A planned storage capacity of 10 million tonnes of CO2 per year moves closer to reality after the Australian government declared an identified greenhouse gas storage formation for INPEX's Bonaparte carbon capture and storage project, roughly 260 km offshore Darwin in the Northern Territory.

The declaration, issued for the storage site within greenhouse gas assessment permit G-7-AP, confirms the technical viability of the proposed CO2 storage formation. For the Bonaparte CCS joint venture, it converts a geological concept into a state-endorsed storage prospect — the regulatory footing the venture needs before it can move into front-end engineering and design.

INPEX Browse E&P Pty Ltd, operator of the joint venture with a 53% interest, received the declaration. TotalEnergies CCS Australia Pty Ltd holds 26% and Woodside Energy Ltd holds 21%.

What does the declaration change?

In practical terms, it settles the question of whether the formation can physically hold injected CO2 at the scale the venture proposes. The joint venture will now continue technical, environmental, regulatory, and commercial activities as it advances the project toward development.

The declaration also adds momentum to a project that already carries government backing. Bonaparte was the first project to receive major project status from the Australian government in 2025.

For practitioners, the takeaway is simple: the storage resource is now confirmed as technically viable, and the project's remaining risks sit in regulation, engineering and commercial terms rather than geology.

Where does the project stand in the development chain?

Pre-front-end engineering and design began in April 2025. First CO2 injection is targeted for the early 2030s, subject to regulatory approvals and commercial agreements.

That timeline places Bonaparte squarely at the pre-FEED, appraisal-advancement stage — not yet a sanctioned project. The venture has not taken a final investment decision, and the injection startup date depends on permits and customer contracts still to be secured.

The designed capacity of up to 10 million tonnes per year positions Bonaparte among the larger offshore CCS schemes in the region.

Who is the anchor customer?

The Ichthys joint venture is expected to be the Bonaparte CCS project's anchor customer. The project has the potential to cut emissions from Ichthys LNG — the Browse Basin development operated from Darwin — by about 40%.

That figure gives the venture its commercial logic: Ichthys LNG faces mounting pressure to decarbonise its operations, and a storage site 260 km offshore Darwin, in the Bonaparte Basin's reach, offers a route to abatement without retrofitting the LNG plant's ownership structure or operations.

For the Ichthys partners, the 40% emissions-reduction potential is the number that matters — it is large enough to materially change the venture's carbon position as LNG buyers increasingly weigh emissions intensity in offtake decisions.

What happens next?

The joint venture continues technical, environmental, regulatory, and commercial workstreams in parallel. The watch items are the regulatory approvals and commercial agreements that gate first injection, and the FEED entry that would signal the venture is converting its pre-FEED studies into a costed development plan.

INPEX has not disclosed projected capital costs or a timeline for FEED entry.

First CO2 injection in the early 2030s is the date to track — and the permits and commercial agreements that stand between here and there are the work now underway.