Bureau of Resources and Energy Economics

Caswell Sub-basin

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Release Areas – W14-2, W14-3, W14-4, W14-5 and W14-23

Work program bids (W14-2 to W14-5) close 2 October 2014

Cash bids (W14-23) close 30 October 2014 (Prequalification) and 5 February 2015 (Auction)


  • Adjacent to the Ichthys and Prelude/Concerto gas developments
  • Proximal to the recent gas discoveries at Bassett West 1 and Crown 1
  • Proximal to gas discoveries at Adele 1, Mimia 1 and Echuca Shoals 1
  • Shallow to deep water depths, 100–400 m
  • Quality reservoirs and seals, multiple potential oil- and gas-prone source rocks and active petroleum systems
  • Special Notices apply, refer to Guidance Notes

Release Areas W14-2 and W14-3 are located within the Caswell Sub-basin, northeast of the Ichthys, Prelude and Concerto gas accumulations, while Release Areas W14-4 and W14-5 are located to the west of these accumulations. The Release Areas lie between 200 to 270 km from the northwest coast of Western Australia.

Release Area W14-23 consists of two graticular blocks and is located to the northeast of the Ichthys, Prelude and Concerto gas accumulations, and at its closest, is 230 km from the northwest coast of Western Australia. This Release Area is considered mature in exploration status and is available for cash bidding.

Numerous petroleum systems have been proven within the Caswell Sub-basin. Proven combined structural and stratigraphic plays include Upper Jurassic to Lower Cretaceous drape over erosional basement highs on the Yampi Shelf, Jurassic horsts/tilted fault blocks and associated drape anticlines, and Cretaceous submarine canyon fill, basin floor fans and ‘ponded’ turbidites. Organic-rich rocks with fair to moderate oil potential occur within the Plover, Vulcan and Echuca Shoals formations. Gas-prone, high-quality coals and pro-delta shales occur within the Plover Formation. Multiple construction activities are in progress, including the Prelude Floating LNG (FLNG) Project, the Ichthys Floating Production, Storage and Offloading (FPSO) Project and gas pipeline, the Browse FLNG Development and the Crux gas and liquids project.

Related documents
Document Title PDF Other Format
Release Area Map – Caswell Sub-basin PDF JPG
Geology – Caswell Sub-basin PDF DOC
Data Listing – Caswell Sub-basin   XLS
Block Listing and Block Diagram – Caswell Sub-basin PDF DOC
Regional Geology – Browse Basin PDF DOC
Bidding for an exploration permit   DOC
2014 Special Notices   DOC

Note: Due to the complexity of these figures no alternative descriptions have been provided.
Please email Geoscience Australia at feedback@ga.gov.au for alternate descriptions.