Pipeline Integrity Assessment

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Pipeline Integrity Assessment

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  • Pipeline Integrity Assessment

  • ?

    ?

    GNP 4% GNP 4%

    (1999) 1/3

    (1999) 1/3

  • Summary of Incident CausesSummary of Incident Causes

    ASME Causes of Gas Transmission Incidents

    External Corrosion

    Third Party Damage

    I t O ti

    Misc

    Natural Forces

    Internal Corrosion

    Constr/Instal

    Other Failures

    Unknown

    Incorrect Operation

    Non-PipePipe

    Malfunction

    Prev. Damgd Pipe

    Mfr

    Constr/Instal Pipe

    0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0

    Vandalism

    Stress Corrosion Cracking

    Avg Annl Incidents, 85-01

  • COST OF CORROSIONCOST OF CORROSION

    $5 0 bil$5.0 bil.

    4Department of Transportation (DOT), USA, 2001 ($276 bil.)

  • Cost Estimate Example Offshore PNG PipelineCost Estimate Example Offshore PNG Pipeline

    C (US $ Milli )Category

    Cost (US $ Million)

    7.4 MPa 8.4 MPa 10 MPa 12 MPa

    Bare Pipe Materials 374.1 314.4 296.5 228.8

    External Coating 44.1 44.1 44.1 42.0

    Internal Coating 21.2 21.3 21.2 21.2

    Weight Coating 67 2 63 7 57 8 54 0Weight Coating 67.2 63.7 57.8 54.0

    Cathodic Protection 20.7 20.5 20.5 20.2

    Pipe Laying 80.7 78.1 80.8 80.8

    Dredging& Backfill 17.7 17.1 16.8 16.1

    Mobil. & Demobil. 8.4 8.4 8.4 8.4

    Total 634 1 567 6 546 1 471 5Total 634.1 567.6 546.1 471.5

    10 15% of total direct construction cost for corrosion protection (coating + CP)(Cited from Feasibility Study Report for Irkutsk PNG pipeline)

  • CASE HISTORIES ON UNDERGROUND CORROSIONCASE HISTORIES ON UNDERGROUND CORROSION

    Corrosion on the pipeline

    Corrosion on the bottom plates of aboveground storage tank

  • CORROSION IN ANAEROBIC SOILCORROSION IN ANAEROBIC SOIL

  • Chemical/microbiological corrosion

    /

    Electrical corrosion

    10

  • (corrosivity)

    , ,

  • 333

    vs. vs. P/S Disbonded area Sulfate

    2

    P

    0

    2

    P

    0

    2

    P

    0

    0 1 2 3 40

    1

    0 20 40 60 80 100 1200

    1

    2 0 1 8 1 6 1 4 1 2 1 00

    1

    3

    2

    100 101 102 103 104

    [SO42-] (mg/g of soil)

    0 20 40 60 80 100 120

    Disbonded Area (cm2)

    -2.0 -1.8 -1.6 -1.4 -1.2 -1.0

    P/S (V/CSE)

    pH SRB

    2

    Resistivity

    2

    P

    0

    1

    P

    0

    1

    P

    0

    0

    1

    4 5 6 7 8 9 100

    0

    1

    103 104 105 106 107 108 109

    SRB (cells/g of soil)

    4 5 6 7 8 9 10

    pH101 102 103 104

    0

    Resistivity (Ohm.cm)

  • Soil Resistivity Soil Resistivity Wenner 4-Pin Resistivity Measurement

    I

    E

    SSS

    . = RA/L (cm) ()

  • 4-pin method

    Soil box

  • SOIL RESISTIVITY SURVEY: EQUIPMENTSSOIL RESISTIVITY SURVEY: EQUIPMENTS

  • Soil pin

    . .

    a/2 .

