Environmental statement - Flyndre and Cawdor - Maersk Oil

Flyndre and Cawdor Environmental Statement
Section 5 Assessment of Potential Impacts and Control Measures
There are not anticipated to be any significant impacts to other marine users as a result of the
proposed Flyndre and Cawdor development.
5.4.4. CUMULATIVE IMPACTS
The cumulative impacts assessment has considered three environmental aspects, atmospheric
emissions, underwater noise and produced discharges.
The Flyndre and Cawdor development will contribute an increase of approximately 2.7% of drilling
emissions when compared to 2009 total rig emissions (Table 5‐2); vessel emissions are expected to be
0.61% of the UK total from shipping emissions when compared to 2008 values (Table 5‐5) and well
test emission are 0.4% when compared to 2009 values from the UKCS (Table 5‐4). The generation of
emissions will add to the greenhouse gases in the atmosphere and hence marginally contribute to the
effects of global warming. The emissions are not significant when considered in context of emissions
from the UKCS oil and gas and shipping activities, consequently no significant cumulative impacts are
anticipated.
The impacts of underwater sound have been receiving increased scientific attention, with potential
cumulative impacts raised as a potential cause of concern for acoustically sensitive marine life
(OSPAR, 2009). The construction sounds, principally vessel and drill rig movements will contribute to
increasing the local sound levels. There are few practical measures that are possible to minimise the
sound from vessels on a project basis and are more appropriately dealt with by international
collaboration within the shipping industry and regulatory bodies. The loudest levels of sounds are
expected to arise during the piling activity, the risk to marine life will be reduced by implementing the
JNCC procedures within the piling protocol (Section 5.2.4). The underwater sound levels will be
principally restricted to the drilling and construction phases of the development which is temporary
and only affect a local area with elevated sound levels, consequently there are not anticipated to be
any significant cumulative or residual impacts as a result of the underwater noise levels.
The produced water from the Flyndre and Cawdor field increases as the reservoirs are depleted, the
maximum volume of oil in water is 10.95 tonnes produced in 2026. When these discharges are
compared to the oil in water discharges arising from the UKCS sector it represents an increase of
0.38%. The result of the increases in oil in water as a result of the Flyndre and Cawdor development
are not anticipated to result in any adverse cumulative impacts.
5.4.5. TRANSBOUNDARY IMPACTS
The impact assessment determined that there are not anticipated to be any significant transboundary
impacts to countries as are result of planned activities and accidental events.
The consideration of transboundary impacts is of relevance as the Flyndre field crosses over the
UK/Norwegian median line, with the Cawdor field being situated approximately 5 km away from the
line in the UK sector.
The oil spill modelling indicated that in a blow out situation there is a probability of 1‐5% that a
surface sheen of 4µm thickness could be present in the waters of nearby European countries
including Norway, Denmark, Germany and Netherlands. There is not anticipated to be any risk of oil
beaching on any neighbouring European countries.
Should a spill be likely to enter into Norwegian waters it will be necessary to implement the NORBRIT
agreement, which outlines procedures to be followed in joint Norwegian / UK spill counter pollution
operations at sea.
D/4114/2011 5 ‐ 23