Action: Remove drill cuttings after decommissioning
Key messagesRead our guidance on Key messages before continuing
- We found no studies that evaluated the effects of removing drill cuttings after decommissioning on subtidal benthic invertebrate populations.
‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.
Routine oil and gas drilling activities can impact subtidal invertebrate seabed communities due to the production of drill cuttings. Drill cuttings consist of the fragments of rock that are removed as each oil or gas well is drilled. The drill cuttings are usually discharged onto the seafloor in the vicinity of the platforms to form a cuttings pile, but are often contaminated with drilling fluids, oil and chemical additives which can leach and pollute the sediments. Drill cuttings can also smother and bury organisms under their weight (Henry et al. 2017). Removing discarded drill cuttings from the seabed following decommissioning (Melton et al. 2000; 2004), instead of leaving them on the seabed, can stop the threat and potentially allow for the community to recover over time. Evidence for a related intervention, relating to mine tailings remediation following decommissioning, are summarised under “Threat: Energy production and mining - Leave mine tailings in place following cessation of activities (submarine tailing disposal operations)”.
Henry L.A., Harries D., Kingston P. & Roberts J.M. (2017) Historic scale and persistence of drill cuttings impacts on North Sea benthos. Marine Environmental Research, 129, 219–228.
Melton H.R., Smith J.P., Mairs H.L., Bernier R.F., Garland E., Glickman A.H., Jones F.V., Ray J.P., Thomas D. & Campbell J.A. (2004) Environmental aspects of the use and disposal of non-aqueous drilling fluids associated with offshore oil & gas operations. In: SPE International Conference on Health, Safety, and Environment in Oil and Gas Exploration and Production. Society of Petroleum Engineers.
Melton H.R., Smith J.P., Martin C.R., Nedwed T.J., Mairs H.L. & Raught D.L. (2000) Offshore discharge of drilling fluids and cuttings–a scientific perspective on public policy. In Rio Oil and Gas Conference. Rio de Janeiro, Brazil.