Route Selection – Pluto LNG Project

Background

The operator of the Pluto Project, Woodside Energy Ltd, selected the route for the 36 inch and 4 inch diameter gas export trunkline system which feeds the Pluto LNG plant in Karratha, Western Australia. Atteris was commissioned by Woodside to assist with the route selection through the particularly challenging nearshore area called Mermaid Sound.

Work Performed by Atteris

In close collaboration with engineering staff from Woodside Energy, Atteris optimised the pipeline route, and developed engineering solutions for the many challenging areas, which included:

  • Rough seabeds with exposed limestone rock formations
  • Erodible calcareous seabed silts and sands, including “glay soils”
  • Two existing large diameter high-pressure gas trunklines
  • Several major shipping channels, of which one needed to be crossed
  • A dredged material dumping ground
  • A shoreline comprising igneous hard rock
  • Simops, including the construction of a new LNG offloading jetty and a new shipping channel.

Benefit

The final pipeline route, which was developed in collaboration between engineers from Woodside Energy and Atteris, resulted in the most cost-effective solution, with manageable levels of risk and limited environmental impact.