MFL-COMBO Tools – Technology and Experiences
Operation and inspection of infield pipelinesStavanger, 9th of December 2009
Hubert Lindner
ROSEN Technology and Research Center
Introduction
The combination of inspection technologies
... improves the performance
... extend the application range
of the pipeline inspection
Combo Tools - Technologies
of the pipeline inspection
The combination of inspection technologies
... reduce the operational risk
... is cost effective
Combined evaluation of independent measurements
Accuracy
two independent methods
improvement of accuracy:
[LEVENSON 2000]
2
MFL
2
UTcomb2
1α+α=α
Probability of Identification
Inspection 1 (UT)
ImprovementProbability of Identification
two independent methods
improvement of POI:
[PITMAN 1993]
)P1()P1(1P MFLUTcom −∗−−= Inspection 2 (MFL)
Improvement
Operation at Magnetic Saturation: 10 – 30 kA/m
Residual Magnetization after MFL Inspection
0.50
1.00
1.50
2.00
2.50
Mag
neti
zati
on
B
(T
)
Range of Operation
for MFL investigation
Combo Tools - High Quality Inspection
-2.50
-2.00
-1.50
-1.00
-0.50
0.00
0.50
-5.00 0.00 5.00 10.00 15.00 20.00 25.00
Exciting Magnetic Field H (kA/m)
Mag
neti
zati
on
B
(T
)
Remnant Magnetization
Importance of Magnetic Saturation
• signal to noise ratio is improved
• reduced spurious effects
(stress, remnant magnetization, speed effects)
Combo Tools - High Quality Inspection
saturated !
H = 18 kA/m
insufficient !
H = 7 kA/m
Combo Tools - AFD measurement principle
Magnetization in circumferential direction
Axial Flaw Detection Tool | Thomas Beuker | August-2008
6’’ – 56’’: 14 Tool sizes
Resolution: 2.9 mm
Detection of small axially orientated features
Combo Tools - AFD 40” with active Speed Control
Axial Flaw Detection Tool | Thomas Beuker | August-2008
168 Carrier => 1344 Channels
Combo Tools - Pipe Body General Corrosion
AFD
Heavy Seamless Pipe
Axial Flaw Detection Tool | Thomas Beuker | August-2008
CDP
The Solution on Accuracy
ROSEN Contour Following Proximity Sensor
(Compensated Deflection)
Radius Measurement
====
δδδδ
====
δδδδ Touchless Proximity Sensor
++++
ββββ Electronic Angle Sensorββββ
Combo Tools - Focus Geometry Inspection
eXtended Resolution Geometry Tools
gouge with dent
RoGeo · Xt 42”
Combo Tools - Focus Corrosion
High Resolution
MFL
shallow internal
corrosion
(SIC)
eXtended Resolution Geometry
MFL
Combo Tools – Shallow Internal Corrosion (SIC)
SIC Sensor (reality) SIC Sensor (schematic)
Sensor over full pipewall Sensor over metal loss
Amplitude change
Phase movement
Pipe wall
Combo Tools – SIC and MFLD
efe
ct
ran
ge
co
ve
red
by e
ac
h
se
ns
or
typ
e:
Sample pipe of 30 mm WT.
+/- 0.5 mm
+/- 3.0 mm DxD
SIC
De
fec
t ra
ng
e c
ove
red
by e
ac
h
se
ns
or
typ
e:
De
pth
Siz
ing
Ac
cu
rac
y
+/- 10% WT
+/- 1.6% WT
+/- 10% WT
+/- 3% WT
Combo Tools - Shallow Internal Corrosion (SIC)
RoCorr · MFL/SIC 24”
Combined MFL/SIC
Typical Applications:
-Heavy Wall Pipelines
-Baseline Surveys
Combo Tools - Focus Corrosion
High Resolution
MFL
shallow internal
corrosion
(SIC)
eXtended Resolution Geometry
UltrasonicMetal Loss Inspection
MFL
Combo Tools - Focus Corrosion
probability
of detection
accuracy
confidence level
wall thickness
general
wall thinning
length, width
probability of
identification
small pitting
pinholes
installations
• Debris or wax on the pipe wall can affect measurements
• deep external feature require minimum wall thickness
Missed CallsEcho Loss
Different Properties UT/MFL
Example - Probability of Detection
thickness
• pipe wall cleaning by MFL brushes
• redundancy by MFL signal
defect dimension
signal
dimension
Lamination
ultrasonic testing is sensitive to 2-dim.
interfaces
Identification of Features (UT/MFL)
Example - Probability of Identification
MFL signals are
proportional to
volume loss
Lamination with cavity,
56% loss of the pipewall
Combo Tools - Focus Cracks
High Resolution
MFL
shallow internal
corrosion
(SIC)
EMAT
Crack
Detection
eXtended Resolution Geometry
UltrasonicMetal Loss Inspection
MFL
Summary
• The combination of different inspection technologies enlarges the application range
• The combination of different inspection technologies improves the characterization and accuracy for features addressed by both technologies
Combined Inspection – Improved Performance
• MFL and UT are complementary in many aspects and therefore beneficial in combination
• The combination of Geometry Inspection with MFL and SIC is providing new inspection possibilities
• Both MFL/UT and MFL/SIC are well applicable for Baseline Inspections