Somare was onsite to turn the well head at the historic discovery, which prompted a 100m high flare.
He urged InterOil to start commercial production as soon as possible, with the Elk reserves to form the basis of a $US3.3 billion liquefied natural gas project.
“This is one of the happiest moments of my time as Prime Minister of PNG,” Somare said.
Both InterOil and the PNG Government are optimistic about the prospects of finding oil under the gas reserve.
Elk was flowing at 100 million cubic feet of gas and gas liquids per day, which InterOil said could indicate a presence of a new PNG petroleum basin.