Regional study on potential CO2 geosequestration in the Collie Basin and the Southern Perth Basin of Western Australia

Coal-fired power stations in Collie, Western Australia emit 10 million tonnes of CO2 per year. This study assesses the potential opportunities of geological storage of CO2 both within the Collie Basin and the onshore part of the adjacent Southern Perth Basin of Western Australia within 50 km of Collie town site through a desktop evaluation of existing data. The aquifers and coal formations within both basins have been evaluated for their suitability for storage based on geological, geographical and environmental criteria related to storage capacity, injectivity, proximity to sources of CO2, location of other natural resources and containment security. The study has concluded that there is limited scope for large-scale storage of CO2 within the Collie Basin. In addition the potential for storage within coals of either basin is not a viable solution. This assessment is based on published criteria for CO2 storage in sedimentary basins and coal-bearing formations.This study has, however, identified the Harvey Ridge, a structural high in the Southern Perth Basin, as having potential for storing a large volume of CO2 within the study area. This potential has been established through a geological and hydrodynamic assessment and a comparison with the results of a previous study of simulated injection within the strata at the nearby Cockburn 1 well to the north of the Harvey Ridge. Comparison of these two locations in terms of the thickness of strata and lithology, amongst other considerations indicates that the area has more favourable characteristics for large storage than that indicated at Cockburn 1. While this provides confidence that the Harvey Ridge would be suitable, considerable further work, however, is required to establish the Harvey Ridge as a viable geosequestration option.