Pipeline Operations and Integrity

Management
Module 4
Inspection Methods

Alan Murray 2017 1

Outline

Pipeline Operations
Pipeline Maintenance
Where are we? Pipeline Integrity management

Inspection and Assessment Methods

Pipeline repairs
Emergency Response Planning.

Alan Murray 2017 2

Module Outline
• In this Module we will look at Right of way
Inspection, the use of ILI tools, hydrotesting
and direct assessment methods to determine
the condition of the pipe and its
surroundings.

Alan Murray 2017 3

Pipeline Integrity Management
Assessment, Prevention, and Mitigation Measures
External Direct Cathodic
ILI Pressure Pipe Coating CIS Anodes &
Corrosion Assessment Protection
Test Ground Beds
Dependent

Direct Gas Internal Corrosion Site Operational Coupon

Threats

Internal
ILI Pressure Specific Plans Pigging Monitoring
Corrosion Assessment Quality
Time

Test
Stress Cathodic Discharge Field Inspections
Pressure Direct
Corrosion ILI Protection Temperature
Test Assessment
Cracking
Long Seam Defects Pipe Inspection during
Manufacturing Pipe Defects
Pressure Test
Specification Manufacturing
Girth Weld
Construction/ Coupled/Pressure Welds Construction
ILI Pressure Test Patrolling
Threats
Stable

Fabrication Wrinkle Bends Practices

Branch Connections
Gaskets Preventive
Equipment
Relief Maintenance
Valves/Regulators

Third Party One Call System Damage Prevention & Patrolling Marking and Excavation
Independent

Damage Ticket Management Public Awareness Locating Monitoring

Threats

Incorrect Operating Audits

Time

Operations Procedures

Continuing Emergency
Weather and Patrolling
Surveillance Preparedness
Outside Forces
Procedures

Alan Murray 2017 INGAA 4

 PIPELINE PROTECTION: External Interference

• Pipeline protection starts with a good design and construction.

• External damage – we can protect our lines from third parties by:
• Thicker pipe wall, or deeper cover (but beware of overburden),
• Locating in remote regions,
• Regular patrols or surveys of the line, and clear markings, and good
communications with third parties including general public,
• Protective measures such as concrete casings,
• Damage detection equipment.

Images © Penspen Group

5

Alan Murray 2017

 PIPELINE PROTECTION: External Interference
• We can reduce the number of times our pipeline is
damaged by external interference by liaising with our
landowners, and excavators, and making them aware of
the location of the pipelines and their dangers.
• We have other methods of preventing or detecting
damage/defects in pipelines; for example, a ‘one call’
system:

Alan Murray 2017

 PIPELINE SURVEILLANCE
• We have various methods of preventing or detecting
damage/defects in pipelines, for example, leak
detection, walking the line looking for damage/leaks,
and surveillance by aircraft:

7
Images from www.uncc.org, Columbia Gas, USA and Transco, UK

Alan Murray 2017

Right of Way Patrol
• It is important to mark and then patrol your
Right of Way to prevent encroachment

Patrol Frequency depends on the Risk posed by the Pipeline

Usually every two weeks in open country ,once per week in
populated areas.
Alan Murray 2017 8
TNPI Pipeline RoW in Montreal...

Pipeline

Alan Murray 2017 9

Alan Murray 2017 10
Alan Murray 2017 11
Alan Murray 2017 12
 Note warning signs above
Centre line of Pipe

Alan Murray 2017 13

Alan Murray 2017 14
Alan Murray 2017 15
Alan Murray 2017 16
Alan Murray 2017 17
 Basics of ILI Tool Design

ID/OD Magnets & Main Magnets &

Odometer Sensors Sensors Bristles
Wheels Bristles

Data Data
Battery
Storage Processing

Tow Body – may have

Body + Coupling
Support Electronics electronics but could be
Wheels or hollow for gas bypass
Support Electrical Support/ Drive Cup
Cups harnessing Drive Cup

18 Alan Murray 2017

ILI Standards
• API 1163 - IN-LINE INSPECTION SYSTEMS QUALIFICATION
STANDARD (reafirm 2012)
– System qualifications
– Umbrella standard requires the following two
– Requires operators to share dig info with service provider
• NACE SP0102 - In-Line Inspection of Pipelines
– Operations safety and worker qualifications
• ASNDT - ILI PQ - Personal Qualification for In-Line Inspection
– Qualification of those that interpret and provide results

Alan Murray 2017 19

Types of Smart Pigs
• Geometry
– Instrumented pig that maps the inside surface of the pipe to
identify ovalities, deformations, and restrictions along the
pipeline
• Electromagnetic - Magnetic Flux Leakage (MFL), Eddy
currents, etc.
– Intelligent pig that characterizes metal loss along the pipeline
• Transverse Magnetic Flux Leakage (TFI)
– Intelligent pig that characterizes metal loss and crack-like
features along the pipeline
• Ultrasonic (UT)
– Intelligent pig that characterizes remaining wall thickness and
crack-like features

20 Alan Murray 2017

 Inspection

Bend Locator Pigs record the severity of bends

and the position along the pipeline.

