Accidents & malfunctions
Context
Offshore drilling takes place in dynamic environments which increases the risks of accidents and malfunctions. Although they are rare, they still happen and require proper mitigation strategies. Accidental events include oil spills, blowouts and batch spills of hydrocarbons or other substances directly involving the drill rig or associated transport vessels. These accidents and malfunctions could vary considerably in terms of nature, scale, duration and potential consequences.
Predicted Effects
Oil spill
Oil spills are the release of liquid petroleum hydrocarbon into the environment. They are caused by human activity and are a form of pollution.
Blowouts
Blowouts happen when there is a loss of well control or uncontrolled flow of formation or other fluids, including flow to an exposed formation (an underground blowout) or at the surface (a surface blowout), flow through a diverter, or uncontrolled flow resulting from a failure of surface equipment or procedures usually resulting a fire.
Batch spill
A small accidental spill that occurs during routine operations (also called “operational spill”).
Agency Decision
The project is not likely to cause significant adverse environmental effects as a result of accidents and malfunctions
(with mitigations in place)
Predicted Effects
The Agency considered the Proponent's analysis, expert advice from federal authorities and comments from Indigenous groups and the public, and identified the following key potential effects caused by accidents and malfunctions:
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on marine biota, including fish, birds, mammals and turtles, leading to potential changes in their presence, abundance, distribution and health (individuals and possibly, populations)
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through direct physical exposure or ingestion, with associated mortality, injury or other health related effects, as well as indirectly by affecting their habitats and food sources.
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large subsea releases could have large adverse effects on specials areas within the scope of the project and even beyond the Projects regional assessment area and international shores lines.
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on fisheries resulting in the closure of fishing areas the fouling of gear and vessels, a reduction in the marketability of commercial fish products, as well as effects on fish and fish habitat affecting Indigenous and non-Indigenous fishers with commercial and communal fishing licenses.
Mitigations
Critique
Strengths
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The EIS requires the proponents to thoroughly engage with other groups that are affected by the prpject ensuring everyone has the same information about accidents and malfunctions.
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The development of spill plans, practice rounds and threshold standards ensure the restriction of the effects on the environment and all valued components.
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The procedures are based on a review of national and international records of historical offshore spills
Weaknesses
Critique
Strengths
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The EIS requires the proponents to thoroughly engage with other groups that are affected by the project ensuring everyone has the same information about accidents and malfunctions.
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The development of spill plans, practice rounds and threshold standards ensure the restriction of the effects on the environment and all valued components.
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The procedures are based on a review of national and international records of historical offshore spills
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The Proponent provided useful figures detailing the generic sequence of response for source control including appropriate figures supporting the timeframe of only 9 to 17 days to cap a well in the case of a subsea blowout compared to capping timelines provided in recent EIS by Husky (13 to 24) days, Nexen (15 to 30 days), ExxonMobil (30 days) and Equinor (36 days). This substantially-reduced mobilization timeframe is possible on account of the air-freightable capping stack, as identified by KMKNO in the initial review of the ExxonMobil and Equinor EIS documents.
Weaknesses
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the spill model used is limited in its ability to predict the degradation and sinking of crude oil heavy ends and corresponding smothering effects on benthic biota. It does not consider the contents of the persistent portions of the crude oil and the biodegradation rates are therefore over- estimated.
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There is insufficient evidence to support the Proponent’s conclusion that dispersants would mitigate the potential adverse effects of oil on migratory birds in colder water temperatures compared to untreated oil.
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The thresholds used are not always appropriate and did not take into consideration all the aspects they referred to.
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In order to be conservative, past oil spill modelling studies for exploratory drilling programs in the Study Area have assessed “unmitigated” potential spill events, and have therefore not included consideration of potential spill response procedures.
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In the analyses used as reference, most spilled oil travelled eastwards, with minimal potential for shoreline contact, although given their project and site specific inputs to such modelling their specific findings about the fate and behaviour, and thus the likely geographic extent and duration of their footprints, this has been found to be quite variable.