The machine has covered more than 1.9 km and extracted more than 24,000 cubic metres of earth since it kicked off in April.
On Curtis Island, where the tunnel boring machine will end its journey, a reception shaft has been cleared and piling works are expected to commence during the next two weeks.
The Santos GLNG Project is a pioneering venture to convert coal seam natural gas to liquefied natural gas for export to global markets.
The project involves the development of gas fields in the Bowen and Surat Basins, the construction of a 420 km underground gas transmission pipeline from Roma to Gladstone, and a two-train LNG processing facility on Curtis Island, Gladstone.
The project is a joint venture between Santos and three of the world’s largest energy companies, PETRONAS, Total and KOGAS.