It is important to know the minimum bend radius

that the Bend Locator pig can negotiate as well
as the minimum local bore restriction capability.

Photo courtesy of TD Williamson

Alan Murray 2017 21

 Inspection

Caliper & Geopig

• 3D to 1.5 D bend radius
• 10% minimum bore restriction

Photos courtesy of BJ Inspection Services

Alan Murray 2017 22

 Range of tool types & uses
Classification Surface Corrosion Internal & Material Anomalies plus Features Pipe Deformation

Surface Breaking Dents, Wrinkles,

General External Axial External Internal Mfg Related Surface Breaking Third Party
Specific Threat SCC Hard Spots Circumferential Pipe Long Seam Pipe Girth Weld Wrinkle Bends Buckels, & Scratch/ Gouges Earth Movement
Corrosion Corrosion Corrosion Defects Axial Cracking Damage
Cracking Ripples

High Resolution
Axial MFL

Transverse MFL

EMAT

Geometry Tool -
Disks to +/- > 1% d/D

Deformation Tool -
to +/- 0.5% d/D
High Resolution

Direct Assessment

Pressure Test

Spike Hydrostatic Test

Inertial Navigation

Direct Examination
(includes NDE for threat)

Red Not appropriate or never used

Yellow Has applicability, provides an ancillary benefit or specific restrictions need to be considered
Green Is appropriate

Notes This matrix is to help those less familiar with the range of integrity assessment technologies, ILI tools, and their capabilities.
Technology improvements may allow color changes in the future.
Direct Assessment requires following all the NACE Standard requirements of EC, IC, or SCC.

Axial & Circumferential Cracking represents surface breaking and partially open cracks unlike tight fatigue.

Alan Murray 2017 INGAA IMCI 23

2b
What does a pigging survey provide

• Pipeline design information

– Welds, wall thickness changes,
– Openings at branch connections,
– Fittings and valves,
• Micro scan – defect sizes by tool type
– Cumulative damage assessment
• Macro scan – pipe changes,
– Record validations, (MAOP verification?)

Alan Murray 2017 24

Launch & Receive

Credit:
Alan Murray 2017 World Pipelines Aug 2012 25
 Types of Smart Pigs
• Geometry - Caliper, Deformation, Gauge
– Detecting changes in ovality (dents, deformations)
• Inertial Navigation (Mapping)
– 3D mapping, route surveying, bend and strain
measurements
• Metal Loss (MFL & UT) UT = EMAT
– Detection and sizing of metal loss corrosion, pits, etc.)
• Crack Detection (UT & MFL)
– Detection and sizing of cracks and crack-like defects

Alan Murray 2017 26

 Geometry Tools
• Pipe sizing and deformation
detection
• Detects girth welds, wall thickness
changes and installations (e.g.
valves, tees, etc.)
– Acceptance of new pipelines
– Mechanical and 3rd party
damage
– Passage of other ILI tools

Alan Murray 2017 Enduro27

 Inertial Guidance Tools
• Inertial navigation - gyroscopes and
accelerometers
– Measures angular and velocity
changes in X, Y and Z coordinates
– Determine 3-D position of the
pipeline.
• Verifying and creating pipe books•
– Determining pipeline movement
– Measuring bends
• Overlaid on geographical maps provide
exact “as is” view of pipeline

Neb Uzelac and Baker Huges

Alan Murray 2017 28
 Metal Loss Tools - MFL
• Field lines increase due to
reduced cross sectional
area

Alan Murray 2017 29

 MFL
• Axial Direction
Magnetize in the axial direction

• Girth or Hoop Direction

Referred to as Transverse or Circumferential

Alan Murray 2017 Pure Tech & GE 30

Alan Murray 2017 31
Metal Loss - UT
• Normal Beam

Alan Murray 2017 GE 32

 UT Tools
• Direct measurement & Wide range of detectable features
• Internal / external + mid-wall defect discrimination
• Reliable sizing
• Supports advanced MAOP assessment
• No upper wall thickness limitation
• Straight forward data analysis
• Operates only in liquids (liquid slug in a gas pipeline)
• EMATs are contactless UT technology in gas
• Angle Beam (Shear Wave) for cracks, SCC, seam, girth weld

