ITB Gen Lect Rev2

5/28/2018 ITB Gen Lect Rev2

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DOC ID Chevron 2005

Riza G. PasikkiChevron Geothermal Salak

Geothermal ReservoirEngineering


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DOC ID Chevron 2005 2

Outline

General Geothermal Resource Characteristic

Extracting Geothermal Energy

Chevron Geothermal Assets

Geothermal Reservoir Management Reservoir Engineers Roles and Responsibilities


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250C

FumarolesH O, CO , HS2 2 2

Na-HCO -SO

Springs3 4

Steaming Ground

Acid-SO4 Pools

Magmatic Source

H O, CO , SO , HCl2 2 2

neutralisation

acid-SO4fluids

GasLoss Dil ut i on

NaCl Springs

2 C00

300C

200C

mete

ori

crech

arg

e

Na-HCO -SO3 4neut ra

lisati

on

CondensatIon

Upflow

General Resource Characteristics (1)Geothermal Resource Conceptual Model


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Heat source (shallow magma, etc)

Heat carrier (water and/or steam)

High permeability (Darcies)

Horizontal and vertical

Fracture flow

Porosity (1 to 20%+)

Recharge (Natural or artificial)

Discharge

Benign chemistry

Low scaling potential (Silica, calcite or anhydrite)

Neutral fluids

Low non-condensable gas content (


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General Resource Characteristics (3)Temperature vs Depth Relationship

gdz

dP

gradientpressdynamicgdz

dP

PTsatT

w

w

GradientPressure

)(

:zonebolingAt


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Single phase; water dominated

Temperatures range from 600F

Two-phase; steam and water

Temperatures >450F

Single phase; steam dominated

Temperatures 465F (generally)

Special conditions

Critical fluid conditions T>705.44F

High salinity brines (up to 30 wt-% solids)

High non-condensable gas content (up to 10 wt-%)

General Resource Characteristics (4)Thermodynamic Conditions


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Extracting the Energy (1)Geothermal Resource Temperature and Uses

Resource Temperature (F)Low

Direct Use

Power GenerationBinary cycle

Nagqu (110C)Husavik (125C)Ormesa (145C)Steamboat (160C)Soda Lake (190C)

Mulka (86C)B ir dsv il le (98C)

Wabuska (106C) Brady HS (165C)

Otake (220C)The Geysers (240C)Wairakei (250C)

Los Azufres (270C)Leyte (270 to 330C)Mokai (320C)Cerro Prieto (350C)

Steam cycle and Combined cycle

Enhanced Geothermal Systems

ModerateHigh

USA (Fenton Hill); UK (Rosemanowes); France (Soultz);Switzerland (Basal); Japan (Hijiori and Ogachi);

Australia (Cooper Basin and Hunter Valley)

400 6002000



Extracting the Energy (2)Geothermal Power Production Schematic

Satellite Station

Well SitePlant Station

Power PlantInj. Well

Transmission

Wellbore

Drill wells

into

productive

geothermal

zones

Mixture of

hot water

and steam

flows up

Separate steam and hot water

and process to produce clean

steam

Purified steam spinsturbine blades and

Turbine generates

electrical power

Electricity is sold to Consumers



Pipelines (two-phase, steam, water)

Pipe diameters: 4-in to 68-in

Pipe lengths: up to 7 miles

Steam/water separators and scrubbers

Turbine/generators

Cooling towers/air coolers

Injection pumps

Gas abatement and fluid treatment

Heat exchangers (plate, shell and tube)

Extracting the Energy (3)Typical Surface Facility Components



Asset Locations

N. Duri Cogen: 300 MW

Darajat: 145 MW

Salak: 377 MW

Tiwi: 232 MW

Mak-Ban: 402 MW

Total: 1,456 MW

Geothermal: 1,161 MW

N. Duri

Cogen

SalakDarajat

Mak-BanTiwi



Salak Geothermal Project, Indonesia

377 MW Installed Capacity

Units 1 to 3: 60.0 MW ea. (1994 97)- PLN

Units 4 to 6: 65.6 MW ea. (1997) -Chevron

69 wells

43 producers (6 shut-in)

