External Corrosion Direct Assessment (ECDA) Method External Corrosion Direct Assessment (ECDA) Method2010. 6. 17.P iblPi liH diPi li Possible Pipeline Hazards in PipelineStress Internal External FatigueStress CorrosionCorrosion CorrosionFatigueMechanical Ground 3rdPartyD Damage MovementDamageCorrosion Corrosion M Mn+ : M Mn++ ne- : O2+ 2H2O + 4e- 4OH- 4 4 (anode) (cathodic)() () () (+) (): -0.5V ~ -0.7VTotal 276 billion $ !!3.1% of GDPReport NoFHWA RD 01 156 Report No. FHWA-RD-01-156Corrosion Cost and Preventive Strategies in the United States, Gerhardus H. Koch, Ph.D.,* Michiel P.H. Brongers,*Neil G. Thompson, Ph.D.,* Y. Paul Virmani, Ph.D.,**Joe H. Payer, Ph.D.*** , Office of Infrastructure Research and Developmenty pFederal Highway Administration C t E ti tE l Off hPNG Pi li Cost Estimate Example Offshore PNG PipelineCat egor yCost( US $Mi l l i on)7. 4 MPa 8. 4 MPa 10 MPa 12 MPaBar e Pi pe Mat er i al s 374. 1 314. 4 296. 5 228. 8Ext er nalCoat i ng 44. 1 44. 1 44. 1 42. 0Int er nal Coat i ng 21. 2 21. 3 21. 2 21. 2Wei ghtCoat i ng 67. 2 63. 7 57. 8 54. 0Cat hodi c Pr ot ect i on 207 205 205 202 Cat hodi c Pr ot ect i on 20. 7 20. 5 20. 5 20. 2Pi pe Layi ng 80. 7 78. 1 80. 8 80. 8Dr edgi ng& Backf i l l 17. 7 17. 1 16. 8 16. 1Mobi l .& Demobi l . 8. 4 8. 4 8. 4 8. 4Tot al 634. 1 567. 6 546. 1 471. 510 15% of total direct construction cost for corrosion protection (coating + CP)(Cited from Feasibility Study Report for Irkutsk PNG pipeline) (1985-2001, ASME)ASME Causes of Gas Transmission IncidentsExternal CorrosionThird Party DamageASME Causes of Gas Transmission IncidentsMiNatural ForcesInternal CorrosionExternal CorrosionUnknownIncorrect OperationMiscNon PipeMfrConstr/InstalOther FailuresNon-PipePipeStress Corrosion CrackingMalfunctionPrev. Damgd Pipe0.0 5.0 10.0 15.0VandalismgG Gas Distribution Pipeline (OPS, DOT, 2002-2003)Number of Incidents% of Total IncidentsProperty Damages% of Total DamagesFatalities InjuriesConstruction/Operation20 8.1 $3,086,000 6.7 0 16Corrosion 3 1.2 $60,000 0.1 2 9Outside Force 153 62.2 $32,334,352 70.1 6 48Other 70 28.5 $10,617,683 23.0 13 31Total 246 $46,098,035 21 104Corrosion Failure Example Corrosion Failure ExampleGas explosion caused by charged soil (crater size: 15 m x 34 m) due to microbial corrosion of gas pipeline (CarlsbedNew MexicoUSAAug192000) (Carlsbed, New Mexico, USA, Aug. 19, 2000)Source: National Transportation Safety Board (USA) www.ntsb.govcorrosion control corrosion control coating & lining () CPCURRENT CURRENT () CP anodic protection corrosion inhibitor t i ll ti material selectionSACRIFICIAL SACRIFICIALANODE ANODE ()+PowerSource+-ENTENT CURRENTCURRENTCURRCURR : Mg, Al, Zn : , PERMANANT PERMANANTANODE ANODE 3 3 SOIL CORROSIVITY ( ) (~8,000 cm)N i!! No corrosion !!