(Innospection) Flexible Riser Inspection · PDF fileFlexible Riser Inspection Tool ... to run defect area, putting a rubber coating on top of defect ... •Defect detection in armoured

UK IndustrySeminar Integrity Management of unbonded flexible pipelinesInverurie, 27th November 2008
Flexible Riser Inspection Tool
Innospection Group Ltd.Andreas BoenischDr. Konrad Reber

CONTENT
Short overview Innospection Background : Eddy Current for Inspection of Flexible
Risers Eddy Current Base inspection technique principle Feasibility Test , Phases of Development Conclusion and Discussions

Innospection Ltd.Advanced Electromagnetic Inspection Solutions
Heat Exchanger Tube Inspection (MF-ET, Mag Biased ET, RFET, Iris)
SLOFEC External Pipe scanning Storage Tank Inspection Vessel Inspection
Inspection with marinised Systems Internal & external Caissons Risers
Electromagnetic Inspection Solutions Advanced crack detection
R&D - Application Developments
Locations: Aberdeen, Rugby, Stutensee (Germany)AbuDhabi, Al-Khobar, Melbourne, Singapore

fast screening of good accessibleareas
detection of corrosion (isolated pits,corrosion areas) & other defects
analysis of defects with wall lossseverity classifications
colored mapping of inspected area low inspection preparations
CORROSION SCREENING AT FE- MATERIAL OBJECTS
Due to the principle andinspection capabilities thetarget of the SLOFECtechnique is :

CONTENT

Background of Eddy Current for Flex Pipes
Tube Inspection:e.g. Multiple Layer /cladded tube inspection
Tank Inspection:e.g. inspecting throughGRP liner (8-10mm)
Pipe/Vessel Inspection:e.g. inspecting WT up to33mm, inspectingthrough cladd layer
Riser Inspection:e.g. inspecting high WTthrough cladd, throughNeoprene
Potentialfor
Inspectionof
FlexibleRisers
Inspection
?

Background of Eddy Current for Flex Pipes
- a wall penetration of up to 33mmwas achieved
- through 15mm (liner) stand offwas possible
- through cladded layers possibleto penetrate
- Differential Mode sensitivedetection of localised defects
- Absolute Mode to be usedanalysing Material changes
Experiences with Eddy Currentbased techniques :
Decision to run aFeasibility Study

CONTENT

CALCULATION OF THE STANDARD DEPTH PENETRATION
1= f0 r
f
0
r
- Standard Depth of Penetration- Electrical Conductivity- Absolute Permeability- Relative Permeability- Frequency
The depth at which eddy current density has decreased to 1/e, or about 37% of the surface density, is calledthe standard depth of penetration (d).
AC
Dept
h of
pe
netra
tion

EDDY CURRENTSENSORS
EDDY CURRENTFIELD LINES
TEST PIECE
r >1
Eddy Current Field LineDistribution inferromagnetic materialwith no DCmagnetisation
TEST PIECE MAGNETIC FIELDLINES
MAGNET
Eddy Current Field LineDistribution inferromagnetic materialwith DC magnetisation
Principle of SLOFEC

EDDYCURRENTSENSORS
MAGNET
TEST PIECE MAGNETICFIELD LINES
EDDYCURRENTFIELD LINES
+ -0
Induced voltage for probein non-defect area
DEFECTCOMPRESSEDMAGNETICFIELD LINES
+ -0
Induced voltage for probein defect area
PRINCIPLE OF SLOFEC

SLOFEC - A COMPARISON METHODCalibration with artificialreference defects
Evaluation of indications incomparison to calibration

Artificial defect (diam.10mm) at the undersideside depth 40%
Signaldisplay ofUNDERSIDEDEFECTS
VERTICALSIGNALORIENTATION
Topside corrosionCorrosion pit diameter15mm, depth 20%
Signaldisplay ofTOPSIDEDEFECTS
HORIZONTALSIGNALORIENTATION
SLOFEC - PHASE SEPERATION

top side phase to defectdepth analysis window
underside phase to defectdepth analysis window
The eddy current differential signal phase in colour imagingbackground for color reporting.
Under SideTop SideSelecting color imagewindow
COLOUR PALETTE DEFECT CLASSIFICATION:
< 20% 20 - 30% 30-40% 40-50% >50%
SLOFEC - AMPLITUDE & PHASE ANALYSIS

