The Atlantic LNG Train 2/3Expansion Project

Turning the ChallengesInto

Successes with Technology

Prepared for

Gastech 2005 in Bilbao, Spain

15 March 2005

Slide 2 of 21

AuthorsDave Messersmith, PE

Bechtel Corporation

LNG Technology Manager

LNG Group Deputy Mgr.

Process Engineer

Carlos Yengle

Bechtel Corporation

Advanced Simulations

Process Engineer

Peter Rutherford

BP America

Controls and Instrument Engineer for Atlantic LNG

Trent Yackimec

BP America

Process Engineer for Atlantic LNG

Slide 3 of 21

Facility InformationFacility Information

Located in Point FortinLocated in Point FortinTrinidad and Tobago, WITrinidad and Tobago, WI

Slide 4 of 21

Facility InformationFacility InformationProject History

96 97 98 99 00 01 02 03 04 05 06

Start EPCMay 96

First LNGMar 99

TurnoverJun 99

Start EPCFeb 01

CompleteJul 02

Start EPCNov 99

First LNGAug 02

TurnoverOct 02

First LNGApr 03

TurnoverJun 03

Start EPCJan 02

First LNG4th qtr 05

TurnoverEarly 06

Train 1

Train 2 Train 3

Train 1Upgrade

Train 4

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Train 2/3 Expansion ChallengesTrain 2/3 Expansion Challenges• Scope – Near Duplicate of Train 1 w/ Key Modifications• Capacity – Train 1 +10%• Key Enhancements

– Turbine Drivers Frame 5D– Propane System hydraulics Improvements– Heat exchanger pressure drop optimization– Heavies Removal Column mechanical design Improvements– Anti-surge valve Upgrades– Inlet Gas Filtration enhancements– Molecular Sieve Bed piping optimization

• Challenges – Schedule, Cost, Lessons Learned from Train 1, Feed Gas Pressure, Inlet Compression

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Inlet CompressionInlet Compression• Expansion included new 24” North Gas Field supply• Demand on existing 36” exceeded initial capacity• Inlet pressure designed for reduction of 15 bar• Compression located immediately upstream of LNG

Facility– Commercial Requirements– Contractual Limitations– Operational Complexities

• No buffer volume for LNG Facility• Engineering committed late in design• Provides gas to all 3 Trains

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Inlet CompressionInlet Compression

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Inlet CompressionInlet Compression

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Inlet CompressionInlet CompressionProcess Requirements• 1280 MMSCFD feed flow (normal) 250 MMSCFD (min)• 37.5 barg Inlet Pressure (min)• 52 barg Outlet Pressure (min)• GE Frame 5C Driver• Follow facility flow transitions as required• Prevent cascading trips

These Process and Operational requirements led to a study utilizing a rigorous dynamic computer simulation model.

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Dynamic ModelDynamic Model• Hysys.plant ver 2.4.1• Scope of Train 1 Model

– Inlet Pipelines– Inlet Gas treatment– Refrigeration Systems– Methane Compression – NGL Recovery

• Equipment & Instruments modeled with unit operations• System volumes and hydraulics based on isos• Equipment information based on vendor data• Control parameters based on actual Train 1 information

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Dynamic ModelDynamic ModelScenarios1. Feed Gas Compression (FGC) Start up w/ Train 1 &

2 running normally2. Train 1 process shutdown – impact on FGC and

Train 2 and 3.3. FGC Trip – impact on Train 1, 2 & 3

New Feed gas

BP - 36" Pipeline

Train 1 gas processing and

liquefactionMetering

Slug catcherPig receiver

compressor

Train 2 gas processing and

liquefaction

Train 3 gas processing and

liquefaction

BG - 24" Pipeline

Metering

Slug catcherPig receiver

100%

50%

50%

75%

25%

Percentage figures represent proportions of Train feed gas sourced from different pipelines

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Dynamic ModelDynamic ModelFGC TripFGC Trip

BP F e e d - P re ssu re [b a r]

3 5

3 7

3 9

4 1

4 3

4 5

4 7

4 9

0 1 2 3 4 5 6 7 8

T i m e ( m i n u t e s )

Tra in 1 LNG Product - Mass Flow [kg/h]

050000

100000150000200000250000300000350000400000450000

0 1 2 3 4 5 6 7 8

T i m e ( m i n u t e s)

BG Feed- Pressure [bar]

61.46

61.48

61.50

61.52

61.54

61.56

61.58

61.60

0 1 2 3 4 5 6 7 8

T ime (min u t e s)

BP Feed - Pressure [bar]

35

37

39

41

43

45

47

49

0 1 2 3 4 5 6 7 8

T ime (min u t e s)

B G F e e d - P re ssu re [b a r]