Alan Murray 2017 33

Alan Murray 2017 34
Pipeline Operator’s Forum
• Ranges

Alan Murray 2017 35

 Inspection Objectives
• Macro View in valve section (NEW)
– Records comprehensive, complete, & validated
• Micro View of Pipeline Surface
– Detection of Defects
• Type - POD
• Geometries – Volumetric, Planar
– Sizing of defects
• Depth width & Length = 3 Cylindrical Profile
• Accuracy of POI

Alan Murray 2017 36

Detection Details - 1
• Pigs can generally find what you expect
– Need to use the right tools for the defect
– Depends on the defect size (smaller = harder)
– Depends on tool performance (API 1163)
– Depends on pipe condition
• Debris & deposits
• Material variations
• Proximity to features such as “T”s & valves

Alan Murray 2017 37

Unity Plot indicates Performance

Statistics help

Feedback to ILI
Vendor Critical

Alan Murray 2017 38

Detection Details - 2
• Will pigs Detect as false calls?
• Sometimes indicates defects where there are none
• Will the pig detect defects it was not
designed to find?
– Probability of detection maybe low
– Use as maintenance information
– Do not use to project safety & reliability

Alan Murray 2017 39

Consider High Accuracy when
• Off shore or when excavation $$$$
• Reliability high – not looped
• Environmentally sensitive - penalties high
• Safety in High Population Densities
• Expect many small defects and only a few
need repair

Alan Murray 2017 40

 Consider Low Accuracy when
• Long pipe runs in remote areas
• Small number of defects expected
• No previous ILI inspections
• Leak & accident free operating history
• Old line / expertise right sized
• Cathodic Protection Performance unreliable
• Plan to dig all the indications

Alan Murray 2017 41

GIS Automated Integrity Sheet

Alan Murray 2017 C Bullock42

GIS Automated Integrity Sheet – Close-up

Church Complex

Anomaly

Ball Field

Alan Murray 2017 43

Aerial of Anomaly Location

Church Complex
Anomaly

Ball Field

Alan Murray 2017 44

Anomaly Investigation Result

Alan Murray 2017 45

Two opinions always better than one
• Ask

Alan Murray 2017 Rosen46

Integrity Management
Assessments

INGAA 2011 survey; 146,000 miles

Alan Murray 2017 47

 Unpiggable?
• Can’t use normal free swimming tools
• Can’t easily get into and out of the pipeline
– Too congested, unsafe access points,
• Pig will get stuck at internal constrictions
• Can’t reduce flow or take line out of service
• Reverse flow needed to drive pig in & back
out
• Too long can’t inspect all

Alan Murray 2017 48

 Definitions of
“Unpiggable”
Simple: unable to be pigged.
Better: pipelines with inherent design or current operational
parameters preventing existing ILI technologies from accessing,
navigating, or inspecting the pipe segment.
Realistic: not pigged because of objections: priority, budgetary,
preferences and/or limited understanding.

Clarion Workshop – “unpiggable” as a concept has value

PRCI - there is no such thing as “unpiggable” it just takes ingenuity &

money.

Alan Murray 2017 49

 Preplanning is Key
• Thomas Beuker Rosen pointed the way

Alan Murray 2017 Rosen & Clarion50

Think ‘Off the Shelf’ Components

Alan Murray 2017 Rosen & Clarion51

NYSEARCH & VGC inspection services
Small Insertion Size

Getting big things in

through small spaces

Alan Murray 2017 BJ Lowe & Clarion52

Explorer II RFEC 6”/8” 2 miles

Explorer II MFL 10”/14” 2 miles

Explorer II MFL 30”/36” 2 miles

Alan Murray 2017 NYSearch & PipeTel 53

Self Powered ILI
• 16” robotic launch

Alan Murray 2017 BJ Lowe & Clarion

54
Might you consider these for access?

Alan Murray 2017 55

 Wall Loss in Perspective
• KAPA?
– Wall &
– Cracks

Alan Murray 2017 56

 Putting it together to plan work
• ILI firms provide
software to help
integrate inspections
• Use API 1163 &
contract to have
them precondition
data to yours

Alan Murray 2017 Rosen ROSOFT Apps 57

Why Hydrotest?
• To demonstrate leak tightness.
• To “prove” strength or soundness (integrity).
• To remove detrimental anomalies.
• To mitigate some types of anomalies.
• To meet codes and regulations.

