Underground storage of carbon dioxide in the Harvey area, south-west Western Australia

Abstract

Underground storage of carbon dioxide as a means of reducing atmospheric emissions of CO2 has been examined both theoretically and practically over the past decade. There is a large amount of research and field experience in the energy sector to show that underground storage of CO2 is feasible. The Global Carbon Capture and Storage Institute has identified 38i large-scale projects (operating and/or in the planning) with many companies currently sequestering tons of CO2 per year. This paper reports on static and dynamic modelling studies conducted on the Harvey structure, onshore Perth Basin, to assess the suitability of the Lesueur Sandstone in the Lower Lesueur Region of Western Australia as a potential geological CO2 sequestration site. The study area for this project within this structure covers 332 km2 and is located approximately 13 km north-west of the town of Harvey, south of Perth. The static and dynamic modelling investigated a suite of full field simulation models that cover a range of subsurface uncertainties providing confidence that the CO2 plume stays below 800 mTVDss (metres true vertical depth sub sea) within the storage complex for more than 1000 years after injection ceases. The results of the modelling show that it could be feasible to inject 800 000 tonnes CO2 per annum over 30 years into the storage complex. Modelling studies shows that the main factors controlling CO2 plume migration are trapped gas saturation and the solubility of CO2 in brine.