Conquering the Challenges in Geothermal Utilization —

the EDC Experience

Resource Management Division, Technical Services Sector

30th UNU-GTP Anniversary Workshop

Reykjavík, Iceland

26-27 August 2008

EC Angcoy Jr., EH Alcober, FXM Sta. Ana, AC Cabel Jr.,LF Bayrante, RCM Malate, MS Ogena

Title

INTRODUCTION

TECHNOLOGIES/EXPERTISE

Tracer Tests

Scale Inhibition

Solids Mitigating Measures

On-line Steam Purity Monitoring

SUMMARY and FUTURE OUTLOOK

Presentation Outline

INTRODUCTION

BBGGPPFF

115500 MMWWee

LLGGPPFF

770088 MMWWee

NNNNGGPPFF

4499 MMWWee

SSNNGGPPFF

119922 MMWWee

MMGGPPFF

110044 MMWWee

1976

2007

~1,200 MWe60% of Total Installed Geothermal Power Plant Capacity in the Philippines

Tracer Tests

Field Date Tracers Used Objective

MGPF 2003 1,6 NDS / 2,6 NDS Brine returns from Matingao and Kullay sectors

LGPF 2003 1,5 NDS/1,6 NDS / 2,6 NDSDefine flow paths of inflowing cooler peripheral

waters and brine injected in Mahanagdong sector.

LGPF 2003 1,5 NDS Condensate returns injected in Upper Mahiao sector

SNGPF 2005 1,5 NDS / 1,6 NDS Brine returns injected in Palinpinon-II sector

LGPF 2006 1,6 NDS Brine returns injected in Upper Mahiao sector

LGPF 2006 1,5 NDS / Tritium Brine returns injected in Tongonan-1 sector

LGPF 2007 1,5 NDS/2,6 NDS/2,7 NDS Brine returns injected in Malitbog sector

Objectives:

Determine flow paths and impact of geothermal fluids injections (mandated by law)

Aid in reservoir simulation

Tracer Test Results

Data reduction using UNU-GTP Icebox package and Anduril software

Provides information to formulate injection strategies

B

Brine injection

optimized

Condensate injection

transferred

GGrroouunnddwwaatteerr

iinnffllooww

Brine injection

optimized

BBrriinnee

RReettuurrnnss

BBrriinnee

rreettuurrnnss

((11,,55 NNDDSS))

((11,,66 NNDDSS))

((22,,66 NNDDSS))

Herras et al., 2005

417D

Dacillo and Herras, 2008

Calcite Inhibition System

TOP VALVE

MASTER

VALVE

WING VALVE

SIDE VALVE

Mixing

Tank

Feed

Tank

PUMP

SYSTEM

Capillary

Tubing

Alternative to costly/risky/periodic mechanical clearing due to calcite blockages.

Lesser decline in total mass flow of production well: 4 kg/s/month (without CIS) vs <0.5 kg/s/month (with CIS).

Siega et al., 2005

Silica Scaling Studies

Chemical tank

2-phaseline

header

Mini-

separator

Mini-

silencer

Open

pipe

Steamline

Thermal Pond

SP-2

SP-3

Brineline

Mini-

silencer

SP-4

0.68 MPa

163°C

Chemical tank

2-phaseline

header

Mini-

separator

Mini-

silencer

Open

pipe

Steamline

Thermal Pond

SP-2

SP-3

Brineline

Mini-

silencer

SP-4

0.68 MPa

163°C

Botong Silica Inhibition Set-up(BGPF)

Panopio et al., 2008

Malitbog Silica Inhibition Set-up(LGPF)

Alcober et al., 2005

Solids Mitigating Measures

WH Washing

Modified Solids Trap

BRANCHLINE

CATCH POT

INVERTED

U-PIPE

BLEED LINE

TO SILENCER

INSPECTION

FLANGE

SOLIDS

CLEAN STEAM

SILENCER

WH Solids Removal System

Reduced suspended solids in steamby 80-100%

Reduced thinning rates by 60-99%

Villa et al., 2007

On-line Steam Purity Monitoring

Accurate and continuous real-time steam purity data.

Prevents scaling and erosion / corrosion in turbine blades.

Prevents plant shutdown / tripping due to brine carry-over.

Monitors separator and drainpot efficiency.

Meets contract obligations with BOT partner on steam purity.

STEAM PIPELINE

DEGASSER

CONDENSER

FLAME PHOTOMETER

NCG OUT

STEAM CONDENSATE

SAMPLE

ISK PROBE

DRAIN

STEAM PIPELINE

DEGASSER

CONDENSER

FLAME PHOTOMETER

NCG OUT

STEAM CONDENSATE

SAMPLE

ISK PROBE

DRAIN

Condensed steam is isokinetically-sampled

Sodium (Na) in condensed steam generates a certain wavelengthonce burned in low temperature.

On-line SPM Display

1.0 ppm

0.5 ppm

0.0 ppm

CONTRACT LIMIT = 0.56 ppm

CALIBRATION:

MP: 1430H

TCP: 1445H

DAILY AVE. = 0.05 ppm

Alarm system: 0.40 ppm Na (high alarm); 0.56 ppm Na (high-high alarm)

0.56 ppm Na limit equivalent to 1 ppm Cl limit

Annual savings of ~USD 400-900 M from manual sampling and analysis Additional savings from minimized shutdowns, increased efficiency

Summary and Future Outlook

Developed practices and technologies (Tracer Tests, Scale Inhibition, Solids Mitigating Measures, On-line SPM) aided the integrated reservoir management of EDC for ~3 decades.

Acid inhibition system in LGPF starts in 2008 (MG9D, 3 MW) potential development of EDC wells with

acidic discharges

Widen installed capacity by putting up new power plants and bidding for state-owned geothermal assets

Expand international cooperation in geothermal services, consultancy and drilling projects

Projects (+310 MWe, to 2015)

Nasulo (20 MWe)

Cotabato (50 MWe)

So. Leyte (50-80 MWe)

Rangas (40 MWe)

Kayabon (40 MWe)

Dauin (40 MWe)

Tanawon (50 MWe)

Erlindo C. Angcoy Jr.GeochemistResource Management DepartmentLeyte Geothermal Production FieldEnergy Development Corporation

e-mail address:

angcoy.ec@energy.com.ph

Takk Fyrir !!!

THANK YOU