kraken development
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EnQuest Heather LimitedKraken Field Development Environmental Statement
DECC Document Ref: D/4155/2013
EnQuest Heather Limited Document Ref: ENQ-KRA-HS-00-STA-0002
Issued 14thFebruary 2013
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EnQuest
Kraken Field Development Area Environmental Statement
Doc Ref No: ENQ-KRA-HS-00-STA-0002 i
STANDARD INFORMATION SHEET
Project Name Kraken Field Development Area
DECC Project Reference No. D/4155/2013
Type of Project Field development with subsea wells connected to a Floating, Production,
Storage and Offloading (FPSO) facility processing fluids from the Kraken
reservoir.
Undertaker Name EnQuest Heather Limited
Undertaker Address 5th
Floor Consort House, Stell Road, Aberdeen, AB11 5QF, United Kingdom
Licences/Owners EnQuest ENS Limited (20%), EnQuest Dons (40%), Cairn Energy (25%) and
First Oil (15%)
Short Description EnQuest is planning to develop the Kraken area as three separate fields:
Kraken North, Kraken Central and Kraken South. All three fields lie in Block
9/02b, approximately 126 km east of the nearest landfall at Noss, Shetland
Islands.
This will be achieved by drilling 14 horizontal production subsea wells and
11 horizontal water injector subsea wells in the Kraken development area.
All wells will be tied back to an FPSO facility which will process and store
the produced fluids and then export stabilised crude via shuttle tankers.
The FPSO power demands will be met through the use of associated gas.
The short fall in associated gas production will be supplemented by the use
of either crude oil or diesel. It is understood that there may be future
opportunity for gas import from the Vesterled line, this shall beinvestigated as an alternative source of fuel when the infrastructure is
available.
All production wells will require artificial lift and Hydraulic Submersible
Pumps (HSPs) have been selected as the preferred technology. The HSPs
will be powered from the FPSO; the power fluid is treated seawater as
there will be little or no formation water produced from the reservoir. The
spent power fluid will be combined with the well production fluids and
returned to the FPSO. All produced water will be re-injected and seawater
will be used for water injection to replace the oil and maintain reservoir
pressure, voidage replacement and to sweep the oil to the producers.
Anticipated Commencement of Works Q2 2014
Previously Submitted EnvironmentalDocuments
N/A
Significant Environmental Impacts
Identified
Impacts resulting from:
Atmospheric emissions during drilling, installation and commissioning
activities and production operations,
Seabed disturbance from flowline installation,
Noise from piling activities and
Loss of hydrocarbons/chemicals during spill, uncontrolled well flow or
collision
Statement Prepared By EnQuest in conjunction with
RPS Energy HSE & Risk Management
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Kraken Field Development Area Environmental Statement
Doc Ref No: ENQ-KRA-HS-00-STA-0002 ii
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Kraken Field Development Area Environmental Statement
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Table of Contents
STANDARD INFORMATION SHEET ........................................................................................................................ iNON-TECHNICAL SUMMARY .............................................................................................................................. ix
Background ........................................................ ................................................................ .................................. ix
Project Overview ........................................................... ................................................................ ....................... ix
The Existing Environment .......................................................... ................................................................ ............. x
Environmental Interactions, Impacts and Mitigation Measures ............................................................................ xiv
Environmental Management ......................................................................... .................................................... xxxv
Conclusions ............................................. ................................................................ ......................................... xxxv
Abbreviations ..............................................................................................................................................xxxviiGlossary ...........................................................................................................................................................xli1 Introduction ........................................................................................................................................... 1-1
1.1 Background and Document Objective ........................................................... .......................................... 1-1
1.2 Overview of the Project .......................................................... ............................................................... 1-1
1.3 The Applicant......................................................................................................................................... 1-4
1.4 Environmental Impact Assessment ................................................................................................ ......... 1-5
1.5 Structure of the Report ................................................................................................................. ......... 1-7
1.6 Contact Addresses ........................................................ ................................................................ ......... 1-7
2 The Proposed Development ..................................................................................................................... 2-12.1 The Kraken Fields .......................................................... ................................................................ ......... 2-1
2.2 Development Objective and Justification ................................................................. ............................... 2-3
2.3 Development Option Selection ........................................................... .................................................... 2-4
2.3.1 Development options initial screening ............................................................. ............................... 2-4
2.3.2 Facilities Option Selection .......................................................... .................................................... 2-9
2.3.3 Development options description ......................................................... ......................................... 2-11
2.3.4 Environmental comparative assessment .......................................................... ..............................2-14
2.4 Outstanding Development Decisions ............................................................ ......................................... 2-14
