ILIA View: In-Line Inspection State-of-the-Art For SCC Presented by: Scott Thetford Manager- Government Relations GE-PII OPS Workshop on SCC December 2, 2003 Houston, Texas

Introduction Current ILI Technologies applied to SCC Detection Next Generation SCC ILI

Current Applied ILI Technologies Magnetic Flux Leakage –Axial –Transverse Ultrasonic –Shear wave Electromagnetic Acoustic Transducer

Magnetic Flux Leakage Goal: Detection of gross SCC MFL Coupled with other data sources –Axial + Transverse –Axial + Elastic Wave (Wheel Coupled Shear Wave) –MFL + DA While results have been good more effort needs to be applied to understand limitations.

Feature seen by Transverse Field Inspection

Feature Seen by Axial is Small to non- existent

Magnetic Flux Leakage Axial Field + Transverse Field = Gross SCC Screening Application

Different tools for liquid and gas pipelines Liquid Coupled UltraSonic Shear Wave – for liquid lines (Natural Gas lines with batching) Emat – for gas pipelines Liquid filled wheel probes – for gas or liquid High resolution tools for –detection and –sizing of smallest cracks of all types Ideal for monitoring crack growth Detection of hairline cracks Ultrasonic Technologies

UltraSonic Shear Wave Crack Detection Outline of Detection Capabilities: Minimum crack length of 30 mm Length accuracy +/- 5 mm Minimum crack depth of 1 mm (2mm for mid-wall cracks) Longitudinal orientation within +/- 10 o Depth categorized as –< 12.5% –12.5% to 25% –25% to 40% –> 40% of wall thickness Probability of Detection > 90%

UltraSonic Shear Wave Crack Tools Tool size range Until 2001: 24”+ diameter ” – 20” ” – 14” Challenge: space restriction in small diameters

16”-20” Tool in Service Launch into tool trap Sensor Carrier Array

Stress Corrosion Cracking Detected by Ultrasonic Crack Detection Excavation comparison Excellent prediction in size and shape

Single Crack Feature

SCC Field SCC feature close-up Excavation vs. tool prediction

10” to 14” Now in Service

EMAT Goals Detection of sub-critical SCC Determination of length and depth of axial cracks Operate without a liquid couplant Cost-effective inspection Discriminate int./ext. & injurious/non-injurious Full wall coverage Robust and reliable design Similar detection targets to UltraSonic Shear Wave Crack Detection Tools.

Wave types Emat

UltraSonic Shear Wave Emat SCC Detection- Live Line

Real feature: SCC Emat length 300 mm, depth 4.5 mm

Next Generation SCC ILI Automated Feature Analysis. Increased Feature Database = Increased accuracy of failure models. Cracking and Corrosion Combination Tools. Other Sensor Developments –Gas coupled ultrasonic –Eddy current

ILI Association – founded April

Thank you.