Victoria Petroleum has estimated the Growler discovery could contain up to 4 million barrels of oil, which would need to be confirmed by subsequent production testing and development drilling.

Over the weekend, VicPet said Growler-1 was drilled to a total depth of 1993m without encountering any further oil shows in the Hutton or basal Jurassic sandstones. Wireline logs and side-wall cores were then run to confirm the extent of the oil-bearing sands in the basal Birkhead sands over the interval 1721-1752m.

Describing the oil recovery as “very encouraging”, VicPet managing director John Kopcheff said the preliminary drill stem test data indicated no pressure depletion occurred during the test.

“If we can string together a few more discoveries of this size in the western part of PEL 104 and 111, and there is a good chance we can do this with the drilling program over the next three months, then we will have a significant producing oil province,” he said.

“Exploration success at Growler-1 has established a new oil production target in the western part of PEL 104 and our adjoining PEL 111 permit.”

Kopcheff said the joint venture has also identified four prospects, including Wirraway and Eagle, near the Growler prospect, as well as a further nine similar prospects in neighbouring PEL 111.

Growler-1was the first well drilled by the PEL 104 joint venture in this under-explored Jurassic area of the permit, which covers the western flank of the productive Patchawarra Trough of the Cooper Basin.

The well is located 16km west of the Santos-operated Callabonna field, which also recovered oil from the Jurassic Basal Birkhead sands on drill stem test.

The PEL 104 JV comprises Victoria Petroleum (operator with a 40% stake), Impress Venture (40%) and Roma Petroleum (20%).