Project Summary

Offshore Gippsland is widely recognised as one of the most promising CCS sites in Australia, with its proximity to large point sources and promising storage offshore.

Storage offshore at Sleipner and SnØvit has been successful, but the monitoring techniques there focused on marine seismic, and did not fully investigate effects at the seabed or in the water column.

The project provides an assessment of some proposed techniques for this type of “shallow focused” monitoring that may be used in offshore Gippsland. The methods considered may be useful for defining baselines and checking for some aspects of possible environmental impact. The study will inform the first phase of purchasing of marine monitoring assets, funded under the Commonwealth educational infrastructure funds (EIF), leading to more detailed investigation of their capabilities.

Existing expertise and databases in CSIRO Oceans and Atmosphere Flagship (O&A) have been used to assess the ability to measure the ingress of stored CO2 into the water column, and to quantify the size and type of loss of containment at the seabed that could be detected. O&A has baseline data and experience, relevant to the likely storage areas, covering tide and current patterns, seasonal and spatial variations in seawater composition, instrumentation, and modelling. This report investigates some elements of a model monitoring programme, namely measurement of water chemistry, and acoustic mapping.

Available Reports

Final Report - An initial study of the utility of some marine M&V methods for subsea CCS: Bass Strait Case Study

Key conclusions of the final report are:

  • Water sampling, from a combination of fixed moorings and gliders, would be able to monitor a region of order 10 x 10 km2 and detect a specific type of leak to the seafloor (point source, 10 kt/yr) anywhere in that area with high confidence and low false alarm rate. Leaks of this size are very unlikely and would probably be detected in other ways much earlier.
  • Natural variability causes changes in water chemistry that are equivalent to much larger releases, so the main application of this type of monitoring would be to characterise the natural background (“baseline”) and hence show that environmental impact (in the specific sense of acidification of the water over a large area) was negligible.
  • Monitoring by acoustic methods is extremely sensitive to bubble streams. The background noise level (mainly biota) is very variable, but streams corresponding to only 10 t/yr should be readily detectable above environmental clutter with high confidence of low false alarm rates.
  • Seafloor mapping will reveal a multitude of features of unknown provenance or duration, and this type of monitoring would have to be approached with an awareness of the need to control false alarm rates.
  • Field assessment of the technologies described will be a priority for future work along with the collection of baseline datasets for potential storage locations along the Gippsland coast.
Project Name:
Marine monitoring scoping study

Research Organisation:

Completed, 2016

Nick Hardman-Mountford, Charles Jenkins, Jim Greenwood, Rudy Kloser, Gordon Keith


Research Program: Carbon Transport + Storage
Demonstration: Gippsland Basin
Research Focus: Public Acceptance, Assurance modelling, Quantifying Potential Environmental Impacts

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