58 Alan Murray 2017

Potential Hydrotest Problems
• Difficult to find leaks.
– Various tracer elements that can be detected above
ground can be used
– Their effectiveness drops as burial depth increases
• Numerous leaks/ruptures
– Difficult to find leaks nearby earlier test leaks
– Running out of tracer elements
• Ballooning pipe
– Relatively new problem
– Considered most probably when there are limited
numbers of under strong pipe joints

59 Alan Murray 2017

Pressure Test Basics - 1
• Test Pressure
– Determined based on the desired results of the test.
– Can range from below SMYS to above SMYS.
– Higher test pressures needed for strength testing.
– Lower test pressures are more appropriate for leak testing.

• Test Pressure Hold Time

– Can range from very short (e.g., 5 seconds), to moderate (e.g.,
30 minutes), to long (e.g., 8 hours).
– Short times are more appropriate for strength testing.
– Long times sometimes needed for leak testing.

60 Alan Murray 2017

Pressure Test Basics - 2
• Test Medium
– Typically water, product (liquid), gas, or air are used as the test medium.
– The amount of “stored energy” can be large regardless of test medium.
– This is true even when short segments are being tested.
– Gas or air tests have a much higher “stored energy” when
used as the test medium
• Detection Methods
– Leaks –
– Inability to hold pressure, pressure drop,
– walking the line, trace element (sniffers), and
– dyes.
– Ruptures –
– Immediate pressure loss.

61 Alan Murray 2017

Pressure Test Basics

• Test Pressure
– Determined based on the desired results of the test.
– Can range from below SMYS to above SMYS.
– Higher test pressures needed for strength testing.
– Lower test pressures are more appropriate for leak testing.

• Test Pressure Hold Time

– Can range from very short (e.g., 5 seconds), to moderate
(e.g., 30 minutes), to long (e.g., 8 hours).
– Short times are more appropriate for strength testing.
– Long times sometimes needed for leak testing.

62 Alan Murray 2017

 Pipe Mill Tests
• Used to “proof test” newly manufactured line pipe.
– Quick test that minimize the time for ductile crack growth

• Included in API pipe specifications since 1928:

– Early tests called for minimum pressures of 40-50% SMYS.
– By 1970, requirements had increased to 60-75% SMYS.
– Later practices and requirements from 85-100% SMYS.

• Short hold times (typically 5 to 10 seconds).

– Pipe mill tests demonstrate strength, not necessarily leak
tightness.

63 Alan Murray 2017

 Hydrostatic Testing Equipment
a) Test Heads and Caps

b)Deadweight Testers
(Accuracy & Calibration)
a) Pressure and Temperature

Pen Recorder
Ground Surface

a) Fill (Centrifugal)Test
andSection
Squeeze (Reciprocating) Pump
Planning and Conducting Pressure
Tests
• Minimum pressure test requirements are given in the regulations,
as well as in industry standards and recommended practices.
– International Standard
– API 1110 “Pressure Testing of Liquid Petroleum
Pipelines”
– United States
– ASME B31.4 Section 437 “Testing” (liquid)
– 49 CFR 195 Subpart E (liquid)
– ASME B31.8 Section 841.31 “Testing after
Construction” (gas)
– 49 CFR 192 Subpart J (gas)
– Canada
– CSA Z662-07 Section 8

65 Alan Murray 2017

 Test Procedures - Pressure-Volume
Charts
• Above the maximum operating pressure and approaching the
target pressure
– Slow and controlled pressurization (e.g., ~10 psi / minute)
• Nonlinearities indicate possible yielding of some pipe joints due
to:
80,000
– Thinner wall 70,000 Target
1,400

– Lower yield 60,000

Pressure 1,200

Hoop Stress, psi 1,000

50,000 Nominal
Operating Yield 800
40,000

600
30,000

400
20,000

10,000 200

66 0 0
Alan Murray 2017
0.000 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009 0.010
Strain (in./in.)
 Test Procedures - Acceptance
Criteria
• Leak tightness
– 49 CFR 195.300 requires a four hour hold
– No unaccounted for pressure drop
– Pressure variations due temperature can cause small increases
and decreases in pressure
• Double stroke rule
– The pressure test should be stopped when it take twice the number of
strokes of the pump to attain the same pressure increase

67 Alan Murray 2017

Pressure v Volume Plot
PRESSURE SHOULD
NOT BE INCREASED
PRESSURE BEYOND THIS POINT

OFFSET LINE

P vs. V
PLOT

0.2% VOLUME
TEST
SECTION
VOLUME

Alan Murray 2017 68

Plotting the Test

Stabilization

Strength Test

Leak Test

69 Alan Murray 2017

Disposal of Test Medium .

