Troll oil pipeline: Pipelaying at the limits of today`s technology
- European Marine Contractors Ltd., Motspur Park (United Kingdom)
- Snamprogetti SpA, Fano (Italy)
- Statoil, Stavanger (Norway)
The construction of the 16-in. Troll Oil Pipeline connecting the Troll field to the Mongstad Oil Terminal is regarded as one of the most technically challenging pipeline construction projects in the North Sea to date. It started with a unique landfall approach which involved pulling the pipeline through a directionally-drilled tunnel up to the oil refinery. Subsequently the Castoro Sei laybarge fitted with a 13m ramp extension, laid away to start a 30 km section of the route through the Fensfjorden. This involved installing the pipeline with low tension onto an undulating seabed in up to 540m water depth, around tight bend radii and onto numerous pre-installed gravel berms. The {+-} 3m laying corridor through many areas of the fjord required guided lay sections, using transponder arrays, to ensure that the pipeline was carefully positioned onto the gravel supports. Outside the fjord, the pipeline was constructed across the Norwegian Trench with high tension (to ensure satisfactory pipeline conditions during operation) up to the Troll field, located 85 km from the landfall. In this paper the challenges of constructing the Troll Oil Pipeline are explained. The specific engineering analyses performed and installation procedures adopted are presented to demonstrate the degree of engineering input to ensure the success of this pipeline installation. The results achieved during the construction activities, together with the lessons learned are presented and discussed.
- OSTI ID:
- 400911
- Report Number(s):
- CONF-9606279--; ISBN 0-7918-1494-7
- Country of Publication:
- United States
- Language:
- English
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