() () () 1.E+061.E+05cm)1.E+04sistivity (.1.E+03Soil Rescor r osi ve1.E+020 10 20 30 40 50 60 70 80 90 100 110 120 130Distance (km) No corrosion !! No corrosion !! () (0)(, )(A) (B) (C) : , : Sta.No. 621+00D1 : 300[mm] PE3[m] 3 - [A] (: 2.5m) - , [B] (: 5m) D2- [C] (: 4.5m, B) D3D4D5D6 (mm) (mm) (mm/y) (mm/y)(A) 1.75 3.0 0.48 0.82(B) 1.74 3.8 0.47 1.04 (B) 0 0 0 0()5835 210035.234.23125.410CP Criteriaon Rate1 1e CorrosioRelative0 040.10.040.0180.01-1000 -800 -600 -400 -200 0 200Potential (mV/CSE)Case HistoriesUndergroundCorrosion Case Histories - UndergroundCorrosionMicrobiologically Influenced Corrosionstray current corrosionAC induced corrosion Crevice corrosionCorrosionAC-induced corrosion Crevice corrosionCorrosionunder disbonded coatingTypical Corrosion of Transmission Gas Pipelines yp pMicrobiologically Influenced Corrosion (MIC)C f S Corrosion of Aboveground Storage Tank Bottom Plate AST AST AST AST AbovegroundT t / AAbovegroundStorage TankGradeTest / AccessStationGradeReference CellMonitoring Rim 25' Center 55' RimOn -1411 -698 -404 -601 -1455TubeOff -902 -664 -402 -578 -911Potentials (mV) Potentials (mV) 3 3 SOIL CORROSIVITY ( ) (DCVG) (DCVG) DCVG (pulsed direct current voltage gradient) method DCVG (pulsed-direct current voltage gradient) method 2~3m 1520 2 3m -10-50510Defectential Difference (mV)0 1 2 3 4 5 6 7 8 9-25-20-1510PoteMeasure Point 1995-2002DCVG 2: Pi i ti f C tiD f t 2. : Pin-pointing of Coating Defects Pipeline current mapper (PCM) Pipeline current mapper (PCM) AC DCVG DCVG (), ( ) ( ) Current Attenuation Current AttenuationAtt ti b/10 000(L I/I )/l tht t Attenuation: mb/m= 10,000(Log10I/Io)/length = constant27Case I. , Case II. , , CCase III./ , Case IV. short Case V Case VI ,/ PCM PCM A i 4H 1A transmitter , 4Hz, 1A ( ) , loss transmitter Receiver PCM A & B PCM A & B100TB1 TB2 TB3 TB460708090-30405060dBmA 010200 500 1000 1500 2000 2500 3000 3500 4000 4500TB DEFECT0 500 1000 1500 2000 2500 3000 3500 4000 4500Di st ance,m2 ClI t l P t ti l S(CIPS) 2. - Close Interval Potential Survey (CIPS) CIPS - (2-3m ) - - - CIPS () CIPS ()-500-700-600-900-800CP criteriaTB 3mVCSE)-1100-1000TB 126 8mATB 414.7mATB 511.4mA15.4mATB 80 mATB 9otential (m-1300-120026.8mATB 255mATB 619.2mATB 734.3mA25.2mAP/S po-1400-13000 1 2 3 4 5 6 7 8 9 10-1500Distance (km)CIPS !!! Test points TPTPCIPS (25 ft to 5 ft) CIPS (25 ft to 5 ft)5 ft interval25 ft intervalCIPS () CIPS ()CIPS () CIPS ()CIPS/DCVG CIPS/DCVG PDAGPS Ant enna Bl uet oot h communi cat i onPDA t ht iPush swi t chMeasur e cabl ePDA scr een t ouch oper at i onDCVG CIPS GPS GIS DCVG-CIPS-GPS-GIS372 2. Chemical/microbiological corrosion/ / Electrical corrosion382 2 2.2. -- (corrosivity) , , CORROSIVITY MAP () CORROSIVITY MAP ()402 2. - (< 3000 ~5,000 ohm.cm) Wenners four electrode method (ASTM G57) Wenner s four electrode method (ASTM G57) ABA, B ?B42SOIL RESISTIVITY SURVEY: DEPENDENCY ON SOIL DEPTHA. . B B. . . C. .D. 43SOIL RESISTIVITY SURVEY: BARNES METHOD T 1 h1 h2 3 h2 h3 S 45 h4 h5 1 1 1 1S + + + = =44n 2 1R R R RSOIL RESISTIVITY SURVEY BARNES METHOD : BARNES METHODTest data Barnes Analysisa (cm) R (Ohms) 1/R (1/R) Layer R Layer ( ) ( ) / ( / ) y y 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 190750 0.083 12 4.9 0.20 190900 0.076 13 1.0 1.0 94R f ) TH L i J D A d S NACE (2000) 7 11 Ref.) T.H. Lewis, Jr., Deep Anode Systems, NACE (2000) p.7-1145() 2. () - - ( (-) - () +()(STA 29+37 91)-3000(STA 29+37.91) STA 73 80V 