Drilling discharges
Effects of drilling discharges
Drilling discharges spread over large areas and particles remain suspended in the water column for a long time. Between 50 – 100.000 tons of barite (weighting material contained in the drilling mud) are discharged in the North Sea each year.
The effects of water based drilling mud on bivalves and fish were investigated in the first two projects below. A third and ongoing project focus on the effects of mud on cold water corals.
Effects of drilling mud discharges on water column organisms and filter feeding bivalves (project 1: 2004-2005; project 2: 2006-2008)
The effects of water based drilling mud on bivalves and fish were investigated. The objective of the two projects was to find out whether metals from the mud were taken up by fish and filter feeding bivalves and to investigate the possible effects of the drilling mud on these organisms. A special exposure system was designed and cods, scallops and mussels were exposed to different concentrations of drilling mud with barite/ilmenite as weighting material. The parameters studied ranged from effects on feeding and growth to DNA and tissue damage. An aim was to find out whether ilmenite could be a more environmentally friendly alternative to barite.
Drilling in the Arctic (2008 - 2011)
This ongoing project focuses on the effects of mud on cold water corals. Impact of water-based drilling mud in the Barents Sea: a study using the epibenthic coral species Lophelia pertusa.The project will contribute to a better knowledge of the long-term impact of offshore drilling activities on ecologically relevant species (the coral Lophelia). Monitoring tools based on biological effects (biomarkers) will be used on an ecologically important species (the coral Lophelia) to document the possible long term impact of offshore drilling activities in the Barents Sea.
Impacts of metals from drill cuttings and mud to marine water column (2002)
The project was a pre-study addressing problems related to many piles of contaminated drilling discharge in the North Sea, an issue becoming pertinent as more oil oilfields enter decommissioning phase. The issue is particularly relevant for “new” exploration areas a like the Arctic and the deep-sea where the environmental sensitivity is uncertain.
Offshore drill cuttings piles (1996 – 2005)
Piles of drilling mud and drill cuttings on the sea floor around oil installations have been seen as an environmental concern in the North Sea, particularly by Norway, Great Britain and Holland, and have received considerable attention for more than a decade.
In the period from 1996 to 2005, projects carried out by IRIS have focused on the following: Mapping of size and location of cuttings piles; sampling and analyses of physical, biological and chemical characteristics; assessment of microbiological activity in the cuttings pile, and the potential for natural degradation of hydrocarbons; independent assessment of treatment technology; estimation and measurement of toxicity and effects from cuttings piles; and recommendations for treatment planning.
IRIS established a cross-specialist team including chemists, engineers, GIS-mapping specialists, oceanographers, ecologists, toxicologists, microbiologists and social scientists. IRIS performed desktop, lab and field studies for both the authorities and industry, and contributed to the development of policy and treatment plans for cuttings piles, and assessed the need for further research in this area.
High profile projects which IRIS has participated in include decommissioning plans for the Ekofisk field, UKOOA drill cuttings programme projects (three consequtive phases), and for OLF the identification of treatment and management methods.
ERMS-programme ( 2002-2006)
Environmental Risk Management System
ERMS is the continuation of the DREAM programme (1998-2002), resulting in a DREAM/EIF model for Drilling Discharges and Sediment – an environmental risk-based decision support tool.
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