Like many of the basins along Australia's eastern seaboard, there is currently only a limited understanding of the geothermal energy potential of the New South Wales extent of the Clarence-Moreton Basin. To date, no study has examined the existing geological information available to produce an estimate of subsurface temperatures throughout the region. Forward modelling of a basin structure using its expected thermal properties is the process generally used in geothermal studies to estimate temperatures at depth in the Earth's crust. This process has been validated for one-dimensional models such as a drill hole, where extensive information can be provided for a specific location. The process has also seen increasing use in more complex three-dimensional (3D) models, including in areas of sparse data. The overall uncertainties of 3D models, including the influence of the broad assumptions required to undertake them, are generally only poorly examined by their authors and sometimes completely ignored. New methods are presented in this study which will allow estimates and uncertainties to be addressed in a quantitative and justifiable way. Specifically, this study applies Monte Carlo Analysis to constrain uncertainties through random sampling of statistically congruent populations. Particular focus has been placed on the uncertainty in assigning thermal conductivity values to complex and spatially extensive geological formations using only limited data. These geological formations will typically consist of a range of lithological compositions, resulting in a range of spatially variable thermal conductivity values. As a case study these new methods are then applied to the New South Wales extent of the Clarence-Moreton Basin. The structure of the basin has been built using Intrepid Geophysics' 3D GeoModeller software package using data from existing petroleum drill holes, surface mapping and information derived from the FrOGTech SEEBASE study. A range of possible lithological compositions was determined for each of the major geological layers through application of compositional data analysis, using data from deep wells only (>2000 m). In turn, a range of possible thermal properties was determined from rock samples held by the New South Wales Department of Primary Industries and analysed at the Geoscience Australia laboratories. These populations of values were then randomly sampled to create 120 different forward models which were computed using SHEMAT. The results of these have been interpreted to present the best estimate of the expected subsurface temperatures of the basin, and their uncertainties, given the current state of knowledge. These results suggest that the Clarence-Moreton Basin has a moderate geothermal energy potential within an economic drilling depth. The results also show a significant degree of variability between the different thermal modelling runs, which is likely due to the limited data available for the region.

Hot Rock exploration and development has progressed rapidly in Australia in the last decade. A wealth of pre-competitive geological data acquired by government surveys and mineral and petroleum explorers is available in Australia, but heat flow data specific to geothermal exploration is sparse. A methodology is presented that sets out the key parameters required in Hot Rock exploration. Mappable practical proxies corresponding to these parameters can utilise existing geological datasets. Australia has an enviable amount of geological data that is publicly available, and this can be used to show that many parts of the continent are attractive Hot Rock exploration areas.

This volume is a compilation of Extended Abstracts presented at the 2008 Australian Geothermal Energy Conference, 19-22 August 2008, Rydges Hotel, Melbourne, organised by the Australian Geothermal Energy Association and the Australian Geothermal Energy Group. This Conference is the first dedicated conference organised by the geothermal energy community in Australia and has been made possible by the seed funding from the Australian Government under the Sir Mark Oliphant Conference funding scheme with additional sponsorship of the companies acknowledged earlier and paying delegates. This Conference is being held at a time of rapid growth in all sectors of the geothermal community. The number of companies engaged in exploration stands at 33, the number of leases held or applied for is 320, and the value of the work program for these companies exceeds $850 million between 2002-2013. The Australian Geothermal Energy Association has been incorporated to serve as the peak industry representative body. The Universities of Queensland, West Australia, Adelaide and Newcastle have new funding specifically for geothermal research programs. The Australian Government has continued its strong support of the sector through the Geothermal Industry Development Framework and Technology Roadmap, the Geothermal Drilling Program, and the Onshore Energy Security Program. All of the States now have legislation regulating geothermal exploration activity in place, and the Northern Territory has drafted legislation for presentation to parliament. This volume of Extended Abstracts starts with a summary snapshot of the global and national geothermal energy sectors. The rest of the volume is organised under three headings: Underground Science and Technology Power Conversion Technologies Legislation, Policy and Infrastructure

