PSWestern Australia’s Geothermal Resources* By Ameed Ghori1 Search and Discovery Article #80023 (2008) Posted August 18, 2008 *Adapted from extended abstract prepared for poster presentation at AAPG Annual Convention, San Antonio, Texas, April 20-2, 2008, together with poster presentation (in PDF format). 1Geological Survey of Western Australia, Department of Industry and Resources, East Perth, WA, Australia ([email protected]) Abstract Western Australia is commencing a new era in the search of energy from geothermal resources. The study for a geothermal energy was initiated in the 1980s from hydrothermal resources and recognised low temperature reservoirs (65-85oC) at greater depths (2-3.5 km), with the best economic potential in the Perth Basin. The high temperature hydrothermal resources that are attractive geothermal energy targets in geologically active areas of the United States, Philippines, Mexico, Indonesia, and Italy are not found in tectonically stable Western Australia. Thus the second study for geothermal energy in 2006 targeted hot rock resources that are currently economic, where the depth to 200oC is less than five km. Petroleum wells in parts of the Canning, Carnarvon, and Perth basins indicate two favourable factors for developing Enhanced Geothermal System (EGS), potentially high-heat generating granitic basements and maximum horizontal stress orientations that are favourable for developing horizontally oriented high temperature geothermal reservoirs. The Carnarvon Basin has the greatest number of wells with high temperature gradients, followed by the Perth and Canning basins. The extent and economic feasibility of hydrothermal and hot rock geothermal resources are presently unknown because studies were qualitative, rather than quantitative, and based on limited datasets. Data gathering, validating, and interpretation of greater than 1000 wells is underway for a quantitative assessment that requires systematic geological, hydrogeological, geophysical, and geochemical evaluation to further delineate and prove these resources. The Australian continent has significant potential for geothermal energy from known high heat-producing granites, and Geodynamic Ltd is a leader of testing the commercial viability of extracting heat energy by EGS at the Habanero project in the Cooper Basin. Geological Survey of Industry and Resources WESTERN AUSTRALIA'S GEOTHERMAL RESOURCES Western Australia Ameed Ghori, Geological Survey of Western Australia, Department of Industry and Resources, Perth, Australia New era Geothermal Energy Western Australia Australia Energy outlook Energy types Australian achievements The first acreage release for geothermal exploration in the South Australia was the first State to develop legislation for The energy outlook for this century indicates that there will be Geothermal Energy includes thermal or electrical power Australia is at the forefront of testing the commercial viability of extracting heat energy by EGS at the Habanero Perth Basin on January 22, 2008 commenced a new era in geothermal exploration and granted the first Australian significant energy supplies from geothermal, solar, wind, and produced from the heat contained in the Earth. There are two project in the Cooper Basin, South Australia. The objective of the Habanero project is to develop Australia's first the search for energy in Western Australia to broaden the Geothermal Exploration Licence (GEL) in 2001. Since then hydro-electric resources. Of these, geothermal energy from hot basic types of energy that can be sourced from Earth's heat: commercial-scale power plant from geothermal resources in stages. A 50 MW power plant is planned for State's energy base (Figure 1). about 12 geothermal wells have been drilled in South Australia rocks shows the greatest potential for long-term, continuous from hydrothermal systems (hot geofluids; Figure 6) and from development by mid-2011, which could gradually be expanded to 100s of MW for commercial base-load power (Figure 2). electricity supply, and Australia is leading the way in EGS hot rocks (hot dry rocks, HDR; Figures 6 and 7). plants. The completion of Habanero 3 at target depth of 4221 m is a significant milestone toward The geothermal acreage release followed the amendments (enhanced geothermal system) technology (Figure 4). commercialization of the HFR (hot fractured rock) geothermal well (Figure 8). to the State's Petroleum Act 1967 that were approved in Darwin shallow-borehole hydrothermal km heat exchangers systems hot dry rock January 2008, now known as the Petroleum and Geothermal 150 0 10° Energy Resources Act 1967. km World population + estimated energy demand 0 Habanero #1 Hydro-electric heat extraction heat pumps from ambient heating with 1 Habanero #3 