THE first gas for the QCLNG project on Gladstone's Curtis Island has been transported from the Surat Basin coal seam gas fields.
BG Group announced on Monday it had successfully reached the key development milestone.
It is the first of the three LNG gas export projects worth $70 billion scheduled to come into production, dramatically altering the shape of eastern state gas markets in the process.
Due to ship its first LNG in the second half of next year, the BG project is the first to link eastern state gas markets to international markets for gas.
Delivery of first gas onto the island marks the successful completion of a two-year task to lay more than 46,000 lengths of one-metre diameter steel pipe over 540km - the longest large-diameter buried pipeline in Australia.
Arrival of first gas onto the island will allow commissioning work to begin on the first of two LNG production trains, with the work expected to begin early next year.
BG Group chief executive Chris Finlayson said having the first gas on Curtis Island in a little over three years from project sanction was an "immense achievement".
"It is a testament to the expertise and dedication of everyone working on this vast and complex mega-project," Mr Finlayson said.
"Delivering this key milestone demonstrates the advanced stage of development at the world's first coal seam gas to LNG project.
"We are now entering the final construction and commissioning phases and we remain firmly on track to deliver first commercial LNG in the second half of 2014, as scheduled and within the $20.4 billion budget.
"We have overcome many challenges along the way, and we still have more hard work in front of us, but last February I set the tough target to have first gas on Curtis Island by the end of this year, and I am delighted that we have met it."