ENEL Green Power
Industrial Strategy to Contrast the Decline anddevelop the Larderello System
Kumamoto, 20 November 2019
Davide Pallotta
Project Drilling Manager
Drilling Unit
Geo CoE & Drilling

Overview

History of Geothermal technologyTechnologies

EGP Geothermal fields

What’s NextHISTORY

25/11/20193

Geothermal calendar
From origin to present
Ancient times: heat from Earth used in many parts of the world for settlings, bathing,curiosity, medicinal and cooking purposes.
1777. H.F. Hoefer discovers Boric Acid in the geothermal lagoons of Larderello (Italy)
1818. Chemin/Prat/De Larderel is born to produce boric acid from natural
manifestations.
1840. First geothermal well to produce boric acid is drilled in Larderello.
1904. Prince Piero Ginori Conti lightens 5 electric bulbs using vapor. The geothermal
epoch begins.
1912. First geothermal power station in Larderello (250 kW).
1928. Iceland started using geothermal heat for domestic heating.
1939. Construction of Larderello 2 (60 MW)
1958. Wairakei field in New Zealand is the second one to use geofluid for commercial
purposes.
1970s. World wide grow of geothermal industry: exploration, development, installedcapacity (14% per year)
1990s. Heat pumps become commonplace2017. Production: 84.8 TWh. 14 GW installed (IEA).
4

Geothermal calendar
Back in1827 Francesco de Larderelboosted the industrial exploitation of theboron-bearing waters, thanks to thebrilliant creation of the “Covered Lagoon”.

The lagoon allowed the utilization of
the endogenous heat as heat supplierinstead of the usual firewood.

Fonte di Calore5Geothermal calendar
Throughout
thenineteenth
century the boric acid industry
was thriving...
...the search for steam waseven led below the groundsurface by means of the firstrudimentary drillings.

Fonte di Calore

New plants were built; trades had been
growing continuously .

6

Geothermal calendar
In 1904, Prince Piero Ginori Conti
foresaw the possibility of producing
electric energy from a geothermal source.
Coupling a 0.75 horsepower piston
engine with a small dynamo, hesucceeded in lighting five light bulbs of 5
watts each

1913, first commercial power plant in the world (250 KWe
capacity, fed by pure steam, to let boric acid be produced
from natural steam; in 1916, two turboalternators of 3.5
MWe each installed at Larderello, indirect thermodynamic
Fonte di Calore
cycle to enable boric acid be extracted from the natural fluid
produced.
7

Geothermal calendar – some dates

In 1922 the first geothermal
well was drilled in the Geysers(USA)

In 1958, first synchronizing of
Wairakei (NZ) group “A” opens thegeothermal development outside Italy

In 1960 the firstcommercial group wasconnected
attheGeysers (USA)Olkaria I (Kenya)commercial in 1981

GEOTHERMAL BUSINESS

25/11/20199

Geothermal PP
O&M of geothermal PP: tip of the iceberg?

INTEGRATED MANAGEMENTCap Rock

O&M

Only a very small part of an iceberg is visible
above the water. About ninety % of it is below
the surface.
Geothermal
It is difficult to imagine the dimensions of thereservoir
underwater part from the observation of theemerged part only.

Res.
Management

SurfaceequipmentGeothermal development
O&M - GOAL
Integrated O&M management

Field management
OPERATION
MAINTENANCE•
Well monitoring•
Maintenance of wells•
Prod. Inj., Obs(workover)•
Fluid separation and conduction•
Repair of wells
system (wellheads, gathering)•Surface facilities•
Period tests and measurements•
Geoscientific studies•
Geology•
Geochemistry•
Geophysics•
Hydrogeology

Plant management
OPERATION•
Steam system•
Water condensation•
Gas extraction•
Turbogenerator and AUX•
Electric system•
Fire safety•
Miscellaneous•
Environmental control

MAINTENANCE• Routine• Major• Corrective• Improvements

EGP geothermal value chain

Centennial experience (since 1913) in geothermal electricity generation and fluid use
Project Development/
Finance

Exploration &Drilling• Risk evaluation
depending on country
and technology• Best practice indrilling target
identification• Transmission System
Access• Geological Modeland reservoir
evaluation• Power sales contract
negotiation• Predictive
methodology for
exploration of deep
geo resources

Plant
design/construction• Well proven concept
design in diverse
technologies: dry
steam , flash andbinary• Provide anenvironment ofcompetition inequipment
procurement andconstruction