16 injectors

6 Exploration/Monitoring

4 P&A

Resource Area: 7.7 square miles

27 miles of pipeline

Cumulative Generation to date:24,300 GWh (45 MM BOE)



Darajat Geothermal Project, Indonesia

145 MW (255 MW)Installed

Capacity Unit I: 55 MW (1994) - PLN

Unit II: 90 MW (2000) -Chevron

Unit III: 110MW (2006) -

Chevron 30 Wells

18 Producers

3 Injectors (condensate)

2 sub-commercial and 3

delineation 4 P&A

6.2 miles of pipeline

Cum. Generation to July2005: 8,509 GWh (16 MM

BOE)



Mak-Ban Geothermal Project, PhilippinesCommercial Operation Started: 1979

2005: 402 MW Baseline / 458 Total

Capacity 4 x 63 MW baseline

2 x 55 MW baseline

4 x 20 MW 2 baseline / 2 standby

16 MW (binary power plant)

132 wells

72 Producers

16 Injectors

25 Idle/Standby/Monitoring

19 P&A


Cum. Gen. to July 2005: 53,600 GWh(99 MM BOE)



Tiwi Geothermal Project, PhilippinesCommercial Operation Started: 1979

2005: 232 MW Baseline Capacity

2 x 59 MW baseline

2 x 57 MW baseline

1 x 55 MW standby

155 wells

40 Producers

20 Injectors

70 Idle/Standby/Monitoring

25 P&A


Cum. Gen. to July 2005: 40,100

GWh(74 MM BOE)



Geothermal Reservoir Management(1)Key Reservoir Processes

Fluid Chemistryscaling

corrosion

dissolved gas

steam contaminants

Depletionpressure

enthalpy

cool influx

Injection

pressure support

prevent cooling



Geothermal Reservoir Management(2)Reservoir / WellSurveillance and Characterization

Flow performance test to producedeliverability curve

Production/Injection logging:(pressure, temperature, flow)

Identify permeable zone locations

Determine productivity index (PI)

Reservoir pressure & temperaturemonitoring:

Static pressure / temperature

survey Pressure at the observed wells

Pressure transient testing:

Pressure fall off test

Pressure build up test

Enthalpy testing and flow metering

tracer injection

orifice plate, anubar

Tracer test on injection wells

Geochemical monitoring (fluid andgas components)

Geophysical monitoring (gravitychanges)

OUTPUT CURVE LOOSING PRESSURE

0

500

1000

1500

2000

2500

0 200 400 600 800 1000

WHP (psi)

TOTALFLOW

(kph)

Pfeed 2800

Pfeed 2400

Pfeed 2000


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Geothermal Reservoir Management(3)Key Technologies

Reservoir simulation

A computer program writtento solve mass and energyconservation equations in thenumerical model

Making prediction of futurereservoir fluid thermodynamicconditions

Wellbore flow simulation

calculate well deliverability

Historic Deliverability of wells

Calibrate PIs by matching theenthalpy and flow rate of thewell

Use reservoir conditions frommodel to make prediction offuture well deliverability

Decline curve analysis

Pressure transient analysis

Calculate skin value andpermeability thickness

X

Y

Z

Reservoir Boundary

Blocks in ReservoirSimulation

X

Y

Z

Reservoir Boundary




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Reservoir Engineers Roles & Responsibilities

Reservoir data acquisition

and quality assurance Well performance

monitoring and forecasting

Development of production

and injection strategies

through multi-disciplinary

teams Drilling program/design for

make-up and workover

wells

Diagnostic of problematic

wells and design

stimulation jobs Reserves estimation

Reservoir conceptual and

numerical modeling

Economics and feasibility

studies of resource projects

Make the Boss happyso he can bemore focus on his task

My engineerfinally stops

talking. Now isyour turnAnyquestion?


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Quiz

Sebutkan sedikitnya 3 aset geohtermal yang dioperasikan

oleh Chevron:

Salak

Darajat

Makban

Tiwi

Sebutkan sedikitnya 2 key geothermal reservoir process

Depletion

Injection

Chemistry


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Thank you for your attention.

Documents

ITB Gen Lect Rev2