Institution: | †Oil Pollution Research Unit, Field Studies Council, Orielton Field Centre, Pembroke, SA 71 5EZ, UK ‡M-Scan Ltd., Silwood Park, Ascot, Berkshire, SL5 7PZ, UK *Britoil plc, 150 St Vincent St., Glasgow, G2 5LJ, UK |
Abstract: | To investigate the effects of drilling discharges on the seabed fauna, surveys were carried out in the Beatrice oilfield after drilling 13 wells with water-based muds, and then after one and five further wells had been drilled using low toxicity oil-based muds. Localized benthic effects were found after the water-based mud drilling. After the use of oil-based muds, the nature of the effects was different, although there was little increase in the area involved. Possible reasons for this are discussed and burial and organic enrichment are suggested as the major influences. It is concluded that the use of low toxicity oil-based mud at Beatrice has resulted in only limited benthic effects, suggesting that the use of these muds is environmentally acceptable. |