The first large-scale projects for geological storage of carbon dioxide on the Australian mainland are likely to occur within sedimentary sequences that underlie or are within the Triassic-Cretaceous, Great Artesian Basin (GAB) aquifer sequence. Recent national1 and state2 assessments have concluded that certain deep formations within the GAB show considerable geological suitability for the storage of greenhouse gases. These same formations contain trapped methane and naturally generated CO2 stored for millions of years. In July 2010, the Queensland government released exploration permits for Greenhouse Gas Storage in the Surat and Galilee 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 few hydrogeochemical studies of these deeper aquifers in the prospective storage areas. Historical hydrogeochemical data are compiled from various State and Federal Government agencies. In addition, hydrogeochemical information is compiled from thousands of petroleum well completion reports in order to obtain more information on the deeper aquifers, not typically used for agriculture or human consumption. The data are passed through a QC procedure to check for mud contamination and to ascertain whether a representative sample had been collected. The large majority of the samples proved to be contaminated but a small selection passed the QC criteria. The full dataset is available for download from GA's Virtual Dataroom. Oral presentation at "Groundwater 2010" Conference, 31 October - 4 November 2010, Canberra

Deployment of Unmanned Aerial Vehicle during surface CO2 release experiments at the Ginninderra greenhouse gas controlled release facility H. Berko (CO2CRC, Geoscience Australia), F. Poppa (The Australian National University), U. Zimmer (The Australian National University) and A. Feitz (CO2CRC, Geoscience Australia) Lagrangian stochastic (LS) forward modelling of CO2 plumes from above-surface release experiments conducted at the GA-CO2CRC Ginninderra controlled release facility demonstrated that small surface leaks are likely to disperse rapidly and unlikely to be detected at heights greater 4 m; this was verified using a rotorcraft to map out the plume. The CO2 sensing rotorcraft unmanned aerial vehicle (RUAV) developed at the Australian National University, Canberra, is equipped with a CO2 sensor, a GPS, lidar and a communication module. It was developed to detect and locate CO2 gas leaks; and estimate CO2 concentration at the emission source. The choice of a rotor-craft UAV allows slower flight speeds compared to speeds of a fixed-wing UAV; and the electric powered motor enables flight times of 12 min. In experiments conducted at the Ginninderra controlled release facility, gaseous CO2 (100 kg per day) was released from a small diffuse source located in the middle of the paddock, and the RUAV was flown repeatedly over the CO2 source at a few meters height. Meteorological parameters measured continuously at the site at the time of the flight were input in the LS model. Mapped out horizontal and vertical CO2 concentrations established the need to be close to the ground in order to detect CO2 leakage using aerial techniques. Using the rotorcraft as a mobile sensor could be an expedient mechanism to detect plumes over large areas, and would be important for early detection of CO2 leaks arising from CCS activities.

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.

Covering an area of approximately 247 000km2, the Galilee Basin is a significant feature of central Queensland. Three main depocentres contain several hundred metres of Late Carboniferous to Middle Triassic sediments. Sedimentation in the Galilee Basin was dominated by fluvial to lacustrine depositional systems. This resulted in a sequence of sandstones, mudstones, siltstones, coals and minor tuff in what was a relatively shallow intracratonic basin with little topographic relief. Forty years or more of exploration in the Galilee Basin has failed to discover any economic accumulations of hydrocarbons, despite the presence of apparently fair to very good reservoirs and seals in both the Permian and Triassic sequence. Despite some relatively large distances (upwards of 500km) between sources and sinks, previous and ongoing work on the Galilee Basin suggests that it has potential to sequester a significant amount of Queensland's carbon dioxide emissions. Potential reservoirs include the Early Permian Aramac Coal Measures, the Late Permian Colinlea Sandstone and the Middle Triassic Clematis Sandstone. These are sealed by several intraformational and local seals as well as the regional Triassic Moolayember Formation. With few suitable structural traps and little faulting throughout the Galilee sequence, residual trapping within saline reservoir is the most likely mechanism for storing CO2. The current study is aimed at building a sound geological model of the basin through activities such as detailed mapping, well correlation, and reservoir and seal analysis leading to reservoir simulations to gain a better understanding of the basin.

Australia has embarked on a process of potential commitment through the Kyoto Protocol to contain growth in greenhouse gas emissions to 8% between 1990 and the reporting period of 2008 - 2012. The target is well below the estimated growth of about 28% under the `business as usual' condition. Australia's greenhouse gas inventory estimates that 502 million tonnes of carbon dioxide equivalents were emitted in the base year of 1990. This report examines over 175 candidate options for reducing greenhouse gas emissions to identify their technical feasibility, cost per tonne of carbon dioxide avoided and capability to reduce emissions under Australian conditions. The candidate options were not intended to represent an exhaustive list but they encompass major and some lesser options being canvassed in Australia and overseas. Preferred options were selected on their performance towards the criteria of technical feasibility, cost and capability.

