The contract will involve Thiess constructing a 1.2 km long tunnelled shore crossing under the ocean. The tunnel will connect two offshore gas reserves to Chevron’s greenfield LNG plant at Ashburton North, near Onslow in the state’s north west.
The Wheatstone microtunnel will be 2.5 m in diameter and will be delivered by a tunnel boring machine (TBM) and lined by pipejacking. The microtunnel will accommodate a 1.1 m diameter pipeline to deliver gas from Chevron’s Wheatstone and Iago reserves.
Thiess Tunnelling General Manager Glen Ashton said “This is an exciting project for Western Australia and Thiess is committed to engage local suppliers and subcontractors, which will in turn boost local employment and training opportunities.”
Engineering and procurement commences immediately for the design of the TBM launch shaft, jacking pipes, and TBM retrieval pit. Construction on site will commence after the cyclone season in 2013.