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Home , Geothermal gradient

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 was initiated in the 1980s from hydrothermal resources and recognised low 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. 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 . 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 QUEENSLAND 4 Condensate heat extraction heat pumps Birdsville 3 heating without WESTERN from thermal water circulation 100° SOUTH Habanero Crude oil 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 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 ubr TroughBunbury

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 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: 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 and Resources South Australia). Geological Survey of Industry and Resources WESTERN AUSTRALIA Western Australia Ameed Ghori, Geological Survey of Western Australia, Department of Industry and Resources, Perth, Australia Data resources Initial study Potential hot rock resources Geothermal gradient (o C/km) Geological Survey of Western Australia (GSWA) has undertaken Northern 114° 116° 118° 120° 122° 124° 126° 122° 124° 126° 0 20406080100120 a) two specific studies in the search for geothermal energy (Figure 11). Bonaparte Hot Spots in Basin 0 Browse Basin Derby Sundown 1-3 Western Australia Whitewell 1 18° 500 km Kimberley Basin 16° Philydrum 1 18° Broome Roebuck Basin Fitzroy Crossing

20° Lamboo Complex Canning Nuytsia 1 2000 Northern Carnarvon Basin Gradiento C/km Basin 5 to 30 Canopus 1 20° 22° 30 to 40 North Pilbara Carnarvon

Terrain Depth (m) 40 to 50 a) b) Canning Basin Basin 50 to 60 PILBARA CRATON Wood Hills 1 60 to 70 Figure 11. Publications: a) GSWA Record 1982/6 “The Potential for Geothermal in Western Australia” by Arunta T. T. Bestow, 1982, b) Earthinsite consultancy report on “Geothermal Energy Potential in Selected Areas of Western Australia” 24° Hamersley Basin Orogen 70 to 80 by Dr P. N. Chopra and Dr F. Holgate, 2007, (GSWA unpublished report G31888 A1). Canning Basin 80 to 90 20° 4000 Bonaparte Officer Basin PHANEROZOIC Basin Carnarvon Basin 90 to 110 NEOPROTEROZOIC 24° Amadeus Wyndham Collier MESOPROTEROZOIC Kimberley and Edmund Basin Speewah Basins Gascoyne Basin Perth Basin CANNING BASIN Southern Carnarvon Complex Basin PALEOPROTEROZOIC Hooper Complex Basin 26° ARCHEAN Derby Ord Broome Narryer 114° 115°00' Basin Earaheedy Fitzroy Crossing Musgrave Estimated depth b) c) Terrane Yerrida Basin o Basin Complex to 200 C (km) Carnarvon Number of Normal High Basin Basin onshore wells Port Hedland Canning Basin Walkaway Dampier 0 to 1 Karratha Yeneena Bight 7 Onslow Basin Figure 16. Geothermal gradient versus depth plot for petroleum wells studied by Chopra and Holgate (2007). 28° Marble Bar P This plot shows that higher than normal geothermal gradients are observed in many wells. In Australian 29°00' Centralian Bonaparte 10 Gunbarrel Basin Superbasin basins, the high crustal are usually associated with local high-heat production under rocks 1 to 2 Exmouth Canning 260 28° Chinty 1 Talandji 1 Hamersley Basin of low thermal conductivity. Tom Price

Carnarvon Basin Paraburdoo Ashburton Basin Carnarvon 257 22° Exmouth Newman 2 to 3 Depot Hill 1 Officer Basin Edmund/Collier 2 Perth Hope Island 1 Edmund Basin Amadeus Trealla 1 Basin Gunbarrel 1 3 to 4 Carnarvon Sandy Point 2 Lefroy Hill 1 Collier Basin 30° Basin Officer 33 YILGARN CRATON Wingette 1 Roberts Hill 1 Mingenew

Bryah and Earaheedy Rough Range 11 Denham Padbury Basins Yerrida Basin Basin Ord 1 4 to 5 Warburton Ningaloo 1 Wiluna Meekatharra Parrot Hill 1 Perth 282 Eucla Basin Bullara 1 Dongara Officer Biranup Cue Gunbarrel Yilgarn Craton 2 Perth Complex 5 to 6 Sandalwood 1 Warradong 1 Kalbarri Leinster Basin Mt Magnet Basin Basin

