Monitoring of onshore and offshore pipelines using Guided ...ndt.sitegen.no/customers/ndt/files/Guided Waves.pdf · Monitoring of onshore and offshore pipelines using Guided Waves

Monitoring of onshore and

offshore pipelines using

Guided Waves

A. Demma

Bergen, Norway

June 2012

Guided Ultrasonics Ltd. -

Milestones - technology

3 Guided Ultrasonics Ltd. -

GWT basics

GWT screening

Transducer

Metal structure

Inspected Area

Transducer Ring

Inspected area Inspected area

UT

GWT

Reflection from a Feature (such as corrosion)

When the guided wave hits a change in cross section (or

impedance), it reflects back toward the transducer

Transducer

Structure

Cross Section Change

The dark grey

Section represents the

Cross-sectional area

Typical targets are corrosion and erosion

System Components (screening)

Wavemaker G4

Transducers

Ring

Lemo Cables

Position of Ring

Decay Curves Corrosion is indicated

by large red component

Iconic representation

of identified features

Forward Backward

Series of Welds

-24dB

0.0 5.0 10.00

90

180

270

360

Angle

(deg)

0.0 5.0 10.00.0

0.5

1.0

1.5

2.0

Distance (m)

Am

p (

Lin

ear)

+F5

+F4

+F3

+F2

+F1

-F1

-F2

Guided Waves (unrolled pipe view)

10 Guided Ultrasonics Ltd. -

gPIMS monitoring

gPIMS Monitoring

Guided Wave Permanently Installed Monitoring System

g-PIMS principle

Inspected area Inspected area

GWT Transducer Ring

13 Guided Ultrasonics Ltd. - 12/06/2012

gPIMS solution

• One time access

• High productivity

• Comparison of data allows for sensitive monitoring capability

• Carried out with pipe on-line


gPIMS transduction

•Can be attached to a pipe and

left in place (repeat GW

inspection over an extended

period of time)

•Sealed in polyurethane to give

lifetime protection

•Connection can be made

through a cable many meters

long.


G-PIMS unit

Wavemaker G3/G4 fully compatible with g-

PIMS rings.

Guided Ultrasonics Ltd. - Rev 1 (Aug 2010) -

• Bare pipes

• Buried pipes

• Road crossings

• Offshore risers

• Subsea lines

• Lines in contaminated or high risk areas

Example locations


gPIMS experience

•First on-site installations in

2006

•3 stages of development to

reach the current level of

performance

•Several hundred gPIMS installed

on site

Current Limitations

• Pipe operating temperature -40°C to +90 °C

• Install temperature 10°C to +70°C

• Pipe size 6-24” for standard install

• Almost any size out side this range by custom

moulding

• Standard cable length up to 25m, up to 200m

cable possible.

gPIMS

Performance


Results comparison with standard rings

Result using G-PIMS collar

(before

back fill)

Result using standard collar

-20.0 -10.0 0.0 10.0

10

5

2.5

1

0.5

0.25

Distance (m)

G3

11

#3

59

0 (

mV

)

-20.0 -10.0 0.0 10.0

10

5

2.5

1

0.5

0.25

G3

11

#3

59

7 (

mV

)

-F1-F2-F3-F4 +F1+F2 +F3-F1-F2-F3-F4 +F1+F2 +F3

Result from buried 8” line

Test pipe for sensitivity to change demo


Sensitivity to change

2.5 3.0 3.5 4.0

0.0

1.0

2.0

3.0

Distance (m)

Am

p (

Lin

ear)

+F1 +F2

baseline

0.5% CSC

0.75% CSC 1% CSC

Stability of results

-10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0

60

50

25

10

5

2.5

1

Distance (m)

Am

p (

mV

)

-F1-F2-F3-F4-F5 +F1

Exposed test sample, results 12 months apart

Onshore

gPIMS case study

Case Study: Cased Crossing pipes

•G-PIMS installed on pipes at a cased road crossing

position prior to back filling. Monitoring tests can be

performed without expensive excavations in the future.

Results from cased section of previous slide

• Ø12”, Pipe 146

• Ø14”, Pipe 140 -1

8dB

-60 -40 -20 012

9

6

3

12

Clo

ck

-60 -40 -20 00.0

2.0

4.0

6.0

8.0

Distance (ft)

Am

p (

Lin

ear)

-F1

-F2

Sup

por

t

-F4

-F5

-F6

Sup

por

t

-F7

+F1

-18d

B

-60 -40 -20 012

9

6

3

12

Clo

ck

-60 -40 -20 00.0

5.0

10.0

15.0

20.0

25.0

Distance (ft)

Am

p (

Lin

ear)

-F1

-F2

-F3

-F4

-F5

-F6

+F1

Case study: buried pipe

• 24” buried line in tank farm

• G-PIMS installed on buried

section beneath instrument

• Connection box on yellow post

Result from buried section of previous slide

-18d

B

-5.0 0.0 5.0 10.0 15.00

90

180

270

360A

ngle

(deg)

-5.0 0.0 5.0 10.0 15.00.0

0.5

1.0

1.5

2.0

Distance (m)

Am

p(m

V)

+F1 +F2 +F3 +F4 +F5-F2-F1-F3

Offshore

gPIMS case study

Riser install - 2008

Guided Ultrasonics Ltd. - Rev 1 (Aug 2010)

-60 -40 -20 00.0

5.0

10.0

15.0

20.0

G3-

163#

1125

(Lin

ear)

-60 -40 -20 00.0

5.0

10.0

15.0

20.0

G3-

16#3

957

(Lin

ear)

-60 -40 -20 00.0

5.0

10.0

15.0

20.0

Distance (m)

G3-

116#

1042

(Lin

ear)

Flange+CaissonWeldWater levelWeldWeldWeldWeldSea bedWeld



a) Old style RA-PIMS installed on North Sea riser 2008. b) Cased riser gave good range, sensitivity and repeatability over successive years. c) Advanced data subtraction gives significant improvement in sensitivity.

a) b)

c)


-10.0 0.0 10.0 20.00.0

5.0

10.0

15.0

Distance (m)

Am

p (

Lin

ear)

-F1

-F2

-F3

+F1

+F2

+F3

+F4

+F5

+F6

gP

IMS

Monito

ring R

esu

lt

Subsea gPIMS

Pipe coated with 3LPE

Conclusions

• Monitoring is providing new solution to old inspection

problems

• Experience gained during past years enables high confidence

on performance of gPIMS

• This approach is low risk, low cost and highly efficient

Questions

• Thank You!

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