The Geoscience Australia (GA) building located in Symonston, ACT utilises one of the largest GSHP systems in the southern hemisphere. It is based on a series of 210 geothermal heat pumps throughout the general office area of the building, which carry water through loops of pipe buried in 352 bore holes each 100 metres deep and 20cm in diameter. The system is one of the largest and longest operating of its type in Australia, providing an opportunity to examine the long term performance of a GSHP system. A 10-year building review conducted in 2007 estimated that the system had saved about $400,000 in electricity costs. When comparing energy performance in the annual 'Energy Use in the Australian Government Operations' reports, the GA building has maintained energy performance and targets that might normally be expected of a general office administration building. This is significant given the requirements to provide additional fresh air to laboratories and 24/7 temperature control to special storage areas. The energy savings can be attributed to the GSHP system and other energy efficient design principles used in the building.

Numerical models are the primary predictive tools for understanding the dynamic behavior of the Antarctic ice sheet. But a key boundary parameter - the magnitude of sub-glacial heat flow - is controlled by geological factors and remains poorly constrained. We show that variations in the abundance and distribution of heat-producing elements (U, Th and K) within the Antarctic continental crust give rise to regional sub-glacial heat flows as much as 2-3 times greater than previously assumed in many ice modeling studies. Such elevated heat flows would fundamentally impact on ice sheet behaviour and predict higher regional basal melt production, enhanced ice surging and streaming. We also recognize that, prior to the breakup of Gondwana, much of the East Antarctic continental crust was contiguous with southern Australia where extensive high heat-producing Proterozoic-aged rocks, and correspondingly elevated regional heat flows, are well documented and such crustal rocks almost certainly extend beneath the modern east Antarctic ice sheet. Such fundamental geological controls on sub-glacial heat flow must be considered in accurately modeling ice dynamics, permitting more refined predictions of ice mass balance and sea level change and is a particularly relevant issue in the context of anthropogenic climate change.

The Habanero Engineered Geothermal System (EGS) in central Australia has been under development since 2002, with several deep (more than 4000 m) wells drilled into the high-heat-producing granites of the Big Lake Suite to date. Multiple hydraulic stimulations have been performed to improve the existing fracture permeability in the granite. The stimulation of the newly-drilled Habanero-4 well (H-4) was completed in late 2012, and micro-seismic data indicated an increase in total stimulated reservoir area to approximately 4 km². Two well doublets have been tested, initially between Habanero-1 (H-1) and Habanero-3 (H-3), and more recently, between H-1 and H-4. Both doublets effectively operated as closed systems and excluding short-term flow tests, all production fluids were re-injected into the reservoir at depth. Two inter-well tracer tests have been conducted since 2008, to evaluate the fluid residence time in the reservoir alongside other hydraulic properties, and to provide comparative information to assess the effectiveness of the hydraulic stimulations. The closed-system and discrete nature of this engineered geothermal reservoir provides a unique opportunity to explore the relationships between the micro-seismic, rock property, production and tracer data. The most recent inter-well tracer test occurred in June 2013, which involved injecting 100 kg of 2,6 naphthalene-disulfonate (NDS) into H-1 to evaluate the hydraulic characteristics of the newly-created H-1/H-4 doublet. Sampling of the production fluids from H-4 occurred throughout the duration of the 3-month closed-circulation test. After correcting for flow hiatuses (i.e. interruptions in injection and production) and non-steady-state flow conditions, tracer breakthrough in H-4 was observed after 6 days (compared to ~4 days for the previous H-1/H-3 doublet), with peak breakthrough occurring after 17 days. Applying moment analysis to the data indicated that approximately 56% of the tracer was returned during the circulation test (vs. approximately 70% from the 2008 H-1/H-3 tracer test). This suggests that a considerable proportion of the tracer may lie trapped in the opposite end of the reservoir from H-4 and/or may have been lost to the far field. Flow capacity:storage capacity plots derived from the H-1/H-4 tracer test indicate that the Habanero reservoir is moderately heterogeneous, with approximately half of the flow travelling via around 25% of the pore volume. The calculated inter-well swept pore volume was approximately 31,000 m³, which is larger than that calculated for the H-1/H-3 doublet (~20,000 m³). This is consistent with the inferred increase in reservoir volume following hydraulic stimulation of H-4.

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.

The economic viability of geothermal energy depends on the depth that must be drilled to reach the required temperature. This depends on the geothermal gradient, which varies vertically and horizontally in the Earth's crust. Traditionally these variations in geothermal gradient have been interpreted in terms of thermal conduction. However, advection and convection influence the temperature distribution in some sedimentary basins. Convection can cause the temperature gradient to vary significantly with depth, such that temperature estimates derived from extrapolation of shallow temperature gradients could be misleading. We use borehole temperature measurements in the Perth Basin (Western Australia) and the Cooper Basin (South Australia and Queensland) to reveal spatial variations in the geothermal gradient, and consider whether these patterns are indicative of convection.

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

Within the Central Australian region, nominally constrained by 22.5oS 134oE and 31.5oS 144oE for this study, lie several systems of stacked basins beneath the extensive Mesozoic Eromanga Basin. Remnants of Proterozoic basins are largely inferred from gravity, unexplored, and are not everywhere differentiated from an extensive cover of the lower Palaeozoic Warburton Formation. This sequence is the central link between the contiguous Amadeus, Officer and Georgina Basins, and the Thomson Fold Belt. Since the Carboniferous, the region has largely experienced intracratonic sag and has accumulated continental sediments, including thick coal measures, with intermittent tectonism and uplift. In late Early Cretaceous, marine conditions briefly invaded this subsiding region, but continental sedimentation resumed in the Late Cretaceous. Tectonism occurred in the Tertiary with basin inversion and subsequent formation of the Great Artesian Basin. In the Cainozoic, the region is again in subsidence and accommodating fluvial and aeolian sediment slowly into the Eyre Basin. The preserved depocentres of the Carboniferous-Permian-Triassic Cooper, Pedirka-Simpson, and Galilee Basins are spatially separate, although all contain comparable, largely organically-mature continental coal measure sequences.

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.

This report is a formal release of 12 new heat flow determinations made by Geoscience Australia. These new data are located in WA, NSW and Tasmania, and add to the 41 heat flow determinations previously released under the Onshore Energy Security Program.

Current understanding of Australia's geothermal resources is based on limited data such as temperature measurements taken in petroleum and mineral boreholes across the country. Heat flow studies are rarer, with existing publicly available compilations containing less than 150 heat flow data-points for Australia. Both temperature and heat flow data are unevenly distributed and, where no data exist, the available information has been interpolated over large areas to generate national-scale maps. Geoscience Australia has acquired the field and laboratory equipment required to measure heat flow. It began thermal logging of boreholes across Australia in late 2008 and has since collected 155 temperature logs. In late 2009, the thermal conductivity meter became operational, allowing the project to begin thermal conductivity measurements of samples collected from logged boreholes. To help clear some of the backlog of samples collected during 2008-09, the measurement of some of these samples has been contracted out. This record details the first set of new heat flow interpretations to be released by Geoscience Australia. The remaining temperature logs will be interpreted for heat flow and released, as thermal conductivity data for these holes become available.