The worldwide intent to urgently mitigate climate change underscores the significance of CCS. However, to date, there is a major deficit in ready, or under development, commercially viable, CO₂ geological storage (CGS) resources. 

Realising the much-espoused potential of CCS requires more effective use of known CGS resources, and pursuit of sub-optimal CGS prospects. This is of particular importance for maximising CGS hubs and providing proximal CGS resources for hard-to-abate sectors. Further, technical solutions are required to address the uncertainty in the prediction of behaviour and long-term fate of the injected CO₂, to hasten resource development, safely approach reservoir technical limits, and enable effective site closure. CO2CRC, in collaboration with international partners, is actively addressing this challenge through the Otway Stage 4 Program.

Otway 4 aims to develop and demonstrate a suite of reservoir management strategies and solutions, that result in cost-effective CO₂ storage optimisation techniques, and to mature these for commercial readiness. New infrastructure is currently being installed at CO2CRC’s Otway International Test Centre to achieve this, including new bores and the CRC-8 monitoring well. From 2024, a series of CO₂ injection and monitoring operations will take place, to provide essential high-resolution data to achieve the Otway Stage 4’s storage optimisation objectives. 

This storage optimisation field R&D program comprises four key elements:

1.       Characterisation of Fine-Scale Heterogeneity and Fault Impact: Gain a deep understanding of how fine-scale heterogeneity and faults influence CO₂ distribution. The GeoCquest Field Validation (GFV) Project and Otway Shallow Fault Project are vital for this element.

2.       Innovative Performance Monitoring Techniques: Develop and test innovative monitoring techniques tailored to evaluate injection and storage performance. The innovative Distributed Strain Sensing (DSS) technique and the Seismic Monitoring Project, applied to all Otway Stage 4 injections, are the key monitoring techniques for this element. 

3.       Enhanced Injection Techniques: Develop and test novel injection techniques designed to improve CO₂ storage sweep efficiency and enhance trapping. Activities include the Microbubble Injection Project and the Surfactant Project. 

4.       Advanced Reservoir Modelling: Advance the capability to comprehensively model CO₂ behaviour and reservoir response to thermal, hydrological, geomechanical and geochemical changes. This includes the integration of the new monitoring data to conform models and the development of the capability to simulate the effects of the newly devised injection techniques.

This presentation forms the basis for several Otway Stage 4 presentations in the symposium, which delve into laboratory and modelling work to date, as well as forward R&D plans that will stem from the CO₂ injection operations commencing next year.