Integrity Management

Spirally welded pipelines (extensively used in liquid transmission pipeline systems) may contain manufacturing anomalies that are susceptible to fatigue growth. To account for the angle of these cracks with respect to the longitudinal pipe axis, modifications to inputs of crack assessment models are required.

Using the widely-used pipeline assessment model CorLAS®, we worked with Enbridge Pipelines to investigate two input modifications:

• Consideration of the normal stress component...

The pipeline industry has established various methodologies to estimate corrosion growth in pipelines. However, growth of corrosion feature length is inconsistently addressed in these methods.

We worked with Enbridge Pipelines to review these methodologies and determine the impact of feature length on corrosion burst pressure predictions.

This review:

• Considered methodologies that are applicable to both feature lengths and depths
• Evaluated the methodologies’ abilities to identify unsafe defects...

A limit states design approach has been developed for geotechnical loads using a strain-based design format. This approach addresses the high level of uncertainty associated with the loading processed, which has limited the availability of design guidance in the past.

Working as part of a joint industry project, we have carried out a project to calibrate risk-consistent limit states checks that can be used for a range of strain demand and capacity distributions applicable to geotechnical loads.

Pipeline operators are looking to understand the risks with their pipeline assets, recognize potential issues and know the best course of action to lower their risk profile. Risk and integrity management programs can help solve problems before they arise, lower costs and decrease environmental impact.

The challenge is these programs can be difficult because of the many variables that may impact the analysis. Risk management software can be complicated to use, slow to calculate...

On June 2, 2016, C-FER’s Brian Wagg presented at the Pipeline Safety Seminar in Daegu, Korea to over 400 industry leaders. During the presentation, Mr. Wagg provided insights on integrity management including:

• Requirements for developing an effective integrity management plan
• Criteria for assessing plan effectiveness
• Hazards that impact integrity
• Objectives for establishing baseline assessments
• Data required to develop detailed risk assessments
• Process for assessing defects
• Impacts of...

Overestimating the detection capability and sizing performance of in-line inspection tools can result in overestimating pipeline reliability, and can lead to failures on previously inspected pipelines.

The performance of in-line inspection (ILI) tools represents their ability to identify and size wall loss, planar (crack-like) defects, dents, and manufacturing defects. It is represented by a number of parameters including: the probability of detection (POD), probability of correct...

Maintaining pipeline integrity in the face of progressive deterioration mechanisms, like corrosion and cracking, is an ongoing challenge for pipeline operators. In general terms, the process for defect specific integrity management involves four key steps: identify significant features; size the features; project feature growth with time; and, assess the features’ remaining life.

Kinder Morgan, Inc. (KMI) is one of the largest midstream energy companies in North America, operating more than 30,000 miles of natural gas and product pipelines. Major interstate natural gas pipeline assets include Natural Gas Pipeline Company of America (NGPL), Kinder Morgan Interstate Gas Transmission, L.L.C., TransColorado and Trailblazer. NGPL transports up to 5.7 billion cubic feet (Bcf)/day) of natural gas through 10,000 miles of pipeline and has 210 Bcf of working gas...

The ductile fracture arrest capability of gas pipelines is seen as one of the most important factors in the future acceptance of new high strength pipeline steels for high pressure applications. It has been acknowledged for some time that the current methods for characterizing and predicting the arrest toughness for ductile fracture propagation in high strength steels are un-conservative. This observation is based on the inability of existing models to predict the required arrest...

The probability of detection (POD) describes the ability of an in-line inspection (ILI) tool to detect cracks and is one of the key performance indicators for ILI system qualification. The POD of an ILI tool is often specified by the vendor as the probability of a feature above a certain threshold size being detected by the tool. To verify the POD performance of ILI tools, selected pipeline sections from the ILI runs are excavated and inspected. The excavation data provide valuable...