Santos’ aging buried gas gathering network had experienced some issues with the existing tape wrap external coating. Santos enaged Nacap to install new replacement flowlines and upgrade the gathering system.
The scope of work included 28 new pipelines, midline risers, 13 manifolds and above ground expansion loops that were installed in the Big Lake East and Big Lake West fields. Construction also included end of line pig launching and receiving facilities installed adjacent to the Big Lake Satellite.
The pipelines consist of one new DN350 spineline, three new DN300 spinelines, three new DN200 flowlines, four new DN150 gathering flowlines and seventeen new DN100 gathering flowlines.
Works were undertaken by a reduced size, multi-skilled composite crew comprising 80 members. All crew and plant were utilised to multiple aspects of the construction, so the crew needed to be able to adapt and change to suit whichever task was presented to them from day to day.
Other works included:
- Flanged tie in connections to live gas wells
- Installation of CP groundbeds and associated CPU’s
- Earthing of all above ground structures
- Installation of nitrogen systems for actuated valves
All works were completed under the Santos permit to work system as the construction was within a live gas field with numerous live crossings and pipelines installed in parallel to existing live gas services.