During the summer of 2008, Heerema's semi-submersible crane vessel Hermod and a small fleet of transportation barges successfully removed the topsides modules from the North West (NW) Hutton platform. The NW Hutton platform was commissioned in 1983 and lies in the northern North Sea in 143m of water roughly half way between Shetland and Norway. The 17,000 tonnes eight leg steel jacket supported a modular topsides with a combined dry weight of approximately 20,000 tonnes. Removal of NW Hutton represents one of the most challenging decommissioning projects tackled by the offshore industry to date.

This paper describes the preparation phase and actual removal of the topsides, including the associated transportation and load-in phases. Topics covered include:

  • History of N W Hutton

  • Decommissioning Philosophy

  • Normally Unmanned Installation Phase

  • Topsides Removal; Engineering and its Challenges

  • Topsides Removal and Transportation; Execution of Work and its Challenges

  • Key Lessons

Overall the topsides removal project was completed safely with no significant Health Safety or Environmental issues despite the very significant offshore scope. Success factors included:

  • A dedicated client team ensuring compliance with standards

  • Pre-agreed go/no go gates and the authority for those gates

  • extensive planning,

  • detailed on-site reviews, and

  • close co-operation between HMC and BP.

Keywords:
strategic planning and management, project management, Upstream Oil & Gas, platform, Engineering, recycling, execution, Offshore, steel jacket, cargo barge
Subjects:
Safety, Strategic Planning and Management, Project management
Copyright 2009, Society of Petroleum Engineers
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