Safety Alert
Semi-submersible MODU Total Failure During Severe Weather Event
Semi-submersible MODU Total Failure During Severe Weather Event
- IADC
- Safety Alert
- IADC Alert 22-06
- Marine OperationsStructural and Asset IntegrityVessel and Mooring
- Mechanical failureStructural and asset integrity
- Mooring operations
- Winch
- Upstream oil and gas
- Offshore installation
Summary
During severe weather on a semi-submersible MODU, an anchor winch chain lifter fractured under chain tension, releasing the anchor and tail chains to the seabed. Metallurgical analysis found a manufacturing cavity extending over approximately one-third of the cross-sectional circumference, reducing wall thickness to around half that of the unaffected portion.
Classifications: Mechanical failure; equipment failure.
Classifications: Structural and asset integrity; asset integrity; structural integrity.
Classifications: Mooring operations; berthing; unmooring.
Classifications: Winch; winches.
Classifications: Upstream oil and gas; oil and gas extraction; upstream petroleum.
Classifications: Offshore installation; offshore platform; offshore rig.
Summary
The alert concerns total failure of a semisubmersible drilling unit during severe weather.
IADC Alert 22-06. Themes: marine operations, structural and asset integrity, vessel and mooring.