  • 5 000 ohm cm 5,000 ohm.cm

  • () ()1.E+06

    1 E+051.E+05

    t

    y

    (

    .

    c

    m

    )

    1.E+04

    S

    o

    i

    l

    R

    e

    s

    i

    s

    t

    i

    v

    i

    t

    1.E+03

    S

    corrosive

    1.E+020 10 20 30 40 50 60 70 80 90 100 110 120 130

    Distance (km)

  • AA

    A B ?

    B

    19

    A, B ?

  • SOIL RESISTIVITY SURVEY: DEPENDENCY ON SOIL DEPTH: DEPENDENCY ON SOIL DEPTH

    A. . B. . . C. .D.

    20

  • SOIL RESISTIVITY SURVEY: BARNES METHOD: BARNES METHOD

    T

    1h1

    2

    3

    h2

    h3 3

    4

    h3

    h4

    h

    S

    1111S

    5h5

    21n21 RRRR

    S

  • SOIL RESISTIVITY SURVEY: BARNES METHOD: BARNES METHOD

    4m 111 42

    4224

    RRR

    RRR

    1. 2m, 4m

    4242

    4242

    RRRR400

    RRR

    1. 2m, 4m (R2, R4)

    2. R2-4 42

    42 RR

    3. 2-4

    22

  • SOIL RESISTIVITY SURVEY: BARNES METHOD: BARNES METHOD

    Pin 2m R2 = 6.3 Pin 4m R4 = 1.3

    2m 2= 22006.3=7,917 cm 2m 4= 22006.3=3,267 cm

    2-4 = 400(R2R4)/(R2-R4)00 ( 3 6 3)/(6 3 3) = 400(1.36.3)/(6.3-1.3)

    = 2,061

    Test data Barnes AnalysisTest data Barnes Analysisa (cm) R (Ohms) Avg. 1/R (1/R) Layer R Layer

    200 6.3 7,917 0.16 - 6.3 7,917

    23

    400 1.3 3,267 0.77 0.61 1.64 2,061

  • SOIL RESISTIVITY SURVEY: BARNES METHOD: BARNES METHOD

    Test data Barnes AnalysisTest data Barnes Analysisa (cm) R (Ohms) 1/R (1/R) Layer R Layer

    150 1.1 0.91 - 1.1 1,040300 0.89 1.1 0.19 5.3 4,995450 0.46 2.2 1.1 0.91 858600 0 14 7 1 4 9 0 20 190600 0.14 7.1 4.9 0.20 190750 0.083 12 4.9 0.20 190900 0.076 13 1.0 1.0 94

    Ref.) T.H. Lewis, Jr., Deep Anode Systems, NACE (2000) p.7-11

    24

  • (sulfate- (sulfatereducing bacteria; SRB)

  • CORROSION IN ANAEROBIC SOILCORROSION IN ANAEROBIC SOIL

  • SULFATE-REDUCING BACTERIA (SRB)

    SO 2 ATP APS PPi

    SULFATE-REDUCING BACTERIA (SRB)

    SO42- SO42- + ATP APS + PPi Pi

    2e-

    SO32- + AMP

    Enters cell

    H+

    S2O52- Metabisulfite

    2e-

    2e- S2-

    S2O42- Dithionite

    S3O62- Trithionate 2e- S2O32-

    Outside cell

    2e 2e Thiosulfate

    Anaerobic bacteriaNeutral environments

    Reducing sulfate to corrosive sulfides

    27

  • SRB Population vs. Soil Key Parameters

    107

    108

    109

    p y

    Resistivity Redox potential

    7

    108

    109

    107

    108

    109

    104

    105

    106

    10

    c

    e

    l

    l

    s

    /

    g

    -

    s

    o

    i

    l

    )

    105

    106

    107

    e

    l

    l

    s

    /

    g

    o

    f

    s

    o

    i

    l

    )

    104

    105

    106

    10

    c

    e

    l

    l

    s

    /

    g

    -

    s

    o

    i

    l

    )

