It also marks the completion of Queensland Curtis LNG - the first of three Queensland CSG-to-LNG export projects to be commissioned.

Queensland Curtis LNG is now Australia's fourth operating LNG project. Another six projects - representing a total investment of more than $180 billion - are still under development.

In 2012-13, Australia shipped 23.9 million tonnes of LNG cargoes, earning $13.7 billion in export revenue. Australian LNG exports are expected to almost quadruple over the next few years.

By 2018, Australia is forecast to overtake Qatar as the world's top producer of LNG. When the three major LNG export projects are completed and fully operational, which is expected to occur by 2017, the Port of Gladstone will have a production capacity of 25.3 million tonnes of LNG a year.

Australian Petroleum Exploration and Production CEO David Byers said that "extraordinary technology and the emergence of a burgeoning Asian market have allowed industry to produce and commercialise Queensland's enormous gas reserves".

And, as natural gas is a "much cleaner-burning fuel than traditional energy sources, exporting gas to places such as China and India is among the most meaningful contributions Australia can make to reducing global greenhouse emissions", Byers added.

LNG is natural gas (methane) that has been chilled to -161C so that it becomes liquid. Once it has been liquefied, it occupies about 1/600th of the space it fills in its gaseous form, meaning it can be transported across the world in purpose-built tankers.

Australia's enormous natural gas reserves and Asia's demand for clean and reliable energy have seen an unprecedented level of investment in Australian projects in recent years.

"The first Queensland LNG cargo represents an historic milestone, not only for the state of Queensland, but for all the people who have worked so hard throughout the past five years to make this enormous project a reality," Byers said.

"Successive state and federal governments, local councils, agricultural bodies and community representatives have shown leadership to realise the emergence of this multi-billion dollar industry.

"Thousands of jobs have been created, regional communities have been renewed, and a long-term stream of royalties will flow to the state, which will benefit all Queenslanders."