Spudded last Monday, Cowrie-1 was also the first onshore exploration well in six years to specifically target oil in southern South Australia.

The joint venture, which also includes Origin Energy, had previously rated the chance of success at Cowrie-1 as good.

Only a handful of wells have encountered oil in the gas-prone Otway, onshore or offshore, since exploration began in the basin in 1866 at Salt Creek in the coastal Coorong region, and only two of them have flowed oil to surface.

The Cowrie prospect was about 5km west of the 1997 Killanoola discovery, which initially flowed oil to surface unaided at about 300 barrels a day. It was then put on pump at a rate of 100 barrels a day, before the recovery fell to 25 barrels a day whereupon Origin abandoned the effort as uneconomic.