    101

    102

    103

    S

    R

    B

    (

    c

    Clay content102

    103

    104

    S

    R

    B

    (

    c

    e

    101

    102

    103

    S

    R

    B

    (

    c

    108

    109

    -0.2 0.0 0.2 0.4 0.6 0.8100

    Eh (V/NHE)

    Clay content102 103 104 105 106

    101

    ( cm)0 10 20 30 40 50 60

    100

    Clay Content (%)

    108

    109

    106

    107

    108

    /

    g

    -

    s

    o

    i

    l

    )

    105

    106

    107

    /

    g

    -

    s

    o

    i

    l

    )

    Anaerobic,Neutral,High clayey,L i ti it

    103

    104

    105

    A

    P

    B

    (

    c

    e

    l

    l

    s

    /

    102

    103

    104

    S

    R

    B

    (

    c

    e

    l

    l

    s

    / Low resistivity,High water content

    102

    10

    102 103 104 105 106 107 108 109

    SRB (cells/g-soil)

    0 10 20 30 40 50100

    101

    Water Content (%)

    Water content APB

  • C i E Ti

    Corrosion vs. Exposure Time

    04A

    -0.6

    -0.4 SRB-active Biocide added APB-active

    V

    /

    S

    C

    E

    )

    2

    U

    n

    i

    t

    )

    25m A

    C

    10

    -0.8E

    c

    o

    r

    r

    (

    m

    V

    0 2 4 6 8 100

    1

    AlSiFe

    O

    C

    P

    SFe

    Fe

    C

    o

    u

    n

    t

    s

    (

    A

    r

    b

    .

    U

    20m

    0.3

    0.4-1.0

    0.36mm/y

    t

    e

    (

    m

    m

    /

    y

    )

    B D

    Energy (keV)

    0.1

    0.2

    o

    r

    r

    o

    s

    i

    o

    n

    R

    a

    t

    20m

    2m

    2.0

    0 50 100 150 2000.0C

    o

    Time (Day)1.0

    1.5

    2.0

    O SFe

    n

    t

    s

    (

    A

    r

    b

    .

    U

    n

    i

    t

    )

    0.5

    1.0

    1.5

    Fe

    O

    C P

    S

    Fe

    C

    o

    u

    n

    t

    s

    (

    A

    r

    b

    .

    U

    n

    i

    t

    )

    0 2 4 6 8 100.0

    0.5

    Al

    SiFe

    CP

    Fe

    C

    o

    u

    n

    Energy (keV)

    0 2 4 6 8 100.0

    Si Fe

    Energy (keV)

  • MIC in Aerobic Condition2.0

    MIC in Aerobic Condition

    1.0

    1.5

    O SFe

    A

    r

    b

    .

    U

    n

    i

    t

    )

    0 0

    0.5

    Al

    SiFe

    CP

    Fe

    C

    o

    u

    n

    t

    s

    (

    A

    0 2 4 6 8 100.0

    Energy (keV)

    SRB

  • CPCP CPCP SRB-active soil

    Ref.) K. Kasahara, et al., Corrosion, 55(1) (1999) 74

    The change of local chemistry at metal

    OH2He2OH2 22

    The change of local chemistry at metal surface, inducing an increase of pH.

    Effective tool for prevention of SRB-induced MIC in soil.

    31

  • CP vs MICCP vs. MIC3

    2

    P

    0

    1

    -2.0 -1.8 -1.6 -1.4 -1.2 -1.00

    P/S (V/CSE)P/S (V/CSE)

    Despite of coating and CP, MIC occurred. All corrosion occurred the region under the disbonded coating. All corrosion occurred the region under the disbonded coating.

  • Pt & Reference

    ~15cm depth

    PtRef2PipeRef1

    15cm depth

    1. Ref 1 vs. Pipe 2. Ref 2 vs. Pipe 3. Ref 2 vs. Pt

    33

  • Potential mV vs. Cu/CuSO4