Overview

Overview developments in failure frequencies

(updated March 2018)

An extensive analysis of data covering the period 1970 to 2016 has lead to the following overview:

Period Interval Number of incidents Total system exposure ·106 km·yr Primary failure frequency per 1,000 km·yr
1970 – 2007 7th report, 38 years 1,173 3.15 0.372
1970 – 2010 8th report, 41 years 1,249 3.55 0.351
1970 – 2013 9th report, 44 years 1,309 3.98 0.329
1970 – 2016 10th report, 47 years 1,366 4.41 0.310
1977 - 2016 40 years 1,143 4.12 0.278
1987 - 2016 30 years 723 3.44 0.210
1997 - 2016 20 years 418 2.53 0.165
2007 - 2016 10 years 208 1.39 0.150
2012 - 2016 5 years 97 0.72 0.136

Conclusions

  • The EGIG database is a valuable source of information on European gas pipelines and pipeline incidents.
     
  • EGIG has maintained and expanded the European Gas pipeline incident database. Seventeen gas transmission system operators in Europe now collect incident data on 142,794 km of pipelines every year. The total exposure, which expresses the length of a pipeline and its period of operation, is 4.41 million km·yr.
     
  • In the EGIG database 1,366 pipeline incidents are recorded in the period from 1970-2016.
     
  • The history of incidents collected in the database gives reliable failure frequencies. The overall failure frequency over the period 1970-2016 is equal to 0.31 incidents per year per 1,000 km.
     
  • The five year moving average failure frequency in 2016, which represents the average failure frequency over the past 5 years, equals 0.134 per year per 1,000 km.
     
  • The five year moving average and overall failure frequency have reduced over the years, although it has tended to stabilise over recent years.
  • Incidents caused by external interference and ground movement are characterised by potentially severe consequences. This emphasises their importance to pipeline operators and authorities.
     
  • Corrosion as a primary cause has now the same frequency rate as external interference, although consequences are much less severe. Over the last ten years, external interference, corrosion, construction defects and ground movement, represent 28%, 25%, 18% and 15%, respectively of the pipeline incidents reported.

Development Safety Performance