Santos Mutineer Exeter – Rig Operations Support

The Scope

Santos were running well operations in the Mutineer Exeter field using the Maersk Drilling operated NH6 drilling rig.  3no. existing Debris Caps were to be removed from Trees for well intervention then replaced with new Debris Caps on completion of operations.  Santos required detailed running schematics for the removal and reinstatement of the Debris Caps.  Lift Plans and Certificates were needed for all new and existing equipment.  Cube Offshore were challenged with certifying the existing Debris Caps for an offshore lift on retrieval to the NH6 so they could be safely demobbed to shore.

The Outcome

Cube Offshore generated detailed running / retrieval schematics for the Debris Caps and identified any clash issues for rectification.  A particular challenge was efficiently meeting Santos’ lifting specifications prior to back-loading the Debris Caps which had been subsea for several years.  Santos lifting specifications required NDT & visual inspection of lifting points prior to backloading.  This would have meant time and cost implications offshore whilst the Debris Caps took up valuable rig space needed for other equipment.  Cube Offshore developed a lifting arrangement which did not rely on the existing Debris Cap padeyes but instead used newly fabricated and tested corner posts so they could be de-mobbed immediately after retrieval.

Debris Cap lifting posts attached to shipping skid

Debris Cap slotting over lifting post arrangement

Trial lift of debris Cap using lifting post arrangement

Extract from detailed Debris Cap running schematics on Maersk NH6

Certfied lift rigging supply