geothermal development in the caribbean and egs perspectives engine launching conference –...
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Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
H. Traineau, B. Herbrich, E. Lasne, D. Tournaye
CFG Services, 3 av. Cl. Guillemin 45064-Orléans cedex 2 – France
A. Genter, B. Sanjuan
BRGM, 3 av. Cl. Guillemin, 45060-Orléans cedex 2 - France
Geothermal Development in the Volcanic Caribbean Islands
and EGS Perspectives
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Map of the Caribbean volcanic islands (red color) and their active
or recent volcanoes.
Subduction of the Atlantic Plate below the Caribbean Plate
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Energy in the Caribbean
- More than 90% of electricity comes from fossils fuels;
- Low contribution of Renewable energy sources :
- Electricity needs increase by 4-5% every year.
- Biomass- Hydro- Solar- Wind- Geothermal
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Volcanic Islands
Survey Pre- feasibility
Deep drillings
Installed capacity (MWe)
Expected Potential (MWe)
Saba yes
St Eustatius yes
St Kitts yes
Nevis yes 10 - 50
Montserrat yes yes
Guadeloupe yes yes yes 15 30 - 50
Dominica yes yes 50 -100
Martinique yes yes yes
Ste Lucia yes yes yes 10 - 50
St Vincent yes yes
Grenada yes
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Geothermal resources might contribute to power generation in some islands instead of fossil fuels
Bouillante, the case history in Caribbean
Dominica, the most promising geothermal potential
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
The Bouillante geothermal field, Guadeloupe
Urban areaSteep topography area
Sea proximity
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
The story of the Bouillante geothermal exploitation
1963 1969 1986 2001 2004
First survey(BRGM)
First drillings(EURAFREP)
First 4,5 MWe power plant
(EDF)
Second 11 MWe power plant
(GEOTHERMIE BOUILLANTE)
Drilling 3 new wells(GEOTHERMIE BOUILLANTE)
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
- Several recent eruptive centers (<1 MA) around the Bouillante Bay, with the possible occurrence of shallow magmatic intrusion under cooling;
- Several main normal faults which promote permeability and fluid circulations at depth and represent potential fractured reservoirs;
- Only a part of the reservoir is now exploited through BO-4 vertical production well, BO-5 and BO-6 deviated and inclined production wells which intersect the Cocagne Fault.
The Bouillante geothermal field
B o - 4
B o - 5
B o - 6
B o - 7
B o - 1
B o - 2B o - 3
C a r ib b e a n
S e a
BouillanteBay
( O ,84 M y )
( 1 ,12 M y )
( O ,6 M y )
( < O ,6 M y )
( N o da te )
( N o da te )
Main zoneof surface manifestations
Hot spring
Recent volcaniccenter (age M. y)
Exploratory well
Main fault zones
Cocagne F.
Descoudes F.
Marsolle F.
Machette F.
Bouillante
Inclined, deviatedproduction well
N
Muscade
Thomas
1 km
Pointeà Lézard
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
S eaw ate rIn filtra tion
F ra ctu re d reservo ir
R a in fa llIn filtra tion
2 5 0 °
500 m
1000 m
Simplified model of fluid circulations in the Bouillante geothermal reservoir
Simplified cross-section along a West-East profile within the Bouillante geothermal field showing the assumed model of fluid circulation with seawater and rainfall recharge, mixing (60% seawater + 40% rainfall) and heating to 250-270°C.
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
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ORKUSTOFNUN
COMPAGNIE FRANCAISE DE GEOTHERMIE
Bouillante Wells 2, 4, 5, 6 and 7
BO-2, 16-03-2002 staticBO-4, 15-03-2002 staticBO-5, 13-03-2002 staticBO-6, 14-03-2002 staticBO-7, 13-03-2002 static
Temperature (°C)
Dep
th(m
)
Selected temperature profiles in the Bouillante wells.
240°C at shallow level (well BO-2)
Reservoir temperature around 250°C
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Cross-section along a NW-SE profile showing well trajectories, location and quality of permeable
zones in relation with faults deduced from surface geology.
- Only the Cocagne Fault appears to be highly permeable.
- Plateau Fault shows low permeability.
- Descoudes Fault has no permeability possibly due to carbonates scaling
1400
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BO-7
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BO-6
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BO-2
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NW SE
Sea level
BO-4
CocagneFault
PlateauFault
DescoudesFault
Location of the main feed zone
High permeable productive zone
Low permeable productive zone
Thickcalcitevein
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
High temperature conditions at shallow depth (< 1000 m deep) but strong anisotropy in permeability related to fracture network and possibly to scaling (carbonates, silica).
Main characteristics of the 7 deep wells drilled at Bouillante
Well Year Trajectory Total length (m)
Bottom hole T (°C)
Result
BO-1 1969 vertical 850 (225) No HP production
BO-2 1970 vertical 350 245-250 Producer
BO-3 1970 vertical 850 (245) No HP production
BO-4 1974-77 vertical 2 500 250 Low producer(Stimulation needed)
BO-5 2001 deviated 1 197 250 Good producer
BO-6 2001 deviated 1 248 250 Good producer
BO-7 2001 deviated 1 400 240 No HP production
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
High temperature conditions at shallow depth (< 1000 m deep) but strong anisotropy in permeability related to fracture network and possibly to scaling (carbonates, silica).
