Magnetic Tomography method

for inspecting pipelines (МТМ)

OOO R&D CENTRE “TRANSKOR-K”, RUSSIA

MTM scanning process

Defective

section № 1

Step of

recording 1

Registers

Movement

of operator with

magnetometer

SKIF MBS

Anomaly № 1

Length of anomaly 1

Diagrams of

SDC (stress-

deformed

condition)

Ears Surface

Pipeline

Lines

Of magnetic fieldSection without

defects

h = 15 D

Step of

recording 2

Step of

recording 3

Step of

recording 4

Step of

recording 5

Step of

recording 6

Step of

recording 7

Anomaly № 2 Anomaly № 3

Length of anomaly 2 Length of anomaly 3

Defective

section № 2

Defective

section № 3

Scheme of complex processing MTM data of

underground (sub-water) object

Data base: X, Y, Z, curves of SDC (stress-deformed condition)

Processing geodesic information

Processing MTM scanning data

Unit for analyzing and processing data

GPSreceiver

1 Unit of MTM detectors

1 data flow :

X

2 data flow :

2 Unit of MTM detectors

Y

3 data flow :

3 Unit of MTM detectors

Z

4 data flow :

SDC diagramsï î ë è ãî í , Òð óá à 1 0 0 0 ï î õî ä ó,

Ó ÷à ñòî ê â ð à é î í å 0 - 3 0 ì ,Í à ï ð à â ë å í è å î á ñë å ä î â à í è ÿ - ï î õ î ä ó ï ð î ä óê òà .

Ñ è òó à ö è î í í à ÿ ñ õ å ì à òð ó á î ï ð î â î ä à

Ä è à ãð à ì ì à í à ï ð ÿ æå í í î ãî ñ î ñ òî ÿ í è ÿ

0.03

0.03

0.02

9

0.02

8

0.02

8

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7

0.02

7

0.02

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6

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2

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1

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1

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0.02

0.01

9

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9

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8

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0.00

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0.00

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1

0.00

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0.00

00

7 0

6 0

5 0

4 0

3 0

2 0

1 0

0

- 1 0

- 2 0

- 3 0

0 5 .0 4 .2 0 0 6

Ä è à ãð à ì ì à î á ù å ãî í à ï ð ÿ æå í è ÿ

0.0

2 0

0

- 2 0

- 4 0

Object name, direction of inspection – according a product flowDiagrams of stress-deformed condition (SDC)

Diagrams of general stress

Pipeline situation scheme

MTM data field registration

PRINCIPLE of the METHOD

Non-destructive testing works (NDT) in a pit

MTM data office processing

Section without SDC (stress-deformed condition) anomalies

Sections with anomalies

Physical grounds of the method enabling the development of the magnetic tomography method

Magnetoelastic hysteresis phenomenon

Part of volume with magnetization oriented lengthwise vector Ir0 and towards it, correspondingly;

Residual magnetization of magnet in adjusted condition, that is, after multi-repeated imposition of stress;

Magnetization of saturation;

Change of magnetoelastic energy when stress is imposed tension σ;

Constant of magnetostriction;

Average angular coefficient;

Change of domains magnetostatic energy;

Demagnetizing index of inclusions (various types of defects of structure);

Complete piezomagnetic change of magnetization in the first and second volumes, correspondingly;

Energy of interaction of magnitization with field, essential for interdomain boundaries to get over potential barriers, Hk – average critical field;

Is developed owing to detention of domains at energy barriers (defects of array) and also owing to additional magnetization of matrix by inclusions having value of residual magnetization higher than matrix’s.

Mechanical stress, MPa

Magnetic field, A/m

Rela

tive m

agn

etic

pen

etra

bil

ity µ

=10-3

H/m

Diagram of distribution of anomalies danger degree / safe operation term

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

1 5 9

13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 85 89 93 97

A calculated parameter - saf e operation term, years

Dan

ger d

egree

3-d rank

2-nd rank

аномалии

1-st rank

аномалии

3 2 1

Good Admissible Inadmissible

Ranks of anomalies danger

CATEGORY OF METAL CONDITION

RECOMMENDATION ON ENHANCING RELIABILITY

Monitoring

without repair

Scheduled

repair

First priority

repair

Diagrams of distribution of anomaly danger degree/ safe operating pressure

3-d rank

2-nd rank

1-st rank

Dan

ger

degr

ee

Parameter of calculation – free accident operation term, years

Calculation of serviceability parameters

0

1

2

3

4

5

6

7

8

0,02 0,08 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9

Механические напряжения R, доля от σт

Градиент магнитного поля

Dependence between a pipeline magnetic field density and mechanical stresses

Mag

netic

fiel

d gr

adie

nt

Mechanical stresses R, a part of σt

F = -0,6245Ln (σ) + 1,5

0

0,5

1

1,5

2

2,5

0,00 0,05 0,10 0,20 0,30 0,40 0,50 0,60 0,70 0,80 0,90

Механические напряжения, σт

Магнитный

показатель,

F

Dependence between complex magnetic index F and mechanical stresses in a pipeline

Mechanical stresses σt

Mag

netic

inde

x F

, con

ditio

nal u

nits

≤≤≤≤ 5 %5 %5 %5 %Odometer error (measuring distance)Odometer error (measuring distance)Odometer error (measuring distance)Odometer error (measuring distance)20оError in determining angular coordinate of anomalyError in determining angular coordinate of anomalyError in determining angular coordinate of anomalyError in determining angular coordinate of anomaly

