Shell Drilling vessel The Nobel Discoverer
Posting by “Outsider”
The incident reported today in which the Discoverer suffered some form of mooring system failure is by far the most serious incident relating to the Arctic drilling programme that you have published.
During drilling operations in water depths such as those expected by Shell, the vessel must remain in position within a watch circle of about 10m (7% of the water depth). If the vessel leaves the watch circle, the drillstring must be cut and the drilling riser disconnected at the seabed.
If a disconnect occurs at the same time as a drilling or well control incident is in progress, the potential for a catastrophe is very significant.
It appears that the vessel cannot even anchor successfully in sheltered waters and a low wind, so what hope is there that the vessel will remain on station during an Arctic storm far from the shelter of land?