Main characteristic of the 7 deep wells drilled at Bouillante
Well Year Trajectory Total length (m)
Bottom hole T (°C)
Result
BO-1 1969 vertical 850 (225) No HP production
BO-2 1970 vertical 350 245-250 Producer
BO-3 1970 vertical 850 (245) No HP production
BO-4 1974-77 vertical 2 500 250 Low producer(Stimulation needed)
BO-5 2001 deviated 1 197 250 Good producer
BO-6 2001 deviated 1 248 250 Good producer
BO-7 2001 deviated 1 400 240 No HP production
Extension of EGS methods might be addressed first to accurate location of faults within the high temperature, fracture-permeable reservoir.
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
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ORKUSTOFNUNCOMPAGNIE FRANCAISE DE GEOTHERMIE
Calculated and Measured Production Characteristics of Well BO-4
Conditions at first production test in 1998 Conditions at second production test in 1998 Measured point during second test in 1998 Measured points in July 1999 Measured points in May 2000 Approximate characteristic curve
Tot
al P
rodu
ctio
n R
ate
(t/h
)
Wellhead Pressure (bar-g)
Stimulation of the low productive well BO-4
A limited, low cost experiment with cold
seawater injected into the well BO-4 has been
conducted from August 10 - 27, 1998 to enhance the
secondary permeability through thermal cracking.
Productivity increases by 50% and fluid discharge
is more stable.
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
0 2 4 6 8 10 12 14 16 18 20 22 24
0
20
40
60
80
100
120
140
160
ORKUSTOFNUNCOMPAGNIE FRANCAISE DE GEOTHERMIE
Calculated and Measured Production Characteristics of Well BO-4
Conditions at first production test in 1998 Conditions at second production test in 1998 Measured point during second test in 1998 Measured points in July 1999 Measured points in May 2000 Approximate characteristic curve
Tot
al P
rodu
ctio
n R
ate
(t/h
)
Wellhead Pressure (bar-g)
Stimulation of the low productive well BO-4
A limited, low cost experiment with cold
seawater injected into the well in steps has been
conducted from August 10 - 27, 1998 to enhance the
secondary permeability through thermal cracking.
Productivity increases by 50% and fluid discharge
is more stable.
Extension of EGS methods could be very useful to improve permeability of low producers.
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
The location of the plant within the city induced strong environmental constraints (no noise, no steam plume, …).
Aerial view of the geothermal plant located within the city
Bouillante 1 Unit(4,5 MWe)
Bouillante 2 Unit(11 MWe)
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Steep topography and urban area reduce land availability for well pads, pipe routes, etc…, and consequently may hinder best locations for production and reinjection zones.
Aerial view of the well pad and the pipe route.
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Sea proximity also reduces surface availability for well siting and might require to reduce distances between production and reinjection zones.
Bouillante
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Sea proximity also reduces surface availability for well siting and might require to reduce distances between production and reinjection zones.
Extension of EGS methods could be very useful to improve and secure reservoir monitoring and exploitation (tracer tests, …)
Bouillante
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Dominica Island
Two promising high enthalpy geothermal fields with abundant surface manifestations, related to very recent volcanic activity.
Wotten Waven
Soufriere
Valley of Desolation
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Dominica Island
Development of geothermal resources in Dominica and reservoir exploitation will face similar problems as experienced in Guadeloupe (remote location, steep topography, national park, …)
Valley of Desolation
Micotrin lava domeWotten Waven
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Conceptual model of the Wotten Waven geothermal reservoir(s) with inferred location of deep chloride reservoirs and fluid flow pattern.
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Permeability within the basement is provided by fault networks. Faults will be the main targets for well siting.
Rose diagram of fractures recorded on the field
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Volcanic islands in the Caribbean have proved or expected high enthalpy geothermal resources which could be used for electricity production.
Due to their location, Bouillante and other fields (will) have to face problems related to :
- Permeability anisotropy within the geothermal reservoir; wells have to intersect main faults in order to be good producers;
- Steep topography and limited land availability for well pad, pipe routes,…;
- Environmental constraints due to urban areas or national park;
- Remote location (extra costs for survey, drilling, logging, stimulation and work over operations, plant maintenance,…);
- Limited size of the exploitation and limited financial capacity of geothermal operators;
CONCLUSIONS
Geothermal Development in the Caribbean and EGS Perspectives
ENGINE Launching Conference – Orléans, Feb. 12th to 15th, 2006
Some problems could be addressed by EGS methods to promote development of their geothermal resources :
- Accurate location of fault network;
- Permeability improvement through well stimulation;
- Reservoir monitoring (tracer tests, logging);
- Management of close production and reinjection zone;
- ….
EGS PERSPECTIVES