YILGARN Laverton Figure 17. Map showing distribution of present-day geothermal gradients of the selected Geraldton 6 to 7 Leonora 32° petroleum exploration wells of the Canning, Carnarvon, and Perth Basins. This map CRATON 32° Coral Bay Dongara shows that the Carnarvon Basin has the greater number of wells with higher gradients, P Airey Hill 1 e followed by the Canning and Perth basins, respectively. r t 7 to 9 h ARG258

B Moora Kalgoorlie–Boulder a Eucla Basin s Nornalup North Yardanogo 1 i n Complex PERTH Norseman Pinjarra Boddington Three Springs Collie EN Bunbury OG Bight Basin OR Nornalup Complex The most prospective basin for geothermal energy appears to be the Carnarvon Basin, followed by the Esperance 112° 116° 120° 124° 128° R S E 500 km 24° Augusta R A Canning and Perth Basins. This is based on the present-day geothermal gradient for wells where the A L B A N Y – F ARG232

AlbanyBight Basin Geothermal Gradient 4°C/100 m Geothermal Gradient 5°C/100 m estimated depth to 200°C is less than 5 km (Figures 16 to 18).

Figure 12. Basins and number of petroleum wells drilled in Western Australia. Figure 14. Map showing hot areas in Western Australia based on BHT (bottom hole temperature) recorded in petroleum wells. This map was generated E The stress conditions are best known for the Perth Basin where the predominant orientation of the maximum Woodada 2 & 5 IN initially to select the areas for further detail study to verify the quality and quantity of subsurface data available for geothermal resource evaluation. L R horizontal stress is east–west, with similar conditions inferred for the Canning and Carnarvon Basins. E W Eneabba O Temperature versus Depth Application The extent and economic feasibility of hydrothermal and hot rock geothermal resources are presently Carnarvon P 0 Temperature Canning Basin Heat Pumps unknown because studies were qualitative, rather than quantitative, and based on limited datasets. Window Carnarvon Basin Perth Basin 1000 DirectDirect Leeman

HHydrothermal Data gathering, validating, and interpretation of more than 900 wells is underway for a quantitative assessment 30°00'

856 2000 that requires systematic geological, hydrogeological, geophysical, and geochemical evaluation to further delineate and prove these resources. Green Head 3000 Denham

Depth (m) Enhanced The estimates of equilibrium geothermal gradient and depth to basement have been used to predict the 26° 4000 ElectricityElectricity Geothermal temperature at the top of the basement and the depth at each well location required to reach the 200o C Figure 13. Wells completed (blue) by Chopra Systems

and Holgate (2007) and the wells currently 5000 Depth Window (EGS) Depth Window isotherm (Figure 18). 273 under study (red) for the evaluation of CARNARVON BASIN PERTH BASIN

274 geothermal resources from hot rocks. ARG259

100 o

256 Total 326 6000 Figure 18. Maps showing selected wells with estimated depths to 200 C shallower than 5 km: a) Canning Basin; b) Carnarvon Basin; c) Perth Basin.

93 Canning 0 50 100 150 200 250 300

80 Carnarvon Temperatureo C KEYWORDS: Geothermal resources, Hydrothermal, Hot rock, Western Australia. Perth Figure 15. Temperature versus depth plot to show recorded subsurface in petroleum wells of the Canning, Carnarvon, and Perth Basins with potential applications. This plot was generated initially to select the wells for further detail study to verify the quality and quantity of subsurface data available SHEET 2 – Western Australia’s Geothermal Resources - 2008 AAPG Annual Convention and Exhibition - 23 April, San Antonio, USA. for geothermal resource evaluation. Geological Survey of Industry and Resources PERTH BASIN Western Australia Ameed Ghori, Geological Survey of Western Australia, Department of Industry and Resources, Perth, Australia Geofluid resources Hydrothermal resources Conceptual models for potential hot rock resources The in Figure 21 shows the distribution of geothermal gradients and Figure 22 shows the Conceptual models for petroleum and geothermal resources have been developed for the Beagle Temperature information is also available from 242 petroleum wells over a larger area and a NORTHAMPTON first Perth Basin geothermal acreage release COMPLEX Western Australia is the beginning of a major expansion temperature versus depth. These figures are based on data available from 145 artesian Ridge (Figure 23) and the Cadda Terrace (Figure 24) in the northern part of the Perth Basin. High greater depth (850 m) from the Perth region water bores. Of theseonly 83 wells have been studied o TERRACE IRWIN in exploration for hot rock geothermal resources (Figure 1). monitoring water bores. Of these, 47 recorded temperature logs that were used to calculate geothermal gradients are observed in Jurien 1 (55 C/km; Figure 25) on the Beagle Ridge and to date (Chopra and Holgate 2007; Figure 13). oo o DONGARA geothermal gradients. The recorded gradients range from 1.1 C/100 m to 4.4 C/100 m, Woodada 02 (40 C/km) within the Woodada Gas Field on the Cadda Terrace (Figure 26). Jurien 1 SADDLE The Perth Basin is a north–south elongated trough in the For the Perth Basin, the estimated geothermal gradients in 83 wells indicate very high to normal a depth of about 1 km. was drilled to a total depth of 1026 m and intersected granitic basement at 967 m. The o southwest of Western Australia (Figure 19), contains o gradients, ranging from 90 to 20 C/km (Figure 16). Gradients in wells deeper than 2 km are 4.4 extrapolated recorded temperatures indicate that 200 C was expected to be reached between Permian to Lower Cretaceous succession under a thin AM3 10 km o considered more reliable and representative for hot rock resources. 4.2 2.5 and 3 km (Figure 25). Temperatures around 200 C at these depths have potential for the

