Marine measurement, monitoring and verification for offshore carbon storage projects – learnings from a coastal Gippsland setting

Designing cost-effective methods for implementing measurement, monitoring and verification (MM&V) plans for subsea CO2 storage is an active area of research globally. Despite some preliminary research and examples overseas, there remains a lack of established protocols and configurations for offshore carbon capture and storage (CCS) monitoring overlying storage sites and an absence of methods to establish environmental impact in the event of leakage. Over the last 4 years, CSIRO in collaboration with ANLEC R&D and CarbonNet have been undertaking research in the Gippsland region to inform the development of assurance monitoring approaches for subsea CCS operations to address three key technical assurance monitoring challenges: The ‘signal-to-noise’ problem: distinguishing CO2 release signatures from similar naturally occurring variability to reduce false alarm rates in future baseline monitoring design; characterising impact: determining the level of CO2 release that would be associated with environmental impact at a range of scales; and attributing impact: distinguishing changes resulting from other drivers and pressures in multiple-use zones (e.g. climate change) from the activities of CCS operations. The research has included a wide variety of approaches and technologies including the development and testing of fixed and mobile autonomous monitoring systems, chemical and acoustic sensing and the collection of biological datasets. These data have been used in the development of biogeochemical models and to define possible integrated MM&V frameworks. This paper will summarise this research and identify how it could be applied for offshore CO2 storage projects around Australia.