Arc said the well was being drilled as a deviated sidetrack of the Apium-1 discovery well, which flowed gas to surface at varying pressures and rates in June 2004.

Apium-2, which is 17 kilometres south-southeast of Dongara, was primarily targeting the Late Permian Dongara Sandstone.

The well is designed to intersect the sandstone 10m updip of the Apium-1 intersection, at a depth of about 2752m, about 70m northeast of the surface location.

The rig was expected to take 13 days to drill to a total depth of 2812m, Arc said.

Arc and Origin hold equal stakes in the L1 licence and Apium-2 well.