ABROLHOS SUB-BASIN cover of Tertiary rocks. These successions are a AM2 development of geothermal energy. Figure 26 shows the subsurface temperatures as a function 4.0 The recorded maximum horizontal stress orientations are east–west across the Perth region source of groundwater and petroleum with potential of depth in 17 wells of the Woodada Gas Field. The extrapolated temperatures indicate that 200o C YILGARN 3.8 (Reynolds and Hillis, 2000). These observations are highly relevant for assessing the hot dry rock for geothermal energy (Figure 20). is expected to be reached between 4 and 5 km. These are potentially suitable depths for 3.6 prospectivity of the basin because maximum horizontal stress creates the most favourable CRATON developing geothermal resources with conditionsfavourable for enhanced geothermal systems . BEAGLE This evaluation is mainly based on GSWA publications : environments (Chopra and Holgate, 2007). 3.4 The reservoir temperature of the Woodada Gas Field is 120o C at a depth range from CADDA TERRACE 3.2 Temperature (°C) Temperature (°C) Geothermal resources 2125 to 2496 m (Owad-Jones and Ellis, 2000). 0 50 100 150 200 250 0 50 100 150 200 250 TURTLE DOVE 30°00' 3.0 0 0 Bestow (1982), Chopra and Holgate (2007), o Temperatu r e Window Temp eratu r e Window RIDGE 2.8 Figures 25 to 27 show that the recorded temperatures and depths are up to 150 C and 4.5 km. Ghori (2007 and 2008). Woodada Gas Field The corrected estimated equilibrium temperatures are expected to be higher (by generally 500 DANDARAGAN 2.6 East Lake Logue 1 RIDGE 10 to 20%) than these recorded temperatures. 500 Indoon 1 2.4 1000 Thorpe and Davidson (1991),. Davidson (1995) Woodada 1 Petroleum geology QUINNS ROCK 2.2 LINE HP 82-221 Sedimentary Woodada 2 Beagle Ridge Thermal Insulation 1500 Woodada 3 2.0 m Geothermal Gradient ( )°C/100 Jurien 1 1000 Crostella (1995), Mory and Iasky (1996), Crostella Beagle Cadda Terrace Woodada 4 W 200 300 400 E and Backhouse (2000), Owad-Jones and Ellis (2000) 1.8 2000 Woodada 5 TROUGH AM28 0.00 Woodada 6 Depth Window WANNEROO 1.6 Middle Jurassic Depth Window Unpublished company reports submitted to GSWA. Hydrothermal Woodada 8 1500 2500

1.4 & Petroleum Sedimentary Thermal Insulation Woodada 9

Depth (m) Systems Depth (m) Woodada 10 See also reference list below. AM33A 1.2 1026 mKB Triassic 3000 Woodada 11

INDIAN 1.0 Sedimentary Woodada 12 1.00 2000 Permian Precambrian OCEAN Thermal Insulation 3500 Woodada 14 Woodada 15 PERTH Precambrian Precambrian Woodada 17 Temperature (°C) 4000 Woodada 19 10 20 30 40 50 60 2500 BASIN 0 2.00 Hot Rock 4500

