The sidetrack is being drilled to see if the joint venture partners – operator Arc and Origin Energy – can get a commercial flow from Senecio, Arc managing director Eric Streitberg said.

“Senecio is a very significant gas discovery which could have up to 50 billion cubic feet of gas,” Streitberg said.

“The flow rates from the well were puzzlingly low but we believe we tested a section with substantial formation damage.”

The sidetrack is designed to penetrate the Dongara and Wagina Sandstone reservoir through the gas column at a relatively high angle to maximise formation contact.

To minimise the formation damage interpreted from the Senecio-1 test results, a non-invasive drilling fluid will be used to drill the sidetrack, and the well will be left as an uncased completion.

Following completion of the sidetrack a cleanup flow will be undertaken while the rig is on location.

Participants in L1 and L2 (excluding the Dongara, Mondarra and Yardarino fields) and Senecio 2 are: Arc Energy (operator) 50%, and Origin Energy Developments Pty Ltd (a wholly owned subsidiary of Origin Energy Limited) 50%.