Decommissioning

Over the last twenty years, DNV has provided support to platform removal operations from desktop assessments through offshore supervision to the provision of staff for package, environmental and safety studies and publication of decommissioning industry - Recommended Practices.   

Decommissioning activities supported have ranged from entire platforms in the Northern North Sea to individual packages and isolated appraisal wells. These exercises have also included risk-based verification methods in decommissioning projects for the dismantling and removal of major topsides where a risk-based verification approach aims at balancing the efforts to control the operational and technological risks.   

Key projects have included:

• Murchison
• Frigg
• Welland
• Asgard
• Brents
• Ekofisk
• Amethyst
• Maureen
• NW Hutton. 

Engineering and preparatory work 

  DNV has provided substantial engineering and management services:

• Offshore condition and readiness surveys
• Environmental impact assessments
• Preparation of hazardous materials inventories
• Technical and marine reviews of equipment and vessels
• Design checks on structural and marine aspects of operation
• Support in presentation of safety case submissions to regulatory bodies (UK – DECC and HSE)
• Technology qualification of new concepts and solutions in decom.

Offshore supervision 

• DNV typically provides offshore supervision through both client representatives and marine warranty surveyors
• On the platform before and during lifting operations
• On the lifting vessel from prior to field entry through to demob
• Including on site approval of marine operations
• May include a presence during towage for critical operations.