Western Australia Carbon Capture and Storage Hub Feasibility Study

Objective

Santos, in collaboration with its project partners, engaged io consulting to assess the feasibility of a large-scale Carbon Capture and Storage (CCS) Hub in Western Australia. The study aimed to define technically and commercially viable pathways for decarbonising industrial emitters in the Pilbara region, leveraging Post-Combustion Capture (PCC) and geological sequestration in depleted gas fields. The ultimate goal was to develop a cost-competitive, scalable and phased CCS solution that aligns with Australia’s net-zero emissions commitments.

Project Scope

The study evaluated multiple decarbonisation concepts, each comprising three key components:

1. PCC – Evaluating technologies for capturing CO₂ emissions from gas turbine generators.
2. CO₂ Pipeline Transmission Network – Designing a regional pipeline infrastructure to transport captured CO₂ to storage sites.
3. Subsurface CO₂ Sequestration – Assessing the feasibility of injecting and permanently storing CO₂ in depleted hydrocarbon reservoirs.

Key activities included:

• Vendor engagement to assess PCC technology readiness and cost reduction potential.
• Economic modelling of the Levelised Cost of Carbon Abatement (LCCA) for different decarbonisation pathways.
• Risk and opportunity analysis for integrating CCS with mining electrification and renewable energy solutions.
• Identification of optimal sequestration sites with sufficient injection capacity.

Findings & Recommendations

Findings

• Post-Combustion Capture Technology Assessment: Two mature PCC technologies were identified as deployment-ready, while emerging alternatives showed promise for future cost reduction.
• Cost Reduction Through Scale & Integration: The PCC component represented the largest cost driver in the CCS value chain. However, integration across multiple emitters and optimised plant configurations could reduce costs by up to 40%.
• CO₂ Pipeline Infrastructure Design: A 1,300 km pipeline network was identified as a critical enabler for regional CCS. Pipeline operators expressed strong interest in a build-own-operate model, reducing upfront CAPEX.
• Optimal CO₂ Storage Solutions: The depleted Reindeer gas field was identified as the primary sequestration site, offering ideal injectivity and capacity characteristics. Additional storage capacity was identified in the East Spar, Spar Halyard and John Brookes reservoirs for future expansion.
• Renewable Energy vs. CCS for Decarbonisation: The study compared CCS-based decarbonisation (PCC with sequestration) with a Variable Renewable Energy (VRE) alternative. While VRE solutions reduced emissions, they required significantly higher CAPEX and land use compared to CCS.
• Mining Electrification & Integration Opportunities: Electrifying mobile mining equipment and replacing diesel generators with grid-connected renewable power could further reduce emissions but required additional investment in firming capacity.

Recommendations

1. Post-Combustion Capture Technology Assessment: Adopt proven amine-based PCC solutions for initial deployment, with phased integration of emerging technologies as they mature.
2. Cost Reduction Through Scale & Integration: Develop a phased approach, starting with concentrated coastal emitters, before expanding to a broader network of inland industrial sites.
3. CO₂ Pipeline Infrastructure Design: Progress discussions with pipeline vendors to secure competitive tariff structures and ensure timely permitting.
4. Optimal CO₂ Storage Solutions: Prioritise Reindeer for early injection, with phased development of supplementary storage sites to accommodate increased CO₂ capture volumes.
5. Renewable Energy vs. CCS for Decarbonisation: Deploy CCS as the most cost-effective solution for reducing emissions from existing gas-fired power generation, with renewables playing a complementary role in new power infrastructure.
6. Mining Electrification & Integration Opportunities: Assess hybrid solutions combining CCS with targeted mining electrification to achieve optimal cost and emissions reduction.