6 1.4 6

6 1.4 8

6 1.5 0

6 1.5 2

6 1.5 4

6 1.5 6

6 1.5 8

6 1.6 0

0 1 2 3 4 5 6 7 8

T i m e ( m i n u t e s )

Train 1 LNG Product - Mass Flow [kg/h]

050000

100000150000200000250000300000350000400000450000

0 1 2 3 4 5 6 7 8

Time ( minut es)

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Dynamic ModelDynamic ModelFGC TripFGC Trip

Inlet Feed Gas Com pressor Inle t/Outle t Pressure

35

40

45

50

55

60

0 1 2 3 4 5 6 7 8

T i m e ( m i n u t e s)

Inle t Feed Gas Compressor Bypass - Molar Flow [kgmole/h]

0

10000

20000

30000

40000

50000

60000

0 1 2 3 4 5 6 7 8

T i m e ( m i n u t e s)

Train 1 Feed - Molar Flow [kgmole/h]

0

5000

10000

15000

20000

25000

30000

0 1 2 3 4 5 6 7 8

Time ( minut es)

Train 1 Feed - Pressure [bar]

40

42

44

46

48

50

52

0 1 2 3 4 5 6 7 8

Ti me ( minut es)Inlet Feed Gas Compressor Inlet/Outlet Pressure

35

40

45

50

55

60

0 1 2 3 4 5 6 7 8

Time ( minut es)

Inlet Feed Gas Compressor Bypass - Molar Flow [kgmole/h]

0

10000

20000

30000

40000

50000

60000

0 1 2 3 4 5 6 7 8

Time ( minut es)

Train 1 Feed - Molar Flow [kgmole/h]

0

5000

10000

15000

20000

25000

30000

0 1 2 3 4 5 6 7 8

Time ( minut es)

Train 1 Feed - Pressure [bar]

40

42

44

46

48

50

52

0 1 2 3 4 5 6 7 8

Time ( minut es)

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Dynamic ModelDynamic ModelInitial Results• Low BP Pressure – no flow for about a minute• Satisfactory BG Pressure• Refrigerant system disturbances• Surge events anticipated for methane system• Line pack allowed temporary increase in BG flowModified Simulation• Conserve BP flow for Train 1• Attempt to satisfy at least ½ feed rate for each train• Modify controls to isolate BP feed to Train 2/3• Increase BG flow to Train 2/3 temporarily

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Fig. 3 - Train 1 Inlet Feed Gas Molar Flow

0

5000

10000

15000

20000

25000

30000

35000

0 2 4 6 8

Time (min)

Mol

ar F

low

(kgm

ole/

h)

Modified Solution

Fig. 4 - Train 1 Inlet Feed Gas Pressure

40

42

44

46

48

50

52

0 2 4 6 8

Time (min)Pr

essu

re (b

ar)

Modified Solution

Dynamic ModelDynamic Model

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Field TestingField TestingPlan• FGC Commissioned May 03• Full processing rates in all three trains• Validate results of simulation

– Trip FGC– Train 3 reduce BP feed to zero, increase BG feed to 50%– Train 2 reduce BP feed to zero, maintain BG feed at 50%– Train 1 Hold BP feed rate to 50%

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Field TestingField TestingFig. 7 - Train 1 Inlet Feed Gas Molar Flow - Field Data

0

5000

10000

15000

20000

25000

30000

35000

0 2 4 6 8

Time (min)

Mol

ar F

low

(kgm

ole/

h)

Field Data

Fig. 8 - Train 1 Inlet Feed Gas Pressure - Field Data

40

42

44

46

48

50

52

54

0 2 4 6 8

Time (min)Pr

essu

re (b

ar)

Field Data

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Response• 3.5 minutes until flow resumes from BP, low pressure• 6.5 minutes until inlet pressure returns to 51 barg• Train 1 flow decreased to 22% of capacity slowly• Many operational deviations, but no equipment trips• Recovery to 50% rates in about 4 minutes• No loss of condensing• Train 2 & 3 rode through the upset smoothly• Machines not driven to surge• After the trip, facility was restricted to 50% rate• The simulation was not limited to ½ rate

Field TestingField Testing

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Closing RemarksClosing Remarks• Dynamic model closely predicted actual field results• Development of safe operating instruction in advance• Illustrated operational concerns prior to start-up• Used to predict other upsets with confidence• Combined team of specialists reduced risks for system

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– Schedule – 65 days early– Production & Efficiency – exceeded requirements– Ease of start up – 68 days first LNG to turnover

– Schedule – 80 days early– Production & Efficiency – exceeded requirements– Ease of start up – 46 days first LNG to turnover

– Over 18 million hours worked at facility since last LTA

Train 2/3 Expansion SuccessesTrain 2/3 Expansion SuccessesTrain 2Train 2

Train 3Train 3

SafetySafety

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Question or CommentsQuestion or Comments

??