Conrie Field Development Environmental Statement - Metoc

ENQUEST DONS LTD
CONRIE FIELD DEVELOPMENT
generation levels of the Northern Producer (as the Northern Producer is currently not
operating at full capacity).
ENVIRONMENTAL IMPACT AND MITIGATION
Mitigation is an integral part of the Conrie Field. All of the potential interactions between
project activities and environment receptors are subject to either standard recognised best
practice mitigation measures or to impact specific, feasible and cost effective mitigation. In
general, the mitigation proposed will be sufficient to reduce the effects of activities to below
levels which will cause a significant residual impact. For those where mitigation isn‟t enough,
the residual impacts are detailed below with a discussion of the mitigation that will help to
reduce the impact to the acceptable levels identified.
The following table summarises the findings of the detailed EIA process undertaken in
relation to the Conrie Field and its potential effects on the physical, biological and human
environment and its potential cumulative and in-combination impacts. All the project impacts
are summarised below.
Receptor & Type
of Impact
Air Quality:
Deterioration of local
air quality
Climate Change:
Loading of
greenhouse gases
Water Resources:
Increased
suspended
sediment loads and
increased turbidity
Seabed
Conditions:
Sediment
contamination
Baseline & Impact Assessment Impact Mitigation
The NNS is generally a windy environment and
concentrations of greenhouse gases will be
diluted to below threshold EC guideline values.
Emissions of greenhouse gases will be relatively
small and comparable to similar activities and/or
gas development of this size.
Transient increase in suspended sediment
loads during well tie-in. Disturbance will be
localised and similar in magnitude to normal
storm conditions.
Sediments are homogenous fine sand.
Discharges of drilling chemicals will be
predominantly at the seabed. The makeup of
the WBM to be discharge is relatively benign
with most chemicals being either Offshore
Chemical Notification Scheme category E
(lowest risk category) or pose little or no risk
(PLONOR) to the environment. Barite and
bentonite, two of the main components of WBM,
have been widely shown to accumulate in
sediments and may be noticeable in sediments
for >10 years.
Insignificant
Insignificant
Minor
Minor
All machinery will be well maintained.
Cleaner lower emission fuels will be
used. Flaring will be kept to the minimum
required for well testing.
All machinery will be well maintained.
Cleaner lower emission fuels will be
used. Flaring will be kept to the minimum
required for well testing.
Mattressed areas will be kept to a
minimum.
Daily recording of chemical use to allow
more refined and efficient use.
Where possible products will be recycled,
skipped and shipped and not discharged.
Selection of chemicals will be made in
accordance with the CEFAS ranked list,
where chemicals ranked as lower
potential hazards are preferentially
chosen
Only chemicals permitted through the
relevant Offshore Chemicals Regulations
chemical permit (i.e., PON15B or
PON15C) and that have been subject to
a risk assessment will be discharged.
Seabed
Conditions:
Physical disturbance
of surface
sediments
Sediments are homogenous fine sand.
0.065km 2 of seabed will be disturbed by the
project. Disturbance will be unnoticeable
against background levels within a year.
Areas of scour may develop around concrete
mattresses.
Minor
The footprint of the development will be
minimised as far as possible.
REPORT REFERENCE: P1534_RN2574_REV1_S1-4 19/04/2011