Inpex, though a regional subsidiary, is working alongside ConocoPhillips and operator Chevron at the field located about 745 miles north of Jakarta in the Natuna Sea in shallow waters.
The company said the South Belut field has the potential to produce as much as 120 million cubic feet of natural gas per day.
Gas produced from the field will be sent to the market in Singapore through an existing pipeline tied to other fields in service in the region.
"The production from the field will contribute significantly to secure long-term sales volumes of natural gas from the Block," Inpex said in its Wednesday announcement.
Natural gas production in Indonesia increased by more than 20 percent in the decade ending in 2012, the U.S. Energy Information Administration reports. The country exports about half of its natural gas and is one of the largest exporters of liquefied natural gas in the world.