Victorian carbon dioxide geological storage options; an engineering evaluation of storage potential in southeastern Australia

Abstract In a carbon constrained environment, the ongoing utilisation of southeastern Australia’s extensive brown coal reserves, largely contained within Victoria’s Latrobe Valley, will require substantial mitigation of the related greenhouse gas emissions. Carbon Dioxide Capture and (geological) Storage (CCS) has been selected as a potential emissions mitigation technology for this region. Three basins were short-listed as potential injection sites within Victoria: The Gippsland Basin (both onshore and offshore); the offshore Bass Basin; and the offshore Torquay Sub-Basin. These sites were taken through a provisional subsurface engineering evaluation, which allowed an evaluation of the likely viability of large-scale CO 2 storage within the three basins, the security of CO 2 containment, achievable injectivity and capacity. The work presented here was premised on CO 2 injection commencing in 2015, at an initial injection rate of 5 MT annually, increasing to 20 MT annually by 2020. The southern flank of the Gippsland Basin (offshore) ranks highest in terms of estimated accessiblity and storage capacity, with over 700 MT of CO 2 storage available, characterised by saline aquifer trapping. The storage capacity of the Bass Basin is estimated to be over 400 MT, available within structural traps. The onshore Gippsland Basin and the Torquay Sub-Basin are ranked as the least suitable for the long-term storage of CO 2 , due to uncertainties associated with injectivity and containment, together with relatively small estimated storage capacities ( 2 storage projects of global importance may be undertaken.