Plant
operation

R&D• Internal safety andoperation procedures
systems• Low Enthalpy
Innovative
Geothermal Plants• Optimized georesource mgmt forsustainable
exploitation• Developing hybrid
system• In house
maintenance andrepair capability• Remote monitoring
and control of power
plants portfolio• Improved
efficiency andflexibility

EGP development in Geothermal business
Integrated approach

Drilling Activities

Optimized field management• Skills and equipment
for deep deviated drilling• Modeling subsurface environment• Reinjection• High temp. logging tools• Wells stimulation

O&M activities

Continuous
improvement for
excellence• Plants efficiency improvement• Fault analysis and predictive approach• In-house maintenanceEnel Green PowerWorld geothermal footprint

Salt Wells (USA)30 MW
Stillwater (USA)57 MW
Cove Fort (USA)30 MW

Mt. Amiata (Italy)
121 MW
Larderello (Italy)
795 MW

Cerro Pabellon(Chile)40 MW

Way Ratai(Indonesia)
Planned55 MW

ITALY

25/11/2019

15

ITALY
Italian geothermal footprint
37 generating
units allequipped with
AMIS1 systems

More than 500
wells
570 km pipelines

916 MW net
installed capacity

5.8 TWh annual
production

Direct heat 310
TCal/Y

600 people
87,3% average loadfactor

1 AMIS is a proprietary technology for H S and Hg emission abatement2

Italian geothermal fields
Classification based on fluid characteristics
The different geothermal systems cultivated in Italy can be classified, according to the thermodynamic
characteristics of the fluid contained in them, in dominant water and dominant steam systems. The latter can in turn
be classified into three distinct clusters according to the degree of fluid overheating.
AREA LARDERELLO/RADICONDOLI

Traditional Area

Steam dominated

Cluster 1 – Shallow fields(Larderello, Molinetto, Castelnuovo, Horst, Graben, Serrazzano, Monterotondo, Lago, Lagoni Rossi)

1

Cluster 2 – Superheated steam fields

2(Gabbro, Sesta, Selva, Val di Cornia, Monteverdi, Carboli/San Martino)

Cluster 3 – Saturated steam(Radicondoli deep reservoir, Travale/Montieri)

AREA AMIATA

Amiata Area

CAMPI «SUPERFICIALI»CAMPI «A VAPORE SURRISCALDATO»CAMPI «A VAPORE SATURO»

Water
dominated

CAMPI «AD ACQUA DOMINANTE»

Cluster 4 – Water dominated fields

44(Bagnore, Piancastagnaio)

1

CAMPI «SUPERICIALI»

2

CAMPI «A VAPORE SURRISCALDATO»

3

CAMPI «A VAPORE SATURO»

4

CAMPI «AD ACQUA DOMINANTE»

1
3

Geothermal fields classification
Thermodynamic characteristics and fluid type

Steam dominated systems

Istalled
capacity[MW]

Energy 2017
[GWh]

Thermodynamic
cond.

G/S ratio[%p/p]

Fluid

1.6 – 7.5

CO2, H2S,
HCl (low)

2.7 – 10.0

CO2, H2S,
HCl (high)

1 – Shallow fields

365

2246

Depressurized
system with Hsuperheating

2 – Superheated steam
fields

290

1687

L-M superheating

3 – Satured steam fields

140

812

Satured fluid

795

4745

Water dominated systems

Istalled
capacity[MW]

Energy 2017
[GWh]

Thermodynamic
cond.

G/S ratio[%p/p]Fluid

4 – Water dominated fields

121

1012

-

7.3 – 8.0
(4.7 – 7.2)

CO2, H2S,
Hg, Sb

121

1012

Total

Total

6.0

Larderello area
Development history

The areal extension of the Larderello
exploited area increased till the ’70, whenthe external boundaries of the systemhave been reached. No new development
was done in the last 30 years

forextending the surface of the field.

19Larderello area
Main characteristics
The explored area is about 250 km2, where 200 wells produce
superheated steam at pressure between 2 and 17 bars andtemperature ranging from 150°C to 270°C.
The non-condensible gas content ranges from 1 to 10% by
weight. The installed capacity is 594.5 MWe as of December
2018, with 22 units in operation.
The deep exploration program showed the presence of
permeable layers within the Metamorphic Basement, up to 3,000– 4,000 m depth, with reservoir pressure and temperature
increasing with depth up to 7 MPa and 350°C.

