GLNG's pipeline is weeks away from completion, with the final stages of construction set to see the pipeline pushed through the under-sea tunnel at The Narrows just north of Gladstone.
The tunnel, which links the pipeline route with Curtis Island, has been filled with sea water to buoy the 42-inch diameter pipe as it is pushed through.
It is expected to take up to four weeks for about 120 segments of pipeline, each measuring 36m in length, to be welded together and pushed through the tunnel using a large hydraulic jack.
With the 420km gas transmission project in its final stages, Santos vice president downstream GLNG Rod Duke said the under-sea tunnel was a feat in itself, and was completed last month without disturbance to the local marine environment and with minimal impact to the surrounding coastal environments.
The 3.45m internal diameter tunnel is about eight metres below the sea bed.
The gas transmission pipeline is being built by contractor Saipem Australia, and the tunnel was constructed by subcontractor Thiess.