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.

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.

Australia has been making major progress towards early deployment of carbon capture and storage from natural gas processing and power generation sources. This paper will review, from the perspective of a government agency, the current state of various Australian initiatives and the advances in technical knowledge up until the 2010 GHGT conference. In November 2008, the Offshore Petroleum and Greenhouse Gas Storage Bill 2006 was passed by the Australian Parliament and established a legal framework to allow interested parties to explore for and evaluate storage potential in offshore sedimentary basins that lie in Australian Commonwealth waters. As a result of this Act, Australia became the first country in the world, in March 2009, to open exploration acreage for storage of greenhouse gases under a system that closely mirrors the well-established Offshore Petroleum Acreage Release. The ten offshore areas offered for geological storage assessment are significantly larger than their offshore petroleum counterparts to account for, and fully contain, the expected migration pathways of the injected GHG substances. The co-incidence of the 2009 Global Financial Crisis may have reduced the number of prospective CCS projects that were reported to be in the 'pipe-line' and the paper examines the implications of this apparent outcome. The Carbon Storage Taskforce has brought together both Australian governments technical experts to build a detailed assessment of the perceived storage potential of Australia's sedimentary basins. This evaluation has been based on existing data, both on and offshore. A pre-competitive exploration programme has also been compiled to address the identified data gaps and to acquire, with state funding, critical geological data which will be made freely available to encourage industrial participation in the search for commercial storage sites.

Matching of CO2 emission sources with storage opportunities or source/sink matching (SSM), involves the integration of a number of technical, social and economic issues. It requires identification of the optimal locations for both the emission source and storage site for CO2 emissions. The choice of optimal sites is a complex process and will not rest solely on the best technical site for storage, but will require a detailed assessment of source issues, transport links and integration with economic and environmental factors. Transport is one of the major costs in CO2 sequestration and in many instances it will strongly influence how locations are chosen, but itself will be dependent on what type of facilities are to be built, be they either onshore or offshore or a combination of both. Comparison of theoretical studies, and the numerous criteria they utilise in their assessments, with current or planned commercial operations indicates that it is only a few of the major criteria that determine site locations.

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.

Having techniques available for the accurate quantification of potential CO2 surface leaks from geological storage sites is critical for regulators, public assurance and for underpinning carbon pricing mechanisms. Currently, there are few options available that enable accurate CO2 quantification of potential leaks at the soil-atmosphere interface. Integrated soil flux measurements can be used to quantify CO2 emission rates from the soil and atmospheric techniques such as eddy covariance or Lagrangian stochastic modelling have been used with some success to quantify CO2 emissions into the atmosphere from simulated surface leaks. The error for all of these techniques for determining the emission rate is not less than 10%. A new technique to quantify CO2 emissions was trialled at the CO2CRC Ginninderra controlled release site in Canberra. The technique, termed atmospheric tomography, used an array of sampling sites and a Bayesian inversion technique to simultaneously solve for the location and magnitude of a simulated CO2 leak. The technique requires knowledge of concentration enhancement downwind of the source and the normalized, three-dimensional distribution (shape) of concentration in the dispersion plume. Continuous measurements of turbulent wind and temperature statistics were used to model the dispersion plume.

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 GEODISC Geographic Information System (GIS) Overview and Demonstration With the understanding that "better information leads to better decisions", Geoscience Australia has produced a Geographic Information System (GIS) that showcases the research completed within Projects 1, 2, and 8 of the GEODISC Program (Geological CO2 storage program in the Australian Petroleum Cooperative Research Centre, 1999-2003). The GIS is an interactive archive of Australia-wide regional analysis of CO2 sources and storage potential, incorporating economic modelling (Projects 1 and 8), as well as four site specific studies of the Dongara Gas field, Carnarvon Basin, Petrel Sub-basin and Gippsland Basin (Project 2). One of the major objectives of a collaborative research program such as GEODISC is to share results and knowledge with clients and fellow researchers, as well as to be able to rapidly access and utilise the research in future technical and policy decisions. With this in mind, the GIS is designed as a complete product, with a user-friendly interface developed with mainstream software to maximise accessibility to stakeholders. It combines tabular results, reports, models, maps, and images from various geoscientific disciplines involved in the geological modelling of the GEODISC site specific studies (ie geochemistry, geomechanics, reservoir simulations, stratigraphy, and geophysics) into one media. The GEODISC GIS is not just an automated display system, but a tool used to query, analyse, and map data in support of the decision making process. It allows the user to overlay different themes and facilitates cross-correlation between many spatially-related data sources. There is a vast difference between seeing data in a table of rows and columns and seeing it presented in the form of a map. For example, tabular results such as salinity data, temperature information and pressure tests, have been displayed as point data linked to well locations. These, in turn, have been superimposed on geophysical maps and images, to enable a better understanding of spatial relationships between features of a potential CO2 injection site. The display of such information allows the instant visualisation of complex concepts associated with site characterisation. In addition, the GEODISC GIS provides a tool for users to interrogate data and perform basic modelling functions. Economic modelling results have been incorporated into the regional study so that simple calculations of source to sink matching can be investigated. The user is also able to design unique views to meet individual needs. Digital and hardcopy map products can then be created on demand, centred on any location, at any scale, and showing selected information symbolised effectively to highlight specific characteristics. A demonstration of the GIS product will illustrate all of these capabilities as well as give examples of how site selection for CO2 sources and storage locations might be made.

