Mooring failures during hurricanes Ivan, Katrina, and Rita caused 16 deepwater MODU’s to go adrift. Drifting MODU’s can potentially damage other critical elements of the offshore oil and gas infrastructure, e.g., colliding with floating or fixed production systems and transportation hubs, or damaging pipelines by dragging anchors. The health of this infrastructure has become a matter of national significance because of the importance of deepwater production for the US oil and gas supply and its influence on worldwide process.
The objective of this research project was to investigate technical solutions that could (1) prevent the total drift-off of a MODU by intervention during the progressive failure of a mooring system during a hurricane, and (2) control or reduce the drift of an unmoored MODU in a hurricane. The approach taken for this study was to:
- develop & calibrate models that could describe the progressive failure of a mooring system and the movement of a drifting MODU,
- develop mitigation ideas to prevent total mooring failure and drift-off and to control drift
- use these models to assess the expected effectiveness and applicability of these and other mitigation ideas,
- formulate a plan to develop the more promising ideas into solutions that could be applied in MODU drilling practices
This project could lead to cost-effective technical options to mitigate MODU drift due to mooring failures in hurricanes and reduce the hazards and risks to the offshore infrastructure (e.g., floating and fixed production structures, pipelines and flowlines, subsea well systems).