Dampier Sub-Basin Exploration

Octanex holds a 25% interest in each of WA-323-P and WA-330-P following a farmout of 75% of the 100% interests originally held in both of these permits.

The Operator of the permits and of the Dampier Joint Venture is Santos Offshore Pty Ltd (Santos), a subsidiary of Santos Limited (ASX code: STO).

The initial 6-year term of both permits expired on 21 December 2010 and renewals for their first 5-year terms were granted by the then Designated Authority commencing on 6 April 2011. The renewed permits each compromise four graticular blocks (approximately 646 km2 or 159,630 acres in total).


The general region is proven for the formation, location and production of both oil and natural gas. Major commercial discoveries in proximity to the permits include the giant gas and condensate fields of the North West Shelf (Goodwyn, North Rankin and Perseus) and the significant oil fields of Lambert, Wanaea and Cossack are in the north of the region. More recently, new and sizeable gas discoveries have been made immediately west of the permits at Julimar, Brunello, Brulimar, Xena, Pluto and Wheatsone, while the Lady Nora and Pemberton discoveries have been made to the north.

The Winchester-1/ST1 discovery well was drilled from a location within WA-323-P during 2013. The estimated size of the Winchester discovery, by itself, is considered to be insufficient to be developed economically. Further contributions from possible deeper or adjacent hydrocarbon zones to the Winchester location would be required to augment the discovered resource. The Winchester discovery is located near existing pipeline and processing infrastructure and likely future infrastructure extensions.

There is further prospectivity in the Parker tilted fault block where the Parker-1/ST1 well in WA-330-P, located 3.2 km to the northeast of Winchester-1/ST1, drilled a separate structure and encountered gas shows in Triassic Mungaroo Formation sandstones over a 211m gross interval.

The 720 km² Winchester 3D seismic survey has been reprocessed with the purpose of obtaining better resolution and definition of Triassic and Jurassic targets within both the WA-323-P and WA-330-P permits.  A large Triassic prospect remains untested below the TD of the Winchester-1/ST1 well within the Winchester structure and AVO supported Triassic leads exist in north western WA-323-P on the Wilcox/Lady Nora/Rankin Trend. In WA-330-P there are Triassic and Jurassic targets that were poorly imaged on the original Winchester 3D.  These include the structure penetrated by the Parker-1/ST1 well that contained Triassic sandstones with good gas shows over 211m gross interval and there is the potential for similar structures along the Parker Terrace towards the Dixon oil and gas discovery.

During the quarter the First phase of the Davros 3D BroadSeis and BroadSource multi-client survey was completed in the Northern Carnarvon Basin. The completed survey area includes WA-323-P and WA-330-P and the Operator has licensed the data over these permits.

Octanex is carried by Santos though all exploration activity in the current term of each permit.

Other activities in the Carnarvon Basin