EN14 Discharge of oil from refineries and offshore installations

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Oil discharges from offshore installations occur mainly through contamination of water used in extraction processes and to a lesser degree from spills and cuttings contaminated with drilling muds. They can cause surface contamination and smothering of marine biota, and the chemical components of oil can cause acute toxic effects and long-term impacts. In addition, disposals of cuttings contaminated with oil and chemicals in the immediate vicinity of the installations harm the benthic biodiversity near the installations by imposing anoxia and toxic contamination.

Oil discharges from refineries and offshore installations have been decreasing significantly since the 1980s. Overall inputs of oil from the offshore oil and gas sector have decreased by 49 % between 1990 and 2004 (similar to last assessment of 1990-2002) and the quantity of oil discharged by refineries decreased by 78 % between 1990 and 2000. These figures indicate a similar trend to that reported by OSPAR (2000) for the period 1985-1997, stating that the decrease of oil inputs from the offshore oil and gas sector was reported to be over 60 % and that from the refineries more than 90 %, albeit at a slower rate.

The reductions in oil discharges have been achieved despite the increased production and the ageing of many major oil fields. Production from offshore installations increased by 27% between 1992 and 2004, although it appears to follow a decreasing pattern since 2000 (the 1992-2002 reported increase was of 38 %). Over the same period, oil discharges from offshore installations of Denmark, United Kingdom, the Netherlands and Norway decreased by 37%. The main reason for this development lies in the measures introduced under the Offshore Strategy (Offshore Oil and Gas Strategy, see policy context section), which have succeeded in sustaining the decreasing trends (OSPAR Commission, 2003).

Despite the one-off increase of oil discharges from offshore installations in 1997, which was mainly due to an exceptional accidental spillage, it is likely that a further reduction of oil discharges will continue in the future. This will be supported by the new regulation on drill cuttings (OSPAR Decision 2000) that entered in force in 2000. The levels of oil discharges recorded since 2000 have been the lowest over the whole period 1990-2002.

Oil discharges from refineries are small compared with discharges of the offshore industry and are decreasing at a faster rate. While in 1990 refineries accounted for 16 % of oil discharges from refineries and offshore installations combined, their share was only 7 % in 2000. Within the North-East Atlantic, refineries are located mainly in coastal areas or on large rivers where discharges can have a localised impact. Their effluents are a source of oil and other substances. However, in general there has been a large reduction in discharged oil due to rationalisations and technical improvements in this sector. Between 1990 and 2000, the total refinery throughput across the EU increased by 2.5 %, while discharges decreased by 77 %. The improvement is reflected in OSPAR's conclusion to cease regular surveys on refineries because of the reduction in their discharges. The releases of a number of hazardous substances from offshore installations will be reported in the future under the European Pollutant Release and Transfer Register (E-PRTR). The European Pollutant Emission Register might subsequently undertake this role.