Experience with Stress Corrosion Cracking SCC

1
Experience with Stress Corrosion Cracking (SCC)

• Scott Davis Director of Pipeline Integrity
• and Facilities Engineering

2
Outline

• KMP Liquids Pipelines
• July 30, 2003 Failure
• Repair and Start-up Sequence
• SCC Investigation Strategy
• SCC Investigation Status and Results

3
KMEP Liquids Pipelines
4
8 Tucson to Phoenix
Release Location
5
July 30, 2003 Failure

• Approximately 1309 line failure
• SCADA alarm and Controller shutdown within 3
  minutes
• Operators dispatched and line isolated
• Line excavated and exposed

6
Repair and Start-up Sequence

• Visual examination, suspected seam weld failure
• Entire joint replaced by August 1, 2003
• Line re-started at 50 of MOP (34 SMYS)

7
Pressure Test Protocol

• Metallurgist identified SCC on August 8, 2003
• Line shut down for further testing
• Pressure test in 2 sections
• Spike test of 1 hour at 139 of MOP
• 8 hours at 125 of MOP
• Testing commenced on August 20, 2003
• One test successful

8
Pressure Test Failure

• 2nd test unsuccessful
• Failed in 1st minute at 139 MOP
• 40 from original failure
• Intermittent SCC cluster length 6
• SCC ranged from 50-86 wt

9
Return to Operation

• Bypassed 8 pipe near failure on August 24
• Replaced 5400 feet of pipe in the immediate
  vicinity
• Successful pressure test of section 2
• Line restarted on September 12, 2003
• Currently operating at 50 MOP
• Increasing pressure dependant on results of SCC
  investigation

10
High pH SCC

• Still requires
• Environment that is conducive to SCC
• Susceptible pipeline material
• Tensile stress in the pipeline steel
• Differences
• No surface corrosion products
• CP is adequately protecting the steel
• Higher published stress threshold

11
SCC InvestigationStrategy

• Gather and investigate pipeline data
• Develop algorithm to predict SCC likelihood
• Complete case study on removed 5400
• Predict terrain conditions conducive to SCC
• Conduct field geotechnical, CIS, and PCM
• Select locations for excavations
• Conduct field excavations
• Reintegrate excavation findings

12
SCC InvestigationStatus and Results

• MPI conducted on 5400 of removed 8
• SCC found in pressure test failure joint
• SCC found in 1 joint approx. 1800 upstream
• Field surveys have been completed
• Finalizing excavation locations
• Anticipated completion prior to year end

13
Contact Information

• Scott P. Davis
• Director Pipeline Integrity and Facility
  Engineering
• Kinder Morgan Energy Partners
• 1100 Town Country Drive
• Orange, California 92868
• E-mail daviss_at_kindermorgan.com