The Australian Government, through the Department of Resources, Energy and Tourism, has supported Geoscience Australia in undertaking a series of regional-scale, geological studies to assess the CO2 storage potential of sedimentary basins, including the Petrel Sub-basin. The studies form part of the National Low Emissions Coal Initiative designed to accelerate the development of CO2 transport and storage infrastructure near the sources of major energy and industrial emissions. The Petrel Sub-basin was identified as a high-priority region for a future pre-competitive work program by the national Carbon Storage Taskforce. The Carbon Storage Taskforce also recommended the release of greenhouse gas assessment permits, which were released within the Petrel Sub-basin in 2009. As a component of the studies at Geoscience Australia, the numerical simulation was hypothetically designed to dynamically model the reservoir behavior and CO2 migration during the injection and post-injection stages using an in-house built 3D geological model of a represented injection site. 14 million tonnes per annum (MTPA) of CO2 was injected into the lower Frigate/Elang/Plover reservoir over 30 years and CO2 plume migration was simulated up to 2,000 years from the initial injection. The injection rate of 14 MTPA of CO2 used in this study was based on the predicted 2020 CO2 emissions of the Darwin Hub, a figure defined by the Carbon Storage Taskforce (2009). The poster highlights the simulation results including CO2 plume migration distance, CO2 trapping mechanisms and reservoir pressure behavior.

This publication is the successor to Oil and Gas Resources of Australia 2001 and continues as the definitive reference on exploration, development and production of Australia's petroleum resources. OGRA 2002 provides the background for much of the advice on petroleum resources given to the Australian Government.

Accurate seismic velocity model is essential for depth conversion and rock property determination in the context of fluid flow modelling to support site selection for secure storage of carbon dioxide. The Bonaparte CO2 Storage project funded by the Australian Government will assess the carbon dioxide geological storage potential of two blocks in the Petrel Sub-basin on the Australian NW Margin. These blocks were offered as part of the 2009 release of offshore areas for greenhouse gas (GHG) storage assessment. The Petrel Sub-basin is a northwest-trending Paleozoic rift within the southern Bonaparte Basin. The geological reservoirs of interest include the Jurassic Plover Formation and the Early Cretaceous Sandpiper Sandstone. Primary and secondary seals of interest include the Late Jurassic Frigate Formation and the Cretaceous Bathurst Island Group (regional seal). Trapping mechanisms for injected CO2 may include faulted anticlines, stratigraphic traps, salt diapirs and/or migration dissolution and residual trapping. Water depths are generally less than 100m and depths to reservoir/seal pairs range between 800-2500m below the sea surface. All three main types of seismic velocity measurements are available within the area of our study: velocities derived from stacking of multi-channel reflection seismic data; velocities determined in the process of ray tracing modelling of large offset refraction data acquired by the ocean bottom seismographs (OBS) along the coincident reflection/refraction transect, and velocities from well log (sonic, vertical seismic profiling and check shot) measurements.

In this paper, we present a high resolution study focussed mainly on the Gorgon field and associated Rankin Trend gas fields, Carnarvon Basin, Australia (Figure 1). These gas fields are characterized by numerous stacked reservoirs with varying CO2 contents and provide a relevant natural laboratory for characterizing CO2 migration, dissolution and reaction by looking at chemical characteristics of the different reservoirs (Figure 2). The data we present reveal interesting trends for CO2 mol% and -13C both spatially and with each other as observed by Edwards et al. (2007). Our interpretation of the data suggests that mineral carbonation in certain fields can be significant and relatively rapid. The Gorgon and Rankin Trend fields natural gases may therefore be a unique natural laboratory, which give further insights into the rates and extent of carbonate mineral sequestration as applied to carbon storage operations.

Groundwater has been sampled from 21 shallow (Port Campbell Limestone) and 3 deep (Dilwyn Formation) groundwater bores within a radius of 10 km around well CRC-1 between June 2006 and March 2008. The objectives of the study are (1) to establish baseline aquifer conditions prior to CO2 injection at CRC-1, which started in April 2008, and (2) to enable detection monitoring for CO2 leakage, should any occur in the future. In addition to sampling, standing water levels have been monitored continuously in 6 of the bores using barometric loggers. The water samples were analysed for pH, electrical conductivity (EC), temperature (T), dissolved oxygen (DO), redox potential (Eh), reduced iron (Fe2+) and alkalinity (dissolved inorganic carbon, DIC, as HCO3-) in the field, and for a suite of major, minor and trace inorganic species in the laboratory. Stable isotopes of O and H in water, of S in sulfate and of C and O in DIC were also determined. The shallow groundwaters have compositions typical of carbonate aquifer hosted waters, being fresh (EC 800-4000 uS/cm), dominated by Ca, Na, HCO3- and Cl-, cool (T 12-23°C), and near-neutral (pH 6.6-7.5). Most deep groundwater samples are similarly fresh or fresher (EC 400-1600 uS/cm), also dominated by Ca, Na, HCO3- and Cl-, cool (T 15-21°C), but are more alkaline (pH 7.5-9.5). Time-series reveal that parameters measured have been relatively stable over the sampling period, although some shallow bores display increasing EC and T, some show decreasing then increasing alkalinity while others show steadily increasing alkalinity (with or without increasing Cl- and Na, and decreasing Ca). Alkalinity of the deep groundwater tends to decrease slightly over the period. Groundwater levels in some of the shallow bores show a seasonal variation with longer term trends evident in both aquifers.