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20

Travale – Radicondoli area
Main characteristics
The explored area covers approximately 50 km2; 38 wells produce superheated steam at pressure
ranging from 8 to 20 bars and temperature of 190-250°C. The non-condensible gas content is in
the range of 5 – 6.5% by weight. The installed capacity is 200 MWe with 8 units in operation.
40Km of pipelines in 200 branches: increasing performance with simulation

Larderello
Travale Radicondoli

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21

Production sustainability in Italy
Improvement to power plants efficiency
37 new units with a range capacity of 8 - 60 MW began operationin the Larderello-Travale area between 1979 - 2005

12 new units (314,5 MW) were installed and began
operation between 2000 - 2005 in the Larderello-

4500

Travale/Radicondoli area

1300

5000

Gross electricity generation

1200

Steam flow-rate

1100

8 units, for a total of 214.5 MW, replaced old units that

4000
1000
3500

700
2500
600
2000

500
400

1500

0
1940

Years

1960

1980

2000

were drilled in Italy, for a total drilled depth of 46.5 km.
Fifteen are make-up wells drilled in Larderello (10) and200

Travale-Radicondoli (5) fields and they are relevant to100

the maintenance program.

0
1920

In the period 2016 - 2018 a total of 27 geothermal wells

300
1000

500

efficiency and lower environmental impact.
[Kg/s][GWh/year]“obsolete”. The new units are characterized by higher

800

3000

1900

were in operation for many years and considered to be900

Geothermal resource management
Injection strategy in a steam dominated system

It consists in the partial reintegration of the mass extracted from the geothermal system by water injection that
evaporates by subtracting heat from the rocks. Characteristic parameters are evaporation efficiency andresponse time.
Advantages
It is a valuable tool for the heat extraction from the rocks;
It helps to reduce the natural decline of the system by reducing the “net” extracted mass from the reservoir;
It helps to reduce the chloride content and gas/steam ratio (with a considerable saving of energy necessary to power
plant compressors).
Disadvantages
Possible reduction of the geothermal system temperature (favorites areas with high degree of overheating);
Possible problems of interference ("break throgh“) between production and injection wells (required carefulmanagement of the injected flow rate is neede);High permeability and low porosity zones are.

Geothermal resource management
Injection strategy in Larderello geothermal system

The intensive cultivation of the Valle Secolo area (Larderello) has gradually decreased the amount of fluid in thereservoir.
This is evidenced by a rapid decline of reservoir pressure and consequent reduction of extracted steam flow rate.
Flow rate history in the Valle Secolo area and shut-in pressure

Favorable conditions for the re-injection:• Presence of a high-productivity areas (high permeability);• Rapid decline of reservoir pressure and steam flow rate
(lower layer of pressure: 0.5-0.8 MPa);• Vast accumulation of thermal energy inside the reservoir
rocks (high temperature: 230-250°C)

Geothermal resource management
Injection strategy in Larderello geothermal system
600
Total flow rate [kg/s]

550

Primary steam [kg/s]

500
450

Flow rate [kg/s]

400
350
300
250
200
150
100

Injection period

50
0
1940

1950

1960

1970

1980
year

1990

2000

2010

The injection strategy has increased the production of
steam of approximately 150 kg/s of fluid in the Valle
Secolo area, corresponding to about 60 MW.

The long injection period did not substantially modify
the temperature of the fluid product.

Geothermal resource management
Injection strategy in Larderello geothermal system
The evaporation of the injected water produces
additional steam free of dissolved gases. It allows areduction in the gas content of total flow rate, with aconsiderable saving of the energy for power plantcompressor.
109

Gas/steam ratio [%]8

The reinjection is a valuable tool to extract heat fromthe reservoir rocks and to reduce flow rate decline
due to resource cultivation.

Gas/steam ratio [%]

7
6
5
4
3
2
1
0
1940

1950

1960

1970

1980
year

1990

2000

2010

Production sustainability in Italy
Reservoir management - reinjection
A secondary effect of reinjection in Larderello is the
NCG/steam ratio decrease together with HCldecrease.
Reinjected water is mainly steam condensate fromthe process itself.