± 1,5 mError in determining longitudinal coordinate of anomalyError in determining longitudinal coordinate of anomalyError in determining longitudinal coordinate of anomalyError in determining longitudinal coordinate of anomaly

0,25 m0,25 m0,25 m0,25 mStep of scanning (registration and data recording by Step of scanning (registration and data recording by Step of scanning (registration and data recording by Step of scanning (registration and data recording by detectors), maximumdetectors), maximumdetectors), maximumdetectors), maximum

20 D 20 D 20 D 20 D Admissible distance between the magnetometer and a pipeline Admissible distance between the magnetometer and a pipeline Admissible distance between the magnetometer and a pipeline Admissible distance between the magnetometer and a pipeline (deviation from axis, depth of bedding)(deviation from axis, depth of bedding)(deviation from axis, depth of bedding)(deviation from axis, depth of bedding)

Not more than 3 DNot more than 3 DNot more than 3 DNot more than 3 DAdmissible deviation from the axis of an underground objectAdmissible deviation from the axis of an underground objectAdmissible deviation from the axis of an underground objectAdmissible deviation from the axis of an underground object100 %100 %100 %100 %Volume of registration along lengthways an object Volume of registration along lengthways an object Volume of registration along lengthways an object Volume of registration along lengthways an object 40 40 40 40 mmmmLength of an inspected section, minimumLength of an inspected section, minimumLength of an inspected section, minimumLength of an inspected section, minimum4,7 kg4,7 kg4,7 kg4,7 kgWeight of the toolWeight of the toolWeight of the toolWeight of the tool

200200200200××××200200200200××××750 mm750 mm750 mm750 mmDimensionsDimensionsDimensionsDimensions

Not limitedNot limitedNot limitedNot limitedInternal minimum diameterInternal minimum diameterInternal minimum diameterInternal minimum diameter

Not limitedNot limitedNot limitedNot limitedMinimum radius of turning (bend)Minimum radius of turning (bend)Minimum radius of turning (bend)Minimum radius of turning (bend)0,02 0,02 0,02 0,02 MPaMPaMPaMPaMinimum pressure for gas pipelinesMinimum pressure for gas pipelinesMinimum pressure for gas pipelinesMinimum pressure for gas pipelinesNot limitedNot limitedNot limitedNot limitedMaximum pressureMaximum pressureMaximum pressureMaximum pressure

2222----5 5 5 5 m/sm/sm/sm/sRate of MTMRate of MTMRate of MTMRate of MTM----inspectioninspectioninspectioninspection

56 56 56 56 ≤≤≤≤ D D D D ≥≥≥≥ 1420 1420 1420 1420 mmmmmmmm ииии >Limits regarding pipelines diameters DLimits regarding pipelines diameters DLimits regarding pipelines diameters DLimits regarding pipelines diameters D

Starting withStarting withStarting withStarting with 2.8 2.8 2.8 2.8 mmmmmmmmRange of an object wall thicknessRange of an object wall thicknessRange of an object wall thicknessRange of an object wall thickness10101010----9999Magnetic field density in Magnetic field density in Magnetic field density in Magnetic field density in НННН or or or or АмАмАмАм----1111

MTM ReportRegister of revealed MTM anomalies

Coordinates

of anomaly, m

GPS-coordinates: latitude, longitude

Type of fixation

№ anomaly

Metal condition: good (3); admissible (2);

inadmissible (1)

Integral index F, conditional units

Angular coordinate of anomaly, hour

Beginning, end , Length of anomaly

Distance from the preceding fixation (-)to the next fixation (+)

Prognosis of anomaly type

Safe operatingpressure, MPa, Tsaf

Free accident operation term, years, at Tsaf

Notes:Rank of

anomaly

Types of anomalies:Metal lossCrack-like defectsGeometry changeWeld joint defectsSDC (stress-deformed condition) anomalies

Recommendation on enhancing

reliability of a pipeline section

Section for the first priority repair (1)Section for the scheduled repair (2)Section without repair - monitoring (3)

Map-scheme with fixing an object

to topo-base (Tierra Del Fugo,

Patagonia, Argentina)

Distribution of anomalies lengthways an object

Плотность распределения анамалийобъекта ООО "ЛУКОЙЛ-Западная Сибирь", ДНС-ЦПС,

Протяженность трубопровода2826242220181614121086420

Градация степени

опасности

0.20 0.20

0.55 0.55

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9Gra

datio

n of

dan

ger

degr

ee (

F)

Length of a pipeline, km

Часовое расположение аномалииобъекта ООО "ЛУКОЙЛ-Западная Сибирь", ДНС-ЦПС,

Протяженность трубопровода2826242220181614121086420

Часовое

расположение аномалии

0 ч

1 ч

2 ч

3 ч

4 ч

5 ч

6 ч

7 ч

8 ч

9 ч

10 ч

11 ч

Distribution of angular coordinates of anomalies

Clo

ck p

ositi

onin

g of

ano

mal

ies

Length of a pipeline, km

1. Situational, geodesic and other schemes, tables describing the MTM results;

2. Data illustrating the methodic of field and office works;

3. Data characterizing principals and peculiarities of revealing SDC anomalies of a ferro-magnetic pipeline;

4. Data relevant to the work results.

The following is included into the text: The following is included as graphic

attachments:

Register Tables Maps

1. Maps of distributing parameters of SDC anomalies of an object;

2. Situational Maps-schemes of an object; diagrams

3. Maps of geodesic positioning of an object by GPS-coordinates;

4. Schemes of comparing the inspection data with topo-base of a pipeline route.

Photos Diagrams Schemes

Typical structure of data submitted during

any Report term