 26 miles southeast of last year's BP Plc Macondo oil well disaster, a Coast Guard spokesman said on Monday.
The spill of either drilling fluid or oil mixed with drilling fluid was reported Sunday by Transocean Ltd's Deepwater Nautilus rig, which was drilling a well at Shell's Appomattox discovery.
"Shell can confirm it has a loss of 319 barrels of drilling fluid," Shell spokeswoman Kelly op de Weegh said by email.
The leak was from a booster line, which provides additional drilling fluid and is separate from the well, she said.
"The leak was isolated, stopped and remedial action has been approved by BSEE (the U.S. Bureau of Safety and Environmental Enforcement), which includes temporarily abandoning the well, and making appropriate repairs," op de Weegh said.
The Coast Guard was attempting to determine what material was spilled, Coast Guard spokesman Steve Lehmann said.