Comparative Resource
Evaluations
Bilateral Collaboration for Enhanced
Geothermal System Assessment

Andrew Coleman, Ph.D., EPRI
Gene Suemnicht, M.S., EGS Consulting Inc.
Geothermal Research Society of Japan
November, 2019
Kumamoto, Japanwww.epri.com© 2019 Electric Power Research Institute, Inc. All rights reserved.

Information Exchange Objectives
 Identify and close technical gaps to raise the profile ofconventional and enhanced/engineered (EGS) geothermalsystems.
 Open-exchange of ideas and data (US-Japan-Italy) New technologies and innovations
 Advance geothermal as an environmentally sustainable,affordable and reliable form of power generation2

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Geysers Overview• Injection– Experience, adaptability and flexibility– Sustainable production• Seismicity– Injection/Production relationship– Frequency/Intensity• EGS– NW Geysers experiment•••3

High temperature reservoir
Conductive heat flow
Successful connection between wells

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Geysers Overview• >800 wells• 117 km2 (45 mi2)
• 322 steam wells• 54 injection wells• 70 steam wells• Current aggregateproduction ~800 MW• 8 injection wells• Current aggregate
production ~ 110MW

4

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Geysers Overview: Geologic setting

View SSE. Top of Felsite in RED. Geothermal reservoir in PURPLE.
Topographic surface in GREEN
5

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Geysers Lessons: Injection
Geysers Total Annual Production and Injection
and Total Installed Generating Capacity
350
2000

250

1500

200
1000

150

100
500
500
1960

01970

1980

Steam Prod.

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2000

2010

YearKoenig, 1992

61990

Injection

Total Generating Capacity© 2019 Electric Power Research Institute, Inc. All rights reserved.

New Plant On-line

Total Generating Capacity(MW)

Steam Produced & Water
Injected (billion lbs/yr)

300

Geysers Lessons: injection

INJECTION COMPONENT OF STEAMCALCULATED FROM ISOTOPE AND NH3/NCG

Steam Flow Weighted Average NCG vs Time
Units 5,6,7,8,11,12 and 17

0.70
0.60

IDS/PROD

0.50
0.40

U 13/16 Iso & NH3
UNOCAL Iso
MODEL

0.30
0.20
0.10

Calculated NCG (ppmw)

11000
10000
9000
8000
7000
6000
5000

Begin Testing
SRGRP Injection
System with SEGEPWater

4000
1/1/990.00
Jun-84

Jul-88Aug-92

Sep-96

Nov-00

Dec-04Jan-09DATE

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1/1/03

1/1/05

1/1/07© 2019 Electric Power Research Institute, Inc. All rights reserved.

1/1/09Date
Source Tests/Mini's

Adapted from Beall et l, 20077

12/31/00

Total Gas Analyses

1/2/11

1/1/13

Geysers Lessons: Seismicity

from Calpine Corp.

8

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Geysers Lessons: Seismicity

Preiss et al., 1996

Beal et al., 1999

Injection wells
9www.epri.com

Recorded events© 2019 Electric Power Research Institute, Inc. All rights reserved.

Cross-section

Geysers Lessons: Seismicity

Smith et al., 2000; Majer et al., 200710

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Geysers Lessons
 EGS– NW Geysers experiment

 High temperature

reservoir (400˚C)
 Conductive heat flow
 Successful connection
between wells
 DOE investment: $6.2M

11

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Geysers Lessons: NW Geysers EGS

Calpine Corp, 201112www.epri.com© 2019 Electric Power Research Institute, Inc. All rights reserved.

Geysers Lessons : NW Geysers EGS

Calpine Corp, 201413www.epri.com© 2019 Electric Power Research Institute, Inc. All rights reserved.

Geysers Lessons: NW Geysers EGS

Max. verticalseparation:305m
Max. lateralseparation: 488m

Garcia et al, 201514www.epri.com© 2019 Electric Power Research Institute, Inc. All rights reserved.

Geysers Lessons: Applied Stimulation

Calpine Corp, 201115www.epri.com© 2019 Electric Power Research Institute, Inc. All rights reserved.

Geysers Lessons: Seismicity

Beall and Wright, 2010; Stark, 1992; 2003

16

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Geysers Lessons: Visualization & Modeling

Hartline, 20191042 Well
Tracks17

Lithology
Steam Entries for
839 Wells

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3D Surfaces

3D Contours
Top SteamFieldwide
Seismicity

Fault Zones© 2019 Electric Power Research Institute, Inc. All rights reserved.

Well Planning

Real-Time Drilling
Assessment

Larderello Overview
 Injection– Different Geologic setting– Success and failures– Monitoring– Modeling Seismicity– Injection/Production relationship– Distinction
 Exploration– Reservoir expansion– Step-out resources18

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Larderello Overview

Razzano and Cei, 201519www.epri.com© 2019 Electric Power Research Institute, Inc. All rights reserved.

Larderello Overview: Geologic setting

after Romagnoli et al. 2010; Giannini et al. 197120

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Larderello Lessons: Geologic Setting

Bertini et al.2006; Arias et al. 201021

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Larderello Lessons: Injection

Arias et al. 201022

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Larderello Lessons: Deep exploration

Bertani et al. 2005

23

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Larderello Lessons: Visualization & Modeling

Romagnoli et al. 201024www.epri.com© 2019 Electric Power Research Institute, Inc. All rights reserved.

Larderello Lessons: DESCRAMBLE
O.H.

g.l.

30"

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
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

6"

Total Depth @ 2909 m
25

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Summary•

Geologic setting– Permeability control•

Resource characteristics– Vapor/liquid dominated, shallow/deep, temporal changes, size•

Injection– Experience, adaptability and flexibility•

Sustainability– Step-out/deep drilling, deep system roots, critical/supercritical resources•

EGS– NW Geysers experiment– DESCRAMBLE

26

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Together…Shaping the Future of Electricity

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