Current status of the high Current status of the high enthalpy conventional enthalpy conventional

geothermal fields in Europe and geothermal fields in Europe and the potential perspectives for the potential perspectives for their exploitation in terms of their exploitation in terms of

EGSEGS

A. ManzellaA. ManzellaCNR – IGG, Pisa, ItalyCNR – IGG, Pisa, Italy

Hervé TraineauHervé TraineauCFG-Services, Orléans, FranceCFG-Services, Orléans, France

Olafur FlovenzOlafur FlovenzISOR, Grensásvegur, IcelandISOR, Grensásvegur, Iceland

The electrical energy production from geothermal The electrical energy production from geothermal power plants in Europe comes almost entirely from power plants in Europe comes almost entirely from Iceland, Italy, Russia (Iceland, Italy, Russia (Kamtchatka and Kuril islandsKamtchatka and Kuril islands), ), France (Guadeloupe, French West Indies), Portugal France (Guadeloupe, French West Indies), Portugal (Azores) and Turkey.(Azores) and Turkey.

ItalyItaly

IcelandIceland

TurkeTurkeyy

Portugal Portugal (Azores)(Azores)

Russia Russia ((Kamtchatka Kamtchatka

and Kuril and Kuril islandsislands) ) France France

(Guadeloupe, (Guadeloupe, French West French West

Indies)Indies)

FranceFrance Volcanic island (Guadaloupe, French West Indies)Volcanic island (Guadaloupe, French West Indies) Brines with 60% seawater, 40% meteoric watersBrines with 60% seawater, 40% meteoric waters Temperature of 250-260Temperature of 250-260°C°C intersected by wells at 300- intersected by wells at 300-1000 m depth1000 m depth 4MW in Bouillante 1 on 1995-1996, 11MW on 2004, for a 4MW in Bouillante 1 on 1995-1996, 11MW on 2004, for a total of 15 MW with 2 power plantstotal of 15 MW with 2 power plants Exploration recognized a large extension of the reservoir. Exploration recognized a large extension of the reservoir. Third unit in the pre-fesibility phaseThird unit in the pre-fesibility phase Two other islands (Two other islands (Martinique and La Réunion)Martinique and La Réunion) in in explorationexploration

IcelandIceland

Volcanic scenario, active Volcanic scenario, active rifting. Large active rifting. Large active volcanic zone running SW-volcanic zone running SW-NENE Various heat sources Various heat sources (dikes or magma chamber) (dikes or magma chamber) and fluids: seawater, and fluids: seawater, meteoric water meteoric water with/without volcanic with/without volcanic gasesgases Water-dominated, > Water-dominated, > 300°C at 2.5 km depth300°C at 2.5 km depth Natural recharge and Natural recharge and reinjectionreinjection

IcelandIceland

Bjarnarflag on 1969, then Bjarnarflag on 1969, then Krafla, Nesjavellir and Krafla, Nesjavellir and SvartsengiSvartsengi 2 new power plants in 2006 2 new power plants in 2006 and 2007 for 220 MWe in and 2007 for 220 MWe in Hengill area Hengill area 7 new production field: 3 in 7 new production field: 3 in N-Iceland, 1 central, 3 in the SN-Iceland, 1 central, 3 in the S

120 MW

IcelandIceland

Min. casing Min. casing depthdepth

Target depthTarget depth

In addition there are plans In addition there are plans to develop to develop Unconventional Unconventional Geothermal SystemsGeothermal Systems. The . The main idea is to drill deep main idea is to drill deep enough into the intrusion enough into the intrusion complexes of the volcanic complexes of the volcanic systems to get systems to get supercriticalsupercritical fluidsfluids and exploit the and exploit the enormous energy stored in enormous energy stored in the depth interval the depth interval 3-5 km3-5 km within the volcanic within the volcanic systems. The systems. The Iceland Deep Iceland Deep Drilling ProjectDrilling Project is a part of is a part of these plans (see these plans (see www.iddp.is)..

ItalyItaly

• 2 exploited areas (Larderello-Travale/Radicondoli and Mt. 2 exploited areas (Larderello-Travale/Radicondoli and Mt. Amiata) in one region (Latera decommisioned)Amiata) in one region (Latera decommisioned)• A shallow reservoir in carbonatic, a deeper reservoir in A shallow reservoir in carbonatic, a deeper reservoir in metamorphic unitsmetamorphic units• Steam dominated in Larderello-T/R, water dominated in Mt. Steam dominated in Larderello-T/R, water dominated in Mt. Amiata (extinct volcano)Amiata (extinct volcano)• 20 MPa and 300-350°C at 3 km20 MPa and 300-350°C at 3 km

ItalyItaly• Larderello-T/R in 400 km2, 202 wells, 27 units, 702 MW Larderello-T/R in 400 km2, 202 wells, 27 units, 702 MW installed capacity, reinjectioninstalled capacity, reinjection• Mt. Amiata 5 units, 88 MW, reinjectionMt. Amiata 5 units, 88 MW, reinjection

