02 fea in pipeline design using ansys at intecsea · introduction - 4 - “global ... analysis...

Finite Element Analysis in Pipeline Design Finite Element Analysis in Pipeline Design

using Ansys at INTECSEAusing Ansys at INTECSEA

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Agenda:Agenda:

••IntroductionIntroduction

••Lateral BucklingLateral Buckling

••Pipeline WalkingPipeline Walking

••Free Span Detailed AnalysisFree Span Detailed Analysis

••OnOn--Shore Installation AnalysisShore Installation Analysis

••Structural DesignStructural Design

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IntroductionIntroduction

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“Global buckling is a response to compressive effective axial force and global buckling reduces the axial

carrying capacity. Pipelines exposed to potential global buckling are then either those with high effective

axial compressive forces, or pipelines with low buckling capacity, typically light pipelines with low lateral

pipe-soil resistance.” DNV-RP-F110

Lateral Buckling AnalysisLateral Buckling Analysis

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Exposed Pipeline on Even Exposed Pipeline on Even

Seabed Seabed -- DNVDNV--RPRP--F110F110

ANSYS Routine PackageANSYS Routine Package

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INPUT:INPUT:

•• Pipe propertiesPipe properties

•• Temperature e Pressure ProfileTemperature e Pressure Profile

•• Boundary ConditionsBoundary Conditions

•• Soil ParametersSoil Parameters

MODEL:MODEL:

••PIPE288 elementPIPE288 element

••Pipe soil interaction: Pipe soil interaction:

* Seabed: TARGE170* Seabed: TARGE170

* Pipe: CONTA175* Pipe: CONTA175

RESULT:RESULT:

•• Export axial force, internal pressure and Export axial force, internal pressure and

bending momentbending moment

•• Assess the Load Controlled Condition Assess the Load Controlled Condition

Check as per DNVCheck as per DNV--OSOS--F101F101

•• Plastic Strain can also be exported and Plastic Strain can also be exported and

used in the calculation of Displacement used in the calculation of Displacement

Controlled Condition Check as per DNVControlled Condition Check as per DNV--

OSOS--F101F101

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“Pipeline walking can occur for short free-ended pipelines subjected to cyclic loading. Pipeline walking

is a phenomena in which start-up / shut-down cycles cause a ratcheting response in the pipeline axial

displacement. Over a number of cycles this ratcheting can lead to very large global axial displacement

with associated overload of jumper or spool pieces.” SAFEBUCK

Pipeline WalkingPipeline Walking

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There are three main mechanisms which drive pipeline walking:

•Thermal gradients during heat-up

•Seabed slope

•Riser tension

0

10

20

30

40

50

60

70

80

0 500 1000 1500 2000 2500 3000 3500 4000

KP (m)

Tem

pe

ratu

re (

ºC)

1st Transient 2nd Transient 3rd Transient 4th Transient Full Temperature

Seabed Elevation (m)

-1800

-1600

-1400

-1200

-1000

-800

-600

-400

-200

0

0 6000 12000 18000 24000 30000 36000 42000

KP (m)

Wate

r D

ep

th (

m)

Rig moveRig move

Riser Tension ForceRiser Tension Force

RiserRiser--Flowline ConnectionFlowline Connection

RiserRiser

- 9 -

-0.2

-0.15

-0.1

-0.05

0

0.05

0 500 1000 1500 2000 2500 3000 3500 4000

Distance along pipeline (m)

Rela

tive A

xia

l D

isp

lacem

en

t (m

)

1st Cooldown

2nd Cooldown

3rd Coo ldown

4th Coo ldown

5th Coo ldown


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Free Span AnalysisFree Span Analysis

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DNVDNV--RPRP--F105F105

In ANSYS, we basicallyIn ANSYS, we basically

calculate the mode shape calculate the mode shape

and the natural frequency.and the natural frequency.

Free Span Analysis Free Span Analysis

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“The free span analysis may be based on approximate response expressions or a refined FE“The free span analysis may be based on approximate response expressions or a refined FE

approach depending on the free span classification and response type, see Sec.6.” DNVapproach depending on the free span classification and response type, see Sec.6.” DNV--RPRP--F105F105

Approximate Response AnalysisApproximate Response Analysis


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-263.00

-261.00

-259.00

-257.00

-255.00

-253.00

-251.00

12003 12103 12203 12303 12403 12503 12603

KP (m)

Wate

r depth

(m

)

Seabed Profile Pipeline Profile

300m300m

Adjacent Length Adjacent Length

Critical Span

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

1.20

201875 201975 202075 202175 202275 202375 202475

KP (m)

Mo

de s

hap

e

-356

-354

-352

-350

-348

-346

-344

-342

-340

-338

Wate

r d

ep

th (

m)

Mode Shape Seabed Profile Pipeline Profile

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-263.00

-261.00

-259.00

-257.00

-255.00

-253.00

-251.00

12003 12103 12203 12303 12403 12503 12603

KP (m)

Wate

r depth

(m

)

Seabed Profile Pipeline Profile

300m300m

Adjacent Length Adjacent Length

Critical Span

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

1.20

201875 201975 202075 202175 202275 202375 202475

KP (m)

Mo

de s

hap

e

-356

-354

-352

-350

-348

-346

-344

-342

-340

-338

Wate

r d

ep

th (

m)

Mode Shape Seabed Profile Pipeline Profile

-0-0-0-0.2.2.2.2.200000

0.00

0.20

0.40

0.60

0.80

1.00

1.20

201875875201875201875 201975 202075 202175 202275 202375375375

KP (m)

003 12103 12203 12303 12403 12503 12603

KP (m)m)m)

Seabed Profile Pipelinenenene P P Prorororofifififilelelele

300m300300300300m

Adjacent Length Ad Ad Adjacjacjacjacentententent Length

Critical Span

Mo

de s

hap

e

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OnOn--Shore Pipeline InstallationShore Pipeline Installation

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Analysis steps:Analysis steps:

1.1. Lay the pipe on the rollerLay the pipe on the roller

2.2. Lift the pipeLift the pipe

3.3. Move the pipe laterallyMove the pipe laterally

4.4. Lower the pipeLower the pipe





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Analysis steps:Analysis steps:









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Client: PETROBRASClient: PETROBRAS

Project: Dutos SergipeProject: Dutos Sergipe


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Structural DesignStructural Design

#2500 12.75’’ Swivel Flange Design for Camorim #2500 12.75’’ Swivel Flange Design for Camorim

Field in SergipeField in Sergipe

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Structural DesignStructural Design

Riser Clamp Design for Dourado FieldRiser Clamp Design for Dourado Field

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Future Development:Future Development:

•Bottom Roughness Analysis

- Substitute SAGE as our main

Software for this type of analysis

•On-Bottom Stability Analysis

- Assess the anchoring effect of

the stable part of the pipeline

SAGE Profile 3DSAGE Profile 3D

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The EndThe End

Thank you All!Thank you All!

02 fea in pipeline design using ansys at intecsea · introduction - 4 - “global ... analysis...

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