Dewater site during discharge

Energy diffuser during discharge

Two cell dewater site post discharge

Two cell dewater 70

site during discharge
 Hydrotest Planning - Test Pressure

• Test pressures are defined by the minimum pressure needed.

• The minimum pressures occur at the highest points. Below that point, the
pipe will see a higher pressure:
– For fresh water, a 100-foot change in elevation corresponds to a 43.3 psi
pressure difference.
– For salt water, a 100-foot change corresponds to a 44.5 psi difference.
• Testing in segments allows you to manage the difference between the
minimum pressure in the line (the highest spot) and the aximum pressure
in the line (the lowest spot).

71 Alan Murray 2017

 Hydro-Test Ruptures

Defects that
Remain in Pipe

125 % MOP
Defects removed
Hydro-test

100 % MOP
Normal
Operating

Alan Murray 2017 72

 2: Hydrotest Planning - Test
Pressure

Note: Hydrotests do not expose short and deep defects.

73 Alan Murray 2017

 PIPELINE PROTECTION: Above Ground Inspections

• Close Interval Potential Survey

• This survey measures the pipe to soil potentials
along the pipeline, to check the CP system
• ‘CIPS’ will detect high or low potentials that may
indicate problems such as interference from other
structures, coating damage, etc..
• Direct Current Voltage Gradient
• ‘DCVG’ detects coating defects in buried pipelines.
• It examines the voltage gradients in the soil from the
CP system, and can locate and estimate a relative
size of the coating defect.
• We check for external corrosion using various ‘above
ground survey’ methods:
• Electromagnetic Methods
• Pearson, ACVG, Pipeline Current Mapping 74 (PCM) can
locate coating defects.

Alan Murray 2017

Alan Murray 2017 75
7
6

ACVG Technique

• AC current on pipe and ground probes in contact with soil above

the line, and off the line away from the electromagnetic field.

Alan Murray 2017

7

ACVG Technique
7

• When a coating fault is present, the AC

current will follow the path of least
resistance between the two ground probes
rather than the higher resistance soil.

Alan Murray 2017

ACVG Technique
• Higher frequency AC current will travel
through higher resistance soil than DC
current = more sensitive than DCVG.
• Cannot determine corrosion potential, or
current direction - stray current going on the
pipe can be misinterpreted as current off the
pipe.
78

Alan Murray 2017

7
9

Electromagnetic Survey Theory

• induction of an
alternating current
onto the pipeline,
which produces a
corresponding
Electric Current flowing in a
electromagnetic conductor creates a magnetic field
that radiates out from the center
field around the of the conductor in concentric
circles.
pipeline

Alan Murray 2017

8
0

Attenuation on Good Coating

• The attenuation of the resulting electromagnetic field

along the length of a pipeline is consistent on pipelines
with continuous homogenous coating

AC Current
Current

Electromagnetic Field

Alan Murray 2017

8
1

Electromagnetic Survey Theory

• Create, Control, Detect and Record the electromagnetic

field from above ground.

Current

Alan Murray 2017

 Attenuation on Good Coating

• The rate of decline (Attenuation) in the field will be primarily dependent

on the electrical resistivity of the coating and the area of pipe per unit
length in contact with the soil.

Perfect Coating

6 90
80
5
Attenuation (mB/m)

RMS Current (mA)

70
4 60
50
3
40
2 30
20
1
10
0 0
0

100

200

300

400

500

600

700

800

900

1000
Attenuation (mB/m) Distance (m)
Current (mA)

Alan Murray 2017 82

8

Electromagnetic Survey
3

Theory
• Lengths of the pipeline with coating faults will allow
larger amounts of the electromagnetic field to return
to ground, causing increased attenuations in the field
AC
Current Current

Electromagnetic
Field

Alan Murray 2017

Sample System

Current

84

Alan Murray 2017

 PIPELINE PROTECTION: Internal
Corrosion
• Pipeline protection starts with a good design and
construction.
• INTERNAL CORROSION – We can include a ‘corrosion
allowance’ (increase thickness of line pipe) to accommodate
in-service, predictable, corrosion.
• But we prefer to prevent internal corrosion by:
Internal corrosion
occurring in water
• Treating the product prior to entry into the line, phase
and checking quality;
• Cleaning the line;
• Mixing chemicals to inhibit any corrosion;
• Lining with a corrosion resistance alloy.

85

Alan Murray 2017

Explorer II
Any
Questions?

Alan Murray 2017 86