In late 2010, Westernport Water awarded a channel crossing contract to Coe Drilling.

The project involved the design, engineering, procurement and construction of an 860 m, 450 mm HDPE water main pipeline to be installed using horizontal directional drilling (HDD). An additional 180 mm pipeline was also installed parallel to the crossing for future use.

Following design approval, Coe Drilling arrived onsite in late April 2011, and set up operations at the Newhaven side of the channel, on Phillip Island.

The CoeDrill 210 drilling rig was supported by a NF1000 Mud Pump and 1000 GPM Mud System.

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The CoeDrill 210 was selected as the most appropriate HDD rig to use due to the limited clearing permitted at the site. Following site establishment, the pilot hole was completed using a 6¾ inch mud motor and 9 ⅞ inch Drill Bit. The 180 mm pipeline was installed beneath the channel and used to allow controlled transfer of the drilling fluids during the later hole-opening operations.

A second pilot hole was completed and the borehole was enlarged up to 24 inch reaming pass, after which a cleaning pass was completed, ensuring the integrity of the borehole prior to the pipeline installation. The formation in which the majority of the drilling occurred was Basalt bedrock.

The pipeline was installed in late July 2011. After the hydrostatic test was completed, Coe demobilised and Westernport Water’s crew completed the tie-in connections at each side of the crossing.

The project was completed during a period of unseasonal weather with record rainfall, and its success was a credit to the Coe Drilling crew, who had the full support of the Westernport Water management throughout the project.