Impact of drill cutting releases on benthic foraminifera at three exploration wells drilled between 1992 and 2012 in the SW Barents Sea, Norway

Dijkstra, Noortje; Junttila, Juho; Aagaard-Sørensen, Steffen

Impact of drill cutting releases on benthic foraminifera at three exploration wells drilled between 1992 and 2012 in the SW Barents Sea, Norway

2020

Dijkstra, Noortje | Junttila, Juho | Aagaard-Sørensen, Steffen

The aim of this study is to identify the environmental impact of drill cuttings (DC) released around three wells drilled in 1992, 2000 and 2012 in the SW Barents Sea. Foraminiferal assemblages are studied in cores taken along transects <250 m from wells. Well E-1992 shows no impact of DC on foraminifera indicating that low amounts of released DC limit environmental impact. Impact at wells G-2000 and S-2012, is confined to <30 m, and attributable to smothering of fauna, resulting in low foraminiferal density. We therefore argue that previous monitoring studies, mainly focusing on samples collected >250 m from wellheads, might not capture the full impact of DC. In well G-2000, a recovery layer indicates partial recovery 15 years after DC releases. In well S-2012, no recovery is observed, 3 years after release. Released DC did not result in faunal composition changes.

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