PERTH Seconds 32°00' 200oC between 2500 and 3000 m 200oC between 3900 and 5000 Geothermal ARG263 3000 5000 0 50 100 150 200 250 0 50 100 150 200 250 VLAMING 200 Systems SUB-BASIN Figure 25. Subsurface temperatures as a function of depth Figure 26. Subsurface temperatures as a function of depth in Reservoirs for significant in Jurien 1. Woodada Gas Field wells. Ma Age Rock Unit Water petroleum occurrences 3.00 0 Temperature (°C) Rockingham 0 50 100 150 200 Ascot/ Yoganup Fms 0

20 Neogene 400 References Bestow, T. T, 1982, The potential for geothermal energy development in Western Australia: Geological Survey of Western Australia, Record 1982/6, 67p. Chopra, P. N, 2005, Status of the geothermal industry in Australia, HARVEY RIDGE 40 KWINANA 2000– 2005: Proceedings, World Geothermal Congress 2005, Antalya, Turkey, 24–29 April 2005. Chopra, P. N, and 500 F. Holgate, 2005, A GIS analysis of temperature in the Australian crust: Proceedings, World Geothermal Congress Kings Park Fm Kings Park 4.00 2005, Antalya, Turkey, 24–29 April 2005. Chopra, P. N, and F. Holgate, 2007, Geothermal energy potential in

Paleogene Figure 23. Conceptual model for petroleum and geothermal resources of the Beagle Ridge, Perth Basin. 60 KWINANA Depth (m) selected areas of Western Australia; a consultancy report by Earthinsite.com Pty Ltd for Geological Survey of 600 Western Australia: Geological Survey of Western Australia, Statutory petroleum exploration report, G31888 A1 VASSE TERRACE 1000 (unpublished). Cull, J. P, 1977, Geothermal energy prospects in Australia: Search, v. 8, no. 4, p. 117–121. Cull, J. 80 LINE HP 82-224 P, 1979, Regional variations in Australian heat flow: Australia BMR, Journal of Australian Geology and , ROCKINGHAM Beagle v. 4, no. 1, p. 113. Cull, J. P, 1982, An appraisal of Australian heat flow data: Australia BMR, Journal of Australian COLLIE Woodada 10 Geology and Geophysics, v. 7, p. 11–21. , , A case for research and development Coolyena Gp 1500 Cull, J. P, and D. Denham 1978 Ridge W E on geothermal energy in Australia: Australia Bureau of Mineral Resources, Record 1978/58, p. 7. Crostella, A., 100 SUB-BASIN 102 Beagle Fault 200 Cadda Terrace 300 385 1995, An evaluation of the hydrocarbon potential of the onshore Perth Basin: Western Australian Geological Survey, Mirrabooka 800 0.00 Report 43, 67 p. Crostella, A., and J. Backhouse, Geology and petroleum exploration of the central and southern Perth Basin, Western Australia: Western Australian Geological Survey, Report 57, 85 p. Davidson, W. A., 1995, Cretaceous 2000 120 Upper Cretaceous Hydrogeology and groundwater resources of the Perth Region, Western Australia: Western Australia Geological Warnbro Gp Leederville Survey, Bulletin 142, 257p. Ghori, K. A. R., 2007, Search for energy from geothermal resources in Western Australia: September 2007 Petroleum in Western Australia, Western Australia's Digest of Petroleum Exploration, 140 Parmelia Fm Middle Jurassic 2500 Development and Production, Department of Industry and Resources, Perth, p. 36–39. Ghori, K. A. R, 2008, The PEELHURST search for Western Australia's geothermal resources: Geological Survey of Western Australia Annual Review

1000 Depth(m) 2006–07, p. 25–31. Hillis, R. R., and S. D. Reynolds, 2000, The Australian Stress Map: Journal of the Geological Yarragadee Fm Yarragadee Warro (GS) SINGLETON ARG262 160 Society, London, v. 157, p. 9159–21. Mory, A. J., and R. P. Iasky, 1996, Stratigraphy and structure of the onshore

COMPLEX Hydrothermal

y Thermal Insulation LEEUWIN MADORA northern Perth Basin, Western Australian Geological Survey, Report 436, 102 p. Narayan, S. P., D. Naseby, Z.

