Comprehensive management plans were prepared for the project covering OH&S and Environmental Management as well as all aspects of the drilling and marine procedures including project risk analysis, engineering analysis covering stress analysis and marine mooring analysis for the marine spread.
Work commenced with mobilisation of the CoeDrill 180 Drilling Spreads direct from another successful shore crossing project in Western Australia. A drilling water supply system was installed from a nearby dam to the drilling site to provide a continuous supply of water for mixing drilling fluids at the site.
The final design of the outfall involved installing a DN 450 HDPE 100 PN 16 pipeline from onshore behind the coastal dune system to terminate 750 m offshore in ten metre water depth. The offshore diffuser was selected as a DN 450 16 mm coated steel pipeline 108 m in length secured to the seabed with galvanised piles at nine metre centres and with 16 outlet diffuser ports.
The location of the drilling site within Cape Liptrap Coastal Park managed by Parks Victoria and the conditions of consent for the project meant that fabrication of the HDPE pipeline and steel diffusers were not possible at the HDD Site. This work would be completed remote to the drilling site at Andersons Inlet near Inverloch some 20 km along the coastline. Selection of the fabrication site was based on access and approvals by Gippsland Ports.
On site at Mahers Landing Road Inverloch, Coe Drilling fabricated the 750 m long DN 450 HDPE 100 PN 16 pipeline onshore in readiness for the 20 km seaward voyage to the offshore HDD Exit Location. A marine spread was mobilised to the site complete with air diving spread to complete the underwater connection of the HDPE pipeline to the HDD drill string.