POLARCUS is halfway through what it says is the largest single 3D seismic survey ever carried out offshore Australia after starting work on it earlier this year.

The Polarcus Capreolus survey covers parts of the Roebuck basin, including the WA 435 P permit area, where Apache Energy made the Phoenix South-1 oil discovery late last year.

The discovery opened up a new oil-prone fairway within one of the few remaining underexplored parts of the north-west shelf, Polarcus said.

Polarcus will acquire at least 22,130 square kilometres of high resolution broadband 3D seismic data covering the discovery and surrounding blocks which it says are assumed to be gas prone.

The Capreolus 3D survey will provide multiple opportunities for reduced risk and play-based exploration targeting Triassic and Jurassic structural and stratigraphic traps.

Over 11,000 square kilometres of 3D seismic data has been delivered by Polarcus in less than three months so far, the company said.

Polarcus A-Class 12-streamer vessels the Polarcus Amani and Polarcus Asima have been working in simultaneous acquisition mode in order to maximise data production from the field.

The data is currently being processed through to pre-stack depth migration by DownUnder GeoSolutions in Perth, Australia, with final data products expected to be delivered within the first quarter of 2016.