Polyester ropes can meet design criiteria to extend MODU mooring capability

摘要

In the mid 1990s, Shell (US) was challenged to drill prospects in water depths nearly twice the water depth ratings of the rigs under contract At the same time, the need to eliminate the risk of drive-off or drift-off, and the ability to disconnect in an emergency without significant capex or opex increases to accommodate storms became a challenge. Shell decided that extending the water depth capability of a moored MODU addressed all the issues. An effective upgrade to a rig's maximum water depth rating requires upgrades to both drilling and stationkeeping capabilities. Shell and its contractors developed a Pre-Installed Mooring (PIM) System to supplement the onboard mooring system and address both problems.