Geoscience Australia and CO2CRC have constructed a greenhouse gas controlled release facility to simulate surface emissions of CO2 (and other greenhouse gases) from the soil into the atmosphere under controlled conditions. The facility is located at an experimental agricultural station maintained by CSIRO Plant Industry at Ginninderra, Canberra. The design of the facility is modelled on the ZERT controlled release facility in Montana. The facility is equipped with a 2.5 tonne liquid CO2 storage vessel, vaporiser and mass flow controller unit with a capacity for 6 individual metered CO2 gas streams (up to 600 kg/d capacity in total). Injection of CO2 into the soil is via a 120m long slotted HDPE pipe installed horizontally 2m underground. This is equipped with a packer system to partition the well into six CO2 injection chambers. The site is characterised by the presence of deep red and yellow podsolic soils with the subsoil containing mainly kaolinite and subdominant illite. Injection is above the water table. The choice of well orientation based upon the effects of various factors such as topography, wind direction, soil properties and ground water depth will be discussed. An above ground release experiment was conducted from July - October 2010 leading to the development of an atmospheric tomography technique for quantifying and locating CO2 emissions1. An overview of monitoring experiments conducted during the first subsurface release (January-March 2012), including application of the atmospheric tomography technique, soil flux surveys, microbiological surveys, and tracer studies, will be presented. Additional CO2 release experiments are planned for late 2012 and 2013. Poster presented at 11th Annual Conference on Carbon Capture Utilization & Sequestration, April 30 - May 3, 2012, Pittsburgh, Pennsylvania

Abstract: The extent to which fluids may leak from sedimentary basins to the seabed is a critical issue for assessing the potential of a basin for carbon capture and storage. The Petrel Sub-basin, located beneath central and eastern Joseph Bonaparte Gulf in tropical northern Australia, is identified as potentially suitable for the geological storage of CO2 because of its geological characteristics and proximity to offshore gas and petroleum resources. In May 2012, a multidisciplinary marine survey was undertaken to collect data in two targeted areas of the Petrel Sub-basin to facilitate an assessment of CO2 storage potential. Multibeam bathymetry and backscatter mapping (650 km2 over 5,300 line km), combined with acoustic sub-bottom profiling (650 line km) and geomorphological and sediment characterisation of the seabed was undertaken above the CO2 supercritical seal boundary of the sub-basin. Features identified in the high resolution (2 m) bathymetry data include carbonate banks, ridges, pockmark fields and fields of low amplitude hummocks located directly adjacent to banks. Unit and composite pockmarks and clusters of pockmarks are present on plains and adjacent to, and on, carbonate ridges. It is postulated that there are three possible sources for fluids and fluidised gas involved in pockmark formation: deep fluids from the basin, post-Cretaceous intra-formational, layer-bound fluids, and shallow-sourced fluidised gas from the breakdown of organic matter following the Holocene marine transgression of Joseph Bonaparte Gulf.

The 2011 United Nations climate change meeting in Durban provided an historic moment for CCS. After five years without progress, the Cancun Decision (2010) put in place a work program to address issues of concern before CCS could be included under the Kyoto Protocol's Clean Development Mechanism (CDM) and so allow projects in developing countries to earn Certified Emission Reductions (CERs). The program - consisting submissions, a synthesis report and workshop - concluded with the UNFCCC Secretariat producing draft 'modalities and procedures describing requirements for CCS projects under the CDM. The twenty page 'rulebook' provided the basis for negotiations in Durban. The challenging negotiations, lasting over 32 hours, concluded on 9th December with Parties agreeing to adopt final modalities and procedures for CCS under the CDM. These include provisions for participation requirements (including host country regulations), site selection and characterisation, risk and safety assessment, monitoring, liabilities, financial provision, environmental and social impact assessments, responsibilities for long term non-permanence, and timing of the CDM-project end. A key issue was the responsibility for any seepage of CO2 emissions in the long-term (non-permanence). The modalities and procedures separate responsibility for non-permanence from the liability for any local damages resulting from operation of the storage site. In relation to the former, they allow for the host country to determine the responsible entity, either the host country or the country purchasing the CERs. Note that a CER which incorporates responsibility for seepage will be less attractive to buyers. Thus a standard is established for managing CCS projects in developing countries, which will ensure a high level of environmental protection and is workable for projects. It sets an important precedent for the inclusion of CCS into other support mechanisms.