BUNBURY Cadda Fm Waterbores 3000 TROUGH Ocean Hill, Gingin, 1.00 & Petroleum Yang, and S. S. Rahman, 1998a, Petroleum and hot dry rock: two of the energy sharing commonalities: APPEA Walyering, (GS) Journal 1998, p. 830–847. Narayan, S. P., D. Naseby, Z. Yang, and S. S. Rahman, 1998b, Creation of HDR 180 Jurassic Cattamarra Mount Horner (oil), Average gradient Lowest gradient

34°00' Hydrothermal Resources Systems Coal Measures North Yardanogo (OS) MANDURAH reservoirs under Australian in-situ stress conditions, in Proceedings of Twenty-third Workshop on Geothermal

Sedimentar Highest gradient High gradient 3500 Reservoir Engineering: Stanford University, Stanford, California, USA, January 1998, p. 322–329. Owad-Jones, D., Eneabba Fm Erregulla (OS) AM68A , Western Australia atlas of petroleum fields, Onshore Perth Basin, Petroleum Division, 200 and G. Ellis, 2000 Figure 21. Distribution of subsurface geothermal gradients from Figure 22. Subsurface temperatures and depth informatoin from water bores of Triassic Department of Mineral and Energy Western Australia, Volume 1, 114 p. Reinecker, J., O. Heidbach, M. Tingay, B. water bores of the Perth region the Perth region. TD 2340mKB Sperner, and B. Müller, 2005, The release of the 2005 World Stress Map: World Stress Map Project, Geophysical Seconds Permian 4000 Institute, Karlsruhe University. Sass, J. H, 1964, Heat-flow values from the Precambrian of Western Australia: 220 Lesueur Ss Journal of Geophysical Research, v. 69, no. 2, p. 299–308. Sass, J. H., J. C. Jaeger, and R. J. Munroe, 1976, Heat 2.00 Sedimentary Thermal Insulation flow and near-surface radioactivity in the Australian : United States Geological Survey, Open-File Triassic Figure 21 indicates that the recorded highest and lowest subsurface temperatures are Report 76–250, 91p. Somerville, M., D. Wyborn, P. Chopra, S. Rahman, D. Estrella, and V. D. M. Theo, 1994, 240 Precambrian 4500 Hot dry rock feasibility study, a report compiled for the Energy Research and Development Corporation: Canberra, Woodada Fm Dongara, Mount Horner, around the Wanneroo area. The lowest temperatures extend towards the north of and the Australia, Energy Research and Development Corporation, ERDC 94/243, 133p. Thorpe, P. M., and W. A. Kockatea Sh Whicher Range, Yardarino Wells = 248 Davidson, 1991, Groundwater age and hydrodynamics of the confined aquifers, Perth, Western Australia, in BHTs = 539 Proceedings of the International Conference on Groundwater in Large Sedimentary Basins, Perth, Western 260 Dongara SS and higher temperatures towards the south of the Wanneroo area. Figure 22 indicates low Beekeeper Fm Australia, 1990: Australian Water Resources Council Series, no. 20, p. 420-436. Carynginia Fm Beharra Springs, Dongara, o Hot Rock 5000 Hakea, Mondarra, Mount Horner, Irwin River Yardarino, Woodada temperature resources up to 50 C at a depth less than 1 km in areas of high geothermal Figure 27. Perth Basin subsurface temperatures as a function of YALLINGUP 280 Coal Measures Permian Arrowsmith, Dongara, Geothermal depth recorded as 540 BHTs in 242 petroleum wells. Holmwood Sh High Cliff Ocean Hill,Yardarino 50 km SHELF Sandstone gradients. 3.00 Nangetty Fm Dongara, Mount Horner, Yardarino 300 Systems 115°00' 116°00' Basement Hot Dry Rocks ARG264 The first West Australian geothermalstudy by Bestow (1982) recognised low temperature Figure 19. Perth Basin structural units and petroleum wells. Figure 20. Generalized stratigraphy of the Perth Basin and distribution of groundwater aquifers, o KEYWORDS: Geothermal resources, Hydrothermal, Hot rock, Western Australia. petroleum reservoirs and potential geothermal resources reservoirs (65-85 C) at greater depths (2 to 3.5 km), with the best economic potential ARG263a in the Perth Basin. Figure 24. Conceptual model for petroleum and geothermal resources of the Cadda Terrace, Perth Basin. SHEET 3 – Western Australia’s Geothermal Resources - 2008 AAPG Annual Convention and Exhibition - 23 April, San Antonio, USA.