The Dongara Sandstone/Wagina Formation was tested with the Century Rig 11 off site. Seven zones were perforated over a gross interval from 2785 to 2860 metres measured depth and a clean-up flow undertaken.

During the cleanup flow period, the Senecio-1 exploration well flowed gas at an initial 2.5 million cubic feet per day, which then more than halved to 1.2 million cfd within the 10-hour evaluation period, the partners said.

But Senecio-1 flowed gas to surface at varying pressures and rates and because a separator was not used, exact flow rates could not be accurately determined.

The partners had previously reported that preliminary wireline logs had recorded a 75-metre hydrocarbon column at Senecio-1. The companies expected about 30 metres to be of potential reservoir quality.

The well would now be logged to determine the extent and contributions from the perforations over the reservoir interval. A further cleanup flow may be undertaken once personnel became available, the companies said.

“This more extended clean-up flow will then allow optimum design of a production test to determine flow characteristics, gas composition and initial reserves information,” said Origin executive general manager of exploration, Rob Willink.

The Senecio-1 well is about 15 kilometres east of the Dongara Production Facility.

Participants in L1 and L2 (excluding the Dongara, Mondarra and Yardarino fields) and Senecio 1 are Arc Energy (operator and 50%) and Origin Energy (50%).