Once in the reservoir it boils generating GASFREE secondary steam ENHANCING PP
performance (lower parasitic consumptions,25/11/2019

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emissions and corrosion)27

Italian fields
AMIS process

AMIS
stands for «Abbattimento Mercurio e Idrogeno Solforato»
Mercury and hydrogen sulfides abatement system
It is a petented process developed by ENEL
To abat Mercury emissions from the plumes
Transform H2S to SO2
Absorb SO2 in liquid phase (reinjected)
Drives H2S dissolved in the liquid toward the gaseous phase28

Italian fields
AMIS process

Simplified schematics
Performances (abatement)
Hg



>90%

H2S



70-80%

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29

Larderello field
Possible criticalities

The presence of Cl- in the steam in quantities from a few mg/kg to
hundreds of mg/l constitutes a criticality for the management of the fluid

Cl -Cl pH<3and of the operation.
In the presence of cold points (piping, well, etc.) the steam can reach thedew point, thus condensing. Since the distribution coefficient of the Cl isin favor of the liquid, the Cl enters the formed drop making it extremely

Cl Cl -

Cl -

Cl -

NaOH
NaCL

acidic (pH <3) and aggressive for the surface equipment.
The solution consists in "washing" the steam with a basic solution(NaOH) to neutralize the acid.

Cl pipeline

Washing is carried out either in the well or on the surface according to theframework of the system and taking into account the superheating
degree of the steam.

NaOH solution

Steam containing HCl

NaOHCorrosion effect in Larderello
Criticalities in O&M

20 cm cuthole31

Larderello field
Scaling issues
 Calcite deposition in Larderello occurs where a liquid
phase enriched in Ca enters in the producing wells fromshallow aquifer not isolated by casings.
 Heating and drying of these solutions in the pipes andwells brings to scale.
 Treatment is made by HCl to dissolve the scale (whenpossible).
 Possible effects: plugging of surface equipment, lost of
production.

32

WHAT’S NEXT

25/11/201933

Geothermal development
About 25 different projects for Innovation in Geothermal energy within
EGP (including EU Horizon 2020 projects)-

Supercritical resources-

Drilling efficiency & new tools/materials for HT/HP enviroment-

NCGs emission reduction/water consumption reduction-

Advanced remote diagnostic and prognostic for O&M-

Alternative uses of geothermal fluids (e.g. algae production)-

Improve reservoir characterization techniques-

Scaling/corrosion
34

Development perspective
Hybridization projects
Hybrid Geothermal – Biomass
STEAM FROM WELLSCornia project
STEAM TURBINE

BIOMASSGRATEBOILER

COOLING TOWERSUNDERGROUNDREINJECTION

Description :Cornia 2 is a revamped geothermal power
plant with a biomass fired boiler. By
allowing superheating of geo steam with a
5MWe increase of power output and an
overall improvement of plant efficiency.
Technology: hybrid Geo-Biomass plant
Installed capacity: 5 MWe
Location: Castelnuovo Val di Cecina (Pisa)
In operation since September 2015

Geothermal development
Geothermal energy can operate in hybrid mode with otherrenewable energy sources (PV, CSP, Biomass and biofuels)with an overall increase in total energy conversion factor;

Cornia-2 (Italy) a hybrid GEO-Biomass PP
Stillwater (US) combines GEO-PV-CSP PP
Breakthroughs in all the technological and crosscutting innovation themes
Reducing costs and increase performance ofgeothermal technologies and installations.

36Geothermal development

Cooled water
Steam
Reinjection well

37

38

BACK-UP

25/11/2019

39

DESCRAMBLE: Drilling in dEep Super-CRitical
AMBient of continentaL Europe

Drilling activities andlessons learnt

DESCRAMBLE

Timeline

28th Apr
2017

SPUD

Apr
2017

May 2017

20th May
2017
Cloggedwell withinert
materialand start
new branch
at 1054 m

21th Jun2017
End of12"1/4drilling
phase at thedepth of
2470 m30th Jun
2017
Run in hole
9"5/8
surfacecasing:shoes 983 m

30th Jun
2017
Run in hole7" deep
liner: shoes
2601 m andhanger 2300m

1st Sep
2017

30th Sep2017

23th Oct
2017

End ofremedial
job

Preparing ofsepiolitic
mud andinstallationof MPD

Replacementof mud withwater

June 2017

July 2017

August 2017

September 2017

25th Jun2017

24th Jul2017

4th Aug2017

19th Sep
2017

Run in hole9"5/8 liner:
shoes 2468
m andhanger 993
m

End of8"1/2 phaseat the depthof 2600 m
and coring

Stop ofcement job
ofintermediat
e liner due
to a fire

Test of API
10000 BOP
end start of6" phase

23th Nov
2017
End ofdrilling
activities
andexecution of
final log

November 2017

Dec
2017

22th Oct
2017

10th Nov
2017

11th Dec
2017

Total loos ofcirculation
at depth of
2708 m andstucks pipe

Clogging
activity
with special
additive

End oftemporaryclosing of
the well

October 201741

DESCRAMBLE

Drilling RIG

 Massarenti 6000;
 1700 HP Drum power; 350 t max hook load;
 2 triplex pump; 4000 kW of GE power installed.