The middle to lower Jurassic sequence in Australia's Surat Basin has been identified as a potential reservoir system for geological CO2 storage. The sequence comprises three major formations with distinctly different mineral compositions, and generally low salinity formation water (TDS<3000 mg/L). Differing geochemical responses between the formations are expected during geological CO2 storage. However, given the prevailing use of saline reservoirs in CCS projects elsewhere, limited data are available on CO2-water-rock dynamics during CO2 storage in such low-salinity formations. Here, a combined batch experiment and numerical modelling approach is used to characterise reaction pathways and to identify geochemical tracers of CO2 migration in the low-salinity Jurassic sandstone units. Reservoir system mineralogy was characterized for 66 core samples from stratigraphic well GSQ Chinchilla 4, and six representative samples were reacted with synthetic formation water and high-purity CO2 for up to 27 days at a range of pressures. Low formation water salinity, temperature, and mineralization yield high solubility trapping capacity (1.18 mol/L at 45°C, 100 bar), while the paucity of divalent cations in groundwater and the silicate reservoir matrix results in very low mineral trapping capacity under storage conditions. Formation water alkalinity buffers pH at elevated CO2 pressures and exerts control on mineral dissolution rates. Non-radiogenic, regional groundwater-like 87Sr/86Sr values (0.7048-0.7066) indicate carbonate and authigenic clay dissolution as the primary reaction pathways regulating solution composition, with limited dissolution of the clastic matrix during the incubations. Several geochemical tracers are mobilised in concentrations greater than found in regional groundwater, most notably cobalt, concentrations of which are significantly elevated regardless of CO2 pressure or sample mineralogy.

Underground gas storage (UGS) facilities provide a wealth of information, which can be used to better understand various aspects of CO2 storage in depleted reservoirs. In some cases UGS facilities can provide important site specific information for carbon storage projects that are planned in similar formations in close proximity. In this paper, we discuss the various ways in which UGS facilities can be used to extract important information, and when possible we draw upon information from the Iona gas storage facility in Australia's Otway basin. The Iona facility is located 20 km away from the CO2CRC Otway Project, in which CO2 65445 tonnes of 77 mole% carbon dioxide, 20 mole% methane and 3 mole% other gas components (containing about 58000 tonnes of carbon dioxide) was injected into the Waarre C formation over a 17 month period. In this paper, we compare the factors that control CO2 seal capacity and discuss how UGS facilities can provide information on sustainable column heights either limited by faults or by cap rocks. We also present dynamic modeling results in which information is gained regarding injectivity, pressure evolution of the reservoir, storage capacity and maximum fluid pressures sustained by the faults. Understanding such parameters is important for the safe operation of any carbon storage project, be it on a demonstration or industrial scale.

Geological storage of CO2 is a leading strategy for large-scale greenhouse gas emission mitigation. Monitoring and verification is important for assuring that CO2 storage poses minimal risk to people's health and the environment, and that it is effective at reducing anthropogenic CO2 emissions. Eddy Covariance (EC) has been proposed as a long-term monitoring solution for geological storage projects and is considered suitable for monitoring areas 1000 - 100,000 m2 in size. Eddy Covariance is a key micrometeorological technique which has traditionally been used for assessing ecosystem exchange of CO2 in a variety of natural and agricultural settings. It measures the vertical transfer of scalar variables such as CO2 via eddies from upwind of the instrumentation, and correlates the measured CO2 flux to the upwind source area based on several key assumptions. These assumptions include that the upwind source area is homogeneous, flat and uniform, which in turn requires that horizontal gradients in CO2 concentration are zero and that horizontal and vertical gradients in the covariance of CO2 concentration and orthogonal wind directions are zero. Work undertaken at the GA-CO2CRC Gininnderra controlled release facility, where CO2 is released from the shallow subsurface (at 2 m depth), suggests that CO2 leakage in the near subsurface will follow paths of least resistance up to the surface. Similar observations have been observed at the ZERT facility in Montana and CO2 Field Lab in Norway. This leads to CO2 leaks having localised, patchy surface expression, rather than a diffuse wide-scale leak which one typically expects (Lewicki et al. 2010). The implication of this is that the source area for a leak is highly inhomogeneous, meaning the magnitudes of CO2 flux values measured using EC are grossly unreliable. These limitations were discussed in Leuning et al.'s (2008) review on CCS atmospheric monitoring technologies yet are not addressed in much of the recent EC leak quantification literature. This presentation will present findings from the first subsurface release at the CO2CRC facility in Canberra (March - May 2012), where EC data was analysed for application in leak detection and quantification. The CO2 release rate was 144 kg/d. Eddy Covariance was successfully used to detect the leak by comparing CO2 fluxes in the direction of the leak to baseline wind sectors. Median CO2 fluxes in the leak direction were 9.1 µmol/m2/s, while the median background flux was 1.0 µmol/m2/s. Separate measurements taken using a soil flux meter found that the daytime background soil flux had a median flux of 1.8 µmol/m2/s but the peak soil flux over a leak was 1100 µmol/m2/s. Quantification and spatially locating the leak were attempted, but due to the problem of source area inhomogeneity, no substantive progress could be made. How an inhomogeneous source area contributes to 'lost' CO2 from the system, through advection and diffusion, will be discussed, coupled with suggestions for how these parameters can be evaluated in future experimental design. Leuning R., Etheridge D., Luhar A., and Dunse B., 2008. Atmospheric monitoring and verification technologies for CO2 sequestration. International Journal of Greenhouse Gas Control, 2(3), 401-414. Lewicki J. L., Hilley G. E., Dobeck L., and Spangler L., 2010. Dynamics of CO2 fluxes and concentrations during a shallow subsurface CO2 release. Environmental Earth Sciences, 60(2), 285-297.

