Carnarvon Basin

Background

 

During September 2012, Karoon entered into a farm-in agreement with Liberty Petroleum (‘Liberty’) to acquire 100% of early stage exploration permit WA-482-P. Karoon satisfied its farm-in obligations with Liberty and was approved by the regulator and registered on title during October 2013.  


The permit is located in the Carnarvon Basin offshore north Western Australia, approximately 280 kilometres north of Karratha in water depths ranging between 400 to 2,000 metres. The permit covers an area of 13,539 square kilometres. 

 

While the permit is in a relatively underexplored part of the Basin, the permit is highly prospective for hydrocarbons and a successful drilling result would open up  new exploration plays in the Basin. 

 

The exploration program is focused on testing the presence of a working petroleum system interpreted to be generating from the oil mature early Jurassic Wigmore sub-basin source kitchen. The sub-basin contains a significant thickness of Jurassic source rocks of the same age and nature, known to charge petroleum accumulations elsewhere in the Basin. The exploration program is designed to evaluate the deeper North Rankin and the shallower Legendre formations.

 

Consistent with the corporate strategy, during May 2014, Karoon farmed out a 50% equity interest in the permit to Apache Northwest Pty Ltd (‘Apache’). As part of the farm-out, Karoon was carried for 90% of the cost of the Levitt-1 exploration well and received US$9 million in back costs. The transfer was approved by the regulator and Apache was registered on title during July 2014. Apache Northwest Pty Ltd was formerly a wholly owned subsidiary of Apache Corporation and is now part of the newly formed Quadrant Energy Australia Ltd.

 

Interest

Equity interests of the participants in WA-482-P are:

 

Karoon Gas (FPSO) Ltd    50%
Apache Northwest Pty Ltd (Operator)    50%

 

Work Program

 

As part of the early work program commitments, Karoon licensed and reprocessed existing 4,355 square kilometres of 3D seismic data and 7,251 kilometres of 2D seismic data. In addition, during 2013 Karoon completed the 2,386 square kilometres Chrysalids marine 3D seismic survey over the western section of the permit using the CGG Veritas vessel, the ‘Geo Caspian’. 

 

During January 2015, Polarcus commenced the acquisition of Australia’s largest ever off-shore basin wide high resolution broadband 3D seismic survey in the northern part of the Carnarvon Basin. The multi-client Capreolus 3D seismic survey is expected to cover a minimum area of 22,130 square kilometres, including a significant area over the eastern part of permit WA-482-P. The joint venture is licencing 5,256 square kilometres of the survey data acquired over the permit. 

 

The eastern part of WA-482-P is an area of significant interest with a number of interesting structures identified from historical 2D seismic data in a relatively underexplored part of the north-west shelf. The Capreolus 3D survey will provide high quality 3D seismic data to better define, risk and rank identified leads and compare those opportunities with other prospects and leads identified from the Chrysalids and historical survey data.

 

The first exploration well Levitt-1, was spud in July 2015 and reached a TD of 4,929 mRT during August 2015. While the Legendre and North Rankin formations were interpreted to be water bearing at this location, the well intersected good quality reservoir sands in both target zones and the stratigraphy was in line with expectations which contributes important information for Karoon’s understanding of the permit.

 

The next well commitment in the permit is slated for permit year 6, scheduled to commence during September 2017. 

 

Carnarvon Basin

 

The main targets within WA-482-P are the North Rankin, the Legendre and the Intra-Mungaroo Formations. The acreage straddles a Jurassic depocentre with good quality oil mature Jurassic source rocks seen in nearby wells and interpreted to be present over large parts of the permit.  Upcoming drilling will target structures positioned to receive migrating oil or wet gas from this source kitchen. 

 

Clastic reservoirs are interpreted to be present in early formed traps and have received hydrocarbon charge from thick Triassic and Lower to Middle Jurassic source rocks in depocentres mainly in the north and east of the Permit. A key element of the work program is to identify prospects unbreached by structural events from late Jurassic onward.

 

 
 

Maps

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Map Carnarvon Basin

Projects