Ekofisk pipelines undergo requalification
- Phillips Petroleum Co. Norway, Stavanger (Norway)
- Det Norske Veritas AS, Oslo (Norway)
Requalification of 19 pipelines and 29 risers in the Ekofisk field required new approaches for loads, capacities, and deterioration evaluations and predictions. Requalification is a re-assessment of an installation`s design with changed design parameters so that the facility can continue to operate. In some cases, original design requirements may have been unrealistically conservative. The Ekofisk field experienced seabed subsidence as a result of compaction of the producing formation. A total of 25 pipeline systems with diameters of 6--36 inches now run within the subsidence bowl. The existing pipelines and the risers had to be requalified because of new design conditions. The paper describes Ekofisk subsidence, reasons and regulations for requalification, structural design, materials and corrosion, deterioration mechanisms, subsidence effects, calculation of forces, capacities, accumulated strain, local buckling, and mine lessons learned from the requalification projects.
- OSTI ID:
- 376266
- Journal Information:
- Oil and Gas Journal, Vol. 94, Issue 39; Other Information: PBD: 23 Sep 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Statpipe experience reveals techniques for seabed problems
Troll Phase I pipelines: Tie-ins to the subsea tunnel