• 1° experiment 1° experiment worldwide 1904, 1° worldwide 1904, 1° production in 1913, production in 1913, increase of production increase of production (apart 2nd WW period)(apart 2nd WW period)• Reinjection and deep Reinjection and deep exploration in the ’70, exploration in the ’70, when field started to when field started to deplate. New rapid deplate. New rapid increase of productionincrease of production• Increase of 100 MW Increase of 100 MW foreseen in 5 yearsforeseen in 5 years

PortugalPortugal• Azores volcanic islands Azores volcanic islands , São Miguel, São Miguel• 2 Power plants, 16 MW2 Power plants, 16 MW• 1 new power plant for 10 MW1 new power plant for 10 MW• Exploratin on-going in Terceira island, project for 12 MW by Exploratin on-going in Terceira island, project for 12 MW by 2008 (50% energy of island)2008 (50% energy of island)

RussiaRussia

1 – suitable for heat pumps; 2 – promising for “direct” utilization; 3 – regions of active volcanism, power generation at binary plants / high capacity GeoPP

• Areas of active volcanism, Areas of active volcanism, Kamchatka and Kuril IslandsKamchatka and Kuril Islands• 2 reservoirs, vapour and water dominated fields, 250-2 reservoirs, vapour and water dominated fields, 250-310°C310°C

• In Kamchatka 3 power plants, 73 MW installed capacity. 106 In Kamchatka 3 power plants, 73 MW installed capacity. 106 MW under developmentMW under development• In Kuril Island 6 MW installed capacity, foreseen increase of In Kuril Island 6 MW installed capacity, foreseen increase of 14MW14MW

RussiaRussia

TurkeyTurkey

• Kizildere geothermal field, Kizildere geothermal field, active tectonic settingactive tectonic setting• Shallow reservoir in Shallow reservoir in limestones and marble (195-limestones and marble (195-205205°C°C at 600-800 m) and at 600-800 m) and deep reservoir in gneiss deep reservoir in gneiss (240(240°C°C at 1.5 km) at 1.5 km)• liquid COliquid CO22 and dry ice and dry ice production factoryproduction factory

TurkeyTurkey• Discovered in 1968, productive since 1984, 20.4 MW of Discovered in 1968, productive since 1984, 20.4 MW of installed capacity, 12-15 MW running capacityinstalled capacity, 12-15 MW running capacity• Reinjection test with positive results. Reinjection wuld solve Reinjection test with positive results. Reinjection wuld solve the decline of production and the pollution due to waste waterthe decline of production and the pollution due to waste water

EUROPEEUROPECountry Field Drilled

area(km2)

Geology Type Depth(m)

TemperatureºC

Wells(production)

Wells(reinjection)

Runningcapacity

France Guadeloupe 1 Volcanic Water 3001100

250 3 15

Iceland Krafla 5-6 Volcanic Water 10002000

190-210350

21 1 60

Nesjavellir 6-8 Volcanic Water 10002000

300-320 18 90

Svartsengi 6-8 Volcanic Water 10002000

240 11 1 46

Reykjanes 4 Volcanic Seawater 3000 290-320 14 0 (100)Hellisheiði 6-8 Volcanic Water 3000 240-280 18 5 (120)

Italy Larderello 250 Metamorphic Steam 10004000

150-270350

180 23 473

TravaleRadicondoli

50 Metamorphic Steam 10004000

190-250350

22 147

Bagnore 5 Metamorphic Water 10003000

200-330 7 4 19

Piancastagnaio 25 Metamorphic Water 10003000

200-300 19 11 60

Portugal Volcanic Water >700 100-150 5 13Russia Pahuzhetka Volcanic Water 200 7 11

Mutnovsky 12-15 Volcanic Water/Steam

7002500

240-300 17 4 62

Turkey Kizildere Metamorphic Water 240 17

EUROPEEUROPECountry Wells

drilled in2000-2005

Installedcapacity

[MW]

Runningcapacity

[MW]

AnnualEnergy

produced[GWh/y]

Numberof

Units

% ofNationalCapacity

% ofNationalEnergy

2005-2000Increase

installed capacity[MW]

France 3 15 15 102 2 9%Guadeloupe

island

9%Guadeloupe

island

11

Iceland 23 202 202 1406 19 13.7% 16.6% 32Italy 21 790 699 5340 32 1.0% 1.9% 5Portugal 2 16 13 90 5 25%

San Miguelisland

Turkey 4 20 18 105 1 Negligible Negligible 0Russia 4 79 79 85 11 Negligible Negligible 56

0

5000

10000

15000

20000

25000

WG

C1995

WG

C2000

Actual

Ferra

ra 2

010

Ferra

ra 2

020

Installed Capacity (MW)

Power Production (GWh/y

0

100

200

300

400

500

600

700

800

France

Icel

and

Italy

Portu

gal

Turkey

Russi

a

Installed Capacity (MW)

Running Capacity (MW)

EGS techniques and how they could EGS techniques and how they could improve high enthalpy geothermal improve high enthalpy geothermal

fieldsfields

Different ways have been tested or are imagined for enhancing and Different ways have been tested or are imagined for enhancing and broadening geothermal energy reserves which can be classified into broadening geothermal energy reserves which can be classified into Unconventional Geothermal Resources, i.e. mainly Enhanced Unconventional Geothermal Resources, i.e. mainly Enhanced Geothermal Systems (EGS) and Supercritical Reservoirs:Geothermal Systems (EGS) and Supercritical Reservoirs:

• stimulating reservoirs in Hot Dry Rock systems,stimulating reservoirs in Hot Dry Rock systems,

• enlarging the extent of productive geothermal fields by enlarging the extent of productive geothermal fields by enhancing/stimulating permeability in the vicinity of naturally enhancing/stimulating permeability in the vicinity of naturally permeable rocks,permeable rocks,

• enhancing the viability of current and potential hydrothermal areas by enhancing the viability of current and potential hydrothermal areas by stimulation technology and improving thermodynamic cycles,stimulation technology and improving thermodynamic cycles,

• defining new targets and new tools for reaching supercritical fluid defining new targets and new tools for reaching supercritical fluid systems, especially high-temperature downhole tools and instruments,systems, especially high-temperature downhole tools and instruments,

• improving drilling and reservoir assessment technology,improving drilling and reservoir assessment technology,

• improving exploration methods for deep geothermal resources.improving exploration methods for deep geothermal resources.

Well Well stimulationstimulation methods to improve permeability of poor-producer methods to improve permeability of poor-producer wells are the most common among the technologies derived from EGS wells are the most common among the technologies derived from EGS and applied to conventional fields. They were successfully applied in and applied to conventional fields. They were successfully applied in Italy, Guadeloupe and could be profitably applied in other fields, Italy, Guadeloupe and could be profitably applied in other fields, wherever the permeability appears reduced and for wherever the permeability appears reduced and for broadeningbroadening the the reservoirs. This would correspond to a potential reservoirs. This would correspond to a potential increase of increase of exploitationexploitation and hence of power production, and at the same time the and hence of power production, and at the same time the sustainabilitysustainability of resources would be guaranteed. of resources would be guaranteed.

Tracer testsTracer tests are now becoming a tool for detection of reservoir are now becoming a tool for detection of reservoir volume and prevent strong interference between wells, in particular volume and prevent strong interference between wells, in particular during reinjection. They have been applied in Turkey, Iceland and may during reinjection. They have been applied in Turkey, Iceland and may provide useful information in all the exploited fields.provide useful information in all the exploited fields.

Efficient Efficient scale inhibitorsscale inhibitors to prevent scaling in wells and surface pipes to prevent scaling in wells and surface pipes are becoming very important for the maintenance of exploitation.are becoming very important for the maintenance of exploitation.

High enthalpy fields are the obvious base for the exploitation of High enthalpy fields are the obvious base for the exploitation of supercritical fluidssupercritical fluids, which can be found in these fields at drillable , which can be found in these fields at drillable depths. High enthalpy steam produced by these fluids would generate depths. High enthalpy steam produced by these fluids would generate a much higher electric power than conventional geothermal wells.a much higher electric power than conventional geothermal wells.

Improved geophysical imagingImproved geophysical imaging tools to determine the extent of tools to determine the extent of faulted reservoirs as well as integrated reservoir modelling have faulted reservoirs as well as integrated reservoir modelling have been developed during the EGS experiments. Their application to been developed during the EGS experiments. Their application to conventional system may provide conventional system may provide a new insight in geothermal a new insight in geothermal structuresstructures that are, by definition, very complex. that are, by definition, very complex.

Time lapse geophysical measurementsTime lapse geophysical measurements have proved to be have proved to be particularly effective in particularly effective in exploringexploring and and monitoringmonitoring the dynamic of the dynamic of EGS, but their application is not common in conventional fields. The EGS, but their application is not common in conventional fields. The improvement of technology and reduction of costs are making them improvement of technology and reduction of costs are making them particularly attractive in any kind of geothermal system. The particularly attractive in any kind of geothermal system. The combination of different data through combination of different data through integrated modellingintegrated modelling are are helping in defining both static and dynamic geothermal features and helping in defining both static and dynamic geothermal features and should be applied in all fields to reduce the mining risks and improve should be applied in all fields to reduce the mining risks and improve the control of the system. the control of the system.

However, the importance of high enthalpy fields is not only However, the importance of high enthalpy fields is not only restricted to themselves, but to the entire geothermal scenario. restricted to themselves, but to the entire geothermal scenario. These fields should be considered as ideal These fields should be considered as ideal laboratorieslaboratories for for experimenting new ideas for geothermal exploitation, since the experimenting new ideas for geothermal exploitation, since the more accessible depth of interesting temperatures would more accessible depth of interesting temperatures would decrease the cost of the experiment, being the drilling usually the decrease the cost of the experiment, being the drilling usually the most expensive part of geothermal exploitation.most expensive part of geothermal exploitation.

Moreover, long-exploited fields such as in Italy and Iceland, where Moreover, long-exploited fields such as in Italy and Iceland, where a huge amount of data is already available, may serve as a huge amount of data is already available, may serve as demonstration plantsdemonstration plants for a variety of tests in order to improve the for a variety of tests in order to improve the reservoir assessment technology and the exploration methods.reservoir assessment technology and the exploration methods.