Geological storage of greenhouse gases is one approach that the Australian Government is pursuing to assist Australia, and the world, to reduce greenhouse gas emissions into the atmosphere. Understanding the geology of Australia's sedimentary basins and their potential for greenhouse gas storage is an important component of Geoscience Australia's work in supporting emission reductions.

Monitoring is an important aspect in verifying the integrity of the geological storage of greenhouse gases. Geoscience Australia is working with CSIRO, the CO2CRC, the Australian National University, the University of Adelaide and the University of Wollongong to develop and evaluate new techniques to detect and quantify greenhouse gas emissions.

Many industries and researchers have been examining ways of substantially reducing greenhouse gas emissions. No single method is likely to be a panacea, however some options do show considerable promise. Geological sequestration is one option that utilises mature technology and has the potential to sequester large volumes of CO2. In Australia geological sequestration has been the subject of research for the last 2? years within the Australian Petroleum Cooperative Research Centre's GEODISC program. A portfolio of potential geological sequestration sites (?sinks?) has been identified across all sedimentary basins in Australia, and these have been compared with nearby known or potential CO2 emission sources. These sources have been identified by incorporating detailed analysis of the national greenhouse gas emission databases with other publicly available data, a process that resulted in recognition of eight regional emission nodes. An earlier generic economic model for geological sequestration in Australia has been updated to accommodate the changes arising from this process of ?source to sink? matching. Preliminary findings have established the relative attractiveness of potential injection sites through a ranking approach. It includes the ability to accommodate the volumes of sequesterable greenhouse gas emissions predicted for the adjacent region, the costs involved in transport, sequestration and ongoing operations, and a variety of technical geological risks. Some nodes with high volumes of emissions and low sequestration costs clearly appear to be suitable, whilst others with technical and economic issues appear to be problematic. This assessment may require further refinement once findings are completed from the GEODISC site-specific research currently underway.

Note: A more recent version of this product is available. This point dataset contains the major power stations in Australia including all those that feed into the electricity transmission network.

Geoscience Australia and CO2CRC have constructed a greenhouse gas controlled release reference facility to simulate surface emissions of CO2 (and other GHG gases) from an underground slotted horizontal well into the atmosphere under controlled conditions. The facility is located in a paddock maintained by CSIRO Plant and Industry at Ginninderra, ACT. The design of the facility is modelled on the ZERT controlled release facility in Montana, which conducts experiments to develop capabilities and test techniques for detecting and monitoring CO2 leakage. The first phase of the installation is complete and has supported an above ground, point source, release experiment, utilising a liquid CO2 storage vessel (2.5 tonnes) with a vaporiser, mass flow controller unit with a capacity for 6 individual metered gas outlet streams, equipment shed and a gas cylinder cage. Phase 2 involved the installation of a shallow (2m depth) underground 120m horizontally drilled slotted well, in June 2011, intended to model a line source of CO2 leakage from a storage site. This presentation will detail the various activities involved in designing and installing the horizontal well, and designing a packer system to partition the well into six CO2 injection chambers. A trenchless drilling technique used for installing the slotted HDPE pipe into the bore hole will be described. The choice of well orientation based upon the effects of various factors such as topography, wind direction and ground water depth, will be discussed. It is envisaged that the facility will be ready for conducting sub-surface controlled release experiments during spring 2011.

Quantification of leakage into the atmosphere from geologically stored CO2 is achievable by means of atmospheric monitoring techniques if the position of the leak can be located and the perturbation above the background concentration is sufficiently large for discrimination. Geoscience Australia and the CO2CRC have recently constructed a site in northern Canberra for the controlled release of greenhouse gases. This facility enables the simulation of leak events and provides an opportunity to investigate techniques for the detection and quantification of emissions of CO2 (and other greenhouse gases) into the atmosphere under controlled conditions. The facility is modelled on the ZERT controlled release facility in Montana. The first phase of the installation is complete and has supported an above ground, point source, release experiment (e.g. simulating leakage from a compromised well). Phase 2 involves the installation of a shallow underground horizontal well for line source CO2 release experiments and this will be installed during the first half of 2011. A release experiment was conducted at the site to explore the application of a technique, termed atmospheric tomography, to simultaneously determine the location and emission rate of a leak when both are unknown. The technique was applied to the release of two gas species, N2O and CO2, with continuous sampling of atmospheric trace gas concentrations from 8 locations 20m distant from a central release point and measurement of atmospheric turbulence and dispersive conditions. The release rate was 1.10 ± 0.02 g min-1 for N2O and 58.5 ± 0.4 g min-1 for CO2 (equivalent to 30.7 ± 0.2 tonnes CO2 yr-1). Localisation using both release species occurred within 0.5 m (2% error) of the known location. Determination of emission rate was possible to within 7% for CO2 and 5% for N2O.