42

DESCRAMBLE

Venelle 2

VENELLE 2 [ORIGINAL WELL]
O.H.
30"

g.l.
csg 24 1/2" @ 182 m

23"

csg 18 5/8" @ 571 m

 Work on Venelle 2 starts with clogging original
branch with inert material; Log executed during the clogging shows anabsorption at 1190 m;
 Top of inherts: 1135 m;

17 1/2"

csg 13 3/8" @ 1029 m

 Over the inert has been executed a cement
plug using cement retainer; Cement plug is need for starting withdirectional drilling with 12’’1/4 rock bit.

12 1/4"

Total Depth @ 2232 m

DESCRAMBLE

Start new branch KOP of the new branch at 1054 m;
 Direction was controlled with Mud motorand MWD (Measure while drilling); Target restore verticality under wellhead from original inclination.
KOP

44

DESCRAMBLE

Mud Logging Service

During drilling activities, well data are monitored andelaborated by a mud logging service with the following
characteristic: Real time data recording and trasmission (ROP, Pit
volume, Flow in/out, weight on bit, ecc);
 First cuttings analysis;
 Gas detection in air ( Explosive mixture, H2S, CO2);
 Gas analysis in mud (CO2, H2, H2S, He, Ar, O2, N2);
 Execution of daily drilling report; Execution of master log;
 First drilling data analysis;

45

DESCRAMBLE

9’’5/8 Casing + Liner The 12’’1/4 drilling phase end at depth of 2470m;
 A casing 9 5/8” was run in hole and cemented
in 2 stages up to the surface.

2334 mDESCRAMBLE
Mud Cooler

The cooling system wasinstalled before thecementing jof of csg 95/8’’.

47

DESCRAMBLE

1° Leak Off Test (Retrivable Packer at 1873 m)
After running in hole of casing column 9 5/8’’ (2500 m of BH), Leak Off Test has been
performed.

48

DESCRAMBLE

Drilling Fluids (Mud System)

A drilling fluid was selected water based mud with SEPIOLITE and MICRODENSE (Ilmenite) used as weighting
and auto-suspending material with following challenges:
 Maintaining of the rheological characteristics in high temperature and pressure environment;
 High evaporation of fluid system that brought of continuous dilution;
 Products degradation for the temperature; Losses in formation minimized by utilization of property system (X-Prima system); Presence of gas (H2S and CO2) that determine the use of scavenger.

49

DESCRAMBLE

2° Leak Off Test (Swellable Packer at 2585 m)

Prior to set the new casing 7’’, at 2585 m was set a swallable packer for
open hole to perform another LOT for the bottom hole 2601 m.
LOT = 214 bar, Mud Density = 1,15 kg/l
Fracture pressure = 513 bar

50

DESCRAMBLE

7’’ Casing Sour Service

 Casing equipment had to resist to the expected high temperature and high pressure,and corrosive environment with presence of H2S and CO2.;51

DESCRAMBLE

ThermaLock™ HT cement slurry for csg 7’’

Geoterm™ / 40% silica after 7 day exposure to 450°C

Intermediate
liner 7’’

Geoterm™ / 70% silica after 7 day exposure to 450°C

Deep liner 7’’

Thermalock after 7 day exposure to 450°C

DESCRAMBLE

Cementing job failure During cementing job ofintermediate liner, float valves failed(fig.1);
 This failure produce a reverse flow
inside the column, and a drop in
cement level into interspace
between 7’’ and 9’’5/8;
 In fig. 2 is possible to see the final
situation after the transient, withthe cement level balanced insideand outside the column;
 In this configuration upper part ofcolumn and hanger weren’t
cemented.

Fig.1

Fig. 253

DESCRAMBLE

Cementing job failure In this figure is schematize the cement situation:••••

From 2300 m to 1460 m: good cementing;From 1460 m to 1240 m: poor cementing;From 1240 m to 1150 m: bad cementing;From 1150 m to 950 m: free pipe.

 This situation not guarantee mechanical and hydraulicresistance of producing casing, and so a remedial job
has been needed.

