European crude oil and petroleum products pipelines in 1992 had fewer incidents of oil spills than in 1991, spilled less in total volume, and recovered a larger portion of what was spilled than in any single year in the 5-year period beginning in 1988.
That's according to the latest report by Concawe, Brussels, on the performance of western European oil-pipelines operating on land. Concawe (Conservation of clean air and water, Europe) is the oil companies' European organization for environmental and health protection. Figures for 1992 are the most recent compiled.
Only seven incidents of oil spills from pipelines or related facilities occurred in 1992, compared with 14 in 1991 and an average of 12.9/year since 1971. Five spills were from pipelines; two from pump stations.
Net loss of oil into the environment was 430 cu m (2,709 bbl) or barely 0.7 ppm of the total volume transported. Gross amount of spills totaled 804 cu m (5,065 bbl), least in the period 1988-92 (Table 1).
EUROPE'S SYSTEM
The total length of oil-industry cross-country pipelines operating in Western Europe at the end of 1992 was 21,300 km (13,352 miles), as reported by 66 respondents to Concawe's survey. The network consists of approximately 215 separate lines.
That total is 500 km (310 miles) more than reported for 1991, says Concawe, with newly added product pipelines in Belgium, Spain, and the U.K. In all, 596 million cu m (3.8 billion bbl) of crude oil and refined products were transported through the pipeline system. Total traffic volume was 105 billion cu m-km, of which products amounted to almost 26 billion cu m-km.
Concawe categorizes spills of more than 1 cu m according to cause. For 1992, there were two spills from mechanical failure; one from operational causes; two from corrosion; none from natural hazards; and two from third-party activity. The seven incidents resulted in spills totaling 804 cu m, as stated, with 374 cu m (47%) recovered. Concawe reports the combined cost of pipeline repair and clean up to be approximately 0.6 million ECUs (1992: $720,000).
TRENDS; INCIDENTS
Concawe data since 1971 show spills from third-party damage have averaged 4/year and accounted for 51% of net spill volumes (oil spilled less oil recovered).
Spills from mechanical failure have averaged 3.2/year and contributed 29% of total net spill volume. Since 1971, spills caused by corrosion have averaged 4.3/year and accounted for 13% of net spill volumes.
Table 2 shows how spills in 1992 compare with the yearly averages since 1971.
In the largest single incident in 1992, 275 cu m of oil were spilled following a manual operation to change filter elements in a filter at a pump station.
A 2-in. drain valve was not closed. The clean up operation recovered approximately 27 cu m.
A 128-cu m spill of product occurred when a cathodic-protection insulating joint on a pipeline section isolation valve failed during routine line packing at a pressure well below maximum allowable.
The spill ran into a river which was cleaned up with booms; some 30 cu m were recovered.
The pipeline company is paying for restocking fish in the river.
A program of changing the insulating joints of all similar valves is under way, says Concawe.
Copyright 1994 Oil & Gas Journal. All Rights Reserved.
