Decommissioning

DNV is now one of the most experienced engineering consultancies in many of the key areas of 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.

Find more information here

DNV-RP-E103 Risk-based abandonment of offshore wells

The objective of this recommended practice (RP) is to provide a risk-based framework for well abandonment design and permanent offshore well abandonment.