9A-600300V-900E, mV-1200-1500-15 -10 -5 0 5 10 15Di st ance, m - , 0 2A ( 9A 2 2%) - : ~0.2A ( 9A 2.2%) 1: 11: 30m(, , , )()(11) 8.1A(0.2x11 = 2.2A )2.5km: 800mmPE 30m 7.1A(2.2A ) 8 4A(2 5A )PE 8.4A(2.5A ) 12.8A 5.9A - -, 120% (5.9A 12.8A)2 2. - (anodic interference) , ( ) (cathodic interference) /(combined interference) (combined interference) :Control of Pipeline Corrosion, A.W. PeabodyT1-17-1012l, VCSE-0.83VT1 15T1-18T/BT1 18 16-5-4-3-2Potentia-4.93VT1-15T1-18-1-60 20 40 60 80 100 120 140 160 180Time, sT1-11T/BT1 10T1-12T1-13T1-10T1-14T1-16 (EPR)T()()T/B T/B-1-2Potential, VCSE-2.66V-4-30 20 40 60 80 100 120 140 160 180Time, s-3.00VGPSGISSatellite WirelessNetworksSatellite Communication Rectifier RectifierTB 1 TB 2Remote MonitoringData LoggerRemote ControlRectifierRemote MonitoringData LoggerRemote ControlRectifierReferenceElectrodeReferenceElectrodeData Logger Data LoggerAnode AnodeCurrent51 []SCR t ype SMPS t ype - (on/off) GPS 10 msec Data Logger Installations Data Logger Installations ata ogge sta at o s ata ogge sta at o s 16 M CIPS (data logger) (#13, #26, #28#30) #28, #30)() ()R19 on/off, 25 (on/off 27mV)R15 on/off, 13 (on/off 192mV) R18 on/off, 21 (on/off -1756mV) R17 on/off, 17 (on/off -74mV) 20mV () ()(m) R1 R2 R3 R4 R5 R7 R8 R9 R11 R12 R13-1 R13-2 R13-3 R14 R15 R17 R18 R19 R20 R21 R22 R23 R24 R2530-1000 000000000000000000000000 136M1 00000000000000192000000000 14864M2 0000000000000036000000000 152028M4 000000000000002802400000028 1823640000000000000069503600000030 162970M5 000000000000002904300000045 173186M6 0000000000000031-7410000000043 193504D2 000000000000000-23940000000 203732M7 000000000000000-222080000000 2143800000-20000000000000-17560000000 224908M9 000000000000000025802600000 235748M10 0000000000000000004300000 246762M12 00000000000000000492900000 25 7488 M13 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 27 0 0 0 0 0 0 257488M13 0000000000000000027000000 267650End 0000000000000000043000000 288650 0000000000000000007600000 () ()(mV) - 100 VDE-0150 20 BS 7361, part 1[ON- OFF]>0 [ON OFF] 10,000 cm 5,000 10,000 cm < 5,000 cmCIPS < -0.85V -0.85V < < -0.75V > -0.75V CIPS I II III IV V VI 3 3. - VI 7 7 13 3 2 0 32/ 6 6 12 11 6 0 41(TB)1 0 3 0 0 0 4 1 1 2 0 0 0 4 2 6 5 4 6 0 23mV) -5003G()CIPSVCSE(m-850-15001: D 63 %IRPCM2.52.0dBmA3 3. D 63 T/BD63D633 3. (1) (2) pH (3) 3 3. : 80cm3 3. 2 8mm 2.8mm3.1mm2.1mm 1.5mm 2.1mm 1.5mm 10% (HCl) (rotten egg 10% (HCl) (rotten egg smell) (FeSx)H2S SRB2) x (0 xCl 2 Fe S xH HCl 2 FeS2< < + + + +2) x (0 xCl 2 Fe S xH HCl 2 FeS22 x< < + + ++(EDS)3000(EDS)20003000O Si1000FeCaSAl30000 1 2 30 Ca2000FeO01000CaSSi0 1 2 3keV S (SRB )S lf t R d iB t i(SRB) Sulfate-Reducing Bacteria (SRB)SO42- SO42- + ATPAPS + PPi Pi 2e- Enters cell SO32- + AMP H+ S2O52-Metabisulfite 2e- S2O42-Dithionite Outside cell 2e- S2- S3O62-Trithionate 2e- S2O32- Thiosulfate O H 4 S H 8 SO22 SRB 24+ + H 8 e 8 H 8 + +O H 4 S H 8 SO22 SRB 24+ + 2 2222 2) OH ( Fe 3 OH 6 Fe 3FeS S Fe + + + +99 + + + + OH 2 ) OH ( Fe 3 FeS O H 4 SO Fe 42 224SRB vs SRB vs. 108109108109108109 105106107g-soil)106107of soil)105106107g-soil)102103104SRB (cells/g103104105SRB (cells/g 102103104SRB (cells/g0 10 20 30 40 50 6010010110Clay Content (%)102103104105106101102(O cm)-0.2 0.0 0.2 0.4 0.6 0.810010110E (V/NHE)Clay Content (%) (O cm)108109Eh (V/NHE)107108109 105106107ells/g-soil)104105106ells/g-soil), 10310410APB (c101102103SRB (c102102103104105106107108109SRB (cells/g-soil)0 10 20 30 40 5010010Water Content (%)APB pH 6 7 7 0 pH 6.7 7.0(%) 22.1 7.4Cl (mg/kg) 1 77 7 09 Cl (mg/kg) 1.77 7.09SO42-(%) 0.205 0.029(%) 42.5 11.1 (%) 42.5 11.1SRB Corrosion vs. Exposure Time06-0.4 SRB-active Biocideadded APB-activeE)225m A C -0.8-0.6corr (mV/SCE1OPFeCounts (Arb. Unit)20m 0.4-1.0036mm/y m/y) Ec0 2 4 6 8 100AlSiFeCSFeEnergy (keV)0.20.30.36mm/yn Rate (mm/B D 0.00.1Corrosion20m 2m 2.01.52.0OS)0 50 100 150 2000.0Time (Day)1.01.5O SFeounts (Arb. Unit)0.51.0SiFeOC PFeFeCounts (Arb. Unit)0 2 4 6 8 100.00.5AlSi FeCPFeCoEnergy (keV)0 2 4 6 8 100.0FeEnergy (keV)(1997) (1997~ ) ~~ ~~*~ SRB() KK h tlC i () K. Kasahara, et al., Corrosion, 55(1) (1999) 74 + + OH 2 H e 2 O H 22 2 .2 2. :950mV : -950mVCSE1044 4. ECDA ? ? pH (~10) p ( ) + + OH 2 H e 2 O H 22 2pH 1) pH(), OH-pH 2) pHpHpH pH>10~11, . pH< 8 (ECDA)() ( ) ( ) and/or ECDAI, II: 14 : D63 (I) SRB () () I, II() ECDA III I, II On -1000-5000(43V, 7A) (43.3V, 17.7A) -3000-2500-2000-1500CSE(mV)-5000-4500-4000-35003000 CDistances(m)-50000 100200300400500600700800900100011001200130014001500160017001800190020002100220023002400 . .ECDA ECDA -1,0000Potential, mV/CSE71-3,000-2,000-5,000-4,0000 1000 2000 3000 4000 5000Distance, Arb. Unit ON OFF DEFECT1.E+051.E+061.E+031.E+041.E+020 1,000 2,000 3,000 4,000 5,000Distance, Arb. UnitECDA ECDA ECDA ECDAIMMEDIATE 0 0 -SCHEDULED 4 3 -MONITORING 91 3 1 DIG 1: DIG 1 (scheduled) : pH>11113: pH>11: pH 6-7: 15cm DIG 4: DIG 4 (monitoring) / / ()(i di t ) ()(immediate) MIC? pH(mV)(cm)STN 10 36221 YES 7 -604 6,513:10,362cm2 :56cm2: 12 : 122 YES 7~9 -735 2,098 :25 ~ 70cm2: 12 7 : 12, 7 23 YES 8 -562 2,538:10,362cm2:1,602cm2 :5 4 ~ 6 1cm2:5.4 ~ 6.1cm24 YES 8~9 -701 1,360, :7.6cm2~47cm2ECDA ECDA K S G T i i N th t G A i ti KeySpan Gas Transmission(2003)Northeast Gas Association(2003-2005) 32km 32km 1944 - 1974 1970 CIS + DCVG + PCM CIS + DCVG (or ACVG) 10 (immediate 6, scheduled 2, monitoring 2)66(Indication (I+S) 43, monitoring 23) 150m 500m Indication11 , 29 , 3 Monitoring 22 , 1 ECDA , ECDA ECDA .Case Study () y ()Leak Detection in Oil Pipeline by ECDA (Jan, 2009) Leak point was excavated based on the ECDA survey results.C ECDA(cf. NACE RP0502)CIPS DCVG Pearson EM AC AttenuationCoating holidays 2 1,2 2 2 1,2Anodic zone or bare pipe 2 3 3 3 3Near river or water crossing 2 3 3 2 2 gUnder frozen ground 3 3 3 2 1,2Stray currents 2 1,2 2 2 1,2Shielded corrosion activity (heat-shrink sheet) 3 3 3 3 3 y ( )Adjacent metallic structures 2 1,2 3 2 1,2Near parallel pipelines 2 1,2 3 2 1,2Under HVAC overhead electric transmission lines 2 1,2 2 3 3 ,Shorted casing 2 2 2 2 2Under paved roads 3 3 3 2 1,2Uncased crossing 2 1,2 2 2 1,2 g , ,Cased piping 3 3 3 3 3At deep burial locations 2 2 2 2 2Wetlands (limited) 2 1,2 2 2 1,2 ( ) , ,Rocky terrain/rock ledges/rock backfill 3 3 3 2 2*1: - (