The environmental impact of cutting discharges has led to a significant change in the way oilbased mud has been used at the Dutch Continental Shelf (DCS). The industry has converted from direct disposal of oilbased cuttings to a zero oil disposal at sea by transfer of cuttings to land. Moreover, distillation of cuttings has resulted in a closed-loop application of the base oil. This method has been developed as a standard operation even before the zero oil disposal limit became effective in 1993. Although the well costs have increased with 2.5 % as a result of the new requirement, the extra costs amount to only a small fraction of the extra well costs if only waterbased mud would be allowed. Both industry and environment benefit and it has resulted in an increased use of oilbased mud since 1991 at the DCS. Further scope for reduction of environmental impact related to waste disposal is limited. The remaining concerns are related to the prevention of oil spills.

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