Santos Ltd said that its fourth rig, Ensign 965, has started operations in the Cooper basin in Australia, according to an Aug. 13 release.

The rig will drill eight wells starting with four deviated wells in the Big Lake field then move on to four appraisal wells in the Moomba South. The addition of the fourth rig will allow the company to drill almost 90 wells in the Cooper basin this year, the most since 2014.

"As Santos has become Australia's lowest cost onshore natural gas developer, reducing development well costs by more than 40 per cent in the Cooper since 2015, we now have the right cost base to invest in making the most of the vast discovered resource base of Cooper Basin natural gas," Santos CEO Kevin Gallagher said.

In its second quarter, the company produced 14.2 million barrels of oil equivalent, which was higher than the previous quarter due to strong production from the Cooper Basin and Western Australia gas, combined with the restart in PNG LNG production following major earthquake activity in February.

The firm said that it is on track to supply 70 petajoules of gas into the Australian east coast domestic market in 2018, which would meet approximately 13% of projected demand.