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Getting More From Your Intelligent Pig Inspection

byRoland Palmer-Jones, Prof. Phil Hopkins, and Andre Goncalves

Penspen Integrity

PPSA SeminarAberdeen

14 Nov 2007

The Problem

Intelligent pigs are widely usedLarge quantities of data are collectedDefects are generally reported in a simple spreadsheet format.Simple clustering and defect sizing leads to safe conservative assessments

Outline

Inspection Technology MFL UT

Defect SizingDefect AssessmentComplex Shape AssessmentCase Study

MFL Inspection

N MAGNET S

Flux Lines

Pipe Wall

Penspen Ltd.

MFL Defect Sizing

Relative measurementDepth Signal amplitude Number of sensors affected

N MAGNET S

Flux Lines

Pipe Wall

MFL Data

Penspen Ltd.

UT Inspection

www.ndt-ag.com

UT Defect Sizing

Absolute Depth/Wall Thickness Time difference between echo

signals

UT Data

Penspen Ltd.

Individual Defects

Penspen Ltd.

Penspen Ltd.

Multiple Defects?

Penspen Ltd.

Penspen Ltd.

Clustering

Penspen Ltd.

Cluster

Evaluation Based on Actual Shape

RSTRENG Riverbottom ProfileDNV RP-F101 Complex Shape Method

RSTRENG

0.00

2.00

4.00

6.00

8.00

10.00

12.00

0.00 50.00 100.00 150.00 200.00 250.00 300.00

Length

Dep

th

DNV RP-F101

Example 1

UT data

Penspen Ltd.

Rectangular Profile Failure Pressure 219 bar

Flat Bottom Profile

0

2

4

6

8

10

12

14

16

18

20

0 20 40 60 80 100 120 140 160 180 200

Distance Along X-Axis (mm)

Rem

aini

ng W

all T

hick

ness

Riverbottom ProfileFailure Pressure 305 bar

River - Bottom Profile

0 20 40 60 80 100 120 140 160 180 200

Distance Along X-Axis (mm)

Rem

aini

ng w

all T

hick

ness

(mm

)

Example 2

Assessment Data Maximum Reported Depth (%t)

Length (mm)

Defect Profile Failure Pressure (Bar)

Standard MFL pig Cluster

63 330 Rectangular 53

Expert MFL pig Boxes

63 330 River-Bottom 113

Expert External UT

50.5 1760 River-Bottom 85

Inspection/Repair Can be Expensive

Penspen Ltd.

Penspen Ltd.

Summary

Defect profile data gives assessment benefitsProfile data is collected anyway and so should be supplied in an accessible format with the inspection report.