The DBNGP is a natural gas pipeline stretching almost 1600km across Western Australia from Bunbury in the south to Dampier in the North. Since construction the DBNGP has undergone a range of expansion projects , the most advanced of these have been undertaken recently , with three major expansion projects known as Stage 4, Stage 5A and the most recent, Stage 5B. These three projects were carried out in direct response to increasing demand for gas in the south-west of WA. Increasing the gas haulage capacity of the pipeline was crucial in supporting economic growth in WA.
The Dampier Bunbury Pipeline (DBP) awarded McConnell Dowell Constructors (Aust) Pty Ltd the Dampier to Bunbury Natural Gas Pipeline (DBNGP) Stage 5B Looping contract in Western Australia. Looping involves installation of pipe lengths parallel to the existing asset.
The project includes 440 km of 26” pipeline construction looping the existing DBNGP pipeline spread from Loop 0 near Karratha to Loop 10 east of Bunbury, W.A.
Construction of loops 9 and 10 required close liaison with all stakeholders including landowners, affected residents, government agencies, local councils and shires, local indigenous leaders and other affected parties.
Looping sections 0 through 8 were in remote locations from Karratha to Gin Gin and involved our teams working from remote base camps. The logistics of continually moving campsites and personnel presented one of the greatest challenges on the project.
Other challenges included:
- Extreme weather conditions including a cyclone during the construction period
- Multiple river crossings and other geological challenges
- Countless road and railway crossings (in most cases, the infrastructure had to remain working throughout the construction process)
- Zero environmental losses of both flora and fauna.
- Construction through working vineyards in the Swan Valley raising construction challenges in trying to cause minimum disruption to the vineyards and it also involved significant and ongoing input from the land management team in working with the growers.
- Works undertaken in the Perth metro area - “Ellenbrook”, a growing suburb developed around the DBNGP Corridor. The corridor is now used as parklands by the community and homes are situated very close to the corridor.
- Works were also undertaken on the ten compressor stations along the pipeline route to enable the higher flow rates of gas and ensure a reliable supply (pipeline remained online during construction)
- Hot tapping was carried out to tie the new pipeline into the existing asset. (hot tapping is highly specialised and involves welding the new lengths to the DBNGP in a live, high pressure environment)
Following a twelve month construction period the Stage 5B Expansion Project was commissioned in early April 2010. The Mac Dow team completed the project with an outstanding safety, environment and community outcome. All works were completed successfully with no impact on customer supply. The Stage 5B project added an extra 110 terajoules of per day of firm, full haul Natural Gas capacity.