Geothermal drilling in Enel Green PowerEGP well schemes, directional drilling, multilateral technology

Larderello, 11th October 2013Larderello, 11th October 2013

EGP standard geothermal well

Well diagram

3000/5000 psi

NEOGENE

FLYSCHCALCAREOMARNOSO

SCAGLIETETTONICHE(SERIE ANIDRITICA

VERRUCANO)

BASAMENTO(FILLADI

500

1000

1500

100 30”

600

23”

1500

17”1/2

24”1/2

18”5/8

13”3/8

November 2010 2

(FILLADIMICASCISTI

GNEISS)2000

2500

3000

3500

2400

12”1/4

3500

8”1/2

9”5/8

Steam cleaning system

Surface equipment

5

Gravity/centrifugal separators

Well heads

Silencers

Water

Steam

2

3

4

November 2010 3

NaOH bailers/cleaning solution preparation

1

Steam cleaning system

Well head equipment

Cleaning system

Production line

Separator line

November 2010 4

Cleaning solution

H2O + NaOH

Master valve

Steam cleaning system

Hole equipment

Pip

es

In

jecti

on

head

November 2010 5

EGP drilling pads

Entrance

Debris pits

Cellar

Mechanical workshop

Fu

el

ta

nks

Waste

area

Power generation area

Fluid preparation area

Cement tanks

November 2010 6

WaterpitM

ud

pit

Cluster of wells

Well heads

November 2010 7

Mining targets

November 2010 8

Mining target

Horizontal section

RAD_17BTR_15

TR_16

TR_3BISTRBCF_3

1666000 1666080 1666160 1666240 1666320 1666400 1666480 1666560 1666640 1666720 1666800 1666880 1666960 1667040 1667120 1667200 1667280 1667360 1667440 1667520 1667600 1667680 1667760 1667840

4782

960

4783

040

47829604783040

RAD_7BIS

RAD_17D_R1

TR_12

TR_15

TR_17

TRHN_2

MD: 2335.00

MD: 2410.00

MD: 2660.00

MD: 2900.00

MD: 3400.00

MD: 3150.00

MD: 3650.00

4782

320

4782

400

4782

480

4782

560

4782

640

4782

720

4782

800

4782

880

47823204782400

47824804782560

47826404782720

47828004782880

MON_5A

November 2010 9

MON_5

1666000 1666080 1666160 1666240 1666320 1666400 1666480 1666560 1666640 1666720 1666800 1666880 1666960 1667040 1667120 1667200 1667280 1667360 1667440 1667520 1667600 1667680 1667760 1667840

4781

840

4781

920

4782

000

4782

080

4782

160

4782

240

47818404781920

47820004782080

47821604782240

0 100 200 300m

1:5000

Target

Wellhead

Mining target

Vertical section

3600 3800 4000 4200 4400 4600 4800 5000 5200 5400 5600 5800 6000 6200

020

0

0200

-800

-600

-400

-200

-800-600

-400-200

MARKER H

November 2010 10

MON_5

RAD_7BIS

TR_SUD_1TR_SUD_1B

TR_SUD_1C_R1MON_5A

3600 3800 4000 4200 4400 4600 4800 5000 5200 5400 5600 5800 6000 6200

-140

0-1

200

-100

0

-1400-1200

-1000

Target

Directional drilling

Directional drilling allows to reach a mining target off line with respect to thevertical axis of the well (offset up to 2000 m)

Deviation program is generally divided into 3 steps:

Phases

Deviation program is generally divided into 3 steps:

KICKOFF POINT

. BUILD-UP

• Drilling of the first vertical section till kick off point (KOP)

• Build-up phase (increase of the angle) where the well inclination is gradually increased to the design value

November 2010 11

.

.MAINTENANCE .

TOTAL VERTICAL DEPT

FINAL INCLINATION

increased to the design value

• Maintenance phase where inclination and direction of the well remain the same till the reaching of the target

Directional drilling

• MUD MOTOR

Used both in the build up phase and in the maintenance phase. Itis set just above the rock bit with the purpose to give it therotation keeping the rest of the drilling string still

Tools

DRILL COLLARS

DRILL PIPES

rotation keeping the rest of the drilling string still

• BENT HOUSING

It is used to facilitate the exit from the vertical axis of the well;generally it has an inclination between 1,5° and 2°

• MWD (Measurement While Drilling)

Performs the measurement of the inclination and direction of thewell real time. The tool has a “pulsar” set above the Mud Motorand a receiver at the surface that works as a decoder of the signalcoming through the drilling fluid

MWD

MUD MOTOR

November 2010 12

coming through the drilling fluid

ROCK BIT

MUD MOTOR

Directional drilling

Well plan

-1400 -1200 -1000 -800 -600 -400 -200 0

N

Design path

400

600

800

1889

2085

2331

2584

2823

3088

3424

Real path

Design path

Real path

November 2010

0

200

974

1292

1500

1704

1889

E

Wellhead

Design path

Exploitation of the field

Complexity

4787000

2510

Well head

Measured Depth [m] n.