SLOFEC Reporting & Scan Imaging
or
20-30
%
30-40
%
40-60
%
60%
Signal of thereferenceinternaldefect(50%depth) inthe signal Y-component /phaseanalysewindow
Sect
ion1
2.230
mm
Sect
ion2
1.900
mm
Secti
on3
3.685
mm
Sect
ion4
2.720
mm
14
13
15
16
17
18
19
20
21
22
23
Distance to GTF[meter]
Flange Weld (FW)
Top of steel (TOS)
Section 5450mm
24
25
26
27
28
29
30
31
32
33
34
Client :Location :Subject :
OIL COMPANY
Oil Rundown LinesREFINERY
Section : 4
Date :K-No. :
. :
July/Agust 2000105/00
Pipe Identif P-53
SLOFEC - PipeScan ReportTM

CONTENT

Feasibility Test and further stages
Target of the feasibility tests at flexible risers withexisting Pipe scanners
performing the tests with existing external pipe scanner.
Analysing : - penetration depth with the existing scanners andsensors.
- detectability of various type of inhomogenities- distinction capabilities between defects and other
caused signals- capabilities of signal pattern distinction defects /armour layer edge effects.- capabilities of fatigue detection & analysis

Layer Description Material T[mm]
1 Interlocked Carcass(72.0 x 1.5) 304 L (Fe 02)
8.7
2 Rislan P40 TL TP01Pressure Sheet Rislan
7.5
3 Zeta Wire FM35 (FI 11)(Carbon Steel)8.0
4 First Armour layer FM35 (FI 11)(Carbon Steel)3.0
5 Second Armour layer FM35 (FI 11)(Carbon Steel)3.0
6 Fabric Tape Type PVC 2.3
7 Polyethylene ExternalSheet Polyethylene
10.0
Sample for Flex Pipe Inspection Test

Test Setup 10 Flex Riser sample
Test Sample SLOFEC Scanner PS200& specific Sensors
ET SLOFEC ComputerSystem & E-magnetpower supply

Feasibility Test - Step 1 : Calibration ?
Setting equipment up at 14inch x WT 18mm CS cal-sampleUnknown settings in comparison to full wall cal sample :
magnetisation , how sensitive, Signal Phase , how the signal phasesetting is in comparison to possible defects

- Scanning with the typical settings(as 1.) the complete pipe (exceptlater known defect area) ,Result : clean signal , noindication detected
- Variation of ET Frequency, major(+24dB) increase of sensitivity, fullmagnitisationResult : 2 areas with indications(later analysed as light deformationat outer armour layer> Result (in step 1.b) : not indicatedas here in 1.a-4 too high sensitivity)
Feasibility Test - Step 2 : Scanning withunknown setting

Putting a piece of ferromagnetic material from inside between the gaps of SSCarcass. Target: analyzing if the external scanner receives an indication dueto magnetic field line changes if sufficient magn. field line penetration.Result: full penetration with the existing pipe scanner
Feasibility Test - Step 3 :Penetration Analysis

Analyzing the influence of armoured layer individual End Effect to the ETSignalResult: no significant influence
Feasibility Test - Step 4 :Armoured layer edge disturbance runningscanner in longitudinal axial direction

Artificial defects (slots) produced in the zeta wire by cut outand re-welded armour layers
Feasibility Test - Step 5 :Artificial Defect detection

Setting equipment up to be ableto run defect area, putting arubber coating on top of defectarea.Limitation: due to cut edges ofexternal sheet, scanner cant runcontinuous over the edge(wheels hit edge/jump)
Feasibility Test - Step 5 :Artificial Defect detection

Result:The reachable andless influenceddefects B & Dhave shownindications. Aslight indication ofC can berecognized belowmisaligned amourlayer
DefectNo. D DefectNo. B
DefectNo. C
Defect No. D insignal display
MisalignedArmour Layer

Analysis of penetration into theZeta Wire from outside withoutdamaged armour layers.A 10mm hole drilled from insidetrough SS Carcass , 3mm deep intothe (8mm) Carcass.Result: Detected
Before drilling
After drilling
Feasibility Test - Step 6 :Defect detection

Conclusion Phase 1Feasibility Test Performance Phase
Penetration into the different layers by the (existing) external pipescanner was deeper than expected. (3mm hole in Zeta wiredetected, ferromagn. Material in Carcass gap gave indication)
No significant influence due to armour layer individual band endeffect
Defects (localized) in armour lay

Documents

(Innospection) Flexible Riser Inspection · PDF fileFlexible Riser Inspection Tool ... to run defect area, putting a rubber coating on top of defect ... •Defect detection in armoured