Transocean Inc. announced on Thursday, Sept. 16, that its deepwater semisubmersibleDeepwater Nautilus was unaccounted for in the Gulf of Mexico in the aftermath of hurricane Ivan.
All personnel had previously been safely evacuated, and the well was secured before the storm approached. The US Coast Guard was notified of the missing rig, which had been moored to the seafloor at its location 160 mi south of Mobile, Alabama.
Later the same day, Transocean reported that theDeepwater Nautilus had been located more than 70 mi northeast of its original location. A visual inspection from a fixed-wing aircraft did not indicate any damage to the unit. Transocean says a complete assessment of the rig's condition will be made once personnel board the unit.
Transocean has reportedly accounted for all of its other drilling rigs in the GoM – five deepwater drillships and three other deepwater semisubmersibles.
Diamond Offshore Drilling Inc. saw one of its GoM semis move off station as well. The company reported that the semisubmersible drilling rigOcean Star drifted from its moored location Wednesday, Sept. 15. A visual inspection of the unit by fixed-wing aircraft confirmed the Ocean Star is afloat with no apparent damage, the company says.
According to Diamond Offshore, visual inspection by aircraft of four additional Diamond Offshore rigs that lay in the path of hurricane Ivan indicated no apparent damage or pollution. All of the well operations conducted by the rigs directly in the path of the storm had been secured and personnel evacuated before hurricane Ivan passed through the area.
TheOcean Star, which is being monitored via a satellite tracking mechanism, is 12 mi from its pre-storm location, which was in 2,423 ft. of water in Viosca Knoll. The company has initiated actions to re-board the Ocean Star to restore power and further assess its condition before moving the rig back to its operating location.
Diamond says all of its rigs operating in the GoM that were evacuated prior to the storm will be re-boarded as soon as practicable and normal operations resumed.