The Early Cretaceous Gage Sandstone and South Perth Shale formations are one of the most prospective reservoir-seal pairs in the Vlaming Sub-basin. Plays include post-breakup pinch-outs with the South Perth Shale forming a top seal. The Gage reservoir has porosities of 23-30% and permeabilities of 200-1800 mD and was deposited in palaeotopographic lows of the Valanginian breakup unconformity. This is overlain by the thick deltaic South Perth (SP) Supersequence. To characterise the reservoir-seal pair, a detailed sequence stratigraphic analysis was conducted by integrating 2D seismic interpretation, well log analysis and new biostratigraphic data. The palaeogeographic reconstructions for the Gage reservoir are based predominantly on the seismic facies mapping, whereas SP Sequence reconstructions are derived from mapping higher-order prograding sequences and establishing changes in sea level and sediment supply. The Gage reservoir forms part of a sand-rich submarine fan system and was deposited in water depths of > 400 m. It ranges from confined canyon fill to fan deposits on a basin plain. Directions of sediment supply are complex, with major sediment contributions from a northern and southern canyon adjacent to the Badaminna Fault Zone. The characteristics of the SP Supersequence differ markedly between the northern and southern parts of the sub-basin due to variations in palaeotopography and sediment supply. Palaeogeographic reconstructions reveal a series of regressions and transgressions leading to infilling of the palaeo-depression. Seven palaeogeographic reconstructions for the SP Supersequence portray a complex early post-rift depositional history in the central Vlaming Sub-basin. The developed approach could be applicable for detailed studies of other sedimentary basins

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.

The Collaborative Research Centre for Greenhouse Gas Technologies (CO2CRC) Program 3.2 Risk Assessment is working toward a risk assessment procedure that integrates risk across the complete CCS system and can be used to meet the needs of a range of stakeholders. Any particular CCS project will hold the interest of multiple stakeholders who will have varied interests in the type of information and in the level of detail they require. It is unlikely that any single risk assessment tool will be able to provide the full range of outputs required to meet the needs of regulators, the general public and project managers; however, in many cases the data and structure behind the outputs will be the same. In using a suite of tools, a well designed procedure will optimize the interaction between the scientists, engineers and other experts contributing to the assessment and will allow for the required information to be presented in a manner appropriate for each stakeholder. Discussions of risk in CCS, even amongst the risk assessment community, often become confused because of the differing emphases on what the risks of interest are. A key question that must be addressed is: 'What questions is the risk analysis trying to answer?' Ultimately, this comes down to the stakeholders, whose interests can be broken into four target questions: - Which part of the capture-transport-storage CCS system? - Which timeline? (project planning, project lifespan, post closure, 1,000 years, etc) - Which risk aspect? (technical, regulatory, economic, public acceptance, or heath safety and environment) - Which risk metric? (Dollars, CO2 lost, dollars/tonne CO2 avoided, etc.) Once the responses to these questions are understood a procedure and suite of tools can be selected that adequately addresses the questions. The key components of the CO2CRC procedure we describe here are: etc

The Browse Basin is located in the southern Timor Sea region of Australia's North West Shelf and covers an area of ~140,000 km2. It was identified as containing potential Environmentally Suitable Sites for carbon dioxide (CO2) Injection (ESSCI) by the Australian Petroleum CRC's GEODISC program (1999-2003). A regional geological reconnaissance of Cenozoic sandstone and carbonate sequences in the Browse Basin was undertaken in 2007 to determine the potential storage and sealing capacity for geological storage of CO2, the results of which are presented in this report. Methods included the review of available literature and well-completion reports, lithological and mineral analysis of selected well cuttings and interpretation of the wire-line and seismic response of the Cenozoic section.