NORTHERN Geothermal, solar, wind rock formation TERRITORY Nuclear 2 500 m 100 Coal 3 Alice Springs Natural gas QUEENSLAND 4 Condensate heat extraction heat pumps Birdsville 3 heating without WESTERN from thermal water circulation 100° SOUTH Habanero Crude oil groundwater through stimulated 5 AUSTRALIA 1, 2 & 3 fractured rock AUSTRALIA Brisbane 50 Water Saturated Coober Pedy Yerila 1 Over pressures Paralana 1B DW1 115° 117° Blanche 1 Leigh Creek 28° per year Billion barrels oil equivalent NEW SOUTH wer Northampton Perth Port Augusta Irwin Terrace WALES Figure 8. Left photo shows steam flowed from Habanero 1 and right photo shows Habanero 3, steam flowed, as part of the well clean up program prior to flow testing.T he well flowed at approximately 23 kg/sec. Mullewa and po process heat Sydney 500 km Adelaide A.C.T. Canberra 1900 2000 2100 © Geothermal Explorers Ltd, 2004 Since 1970 research has been undertaken worldwide aimed at commercial utilization of the Earth's heat using Geraldton 6 ARG255 >220° Abrolhos Sub-basin Heat Flow 4 VICTORIA Figure 4. World’s energy outlook for this century EGS technology applied to HDR (hot dry rock) sources so that energy can be extracted (Figures 9 and 10). Heat Flow 1A,3A (Courtesy of Geothermal Explorers Ltd). Figure 6. Type of geothermal resources from Earth’s heat, Geothermal well Portland Melbourne (courtesy of Geothermal Explorers Ltd). Geothermal exploration license application Three Springs Dandar Beagle Ridge Geothermal exploration license Turtle Dove Ridge TASMANIA The trend in EGS technological advances indicates that within Cadda Loop 1 Loop 2 Australia France Germany Japan Sweden UK USA Geothermal gazettal Hobart agan Trough decades the cost for electricity generation from EGS will be 30° YILGARN Figure 2. Map showing geothermal exploration in Australia. 1975 Terrace CRATON competitive with conventional energy generation from coal binary geothermal and natural gas, and lower than any other form of renewable power plant 3000 m There has been an exponential increase since 2002 in the Urach 7 Moora heat 300 m Beermullah Trough energy (Figure 5). 300 m interest shown by companies that is reflected by increasing exchanger Cooper Basin 3500 m GEOTHERMAL investment in the exploration and development of geothermal 1980 Ogachi 2100 m Lancelin RELEASE energy resources in Australia (Figure 3). 300 m 6 AVERAGE CASE COST Falkenberg Wells 80 0 PERTH Gingin Soultz Deep Phase II An investment totalling $686 million has been proposed for 1985 4000 to BASIN 5 wes 5000 m Cunderdin 800 m Hijiori Northam five-year work programs by 27 companies over 166 licences. Le Mayet Small hydro 100 m Fenton Vlaming 160 Hill 1 2700 m Sub-basin Perth 70 Biomass 2000 m 32° Wind 1990 4 Rosemano Proposed Research Geothermal insulating OGC 1 Fijallbacka 140 Proposed 4500 m & sedimentary Coso Brookton OGC 2 2300 m rocks 2 3 Desert Peak 60 1000 m 120 Soultz 1995 3500 m South Australia Field Boddington equivalent) Thermal output (MWe Mandurah Terrace test Field Vasse 100 Other States Terrace test 2 3 Soultz deep Bunbury Trough Soutlz shallow Fenton Hill Phase II Fenton Collie LRAC, $/MWh 50 2000 Hunter wes Bunbury Collie Wagin 80 OGC 3 Circulation Sub-basin Valley Hijiori Busselton 5000 m 1300 m long term Coso 1 3500 m Hill Phase I Fenton COMPLEX LEEUWIN granite 4 Cooper test & 60 4300 m Desert Rosemano Yallingup Shelf 40 Ogachi 34° 4.5 2005 Plant Peak 0 40 270°C km 1975 1980 1985 1990 1995 2000 2005 2010 Figure 9. Major HDR and EGS projects worldwide. Cumulative Expenditure (A$ million) Cumulative (source: http://geothermal.inel.gov). Figure 10. Estimated electrical power output per production well, with time from EGS projects. 20 (source: http://geothermal.inel.gov) 30 Gas well ARG253 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 Oil well 0 Figure 7. Concepts for electricity generation from hot rock at Geodynamics Ltd’s Habanero project, Cooper Basin, South Australia. Loop 1 includes injection and production wells to circulate water for extraction and transfer of heat from 2000 2001 2002 2003 2004 2005 2006 2007 KEYWORDS: Geothermal resources, Hydrothermal, Hot rock, Western Australia. 50 km Other well Figure 5. Outlook for electricity generation from alternative energy hot rocks at depth to the surface. Loop 2 includes a surface heat exchanger to run a turbine for electricity generation, Year (source: Renewable Energy Generators Australia Ltd). (courtesy of Geodynamics Ltd.) ARG266 Figure 3. Australian expenditure growth in geothermal exploration from 2000 to 2007 SHEET 1 – Western Australia’s Geothermal Resources - 2008 AAPG Annual Convention and Exhibition - 23 April, San Antonio, USA. Figure 1. Map showing acreage release and petroleum wells locations in the Perth Basin. (source: Primary Industries