Atmospheric tomography is a monitoring technique that uses an array of sampling sites and a Bayesian inversion technique to simultaneously solve for the location and magnitude of a gaseous emission. Application of the technique to date has relied on air samples being pumped over short distances to a high precision FTIR Spectrometer, which is impractical at larger scales. We have deployed a network of cheaper, less precise sensors during three recent large scale controlled CO2 release experiments; one at the CO2CRC Ginninderra site, one at the CO2CRC Otway Site and another at the Australian Grains Free Air CO2 Enrichment (AGFACE) facility in Horsham, Victoria. The purpose of these deployments was to assess whether an array of independently powered, less precise, less accurate sensors could collect data of sufficient quality to enable application of the atmospheric tomography technique. With careful data manipulation a signal suitable for an inversion study can be seen. A signal processing workflow based on results obtained from the atmospheric array deployed at the CO2CRC Otway experiment is presented.

Abstract for submission to 11th IEA GHG International Conference on Greenhouse Gas Control Technologies. Conference paper to follow pending selection for oral or poster presentation. Abstract covers the GA-ACCA21 China Australia Geological Storage of CO2 (CAGS) Project run through PMD/ED 2009-2012.

Identification of major hydrocarbon provinces from existing world assessments for hydrocarbon potential can be used to identify those sedimentary basins at a global level that will be highly prospective for CO2 storage. Most sedimentary basins which are minor petroleum provinces and many non-petroliferous sedimentary basins will also be prospective for CO2 storage. Accurate storage potential estimates will require that each basin be assessed individually, but many of the prospective basins may have ranges from high to low prospectivity. The degree to which geological storage of CO2 will be implemented in the future will depend on the geographical and technical relationships between emission sites and storage locations, and the economic drivers that affect the implementation for each source to sink match. CO2 storage potential is a naturally occurring resource, and like any other natural resource there will be a need to provide regional access to the better sites if the full potential of the technology is to be realized. Whilst some regions of the world have a paucity of opportunities in their immediate geographic confines, others are well endowed. Some areas whilst having good storage potential in their local region may be challenged by the enormous volume of CO2 emissions that are locally generated. Hubs which centralize the collection and transport of CO2 in a region could encourage the building of longer and larger pipelines to larger and technically more viable storage sites and so reduce costs due to economies of scale.

No abstract available

Between March 2008 and August 2009, 65,445 tonnes of ~75 mol% CO2 gas were injected in a depleted natural gas reservoir approximately 2000 m below surface at the Otway project site in Victoria, Australia. Groundwater flow and composition were monitored biannually in 2 near-surface aquifers between June 2006 and March 2011, spanning the pre-, syn- and post-injection periods. The shallow (~0-100 m), unconfined, porous and karstic aquifer of the Port Campbell Limestone and the deeper (~600-900 m), confined and porous aquifer of the Dilwyn Formation contain valuable fresh water resources. Groundwater levels in either aquifer have not been affected by the drilling, pumping and injection activities that were taking place, or by the rainfall increase observed during the project. In terms of groundwater composition, the Port Campbell Limestone groundwater is fresh (electrical conductivity = 801-3900 ?S/cm), cool (temperature = 12.9-22.5 C), and near-neutral (pH 6.62-7.45), whilst the Dilwyn Formation groundwater is fresher (electrical conductivity 505-1473 ?S/cm), warmer (temperature = 42.5-48.5 C), and more alkaline (pH 7.43-9.35). Evapotranspiration and carbonate dissolution control the composition of the groundwaters. Comparing the chemical and isotopic composition of the groundwaters collected before, during and after injection shows either no sign of statistically significant changes or, where they are statistically significant, changes that are generally opposite those expected if CO2 addition had taken place. The monitoring program demonstrates that the physical and chemical properties of the groundwaters at the sampled bores have not been affected by CO2 sequestration.