4783000

4784000

4785000

4786000

3210

2749

3941

23042234

3314

2893

4077

3621

3891

27722772

2299

2555

27112671

3502

2591

Gauss B

oaga

Nort

h [

m]

November 2010 141660000 1661000 1662000 1663000 1664000 1665000 1666000 1667000 1668000 1669000 1670000 1671000

4780000

4781000

4782000

2586

2861

27243556

2990

Gauss

Gauss Boaga Est [m]

Drilling pad

Complexity Well head

Measured Depth [m] n.

4780840

1676

2044

986

1125

1239

1385

1443

Gauss B

oaga

Nort

h [

m]

4780800

4780810

4780820

4780830

916

1112

1414

710

8861008

1064

1113

1150

819

986

900

1029

1147

900

1029

1215

1272

1333

398

508

757

948

1223

1261

1298

1329

1357Well 5

Rig footprint

November 2010 15

Gauss

1667740 1667750 1667760 1667770 1667780 1667790 1667800 1667810 1667820 1667830 1667840 1667850

4780780

4780790

4521187

1224

750750

398

1384

1412

1439

Well 1

Well 2

Well 3

Well 4 Natural deviation

Gauss Boaga Est [m]

Risk of collision

High risk High risk of

collision

November 2010 16

Magnetic interference

Survey report

BTOTAL – Magnetic flux density

B – Magnetic field dip

Time Depth (m) Gtot Btot GTF Incl Az Dip

1st

15:53:59 199.00 1.002 51.191 96.95 7.44 124.54 62.38

15:54:59 199.00 1.003 51.159 96.43 7.49 124.98 62.47

15:55:59 199.00 1.002 51.191 96.78 7.46 124.71 62.41

15:56:59 199.00 1.002 51.192 96.47 7.46 125.12 62.44

Average value 1.002 51.183 96.66 7.46 124.84 62.43

Survey report

November 2010 17

BDIP – Magnetic field dip

BTOTAL (Measured) vs BTOTAL (Local)

BDIP (Measured) vs BDIP (Local)MagneticMagnetic InterferenceInterference

Magnetic interference

Magnetic Interference monitoringMagnetic interference

Trig

ger v

alu

e

exceed

ed

Btot Bdip46.636 59.40

194 52.002 62.79 -5.366 -3.39

Survey depth [m]

Magnetic interference

Reference values∆ Btot [ µµµµT] ∆ BDip [°]

Trig

ger v

alu

e

Collis

ion v

alu

e

Trig

ger v

alu

e

exceed

ed300 51.917 62.30 -5.281 -2.90

445 49.566 61.87 -2.930 -2.47514 48.299 63.76 -1.663 -4.36524 47.042 60.74 -0.406 -1.34534 46.363 60.76 0.273 -1.36544 47.425 60.36 -0.789 -0.96553 47.002 59.57 -0.366 -0.17562 46.539 59.83 0.097 -0.43571 46.903 59.17 -0.267 0.23581 47.060 59.56 -0.424 -0.16590 46.621 58.99 0.015 0.41600 46.742 59.54 -0.106 -0.14610 46.913 59.21 -0.277 0.19619 46.805 59.33 -0.169 0.07628 46.797 59.37 -0.161 0.03638 46.766 59.51 -0.130 -0.11648 46.800 59.35 -0.164 0.05657 46.601 59.44 0.035 -0.04

November 2010 18

Dep

th

Trig

ger v

alu

e

Collis

ion v

alu

e

657 46.601 59.44 0.035 -0.04666 46.535 59.58 0.101 -0.18676 46.619 59.06 0.017 0.34686 46.780 59.59 -0.144 -0.19696 46.789 59.35 -0.153 0.05705 46.772 59.77 -0.136 -0.37714 46.787 59.48 -0.151 -0.08724 46.626 59.32 0.010 0.08733 46.810 59.59 -0.174 -0.19743 46.732 59.10 -0.096 0.30752 46.845 59.12 -0.209 0.28

Multilateral technology

November 2010 19

Multilateral technology

Co

ncave

November 2010 20

An

ch

or

Multilateral technology

Sequence of operations

1. Multifinger

2. Set Packer

3. Cement plug3. Cement plug

4. Gauge Run + Scraper

5. Orient Whipstock (Multishot)

6. Set Whipstock (release 3 t to break shear pins)

7. Release 20 t to break shear bolt between Mill and Concave

8. Rat hole

9. POOH

November 2010 21

9. POOH

10. Run BHA for directional drilling

11. Drilling of the new branch

Multilateral technology

Retrieving systems

Concave Anchor

Ho

ok

Die

co

llar

QuickChangeAdapter

Retrieving slot

1

2

November 2010 22

1

3

N

MV 3C - Actual branch

Multilateral technology

Case study - Monteverdi 3C

E

November 2010

MV 3C - New branch

23

Kick Off Point 1750m