Shallow Internal Corrosion Sensor Technology for Heavy Pipe

Contents • • Motivation Measurement Principle Mechatronic Principle Inspection Tool Design Combining SIC with

Motivation Risks for Pipeline Integrity and Operational Manufacturing Steel Production Welding (SAW, ERW) …

Motivation Corrosion plays a crucial role in pipeline integrity … it is a time-dependent

Motivation Top of Line Corrosion (TLC) or Dewing Corrosion … starts as Shallow Internal

Motivation Droplet Condensation of Vapor Phase Vapor H 2 O, CO 2, H 2

Motivation TLC Controlling Parameters • Partial Pressure of CO 2 • Partial Pressure of

Motivation What kind of inspection technology is required? Due to feature sizes and high

Measurement Principle Alternating current triggers Primary Magnetic Field Magnetic flux change causes Eddy Currents

Measurement Principle Coil Impedance: Z = R + j ωL R Ohmic Resistance ω

Measurement Principle Penetration Depth determined by Skin Effect Skin Depth δ ~ 1/(ω μσ)1/2

Mechatronic Principle SIC Sensor = Contour Following Touchless Proximity Sensor (Compensated Deflection) Radius Measurement

Inspection Tool Design Ro. Corr·MFL/SIC 24" Combo Tool MFL Two plane sensor system Available

Combining SIC with MFL Depth Measurement of Metal Loss Features MFL SIC relative absolute

Combining SIC with MFL SIC feature sizing customizes MFL sizing model Defect Depth [mm]

Test Results SIC Scan of Steel Plate with Spherical Pits Depth [mm] y-direction [mm]

Test Results Surface Diameters Aspect Ratio P 35. x P 30. x P 25.

Test Results Depth [mm] y-direction [mm] SIC Scan of Steel Plate with TLC x-direction

Test Results SIC Depth [mm] SIC Scan of Steel Plate with TLC Real Depth

Test Results 16" Pump Test Line Dent Simulation Spiral Weld Internal Defects Flange Dent

Test Results 16" Test Joint, WT = 12. 6 mm SIC MFL Copyright ©

Test Results TLC in 16" Test Pipeline AUT Copyright © ROSEN Group 2009 -

On-Site Example - World Longest Subsea Run Requirements - 42" /44" Langeled Pipeline Inspection

On-Site Example - World Longest Subsea Run CDP 624 MFL Channels Ro. Geo·Xt 330

On-Site Example - World Longest Subsea Run Results • Traveling time 127. 3 hrs

Summary • Based on Eddy Current Technology, SIC Sensors have been developed for metal

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Shallow Internal Corrosion Sensor Technology for Heavy Pipe Wall Inspection ROSEN Technology & Research Center Germany Dr. Olaf Stawicki 18 -Nov-2009

