In April 2003, the Brookfield Multiplex – Saipem Joint Venture (MSJV) was awarded the contract for the installation of the gas export pipeline from the Bayu Undan Drilling, Production & Processing (DPP) Platform in the Timor Sea to the Wickham Point Liquefied Natural Gas (LNG) plant located in Darwin.
The pipeline, at 502 kilometres in length, was at the time, the longest subsea pipeline ever installed in Australian waters.
The initial step was to address the installation engineering, methodology and permit approvals. This coincided with the organisation and delivery of 502 kilometres of 26 inch (660mm) OD concrete coated pipes in Kuantan, Malaysia. Brookfield Multiplex oversaw the transport and shipment of the coated pipe to the Semac 1, a semi-submersible pipe-lay barge operated by Saipem.
Prior to the pipe being laid, the seabed was prepared. This included pre-sweeping, trenching and rock dumping to cut a clear swathe for the course.
The welding and laying of the 26’ inch Outside Diameter (OD) pipeline from the Semac 1, including the tie-in to the operational DPP Platform, was a 24-hour operation. The pipe was then stabilised with rock-dumping, trenching and installation of free-span supports, and installation through the shore to a tie-in point/isolation valve.
Practical completion for the Bayu to Darwin Pipeline Project in 2005 saw the pipeline up-and-running within schedule and successfully pressure tested for the receipt and transport of gas from the offshore platform to the Darwin LNG facility.
The Brookfield Multiplex joint venture successfully installed the longest subsea pipeline in the southern hemisphere and the longest ever installed in Australian waters.