Petroleum retention lease WA-91-R revoked over Western Poseidon block

The Commonwealth–Western Australia Offshore Petroleum Joint Authority has revoked the declared location over the Western Poseidon block, on the grounds that the block is no longer the subject of a petroleum retention lease. The revocation was published in the Government Notices Gazette (C2026G00588) registered on 2 September 2026.

The notice was made under subsection 132(3) of the Offshore Petroleum and Greenhouse Gas Storage Act 2006 and takes effect on the day it appears in the Australian Government Gazette.

Revocation of the declared location

The declaration of a location over the block is revoked because the underlying petroleum retention lease has lapsed or otherwise ceased to apply. Under the Act, a declared location can only remain in force while the block is subject to a valid retention lease.

The affected block is identified as follows:

• Block No.: 1465 (part)
• Map Sheet: SD51 (Brunswick Bay)
• Name: Western Poseidon

This block was the subject of Petroleum Retention Lease WA-91-R.

Signing authority

The instrument was signed by Nicole Lynette Filbay, Delegate of the National Offshore Petroleum Titles Administrator, acting on behalf of the Commonwealth–Western Australia Offshore Petroleum Joint Authority.

The Joint Authority is the body established under the Offshore Petroleum and Greenhouse Gas Storage Act 2006 to administer offshore petroleum titles in the waters off Western Australia, jointly exercising Commonwealth and State powers.

Effect of the revocation

With the declared location revoked, the block reverts to the ordinary status of an area not covered by a declared location, and any rights that depended on that declaration cease. Offshore petroleum title holders and prospective applicants should note that the block is no longer held under retention lease WA-91-R.

The revocation is effective immediately upon publication in the Australian Government Gazette on 2 September 2026.

Source: Commonwealth of Australia Gazette, Government Notices, 2 September 2026, notices (official reference: C2026G00588).