Discovered in 2005, the Halladale and Black Watch fields lie off the southwest Victorian coast and are estimated to contain a 55-petajoule recoverable gas and condensate contingent resource.

Only 4-5km offshore, the fields are about 6km from the Santos-operated Martha gas field, and about 20km from Casino and Henry. They are also relatively close to the Otway gas Project’s onshore facilities. Origin is a partner in that Woodside-operated project.

Halladale and Black Watch can potentially be accessed via extended-reach drilling from onshore, Origin said.

This would provide an economic means of tying the field into either new or existing pipelines and plant infrastructure in the area, according to managing director Grant King.

"The purchase provides Origin with the ability to undertake the necessary exploration and potential development activity to bring this small but valuable gas and liquids resource to market,” King said.

"Securing Halladale and Black Watch complements Origin's integrated portfolio strategy and provides added flexibility in managing its southern gas requirements. The anticipated reserves will be used to support Origin's existing gas retail business and the proposed Mortlake Power Station.”

The fields could potentially also be used for gas storage in the future to support winter peak demand requirements in Origin's retail businesses, King said.