Performance of European cross-country oil pipelines in 2020
01 July 2022
Concawe, the European pipeline safety and environmental monitoring organisation, has collected 50 years of spillage data on European cross-country oil pipelines. This article, based on selected sections of Concawe Report 6/22 - 'Statistical summary of reported spillages in 2020 and since 1971’ released in April 2022, will primarily cover the performance of these pipelines in 2020.
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At nearly 36,000km, the current inventory of European cross-country oil pipelines includes the majority of such pipelines in Europe, transporting some 615 million m3 per year of crude oil and oil products. The full report covers the performance of these pipelines in 2020 and a full historical perspective since 1971.
A total of eight spillages were reported in 2020, four of which were theft related. Excluding theft, this corresponds to a frequency of 0.12 spillages per 1,000km of pipeline, equal to the five-year average but well below the long-term running average of 0.43 spillages per 1,000km of line, which has been steadily decreasing over the years from a value of 1.1 spillages per 1,000km of line in the mid 1970s.
Two of the four non-theft related spills fall under the Mechanical category (one classified under Construction and the other under Design and Materials). One spillage was related to internal Corrosion while the fourth was related to accidental third-party activity. There were no reported fires, fatalities or injuries connected with these spills. For the four theft-related events, the estimated total spilled volume was 114m3, none of which could be recovered. These four spillages accounted for an estimated gross spillage volume of 101m3 or 3m3 per 1000km of pipeline, much lower than the 50-year average of 60m3 per 1000km of pipeline.
In 2020, a total of 71 sections covering a total of 9,120km were inspected by one or more type of in-line inspection tool. Most inspection programmes involved the running of more than one type of inspection tool in the same section, so that the total actual length inspected was 5,059km (15% of the inventory, lower than the 10-year average of 20%). This is significantly lower than in recent years, suggesting that such operational activities may have been limited by the effect of the pandemic, Concawe says.
Overview of the main issues affecting pipeline integrity
Corrosion in hot pipelines
External corrosion of insulated pipelines transporting hot products has been a major issue in the past, particularly in the 70s and 80s with several failures reported in any one year. The problem was inherent to the design of these lines. Over time most such lines have been taken out of service (only 52km remains today from a peak of over 1,100 in the late 70s) and the issue disappeared with them, with only 2 cases recorded in the last 20 years.
Mechanical integrity and ageing
Most European pipeline systems were built in the 60s and 70s. Whereas, in 1971, 70% of the pipelines in the inventory were 10 years old or less, by 2020 only 1.5% were 10 years old or less and 72% were over 40 years old. Over the last two decades, operators and regulators became concerned that ageing lines may be increasingly prone to mechanical (e.g. metal fatigue) or corrosion-related failures. A spike in mechanical failures observed towards the end of the last decade caused some concern. However, a detailed analysis showed that there was no correlation between the frequency of reported fatigue related failures and actual pipeline age. Over the last 10 years, the downward trend has resumed. There is therefore no evidence that the ageing of the pipeline inventory implies a greater risk of loss of integrity, Concawe says in the report.
The historical data shows a long-term downward trend in the frequency of corrosion related spillages since the early 1980s, albeit with notable shorter-term peaks and troughs. The relatively high number of cases reported in the last decade suggests that the long-term trend may now be flat-lining.
The sophisticated integrity management and maintenance systems developed over the years, including the use of new techniques such as internal inspection with intelligent tools, have doubtlessly played a role in maintaining safe and reliable operation of pipelines and will continue to be an essential tool in the future. Concawe pipeline statistics, in particular those covering the mechanical and corrosion incidents, will continue to be used to monitor performance.
Accidental third-party interference
Pipelines are vulnerable to accidental damage caused by parties involved in digging, excavating and other earth moving activities. This has been an issue ever since buried pipelines were first laid. A variety of measures have been put in place and actions taken over the years, including marking, enhanced surveillance, regular contacts with landowners, utility organisations and civil contractors and, in some countries, the development of “one-call systems”. The latter are specifically designed to encourage (or, in some countries, obligate) potential “excavators” to declare their intentions in advance. These measures, though partly successful, require continual review and adaptation and, although the frequency of related incidents has decreased following the general trend, accidental third-party interference remains one of the major causes of spillage for European oil pipelines.
