Amir Hamad bin Khalifa Al Thani on Tuesday lifted up a light bulb in the shape of an oil drop to inaugurate the Train Three Project, which has seen $2.3bn of investment in both Qatar and India.
"This is the world's largest LNG train with a production capacity of 4.7m tonnes per annum," said Qatari Energy Minister Abd Allah bin Hamad al-Attiyah.
The deal has been a groundbreaking agreement due to the sheer size of supplies involved.
"The vision that the Qatari and Indian governments share is to transfer a safe and reliable and environmentally friendly source of energy from one country with an abundance of supply to another with a huge and growing demand," said al-Attiyah.
All output of train three, which refers to the series of gas treatment and cooling units, will go towards fulfilling a July 1999 agreement to supply 7.5m tonnes of LNG per year, over a period of 25 years to the terminal at Dahej in the north-western Gujarat state.
It will meet energy demand in that state and the southern Kerala state.
Qatar pumped $1.3bn into the project. India spent $600m to build the Dahej terminal and $200m on pipelines. The remaining money goes to leasing tankers.
"This is the world's largest LNG train with a production capacity of 4.7m tonnes per annum"
Abd Allah bin Hamad al-Attiyah,
energy minister, Qatar
Qatar's giant North Field has recoverable reserves of more than 900 trillion cubic feet (25 trillion cubic metres) of gas, the third largest in the world. It plans to boost annual LNG production to 60m tonnes by 2010 from the current 18m.
Qatar on Tuesday also signed a $6bn memorandum of understanding with South African-US partnership Sasol-Chevron for three gas-to-liquid (GTL) projects.
One project involves the $1.4bn expansion of a GTL plant from 34,000 to 100,000 barrels per day (bpd), while another is a $4.5bn project to build an integrated facility to produce 130,000 bpd of GTL, al-Attiyah said.
The third project is to produce a GTL by-product at a cost of $150m.
"I welcome these projects and I welcome the participation of Sasol-Chevron. We are working hard to realise the ambition of the state of Qatar to become the GTL capital of the world and these projects will make an important contribution to achieving that aim," the minister said.