Interpretation of wireline logging data has confirmed oil saturations over a gross Dongara Sandstone/Wagina Formation interval of about 20 metres between 2,293 metres and 2,313 metres measured depth. Up to 11 metres of this interval is interpreted to have the potential to produce oil.

But wireline pressure data however indicates that the reservoir quality is poor.

The well will now be cased for later production testing to determine the deliverability and commercial significance of the hydrocarbons, according to Arc managing director Eric Streitberg.

“Evandra-1 is the first exploration well to be drilled on the basis of the recently acquired Denison 3D seismic survey,” Streitberg said.

“The presence of an oil column in this well has validated the exploration model, including the Denison 3D survey, and the overall prospectivity of the area.

“But reservoir quality was the biggest pre-drill uncertainty in this well as it is in an area where prediction of reservoir quality is difficult due to the early stage of exploration in the area.”

While Evandra’s reserves were likely to be modest, and needed to be confirmed through production testing, the well could be quickly brought onto production using the joint venture’s mobile early production system (MEPS), according to Streitberg.

“MEPS has been specially designed and constructed to allow the early production of oil discoveries made in the course of the drilling program on the Denison 3D survey,” he said.

Evandra-1 is about 12.5km south-east of the town of Dongara and 3km south-east of the Jingemia oil field.

Participants in L1 and L2 (excluding the Dongara, Mondarra and Yardarino fields) and Evandra-1 are Arc Energy Limited 50% (operator) and Origin Energy Developments Pty Ltd 50%.