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Updated June 2022



The most common metric for reporting pipeline performance is the number of incidents per 1000 kilometres of pipeline per year. This metric is useful when comparing different companies, but it does not tell the full story. A lot goes into determining how a pipeline company performs, and the results might differ depending on the metric used.

For a meaningful comparison of pipeline performance between companies, we must compare companies with similar operations, including the number, size, and type (pipeline materials and substances transported) of pipelines they operate.

We use the following performance metrics:

  • the number of incidents per 1000 kilometres per year of pipeline
  • the total number of incidents
  • the number of incidents by consequence rating (low, medium, high)
  • the volume and type of product released

Some companies are examined more closely than others because of their compliance history or the location of their pipelines and the products those pipelines carry. For example, a pipeline near a water body that transports a hazardous substance (e.g., sour gas, produced water, or oil-well effluent) may pose a greater risk to the public, the environment, wildlife, and livestock.

Figure 5 shows data by company for each performance metric.

Products Released

In 2021, the total volume of hydrocarbon liquid and produced water released was 68 per cent lower than 2020. Based on liquid release volumes, the following table lists the top five incidents rated as a high consequence in 2021, which made up 40 per cent of the total volume of hydrocarbon liquid and produced water released.

Company Liquid volume released (m3) Substance released Incident date Field operations area
1. Canadian Natural Resources Limited
(incident number: 20212682)
386 Produced water November 22, 2021 Central
2. Summerland Energy Inc
(incident number: 20212255)
302 Produced water October 8, 2021 Central
3. Razor Energy Corp
(incident number: 20210082)
200 Produced water and crude oil January 10, 2021 Central
4. Summerland Energy Inc
(incident number: 20212221)
160 Produced water October 4, 2021 Central
5. Canadian Natural Resources Limited
(incident number: 20210787)
150 Produced water and crude oil April 5, 2021 South

Note: Additional information about incidents can be found in the Data section of this report.

Figure 6 shows the volume and category of liquids released by year.

Pipeline Failure

Leaks and ruptures are grouped into category called pipeline failures. Of the 344 pipeline incidents that occurred in 2021, 265 were pipeline failures.

If a failure occurs, companies must investigate the cause, implement a plan to prevent it from happening again, and provide us with the details of the investigation and remedial actions.

Leading Causes of Failure

Incidents are categorized by their leading cause of failure. However, it is difficult to identify the root cause as it could include poor design or poor operations and maintenance. For companies to select a suitable pipeline material, an assessment based on a thorough understanding of the intended service conditions, potential upset conditions, future development or changes in services, temperature and pressure variations, production rates, and other factors is required on a project-by-project basis. In addition, companies must continually monitor and assess their pipelines for these conditions throughout the life of the pipeline. 

In 2021, the following were the most common causes of pipeline failure:

  • internal corrosion (51 per cent)
  • external corrosion (9 per cent)
  • construction deficiency (9 per cent)
  • valves or fittings (8 per cent)

More than 85 per cent of the pipelines we license are made of steel, which is highly susceptible to corrosion. Effective programs must be in place to monitor and prevent these pipelines from corroding to an unacceptable level, and confirming that companies have such programs is the focus of our pipeline inspections and assessments.
Figure 7 shows the percentage of failure types and a ranking of causes.

Internal Corrosion

In 2021, internal corrosion remained the leading type of pipeline failure, representing 51 per cent of all pipeline leaks and ruptures. More than 76 per cent of internal corrosion failures were on uncoated steel pipelines; the remaining failures were on nonmetallic pipelines with metallic risers and connections that are susceptible to corrosion.

In 2021, 38 per cent of pipeline failures from internal corrosion were due to multiple corrosion mechanisms (called multimechanism corrosion). The most common internal corrosion cause types were under deposit corrosion (14 per cent) and at nine per cent each: carbon dioxide (CO2) corrosion, corrosion under internal coating, and microbiologically influenced corrosion.

Forty-seven per cent of internal corrosion failures were on pipelines transporting oil-well effluent, which can be attributed to the corrosive agents in these fluids.

For pipelines transporting corrosive fluids, companies must develop a program to monitor for corrosion and, where corrosion occurs, minimize its progression, or replace the pipe.

Typically, internal corrosion can be mitigated by

  • doing effective cleaning (called "pigging") of pipeline segments to remove solids and debris,
  • using biocide chemical treatments to kill microbial organisms in the pipeline,
  • periodically applying or batching large quantities of a corrosion inhibitor as a protective barrier on the inside of the pipe,
  • continuously injecting an inhibitor chemical to reduce the corrosiveness of the transported fluid or to function as a protective barrier on the inside of the pipe,
  • removing water from the pipeline or preventing it from entering, and
  • installing pipe with a permanent protective inner coating or installing a corrosion-resistant liner inside an uncoated steel pipeline.

The risk of internal corrosion increases the longer a pipeline is inactive and not purged. Water and solids left inside a pipeline accelerate the rate of corrosion. Companies must properly clean inactive pipelines and apply corrosion inhibitors to prevent corrosion from happening whenever a pipeline will be inactive for extended periods to preserve it for future use.

External Corrosion

The exterior surface of a steel pipe is susceptible to corrosion. In 2021, external corrosion was the second leading type of pipeline failure, representing 9 per cent of all failures. Buried pipelines must have an external coating that must be inspected before the pipeline is buried. All underground steel pipelines must use cathodic protection to counteract corrosion in areas where the external coating may be compromised. Cathodic protection must be periodically measured and actively maintained to ensure an appropriate voltage along the entire pipeline.

In 2021, 33 per cent of the external corrosion pipeline failures were because the coating no longer adhered to the pipe (i.e., disbonded), preventing effective cathodic protection. Disbonding can occur due to improper installation, age, or excessive operating temperature. Other causes for external corrosion failures were missing or damaged coating on the pipeline (33 per cent) and inadequate coating on the pipeline (13 per cent).

Construction Deficiency

In 2021, the third leading type of pipeline failure was construction deficiency (9 per cent). This includes incidents caused by overstressing or improper support or restraint at tie-in points or where the pipeline transitions from below the ground to aboveground (the riser) (38 per cent). 

About 67 per cent of construction deficiency failures occurred on nonmetallic pipelines, and 75 per cent of those nonmetallic pipelines were carrying oil-well effluent.

Damage during installation is usually unintentional and results from installing nonmetallic pipelines using practices like those used for steel pipelines. Nonmetallic pipelines are corrosion-resistant but require careful handling and specific installation practices.

Valve or Fitting Failures

In 2021, the fourth leading type of pipeline failure was valve or fitting related (8 per cent). The leading cause of these incidents were related to gasket, seal, or packing issues (33 per cent). This failure type is indicative of poor maintenance of pipeline components. Although these failures typically involve small release volumes and are rated as low-consequence incidents, improper maintenance can lead to higher-consequence incidents if not addressed. 

Additional Information

Additional data about pipeline performance in Alberta is available in the full workbook.