Threats From Pipeline Corrosion

A Federal Perspective

Robert Smith – Research Program Manager U.S. DOT/Pipeline and Hazardous Materials Safety Administration robert.w.smith@dot.gov 919-238-4759 September 20-21, 2012

Corrosion Forum 2012

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Who Is PHMSA?

We develop and enforce regulations for the safe, reliable and environmentally sound operation of: Approximately • 2.5 M pipeline miles • 2,500 pipeline operators • 1M daily hazmat shipments

• By land, sea and air

http://www.phmsa.dot.gov/pipeline

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Pipeline System Components Pipeline Mileage %

Total

Operators %

Total

Hazardous Liquid 173,396 7 306 12

Gas Transmission 317,516 13 939 38

Gas Distribution

(main)

(service)

2,035,253 80 1,245 50

1,200,803 48 834,450 32

Total 2,526,165 100 2,490 100

Diverse Infrastructure

A: Interstate B: Intrastate

Pipeline A

Pipeline B

Transmission Pipeline Types

Example Commodities • Natural Gas

• Hydrogen • Liquid Hydrocarbons such as Crude Oil, Gasoline, Jet Fuels, Diesel, and Propane

• Anhydrous Ammonia • Carbon Dioxide (liquid) • Ethanol (batched with gasoline)

Example Operating Pressures • Gas 50psig-2,500psig • Liq 100psig-800psig

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Aging Infrastructure?

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Construction Vintage

Corrosion: Threat and Frequency Differ by Pipeline Type

7 http://primis.phmsa.dot.gov/comm/reports/safety/AllPSIDet_1992_2011_US.html

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Corrosion: Consequence

Reported Cause of Incident Number % Fatalities Injuries Property

Damage

% of Property Damage

EXTERNAL CORROSION 797 7.7% 10 69 $329,645,057 5.9%

INTERNAL CORROSION 753 7.3% 13 6 $222,118,708 3.9%

UNSPECIFIED CORROSION 291 2.8% 1 11 $8,340,845 0.1%

Total: 1,841 17.9% 24 86 $560,104,610 10.0%

National All Pipeline Systems: All Reported Incident Details: 1992-2011 http://primis.phmsa.dot.gov/comm/reports/safety/AllPSIDet_1992_2011_US.html

Common Pipeline Corrosion Types

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General Corrosion Pitting Corrosion

Microbial Induced Corrosion Stress Corrosion Cracking

Unique Corrosion Types

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Ethanol Induced Stress Corrosion Cracking (eSCC)

Carbonic Corrosion Liquid and

Gaseous CO2 Microbial Induced Corrosion - Biogas

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DA typically involves a four step process:

1. Pre-assessment involving integrating pipeline physical characteristics and operating history to identify areas of DA applicability and appropriate tools

2. Indirect inspection involving gathering data without exposing the pipeline to determine where defects may exist and to support ranking of possible excavation sites

3. Direct examination involving excavation and physical examination of the pipe in locations where defects are expected to exist

4. Post assessment involving evaluating the data from the earlier steps to validate the assessment process and possibly to refine the specifics of how it is applied

Direct Assessment (DA)

Direct Assessment (DA)

• External Corrosion Direct Assessment improving since 2004

• Internal Corrosion DA slowly getting wetter

• DA now expanding into other threats including: • Stress Corrosion Cracking • Mechanical Damage • Ethanol

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Dry Gas ICDA

Wet Gas ICDA

Liquid ICDA

Existing Standard

Existing Standard

Research/ Standard

Development Underway

Congress & NTSB Drivers • Acts in 2002/2006/2011 – calling for “a program

of corrosion technology” specifically “corrosion detection and improving methods, best practices, and technologies for identifying, detecting, preventing, and managing internal and external corrosion and other safety risks”

• NTSB (PAR-12-01) calling for focus on “cracks with associated corrosion” & “corrosion under disbonded coatings”

13 Enbridge's 2010 Marshall, Michigan, spill

Corrosion Considerations

• Implications of San Bruno disaster to Direct Assessment – Role of professional engineering

judgment/license – Limitations on use when

records are inadequate – Can a process like this really

work given economic constraints of the rate-sensitive environment?

• Transportation of diluted bitumen

– Technical risks of moving oil/tar sands “crude” • Study awarded to National Academies of Science

• Consensus standards development process – Is it inclusive enough, balanced, and quick enough? – Is it transparent enough?

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Corrosion Considerations (cont.) • How does corrosion factor into an integrated Fitness For

Service model? How does FFS play into the Integrity Management framework?

• What level of conservatism needs to be applied to assessment (e.g., types, intervals) and prevention/ mitigation, when fundamental records are less that complete, traceable, and verifiable? Think pre-code pipe.

• Where records are incomplete what risk reduction/ monitoring measures must be applied to ensure safe operations? ASME says conservative measures/ estimates must be made.

• What does “piggable” really mean, and how is equivalency going to be assured for alternatives?

• Does “design life” really mean anything at all out side of tax purposes?

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Thank You!

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Jim Merritt Department of Transportation Pipeline & Hazardous Materials Safety Administration Office of Pipeline Safety P(303) 638-4758 Email james.merritt@dot.gov

Robert Smith Department of Transportation Pipeline & Hazardous Materials Safety Administration Office of Pipeline Safety P(919) 238-4759 Email robert.w.smith@dot.gov

Jeffery Gilliam Director, Engineering Pipeline & Hazardous Materials Safety Administration P( 202) 366-0568 Email Jeffery.Gilliam@dot.gov

Max Kieba Department of Transportation Pipeline & Hazardous Materials Safety Administration Office of Pipeline Safety P(202) 493-0595 Email max.kieba@dot.gov