In addition, preliminary analysis of log suites also indicated the Facies 2 zone to be gas-bearing in Heron-2, MEO said.

But MEO and partner Petrofac Energy Developments have yet to decide whether to flow-test these zones.

“Until the hydrocarbons are recovered and analysed, MEO is unable to confirm gas quality or that a recoverable resource is present in Epenarra,” the company said.

“Production testing of Epenarra can only be undertaken after the drilling – and if warranted flow testing – of the underlying Heron North structure.”

MEO said the West Atlas jack-up rig was currently running 9 5/8-inch casing to the 3360m section depth, after which drilling will restart in an 8 ½-inch hole into the Heron North/Plover formation.

Following Heron-2, the rig will move to the Heron-3 well, aimed at testing the commercial viability of hydrocarbons in a 500-metre horizontal section through the Darwin Formation, the reservoir section of the large Epenarra structure.

The Heron-2 and Heron-3 wells are targeting the two gas-bearing horizons in the Darwin formation and the deeper Elang-Plover Formation, observed in the Heron-1 well.

The two-well campaign will be funded 75% by MEO and 25% by farminee Petrofac, in return for a 10% stake in the permit.

Petrofac has an option to increase this stake to 15% by funding 37.5% of the well costs.