54

DESCRAMBLE
Remedial job

 First part of remedial consist of cutting
casing at lower part of free pipe using
casing cutters (fig.1);
 The part of column cutted shall pulled out
from the hole by a grapple called releasing
spear (fig.2).
 First cut has been performed at 1205 m
and fishing has been completed
successfully.

Fig.1

Fig.2

55

DESCRAMBLE

Remedial job During second cut at 1407 m, releasing
spear has broken away and a stop collar islost in hole; After some round trip stop collar has been
fished using a taper tap.

56

DESCRAMBLE

Remedial job

Because the second part of the column has not fished, the second
part of the job consist of milling casing from 1205 m (first cut) to1407 m (second cut)57

DESCRAMBLE

Final well profile

58

DESCRAMBLE

6’’ Drilling Phase
The critical aspects of the last drilling phase wereconstituted by high temperature above 450 °C andhigh pressure above 450 bar expected.

59

DESCRAMBLE

Menaged Pressure Drilling The most important parts of MDP system are the RCD (Rotating
Circulation Device) and the automatic choke valve with Coriolis’s flow
meter;
 The flow meter can detect all the minimum difference between flow inand flow out, and in case of differences the MPD’s system controls choke
valves and regulates the Surface Back Pressure; In case of complete well shut in by the use of the BOP, the traditional
Driller’s Method could be applied;60

DESCRAMBLE

MPD Well Control Response Strategy

61

DESCRAMBLE

StingBlade™ 6” Rock Bit

In the 6” phase, working with 3 ½ DPs, thecirculation flow rate was low, causing a very highworking temperature at bottom hole.
In such conditions, the risk to damage theelastomer, part of the bearings of the standard
tricone bits increased significantly.
Then was used 6’’ full stinger rock bit;
This particular RB has allowed to obtain great
performance in drilling phase, characterized by high
ROP and low wear of the tool.

62

DESCRAMBLE

Stuck Pipe Problems

 At the increase of temperature, the mud rheologicalcharacteristics changed, increasing viscosity anddecantation;
 consequence of pumping problems from 2695 m;
 To resolve stuck pipe was decrease mud density and use
synthetic polyelectrolyte able to remove bentonite cake
(REOTAN).

63

DESCRAMBLE

Loss curing material

 At 2709 m a temporary total loss of circulation had occurred; After this event another stuck pipe occurred and from this point the high permeability of the formation make impossible tocontinue drilling with mud; To increase formation resistance a lot of squeeze with clogging materials has been performed.

64

DESCRAMBLE
 To continue drilling operation it has been needed to switch from mud to clean water, withthe purpose to decrease hydrostatic pressure; Up to 2700 m, drilling is characterized by high ROP; Due to the impossibility to carry on the drilling of the K horizon in safe condition, it was
decided to deep the well in control condition at the maximum depth possible;
 To carry on drilling activity was applied a new procedure and evaluated the residual risk,that was considered acceptable.

Pfrac=300 bar

450 barDESCRAMBLE

Drilling Procedures
Monitoring ROP, D-Exponent,
Drilling Gas
Parameters are constant?

YES

NO

Formation has not changed
We are in seismic reflector H

Stop Drilling

Max fracture pressure lower than
300 bar

Close the well and monitoring
SIDPP and SICP
Circulate bottom hole

66

DESCRAMBLE
Final activities

 Last part of the project has been characterized by execution of a lot of physical tests:•

Coring from 2830 to 2839 m full recovered;•Coring from 2900 to 2909 m full recovered;•Temperature log using Kuster;•Temperature log using SINTEF;•

Temperature indirect evaluation with synthetic fluid inclusions.

 The final LOT has not been executed because the 6’’ swellable packer after its test notguarantee the hydraulic sealing.

67

O.H.

g.l.

30"

DESCRAMBLE

Temporary Mining Plugging

csg 24 1/2" @ 182 m

23"

csg 18 5/8" @ 571 m

Cement plug [#3] @1450 -1230 m

17 1/2"

Tie-back 9 5/8" @ 993 m
csg 13 3/8" @ 1029 m

At the end of activities the well has been put
in safe condition temporary plugging
Alternate cement plug with weight mud layer

Tie-back 7" @ 1409 m

12 1/4"1600 mCement plug [#2] @2350 -2150 m
1900 mLiner [#2] 7" @ 2300 m
liner 9 5/8" @ 2468 m

8 1/2"

Cement plug [#1] @2650 -2450 m
Liner [#1] 7" @ 2601 m

Thermalock6"

Geoterm
Total Depth @ 2909 m

68