The achievement comes after testing of the third and final hub, near Roma, was completed and handed over to the long-term operations team.

"The construction and commissioning of these three major hubs is a significant milestone on our pathway to first LNG production around the end of the third quarter of this year," Santos vice-president Queensland Trevor Brown said.

"This is a year of delivery for Santos GLNG. Our gas field facilities are complete, our wells are performing strongly, our pipeline is supplying gas to our LNG plant, and we're approaching 95% completion overall," he said.

Work on the hubs began in 2012 and required 18.6 million work hours to complete construction and commissioning. Importantly, work was completed with an excellent safety record.

Together, the three hubs required 2900 tonnes of steel, 21,700 cubic metres of concrete, 1050 kilometres of cabling, and 105km of pipework.

The three hubs service an area of some 7000sq.km and at nameplate capacity will be able to process 555 terajoules of gas per day - the equivalent daily consumption of more than nine million homes.

Santos GLNG is a joint venture between Santos, Malaysia's Petronas, France's Total and the Korea Gas Corporation to supply LNG to global markets.

LNG sales from Qld's CSG fields began on January 5 with the first cargo commissioned from BG Group's Queensland Curtis LNG.

Already more than 1 million tonnes per annum has been sold from the first commissioned train.

In Queensland there will be six trains all up with the potential for about 25MMtpa.

QCLNG will have nameplate capacity for 8.5MMtpa, GLNG with potential for 7.8MMtpa and Australia Pacific LNG with up to 9MMtpa potential.