Recent national and state assessments have concluded that sedimentary formations that underlie or are within the Great Artesian Basin (GAB) may be suitable for the storage of greenhouse gases. These same formations contain methane and naturally generated carbon dioxide that has been trapped for millions of years. The Queensland government has released exploration permits for Greenhouse Gas Storage in the Bowen and Surat basins. An important consideration in assessing the potential economic, environmental, health and safety risks of such projects is the potential impact CO2 migrating out of storage reservoirs could have on overlying groundwater resources. The risk and impact of CO2 migrating from a greenhouse gas storage reservoir into groundwater cannot be objectively assessed without knowledge of the natural baseline characteristics of the groundwater within these systems. Due to the phase behaviour of CO2, geological storage of carbon dioxide in the supercritical state requires depths greater than 800m, but there are no hydrochemical studies of such deeper aquifers in the prospective storage areas. Geoscience Australia (GA) and the Geological Survey of Queensland (GSQ), Queensland Department of Mines and Energy, worked collaboratively under the National Geoscience Agreement (NGA) to characterise the regional hydrochemistry of the Denison Trough and Surat Basin and trialled different groundwater monitoring strategies. The output from this Project constitutes part of a regional baseline reference set for future site-specific and semi-regional monitoring and verification programmes conducted by geological storage proponents. The dataset provides a reference of hydrochemistry for future competing resource users.

Approximately one quarter of Australia's CO2 emissions come from southeast and central Queensland. This poster presents the geoscientific interpretations which lead to constructing a simplified 3-D model of a potential geological storage site for CO2. The Bowen Basin is located in northeast Australia, approximately 200 to 500 km from major CO2 emission hubs in southeast Queensland. The resources of the Bowen Basin include coal, oil and gas, and there are water resources within the overlying Great Artesian Basin. Defining trap integrity within the Bowen Basin is important to ensure that none of these resources are compromised. The Wunger Ridge area has been the focus of petroleum exploration for hydrocarbons. Geological, geophysical, hydrodynamic, petrological, petrophysical and seal capacity interpretations of datasets from the area were undertaken. These interpretations indicate that the Triassic fluvial - deltaic Showgrounds Sandstone is the most suitable for CO2 storage and injection as it is permeable and saturated with brackish to saline water except where hydrocarbons have accumulated. Geological profiles were developed using sequence stratigraphic concepts and combined with rock properties, measured from core, to produce simplified 3-D models with the goal of assessing parameters for CO2 injection and migration. Simulation runs using simple models, based on a coarse-scale grid, suggest that either one horizontal or two vertical wells are required to inject at the proposed rate. Geological heterogeneity increases injection pressure around the wellbore and reduces injection rates compared to homogeneous models, resulting in the need for more injection wells.

A short animation of an atmospheric simulation of methane emissions from a coal mine (produced using TAPM) compared to actual methane concentrations detected by the Atmospheric Monitoring Station, Arcturus in Central Queensland. It illustrates the effectiveness of both the detection and simulation techniques in the monitoring of atmospheric methane emissions. The animation shows a moving trace of both the simulated and actual recorded emissions data, along with windspeed and direction indicators. Some data provided by CSIRO Marine and Atmospheric Research.

Hydrothermal and hot fractured rock (HFR) resources are prevalent in Australia. This, and evidence of risks posed by climate change are factors stimulating growth in geothermal energy exploration, proof-of-concept and demonstration power generation projects in Australia. In the six years since the grant of the first Geothermal Exploration Licence (GEL) in Australia in 2001, 16 companies have joined the hunt for renewable and emissions-free geothermal energy resources in 122 licence application areas covering ~ 68,000 km2. The associated work programs correspond to an investment of $570 million, a tally which excludes up-scaling and deployment projects assumed in the Energy Supply Association of Australia's scenario for 6.8% (~ 5.5 GWe) of Australia's base-load power coming from geothermal resources by 2030. Most investment is focused on HFR for enhanced geothermal systems (EGS) to fuel binary power plants. At least two companies are also focused on hydrothermal resources, also to fuel binary power plants. A national EGS resource assessment and a road-map for the commercialisation of Australian EGS are expected to be published in 2008. Geoscience Australia's preliminary work suggests Australia's hot rock energy between 150oC and 5 km is roughly 1.2 billion PJ (roughly 20,000 years of Australia's primary energy use in 2005), without taking account of the renewable characteristics of hot rock EGS plays. The presentation will provide up-to-date accounts of: 1. Exploration, proof-of-concept and demonstration projects on the path to commercializing hot rock resources in Australia; 2. Government designed investment frameworks that aim to attract and facilitate progress to commercializing hot rock resources in Australia; 3. Methods adopted by regulators to meet community expectations that only safe operations (including EGS projects) will be approved by regulators; and 4. Proposed methods for the portfolio management of EGS projects vying for funding within companies, and competing for research and demonstration grants from governments.