The Ichthys development revolves around the construction of a new 42-inch deep sea natural gas pipeline from the Ichthys field in the Browse Basin 880 kilometers to Darwin onshore. The pipeline will run through the Darwin harbor, requiring dredging services in the near shore area, rock installation and the construction of a landfall. Owner INPEX Operations Australia Pty Ltd is developing LNG process facilities on Blaydin Point near Darwin, Northern Territory of Australia.
Boskalis’ scope of work for this project included:
Design & engineering
Boskalis was responsible for the design of the trench slope based on the seabed and geophysical data available in each section.
Shore approach construction
The shore approach works consisted of the following:
- Setup of on shore site, including temporary access roads, lay down areas and office accommodation
- Design, fabrication and installation of rollers inside the trench
- Provision and installation of a 600 t socket passing linear winch
- Provision and installation of a 3,300 m long pulling wire
- Removal of 20x buoyancy modules from the pipeline
- Rock installation and backfilling
- Site reinstatement and rehabilitation
Pre-lay dredging
The pre-lay dredging works consisted of the following activities:
- Shore crossing and near-shore dredging
- Onshore dredge disposal
- Near-shore dredge disposal
- Stockpiling, disposal and treatment of acid sulphate soils
- Plume monitoring
Rock supply and installation
The rock supply & installation works included the following activities:
- Quarrying / procurement of rocks of specified grade
- Transportation of rocks to Darwin Harbour temporary stockpile area
- Load out of rocks onto offshore marine vessels
- Rock installation
Survey and positioning
Boskalis was responsible for all survey and positioning services required for the onshore and offshore scope of work, including pre and post dredging surveys, shore pull wire as-laid survey, as laid pipeline surveys, as installed backfill and rock installation surveys and land site reinstatement surveys.
