EGS Permeability Enhancement - IEA...
Transcript of EGS Permeability Enhancement - IEA...
August 2008
IEA-GIA/EDC Joint Geothermal Seminar
Tagaytay, Philippines, September 21, 2013
Adrian Larking – Green Rock Energy Limited
Barry Goldstein - Government of South Australia
Robert Hogarth – Geodynamics
Peter Reid – Petratherm
EGS Permeability EnhancementAustralian Experience
Australian Geothermal EGS Activities
■Overview of past geothermal activities
■Update of key projects
■Lessons learned & future directions
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Overview of Geothermal in Australia
• 9 ‘deep’ wells drilled to reservoir depths by 3 different companies/ Joint Ventures
• 7 are EGS wells, 2 are HSA wells. 6 of the EGS wells have had major hydraulic stimulation
� EGS projects all in South Australia
� EGS projects at reservoir depth:• Petratherm – in Mesoproterozoic
metasediments• Geodynamics
- in granites below complex Cooper sedimentary basin, a petroleum province;
- 1MWe capacity pilot plant commissioned
Image courtesy Panax Geothermal
Why EGS in Australia?
Below Ground actors
� Extensive radiogenic basement (heat source) below insulating sediments
� Australia n plate converging with Indonesia – giving rise to horizontal compression and common naturally occurring horizontal fractures (reservoir)
Above Ground
� Land access / title to resources� Government stimulus for low emission
renewable energy RDD&D
� Market recognition of extensive, hot rocks
� Political will to attain energy security & mitigate risks of climate change
� Growth in energy demand
Temperature at 5 km, Somerville et al. (1994)Temperature at 5 km, Somerville et al. (1994)Temperature at 5 km, Somerville et al. (1994)Temperature at 5 km, Somerville et al. (1994)
Rosemanowes Cornwall, UK
1984-91
Fenton Hill, Los Alamos
USA 1970-95 500 metres
Soultz, France
Since 1987
Epicenters of stimulated fracture growth
Courtesy of Geodynamics
EGS Trials (Displayed)
• Fenton Hill, USA: 70 –95
• Fjalbacka, Sweden: 84 - 88
• Rosemanowes, UK : 84 - 91
• Hijiori, Japan: 85 - 00
• Soultz, France: 87 – Current
• Ogachi, Japan: 89 - 00
• Habanero, Australia: Current
• Bad Urach, Germany: Current
• Basel, Switzerland: Abeyance
• Landau, Germany: Current
Engineered Geothermal Systems - Seismic Cloud, Plan View, Same Scale
Habanero 1, 2 & 3 South Australia2005- ongoing
Australian EGS
> 4x’s than
attained
elsewhere
EGSWater is injected under pressure into naturally fractured rocks to increase the intensity and extent of fractures. The micro-shifting of rocks during that fracture stimulation process is located in the same way epicentres of blasting and earth tremors are determined
Olympic Dam Project
4km
Approximate
Scale
Blanche 1
2000m
8000m
4000m
6000m
0m
1590Ma GraniteResource
Reprocessed Geoscience Australia Seismic Line
Cover Sediments
Cored well drilled 1954m into granite at a site where natural fractures were apparently not abundant
Analysis of stress field in 1954m well from diamond drill core, borehole breakouts, impression packer, core-discing & hydraulic injection testing:
• Winch & wireline hydraulic packer system allows injecting without a rig
• 71mm inflatable straddle packers
– system operable up to 100ºC, 60MPa
– packer test interval 0.7m
– Water injected via (10mm) coiled tubing
– limit of tool about 40MPa differential P
– Maximum water injection rate is 12 l/min.
• Below 1700m the minimum principal stress is vertical which should result in horizontal hydraulic fracture plane
• Small scale hydraulic injection has opened fractures in the granites but with low permeability
Olympic Dam – Hydraulic Injection Test
Petratherm’s Paralana, Arrowie Basin
� Targeted fracture permeability in Mesoproterozoic metasediments above hot granites
� Fractured sediments were overpressured
� Successful fracture stimulation
� Lessons learned
� need to target natural fractures to obtain sufficient total flow rates
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Petratherm Flow Test of Paralana–2, Oct 2011
2011
• 1.28 million litres of brines (22.4MPa over-pressured) from fractured meta-sediments from 3670 to 3864m
• Bottom hole temperature 190°C (4030m)
• Fracture stimulation & flow testing produced 1.28 million litres fluid at flow rate of1-6 l/s
• 171°C from bottom 200m tested
• Image courtesy Petratherm
2013-2013 Planned Activities
� June 2013 –granted A$13 million (requires matching funds) for 7MWe project by ARENA for research into site’s commercial potential
� $24.5m to be used :
• from late 2013 - drill Paralana 3 deep production well & carry out hydraulic stimulation of Paralana 2 & 3
• 2014 circulation and flow testing
• 2015 commission 3.75 MWe plant & connect to Beverley U mine 10km away
Geodynamics 3 EGS Fields
Cooper BasinHabanero EGS Field
� 4 stimulated wells >4500m into fractured, >250°C over pressured granite
� Granite reservoir stimulated
� Connection between HAB 1 & HAB 3 proven via tracer & pressure testing
Jolokia & Savina EGS Fields
� 1 well in each field – Jolokia 1 (4911m), Savina-1 (3700m)
� Jolokia reservoir is hotter but tighter than Habanero & had drilling mud problems
Image courtesy Geodynamics Ltd
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Habanero Field
Stimulation and Circulation Experience
(see presentation prepared by
Robert Hogarth of Geodynamics)
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▐ Geothermal drilling engineering experience & expertise is essential
▐ Main EGS resource challenge is not temperature but to engineer
sustainable reservoirs with sufficient permeability and size
▐ Inadequate permeability obtained to date from engineering fractures in large
open hole sections
▐ Multiple fractures/faults are required to provide sufficient flow
▐ Advisable to target natural open fractures and enhance natural permeability
to attain sufficient sustainable flow rates
▐ Natural open fractures are mostly water saturated, some are overpressured
▐ Geodynamics says it’s challenge is to complete at least two zones/well
▐ Two EGS projects in South Australia are moving forward with operations
scheduled for the next 12 – 18 months
� Geodynamics EGS project in the Cooper Basin – now on reduced scale, needs
to find local markets.
� Petratherm’s Paralana Project in Sth Australia – is seeking A$5 million
Lessons Learned
August 2008
Thank you
Contact us at:Adrian Larking – Green Rock Energy [email protected]
www.greenrock.com.au
Barry Goldstein – Government of South Australia
www.dmitre.sa.gov.au