By the nature of their location and the fact that they transport valuable commodities, oil pipelines have always been a potential target for criminals, vandals or even terrorists. Up to the beginning of this decade, only a few incidents involving any of the above had been recorded in Europe (less than one incident per year on average), mostly related to theft attempts and geographically concentrated in South-Eastern Europe.
From 2011, there was a sharp increase in the number of theft attempts culminating at 147 in 2015, 87 of which resulted in a spill. These occurred in several different countries across the continent, often with evidence of sophisticated criminal operations.
Beyond the potential loss of product and/or disturbance to operations, such interference with pipelines, which involve drilling through the pipeline to install a small-bore connection, can cause serious environmental damage and potentially injuries or even fatalities.
Faced with this serious new threat, operators reacted promptly, enhancing surveillance, improving leak detection system capabilities, increasing awareness of the problem with their own staff, contractors and law enforcement authorities and enhancing their capability for fast response and quick repairs. These efforts have paid off and the trend was reversed with 112 events recorded in 2016, 46 in 2017, 35 in 2018, 13 in 2019 (with no reportable spill) and nine in 2020. Early indications show that the downward trend continued in 2021 with a provisional total of six incidents and two spills. Nonetheless, the annual rate is still above the 50-year average, requiring continued focus and vigilance, Concawe states.
No spillage-related fatalities or injuries were reported in 2020. Over the 50 reporting years there have been a total of 14 fatalities in five separate incidents in 1975, 1979, 1989, 1996 and 1999. All but one of these fatalities occurred when people were caught in a fire following a spillage.
In three of the four fire-related incidents, the ignition was a delayed event that occurred hours or days after the spillage detection and demarcation of the spillage area had taken place. In one incident involving a spillage of chemical feedstock naphtha, three people were engulfed in fire, having themselves possibly been the cause of ignition. In another incident, ignition of spilled crude oil occurred during attempts to repair the damaged pipeline. The repairers escaped but the spread of the fire caught four people who had entered inside the marked spillage boundary some distance away. The third incident also involved a maintenance crew of five people carrying out repair activities following a crude oil spill, none of whom escaped. These fatalities all occurred after the spillage flows had been stemmed, i.e. during the subsequent incident management and reinstatement period. In all three cases the fatalities were not directly caused by the spillages but by fires occurring during the remediation process. Stronger management of spillage area security and working procedures might well have prevented these fires and subsequent fatalities, Concawe states.
In just one case, fire ensued almost immediately when a bulldozer doing construction work hit and ruptured a gasoline pipeline. A truck driver engaged in the works received fatal injuries. The single non-fire fatality was a person engaged in a theft attempt who was unable to escape from a pit which they had dug to expose and drill into the pipeline. This caused a leak that filled the pit with product in which the person drowned. A total of three injuries have been reported over the years. Single non-fatal injuries were recorded in both 1988 and 1989, both resulting from inhalation/ingestion of oil spray/aerosol. There was one injury to a third party in 2006.
There was no spillage-related fire reported in 2020. Apart from the four fire-related incidents with fatalities, as mentioned before, five other fires are on record:
- A large crude oil spill near a motorway probably ignited by the traffic.
- A gasoline theft attempt in a section of pipeline located on a pipe bridge. The perpetrators may have deliberately ignited it.
- A slow leak in a crude production line in a remote country area was found to be burning when discovered. It could have been ignited purposely to limit the pollution.
- A tractor and plough that had caused a gasoline spill caught fire, and the fire also damaged a house and a railway line.
- A mechanical digger damaged a gasoline pipeline and also an electricity cable, which ignited the spill.
There were no injuries or fatalities reported in any of these incidents.
To read the full report, visit: https://www.concawe.eu/publication/performance-of-european-cross-country-oil-pipelines-4/