Background research for selection of potential geostorage targets-case studies from the Surat Basin, Queensland

Carbon dioxide injection into subsurface reservoirs appears to be a promising solution for decreasing atmospheric CO2 concentrations. Results and recommendations of a preliminary investigation of sedimentary basins suitable for carbon geostorage in Queensland designated the Surat Basin as a target area for further investigation. As a result, a comprehensive gap analysis of the Surat Basin datasets was followed by regional desktop studies, hydrodynamic analysis using petroleum well and groundwater bore data and a program of mineralogical data collection and interpretation. Allavailable open-file data (petroleum wells, department stratigraphic wells, department of the environment and resource management and Geological Survey of Queensland groundwater bores and seismic data) were reassessed, reinterpreted and/or refined. Petroseis (R) and GOCAD (R) were used for regional geological modelling of seismic horizons and fault systems, respectively. PressureQC was the quality control platform used for assessing petroleum well pressure data and the Geochemist's Workbench software was used for preliminary geochemical simulations of carbon dioxide impacts on groundwater and host rocks. The precompetitive studies and datasets recently released by the Carbon Geostorage Initiative address some issues, which are geostorage-specific, such as defining the supercritical boundary (800m depth), fault plane geometry, groundwater flow vectors and the potential impact of carbon dioxide injection on the groundwater system and its mineral framework. Theprimary conclusions derived from this work are that the applicability of a given dataset must be considered prior to implementation. This is of particular importance for geological modelling studies where quality assurance processes are needed to validate the various datasets that have been used. In addition to this, the modelling methodologies themselves have been assessed in an appropriate context for geostorage investigations.