A shallow vertical CO2 injection test was conducted over a 21 day period at the Ginninderra Controlled Release Facility in May 2011. The objective of this test was to determine the extent of lateral CO2 dispersion, breakthrough times and permeability of the soil present at the Ginninderra site. The facility is located in Canberra on the CSIRO agricultural Ginninderra Experiment Station. A 2.15m deep, 15cm stainless steel screened, soil gas sampling well was installed at the site and this was used as the CO2 injection well. The CO2 flow rate was 1.6 L/min (STP). CO2 soil effluxes (respiration and seepage) were measured continuously using a LICOR LI-8100A Automated Soil CO2 Flux System equipped with 5 accumulation chambers spaced 1m apart in a radial pattern from the injection well. These measurements were supplemented with CO2 flux spot measurements using a WestSystems portable fluxmeter. Breakthrough at 1m from the injection point occurred within 6 hrs of injection, 32hrs at 2m and after almost 5 days at 3m. The average steady state CO2 efflux was 85 ?mol/m2/s at 1m, 15 ?mol/m2/s at 2m and 5.0 ?mol/m2/s at 3m. The average background CO2 soil respiration efflux was 1.1 - 0.6 ?mol/m2/s. Under windy conditions, higher soil CO2 efflux could be expected due to pressure pumping but this is contrary to the observed results. Prolonged windy periods led to a reduction in the CO2 efflux, up to 30% lower than the typical steady state value.

The decision at the 2011 United Nations climate change meeting in Durban to accept CCS as a CDM project activity was truly historic and long overdue. The United Nations Clean Development Mechanism (CDM) allows emission reduction projects in developing countries to earn certified emission reduction (CER) credits, each equivalent to one tonne of CO2. CERs can be traded and sold, and used by developed countries to meet part of their emission reduction targets under the Kyoto Protocol. The intention of the mechanism is to stimulate sustainable development and emission reductions, while providing developed countries with some flexibility in how they achieve their emission reduction targets. The CDM allows developed countries to invest in emission reductions at lowest cost. Since its inception, the CDM has been identified as a means to reduce the cost of CCS projects and so initiate more projects. After five years of negotiations to get CCS accepted as a CDM project activity, the Cancun Decision (2010) put in place a work program to address issues of general concern before CCS could be included in the CDM. The 2010 work program consisted of submissions, a synthesis report, a technical workshop, and concluded with the UNFCCC Secretariat producing draft 'modalities and procedures' describing comprehensive requirements for CCS projects within the CDM. This twenty page 'rulebook' provided the basis for negotiations in Durban. The challenging negotiations, lasting over 32 hours, concluded on 9th December, 2012, with Parties agreeing to the text specifying the modalities and procedures for CCS as CDM project activities. The provisions of the Durban Decision (2011) cover a range of technical issues including site selection and characterisation, risk and safety assessment, monitoring, liabilities, verification and certification, environmental and social impact assessments, responsibilities for non-permanence, and timing of the CDM-project end. etc

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.

There is increasing recognition that minimising methane emissions from the oil and gas sector is a key step in reducing global greenhouse gas emissions in the near term. Atmospheric monitoring techniques are likely to play an important future role in measuring the extent of existing emissions and verifying emission reductions. They can be very suitable for monitoring gas fields as they are continuous and integrate emissions from a number of potential point and diffuse sources that may vary in time. Geoscience Australia and CSIRO Marine & Atmospheric Research have collected three years of continuous methane and carbon dioxide measurements at their atmospheric composition monitoring station ('Arcturus') in the Bowen Basin, Australia. Methane signals in the Bowen Basin are likely to be influenced by cattle production, landfill, coal production, and conventional and coal seam gas (CSG) production. Australian CSG is typically 'dry' and is characterised by a mixed thermogenic-biogenic methane source with an absence of C3-C6+ alkanes. The range of '13C isotopic signatures of the CSG is similar to methane from landfill gas and cattle emissions. The absence of standard in-situ tracers for CSG fugitive emissions suggests that having a comprehensive baseline will be critical for successful measurement of fugitive emissions using atmospheric techniques. In this paper we report on the sensitivity of atmospheric techniques for the detection of fugitive emissions from a simulated new CSG field against a three year baseline signal. Simulation of emissions was performed for a 1-year period using the coupled prognostic meteorological and air pollution model TAPM at different fugitive emission rates (i.e. estimates of <1% to up to 10% of production lost) and distances (i.e. 10 - 50 km) from the station. Emissions from the simulated CSG field are based on well density, production volumes, and field size typical of CSG fields in Australia. The distributions of the perturbed and baseline signals were evaluated and statistically compared to test for the presence of fugitive methane emissions. In addition, a time series model of the methane baseline was developed in order to generate alternative realizations of the baseline signal. These were used to provide measures of both the likelihood of detecting fugitive emissions at various emission levels and of the false alarm rate. Results of the statistical analysis and an indicative minimum fugitive methane emission rate that can be detected using a single monitoring station are presented. Poster presented at the American Geophysical Union meeting, December 2013, San Francisco

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.