Persephone Rigid Riser System AC4 Review

The Scope

Woodside’s Persephone project is a tie-back of a subsea step out well to their North Rankin A Platform. As part of their OPREP process, Woodside required an “AC4” – an assurance check – for their Persephone Riser design to support their financial investment decision (FID).

The Outcome

Cube Offshore worked closely with Atteris to conduct a thorough review of structural aspects of the Persephone Risers design to support Woodside’s AC4 assurance checks.¬† Cube Offshore identified risks and opportunities where improvements could be made. Recommendations were made to minimise risks and maximise the opportunities identified.

Structural aspects included:

  • design basis
  • lessons learnt from Echo Yodel and PoG
  • fatigue
  • dropped object
  • constructability/installability
  • clamp design
  • riser supports and guides