Pipeline Integrity and Risk Assessment: Protecting Critical Infrastructure Through Proactive Management

By Jay Beam, HSE Engineer & Advisor

What you need to know:

• Comprehensive threat identification is the first line of defense

• Inline inspection (ILI) tools are the backbone of modern integrity programs

• Quantitative risk models help you prioritize maintenance and decision-making

Pipeline integrity and risk assessment are vital to modern pipeline operations, helping you prevent failures from occurring in the first place.

At its core, pipeline integrity management is the systematic process of evaluating, monitoring and mitigating threats that could affect a pipeline's safe operation.

Pipeline integrity management combines:

• Materials engineering

• Corrosion science

• Data analytics

• Regulatory compliance

In addition, PHMSA regulations under 49 CFR Part 192 and 195 require pipeline operators to maintain integrity management programs that are risk-informed and data-driven. Advanced operators now incorporate machine learning into these models to continuously refine predictions as new data comes in.

Comprehensive Threat Identification: the First Line of Defense

The foundation of any pipeline integrity assessment is thorough threat identification. Each pipeline segment may face multiple threats, including:

Time-dependent threats that worsen over time

o External corrosion due to inadequate coating or cathodic protection

o Internal corrosion from water or corrosive gases in the transported product

o Stress corrosion cracking (SCC) that occurs under specific environmental and stress conditions.

· Time-independent threats not influenced by the pipeline’s age or operational wear and tear over time

o Geotechnical hazards from landslides, soil movement, frost heave

o Seismic events due to earthquakes or induced seismic activity

o Hydrological events from river scour, flooding or erosion

o Vandalism from deliberate interference with pipeline systems

o Lightning and electrical faults from weather events or nearby surface activity

· Third-party damage

o Mechanical damage from excavation or heavy equipment.

o Vehicle impacts from off-road vehicles, aircraft or trains

o Unauthorized construction like infrastructure development near existing systems

o Improper land use like illegal burning, dumping or encroachment o Example

Effective threat identification also involves records verification and historical leak data analysis, especially for older assets constructed before traceable, verifiable, and complete (TVC) records became standard.

For example: In aging natural gas pipelines in the Midwest, operators frequently encounter internal corrosion caused by carbon dioxide and trace amounts of hydrogen sulfide. A transmission line in Ohio required extensive rehabilitation after a smart pig revealed internal corrosion pitting beyond acceptable limits. If left unchecked, the defects could have led to a rupture.

In-line Inspection (ILI) Tools: the Backbone of Modern Integrity Programs

Once threats are identified, in-line inspection (ILI) technologies (or “smart pigs”) are deployed to collect quantitative data on pipeline conditions. These tools are inserted into pipelines and travel with the product flow, capturing data through sensors and magnetic fields.

Modern ILI technologies include:

· Magnetic flux leakage (MFL) for metal loss detection

· Ultrasonic testing (UT) for crack and wall thickness measurement

· Geometry tools for identifying dents, wrinkles, and deformation

For example: An MFL of a 36-inch crude oil pipeline in Texas revealed over 150 indications of external corrosion near river crossings, primarily where coating had disbonded. Targeted excavations confirmed the tool’s predictions and allowed the operator to perform composite sleeve repairs before failure could occur.

ILI data supports fitness-for-service (FFS) assessments, allowing engineers to model defect growth rates and remaining life of components. According to API RP 1163, operators must validate tool performance and incorporate tool tolerances in their assessments.

Quantitative Risk Models Help You Prioritize Maintenance and Decision-Making

With hundreds or thousands of miles of pipe under management, operators cannot inspect or dig up every segment. That’s where quantitative risk models become essential. These models integrate:

· Probability of failure (PoF) based on defect types, material properties, and ILI data

· Consequence of failure (CoF), considering population density, environmental sensitivity, and product type

· Risk scoring matrices that combine PoF and CoF to prioritize high-risk areas

For example: A 12-inch pipeline carrying natural gas liquids in a high-consequence area (HCA) running through a suburban neighborhood, received a high-risk score due to its proximity to schools and homes. Even though defect growth was moderate, the consequence of a rupture was severe. The operator opted for immediate remediation, including pressure reduction and composite sleeve installation.

Final Thoughts

Pipeline integrity and risk assessment are not one-time activities but ongoing, iterative processes that evolve with technology, regulation, and operational data. As the industry continues to face new challenges, from aging infrastructure to emerging environmental regulations—operators must embrace proactive, data-driven approaches to maintain safe and reliable operations.

In short, integrity management is the bridge between prevention and performance—where safety, efficiency, and sustainability intersect.

References

Pipeline and Hazardous Materials Safety Administration. (2023). Pipeline Integrity Management Program Requirements under 49 CFR 192 and 195. Retrieved from https://www.phmsa.dot.gov

American Petroleum Institute. (2022). API Recommended Practice 1163: In-line Inspection Systems Qualification Standard