Contents • • Motivation Measurement Principle Mechatronic Principle Inspection Tool Design Combining SIC with MFL Test Results On-Site Example Summary Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Motivation Risks for Pipeline Integrity and Operational Manufacturing Steel Production Welding (SAW, ERW) … Pipeline Integrity Assessment Corrosion Erosion, Fatigue Ground Movement Mechanical Damage … Construction Coating and CP Girth Weld Faults Poor Pipe Support … Poor Surface Preparation Inadequate Material Storage … Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Motivation Corrosion plays a crucial role in pipeline integrity … it is a time-dependent deterioration process Heavy Wall Pipelines for Offshore Applications • Specified maximum corrosion growth rate • Controlled wall thickness reduction during the lifespan Monitoring Internal Corrosion is inevitable for reliable and save operation! Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Motivation Top of Line Corrosion (TLC) or Dewing Corrosion … starts as Shallow Internal Corrosion (SIC) Origin of TLC • Unprocessed wet gas is transported from an offshore well • Heat exchange between pipeline and cold surrounding (such as sea water) • Low p. H water droplet condensation on the upper half of the pipeline • Dissolution of aggressive gases in droplets support corrosion Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Motivation Droplet Condensation of Vapor Phase Vapor H 2 O, CO 2, H 2 S Organic Acid (HAc) TExt « TGas Water Drain TGas TExt Stratified Water Flow Droplet Size Distribution ~ r -2/3 localized, small-scale corrosion Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Motivation TLC Controlling Parameters • Partial Pressure of CO 2 • Partial Pressure of H 2 S • Water Condensation Rate • Gas Pressure, Velocity, Temperature • Organic Acid (HAc) Concentration TLC can reveal high growth rates, up to several mm/year (Singer et al. , 2009) Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Motivation What kind of inspection technology is required? Due to feature sizes and high Corrosion Growth Rates (CGRs), an approach is required with … … High Sensitivity for early detection and excellent feature discrimination … Accurate Sizing Properties for determining CGRs effectively Both primarily for Heavy Wall Gas Pipelines Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Measurement Principle Alternating current triggers Primary Magnetic Field Magnetic flux change causes Eddy Currents in conductive material, e. g. , pipe wall Eddy Currents generate Secondary Magnetic Field Secondary Field modifies Primary Field via mutual inductance Eddy Currents imply change of coil impedance Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Measurement Principle Coil Impedance: Z = R + j ωL R Ohmic Resistance ω Frequency of driving current L Inductance of Coil ωL • In Air Li ft- • Metal Loss O ff • Material “In Air” R “Over Material” “Over Metal Loss” Lift-Off Eddy Currents Copyright © ROSEN Group 2009 - Copy prepared for PPSA Eddy Current Distortion SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Measurement Principle Penetration Depth determined by Skin Effect Skin Depth δ ~ 1/(ω μσ)1/2 Eddy Current Density decreases with depth. Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Mechatronic Principle SIC Sensor = Contour Following Touchless Proximity Sensor (Compensated Deflection) Radius Measurement = δ Proximity Sensor (Lift-Off) + β Electronic Angle Sensor Copyright © ROSEN Group 2009 - Copy prepared for PPSA counts SIC sensor schematic view Lift-Off SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Inspection Tool Design Ro. Corr·MFL/SIC 24" Combo Tool MFL Two plane sensor system Available tool sizes SIC 100% coverage 6" – 56" Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Combining SIC with MFL Depth Measurement of Metal Loss Features MFL SIC relative absolute Compensation for Lift-off Sensitive Pitting Discrimination Inner Pipe Wall Surface SIC Regime Wall Thickness MFL Regime Detection & Sizing of External Defects Copyright © ROSEN Group 2009 - Copy prepared for PPSA Outer Pipe Wall Surface SIC Sensor Technology | O. Stawicki | 18 -Nov-2009 14

Combining SIC with MFL SIC feature sizing customizes MFL sizing model Defect Depth [mm] Sample pipe with WT = 20 mm Detection Regime MFL SIC Probe Depth Sizing Accuracies MFL ± 2 mm SIC ± 0. 5 mm Defect Diameter [mm] Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Test Results SIC Scan of Steel Plate with Spherical Pits Depth [mm] y-direction [mm] Lift-Off 3 mm Resolution 2 x 2 mm EDM-made pits x-direction [mm] Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Test Results Surface Diameters Aspect Ratio P 35. x P 30. x P 25. x P 20. x P 15. x 35 Aspect Ratio D/t ≥ 3 Depth t Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

On-Site Example - World Longest Subsea Run Requirements - 42" /44" Langeled Pipeline Inspection Range 1200 km Gas Speed 8 m/s Active Speed Control set at 3 m/s WT Range 3 – 38 mm Maximum Pressure 220 bar Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

On-Site Example - World Longest Subsea Run CDP 624 MFL Channels Ro. Geo·Xt 330 Geometry Channels SIC 864 Channels Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

On-Site Example - World Longest Subsea Run Results • Traveling time 127. 3 hrs • Tool velocity 1. 5 – 3. 0 m/s • Almost full pipeline length recorded • 3. 82 km 2 of pipe wall inspected ( = 521 football fields) • 11, 7 measurement points per cm 2 • 450 billion measurement points • 374 GB data recorded … but data evaluation is still in process Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

Summary • Based on Eddy Current Technology, SIC Sensors have been developed for metal loss inspection on inner pipe wall • Compared to other measurement technologies: • SIC: Absolute depth of metal loss features • MFL: Relative depth based on wall thickness • SIC tools have less friction compared to tools with magnet yokes • SIC Inspection is contactless, i. e. no direct coupling to the pipe wall • SIC sensor metal loss depth sizing Typically between 1 mm and 10 mm depth Copyright © ROSEN Group 2009 - Copy prepared for PPSA SIC Sensor Technology | O. Stawicki | 18 -Nov-2009

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