The initial cleanup flow was undertaken without a separator, making it impossible to precisely determine flow rates. But the well was flowed at varying pressures and rates. The calculated rate on a 40/64-inch choke was 7 MMscfd with a wellhead pressure of about 700psi. The well was still unloading some fluid at the end of the flow period.

“This is an extremely encouraging result and the well will now be connected to the nearby Dongara-24 flowline and produced to the Dongara gas processing plant for a test period to acquire reservoir and production data,” said managing director Eric Streitberg.

“Long-term flow rates are required to be able to accurately determine the potential reserves of the Arranoo pool accessed by Dongara-31. This result is particularly important for Arc in that the company has 100% of the production in contrast to the other recent gas discoveries where ARC is a 50% partner.”

Streitberg said this prospect represented a significant advance in Arc’s drilling capabilities with the reservoir being drilled at an angle of 60 degrees and a lateral being completed off the main well bore. This gave a four-fold increase in exposure to the reservoir compared to the previous vertical wells drilled in the reservoir.

“It is understood to be the first time that multiple reservoir well bores have been completed from a single well in onshore Western Australia,” he said.

More wells could be possibly drilled to access additional reserves of gas and oil in the Arranoo pool, he said.

“Century Rig 11 is now drilling the Eremia-3 oil appraisal well allowing the potential for drilling a further Arranoo well to be considered,” Steitberg said.

The Eremia-3 well, which spudded last Friday, is intended to appraise the southern extent of the Eremia field.

It is being drilled as a deviated well. Its surface location is adjacent to the Eremia-1 well and the target top Dongara Sandstone intersection is about 460m south-west of the surface location.

The depth to the prognosed top of the primary objective Dongara Sandstone is about 2060m measured depth. The prognosed top of the well is 2160m measured depth and is expected to take 16 days to drill on a pre-completion basis.

Interests in the L1 and L2 permits (excluding the Dongara, Mondarra and Yardarino fields but including the Eremia field) are Arc Energy 50% and Origin Energy Developments Pty Ltd 50%.