On the short-term and long-term impact of drilling activities in the Dutch sector of the North Sea

A research programme on the effects of drill-cutting discharges on the benthic system around platforms on the Dutch continental shelf has been running since 1985, with emphasis on locations where oil-based drilling muds (OBM) have been used and discharged. A few locations where only water-based muds (WBM) have been used were also investigated. At OBM locations, elevated total hydrocarbon concentrations in the sediment occurred up to 750–1000 m from well sites during the first year after discharges had stopped. Concentrations tended to decrease to natural background levels during the following... Mehr ...