Geoscience Australia's $58.9M 5-year Onshore Energy Security Program began in 2006 and includes a new Geothermal Energy Project. The Project aims to assist in the development of a geothermal industry in Australia by: providing precompetitive geoscience information, including acquisition of new data; informing the public and government about Australia's geothermal potential; and partnering with industry in international promotional events for the purpose of attracting investment. This abstract gives a brief summation of activities undertaken by Geoscience Australia within the Onshore Energy Security Program, principally those of the Geothermal Energy Project.

Processed seismic data (SEG-Y format) and TIFF images for the 2009 Rankins Springs Extension Seismic Survey (L188), acquired by Geoscience Australia (GA) under the Onshore Energy Security Program (OESP), in conjunction with the New South Wales Department of Primary Industries (NSWDPI). Stack and migrated data are included for line 09GA-RS2, as well as CDP coordinates. Raw data for this survey are available on request from clientservices@ga.gov.au

Geoscience Australia has been acquiring deep crustal reflection seismic transects throughout Australia since the 1960s. The results of these surveys have motivated major interpretations of important geological regions, contributed to the development of continental-scale geodynamic models and improved understanding about large-scale controls on mineral systems. Under the Onshore Energy Security Program, Geoscience Australia has acquired, processed and interpreted over 5000 km of new seismic reflection data. These transects are targeted over geological terrains in all mainland states which have potential for hydrocarbons, uranium and geothermal energy systems. The first project was undertaken in the Mt Isa and Georgetown regions of North Queensland. Interpretations of these results have identified several features of interest to mineral and energy explorers: a previously unknown basin with possible hydrocarbon and geothermal potential; a favourable setting for iron oxide uranium-copper-gold deposits; and, a favourable structural setting for orogenic gold deposits under basin cover. Other geophysical data were used to map these features in 3D, particularly into areas under cover. Seismic imaging of the full thickness of the crust provides essential, fundamental data to economic geologists about why major deposits occur where they do and reduces risk for companies considering expensive exploration programs under cover.

This service is for the 'OZTemp Interpreted Temperature at 5km Depth' image of Australia product. It includes an interpretation of the crustal temperature at 5km depth, based on the OZTemp bottom hole temperature database and additional confidential company data.

The borehole temperature data collection contains Logs recorded by Geoscience Australia from a ranges of wells and boreholes throughout Australia.

This is an extract from the OZTemp database, an updated and improved version of the AUSTHERM05 borehole temperature database previously described by Chopra and Holgate (2005). OZTemp currently contains 5513 individual wells and 17 247 temperature and/or temperature gradient data records.

The Australian geothermal industry has drilled into two deep Enhanced Geothermal System (EGS) reservoirs and two deep sedimentary reservoirs. All four projects have encountered significant technical challenges in developing these resources which have added to the uncertainty around the development of other geothermal projects in Australia. The Australian geothermal research community has established the Geothermal Research Initiative (GRI) to provide a mechanism for coordinating research activities to address these challenges. The goals of the GRI are to assist the industry in demonstrating the technical viability of geothermal energy in Australia and to then develop technologies that help to drive down the costs of energy produced from geothermal resources, providing a secure, competitive energy source for the nation's future. An evaluation of the impacts of various technology improvements on reducing the levelised cost of electricity (LCOE) was made for the Australian EGS situation using the Geothermal Electricity Technology Evaluation Model. Technologies evaluated were doubling and tripling the flow, reducing drilling costs, increasing conversion efficiency, reducing parasitic loads, and supercritical cycles. Improving flow was found to have the biggest single impact on LCOE. A research portfolio comprising four programs has been devised to pursue funding - Optimising Resource Discovery, Reservoir Enhancement, Subsurface Systems Engineering and Technology in Context.