BARCUT
Barents Sea drill cuttings research initiative
Multidisciplinary approach to effects linked to drill cuttings
2013-2019
BARCUT 2013-2019 supported by Eni Norge
Scope
• Identify local environmental impact of released drill cuttings and address relevant societal concerns
• Applied sea floor research, Akvaplan-niva and UiT
• Impact of discharges on sediment conditions, microbiota and macro fauna
• Current calculations and distribution modelling of drill cuttings
• Spreading and deposition of drill cuttings, UiT
• Spreading and thickness of drill cuttings
• Effect of drill cutting discharge on sediment quality and micro fauna
• Economic and social aspects ,UiT and Norut
• Science-policy interface of waste management
• Comparison with the science-policy interface of waste management in mineral
industry
Barents Sea drill cuttings research initiative (BARCUT) -Spreading and deposition of drill cuttings (WP3)
Juho Junttila¹, Noortje Dijkstra¹, Steffen Aagaard Sørensen¹
¹Department of Geosciences, UiT The Arctic University of Norway in Tromsø Contact: tel. 776 44460, email: [email protected]
More info: http://site.uit.no/ewma/barcut/
BARCUT WP3
Objectives
Site specific spreading of drill cuttings on the sea floor (<250m from wellhead) and their influence on marine environment.
TASK I
Sediment condition
a) baseline
b) impact and spreading c) recovery
Classification
of contaminants
Aagaard-Sørensen et al. 2018
TASK II
Foraminiferal response
Studying living (sediment core surface) and fossilized (deeper in the sediment core) foraminiferal assemblages allow reconstruction and/or monitoring of:
a) baseline b) impact c) recovery
BARCUT WP3
= unicellular organisms living on top of and in the first cm’s of the sediment 100 µm in size (salt grain size)
Benthic foraminifera
Specific habitat Preservation of test
Monitor environmental change Natural variability Fast reproduction
Photo by: Patrycja Jernas
Methods
• Grain-size analyses
• Heavy metal concentration
• Benthic foraminiferal analyses
• TOC
•
210Pb-dating
• PAH-NPD
Environmental impact of exploration wells - BARCUT
5m 30m
60m 125m
250m
Same sample stations studied for microbiota and macrofauna
Wells drilled in Barents Sea 1980-2016
1993 Cuttings with
≤1% oil based allowed
Wells
sampled
(Junttila et al., 2018)
Well T – drilled 1987 Potential recovery time: 28 years
Junttila et al. 2018
Drilled 1987 3353 tons released
Well T (1987)
(Aagaard-Sørensenet al., submitted)
Benthic foraminiferal parameters
• 10 m from drill site:
- Smothering of foraminifera
- Low density foraminifera only observed at 0-5 cm core depth representing recovery
• ≥30-250m from drill site:
-No present day impact on the fauna even though elevated Ba levels
(Aagaard-Sørensen et al., 2018)
(Aagaaard-Sørensen et al., 2018)
Well G2006 – drilled 2006 Potential recovery time: 8 years
(Aagaaard-Sørensen et al., 2018)
Drilled 2006 412 tons released
Benthi c foraminiferal parameters
• 5-30 m from drill site: Smothered foraminiferal fauna
• 60 m from drill site: ca. 3 cm of drilling mud settled, resulting in survival of the foraminiferal fauna
• Natural foraminiferal species have recovered at all distances after ~8 years
Well G 2006 (2006)
(Aagaard-Sørensen et al., 2018)
Well S – drilled 2012 Potential recovery time: 3 years
(Junttila et al., 2018)
Junttila et al. 2018
Drilled 2012
S 2012
(Dijkstra et al., in prep.)
8 m:
• > 20 cm of DC resulted in smothering of fauna
• no recovery after 3 years, both live and dead fauna
• High Cu concentrations
• Coarse pebbles in DC 30-250 m:
• Faunal changes reflect natural variability
• warming after LIA + inflow Atlantic Water
>20 cm
4 cm
1 cm DC
2 cm
2 cm
Dijkstra et al. in prep.
Drill cutting spreading model
Bottom current direction =20cm
Drill cutting spreading model
Junttila et al. 2018
3353 tons released
Ba <500mg/kg 688 tons released
Bottom current direction =20cm
Drill cutting spreading model
Bottom current direction =20cm
Drill cutting spreading model
412 tons released 805 tons released
Aagaard-Sørensen et al. 2018
Bottom current direction =20cm
Outcome
- Sediment quality affected ≤ 10m from the wellheads
- Difference in sediment quality before and after legislation in 1993 - Spreading of the drill cuttings ≤125m from the wellheads
- Drill cutting impacted layer generally thickest closest to the wellhead - Sediment recovery in some wells but not in Ba content
- Smothering main effect on foraminifera - Recovery of foraminifera
- Impact site specific
References
Dijkstra, N., Junttila, J., Carroll, J., Husum, K., Hald, M., Elvebakk, G., Godtliebsen,. F., 2013. Baseline benthic foraminiferal assemblages and habitat conditions in a sub-Arctic region of increasing petroleum development. Marine Environmental Research, Vol. 92, pp. 178-196.
Junttila, J., Carroll, J., Husum, K., Dijkstra, N., 2014. Sediment transport and deposition in the Ingøydjupet trough, SW Barents Sea.
Continental Shelf Research, Vol. 76, pp. 53-63.
Dijkstra, N., Junttila, J., Husum, K., Carroll, J., Hald, M., 2015. Natural variability of benthic foraminiferal assemblages and metal concentrations during the last 150 years in the Ingøydjupet trough, SW Barents Sea. Marine Micropaleontology 121, 16-31.
Alve, E., Korsun, S., Schönfeld, J., Dijkstra, N., Golikova, E., Hess, S., Husum, K., Panieri, G., 2016. Foram-AMBI: A sensitivity index based on benthic foraminiferal faunas from North-East Atlantic and Arctic fjords, continental shelves and slopes. Marine Micropaleontology 122, 1- 22.
Junttila, J., Carroll, J., Dijkstra, N., 2015. Variability of present and past PAH concentrations in sediments of the SW Barents Sea.
Norwegian Journal of Geology 95, 191–210.
Dijkstra, N., Junttila, J., Skirbekk, K., Husum, K., Carroll, J., Hald, M., 2017. Benthic foraminifera as bio-indicators of chemical and physical stressors in Hammerfest harbor (Northern Norway). Marine Pollution Bulletin, 114, 384-396.
Dijkstra, N, Junttila, J., Aagaard-Sørensen, S., 2017. Environmental baselines and reconstruction of Atlantic Water inflow in Bjørnøyrenna, SW Barents Sea, since 1800 CE. Marine Environmental Research, 132, 117 - 131.
Aagaard-Sørensen, S., Junttila, J., Dijkstra, N., 2018. Impact of drill cutting release on marine environments and response of benthic foraminiferal faunal communities, Goliat Field, SW Barents Sea, Norway. Marine pollution Bulletin, 129, 592-608.
Junttila, J., Dijkstra, N., Aagaard-Sørensen, S., 2018. Spreading of the drill cuttings and recovery of the sediments on three different age exploration wells in the SW Barents, Norway. Marine Pollution Bulletin, 135, 224-238.
Aagaard-Sørensen, S., Berg, J., Junttila, J., Dijkstra, N., in review. Lingering effect from petroleum exploration related pollution on benthic foraminiferal fauna compositions in the Ingøydjupet, SW Barents Sea. Polar Research.