An atmospheric greenhouse gas (GHG) monitoring station began operation in July 2010 near Emerald, Queensland. The station is part of a collaborative project between Geoscience Australia (GA) and CSIRO Marine and Atmospheric Research (CMAR) to establish and operate a high precision atmospheric monitoring facility for measurement of baseline greenhouse gases (GHG) in a high priority geological carbon dioxide storage region. The primary purpose of the station is to field test newly developed greenhouse gas monitoring technology and demonstrate best practice for regional baseline atmospheric monitoring appropriate for geological storage of carbon dioxide. The GHG records were to be used as a reference for monitoring of the atmosphere at a CO2 storage project, providing a baseline to quantify typical variations in the area and a background against which any anomalies in the immediate vicinity of the storage might be detected. The site chosen for the GHG atmospheric monitoring station is in the locality of Arcturus, 50 km southeast of Emerald in the Central Highlands, Queensland. Site selection was based on the recommendations of the Carbon Storage Taskforce's National Carbon Mapping and Infrastructure Plan, regional assessments of prospective basins, regional atmospheric modelling, and consultation with key stakeholders. The key driver for the stakeholder consultation group was to support early projects for large scale onshore geological storage. Both the Bowen and Surat basins were identified as potential early mover onshore storage regions by the group and suitable for a regional atmospheric monitoring station. During early 2010, ZeroGen had an active exploration program for geological storage and the site was eventually located approximately 8km upwind from the boundary of ZeroGen's most prospective storage area in the northern Denison Trough, part of the larger Bowen Basin. The Arcturus site and environs is representative of the activities and ecology of Queenslan's Central Highlands and the greenhouse gas signals are likely be influenced by cropping, pasture, cattle production, and gas and coal activities. These same activities are also likely to be dominant sources of greenhouse gases in the Surat Basin. Importantly, the site is secure, can be accessed via an existing road, is not subject to flooding, and has easy access to electrical lines that only required the installation of a transformer on an electric pole. A long lead time for new electricity connections at remote sites (potentially greater than 12 months) was identified as a key risk to the project. Negotiations with the electricity supplier resulted in connection in less than 4 months. An access agreement was negotiated with the landowner to enable the installation of the monitoring station and access to the site.

A major concern for regulators and the public with geologically storage of gas is the potential for the migration of gas (e.g. CO2) via a leaky fault or well into potable groundwater supplies. Given sufficient CO2, an immediate effect on groundwater would be a decrease in pH which could lead to accelerated weathering, an increase in alkalinity and the release of major and minor ions. Laboratory and core studies have demonstrated that on contact with CO2 heavy metals can be released under low pH and high CO2 conditions (particularly Pd, Ni and Cr). There is also a concern that trace organic contaminants could be mobilised due to the high solubility of many organics in supercritical CO2. These scenarios could potentially occur under a high CO2 leakage event but a small leak might be barely perceptible yet could provide an important early warning for a subsequent and more substantial impact. Different approaches are required for the detection and quantification of these low level leaks and are the subject of this paper. A 3 year groundwater survey was recently completed in the Surat Basin, which forms part of the Triassic-Cretaceous, Great Artesian Basin (GAB) aquifer sequence. In addition to a comprehensive water and isotopic analysis of samples from groundwater wells, gases were collected from groundwater samples and analysed for composition, '13CCO2, '13CCH4 and '2HCH4. Methane is prevalent in the major aquifers in the Surat Basin (e.g. Mooga, Gubbermunda and Hutton sandstones) and is invariably associated with a bacterial (methanogenic) carbonate reduction source, evident from its isotopic signature ('13CCH4 ~ -70', '2HCH4 ~ 220'). In addition to methane and low levels of CO2, trace levels of ethane are often detected.