Riser Securing Clamps | AH001 Ivanhoe Oil Field

Background / Challenge

• North Sea Floating vessel had been decommissioned
• Requirement to release multiple flexible risers from the platform for abandonment
• Serviceability of Remote Release Connectors (RRC) between platform and risers unknown
• Restricted vertical access to riser heads
• Design a clamp that could support the weight of the riser should the RRC fail to release
• Provide a means of riser attachment for a controlled decent to the seabed
• Engineer a means of deploying the clamps with diver assistance, around various sized risers, set at 11° angle to the vertical
• Allow for restricted vertical access

Solution

• Design and manufacture of 8 Riser Release Clamps (2 × 5”, 4 × 8”, 1 × 10”, 1 × 12”)
• Clamps hinge around riser and provide a hold open device aiding clamp deployment
• Counterbalance arms precision engineered to maintain 11° angle to riser
• Lifting points positioned on counterbalance arms aid deployment around RRC casing above riser head
• Each clamp capable of withstanding the weight of their respective riser during release and lowering phases