2.5 Summary of Selected Kraken Development Option ............................................................. ................... 2-14
2.6 Proposed Development Schedule ................................................................. ......................................... 2-15
2.7 Kraken Development Facilities Overview ................................................................. ..............................2-16
2.7.1 Flowlines, Umbilicals and Subsea Infrastructure ......................................................... ................... 2-16
2.7.2 The Kraken Installation .............................................................. ................................................... 2-21
2.8 Kraken Development Project Phases ............................................................ ......................................... 2-24
2.9 Installation and Commissioning Operations ............................................................. ..............................2-24
2.9.1 Introduction ......................................................... ................................................................ ........2-24
2.9.2 Installation of Flowlines, Umbilicals and Subsea Infrastructure ......................................................2-24
2.9.3 Commissioning ............................................................... ..............................................................2-28
2.9.4 Subsea Tie-Ins ....................................................... ................................................................ ........2-29
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2.9.5 FPSO Installation ............................................................. ..............................................................2-29
2.9.6 Riser System ......................................................... ................................................................ ........2-33
2.9.7 Installation and Commissioning Fuel Consumption, Emissions and Discharges ................................2-36
2.10 Development Drilling Operations ................................................................. ......................................... 2-37
2.10.1 Overview .............................................................. ................................................................ ........ 2-37
2.10.2 Drilling Rig ............................................................ ................................................................ ........ 2-39
2.10.3 Well Construction ........................................................... ..............................................................2-40
2.10.4 Drilling Chemicals ........................................................... ..............................................................2-43
2.10.5 Cementing ............................................................ ................................................................ ........ 2-43
2.10.6 Well Clean-up and Completion ............................................................. ......................................... 2-43
2.10.7 Well Testing .......................................................... ................................................................ ........ 2-46
2.10.8 Well Control Equipment ............................................................. ................................................... 2-46
2.10.9 Support Operations ......................................................... .............................................................. 2-46
2.10.10 Waste ........................................................ ................................................................ ................... 2-47
2.10.11 Intervention and Workover Requirements ....................................................... .............................. 2-47
2.10.12 Total Drilling Discharges and Emissions Summary ................................................................ ..........2-47
2.11 Production Operations ............................................................ ..............................................................2-48
2.11.1 Overview .............................................................. ................................................................ ........ 2-48
2.11.2 Oil Processing, Storage and Export ....................................................... .........................................2-49
2.11.3 Produced Water and Water Injection System................................................................................. 2-53
2.11.4 Utility Systems and Quarters ................................................................ ......................................... 2-53
2.11.5 Power Generation ........................................................... ..............................................................2-54
2.11.6 Helifuel and Chemical Storage .............................................................. ......................................... 2-55
2.11.7 Flare System ......................................................... ................................................................ ........2-55
2.11.8 Cooling Water System ................................................................ ................................................... 2-55
2.11.9 Waste Heat Recovery Unit / Heating Medium ............................................................. ................... 2-56
2.11.10 Drain Systems ....................................................... ................................................................ ........2-56
2.11.11 Waste Treatment and Disposal ............................................................. ......................................... 2-56
2.11.12 Firewater System ............................................................ ..............................................................2-56
2.11.13 Potable Water System ................................................................ ................................................... 2-57
2.11.14 Oil Production Profile ................................................................ .................................................... 2-57
2.11.15 Produced Water Profiles ............................................................ ................................................... 2-58
2.11.16 Production Chemistry ................................................................ ................................................... 2-59
2.11.17 Pipeline Maintenance ................................................................ ................................................... 2-61
2.12 Decommissioning .......................................................... ................................................................ ........ 2-61
3 Environmental Description ...................................................................................................................... 3-1
3.1 Introduction ...................................................... ................................................................ .................... 3-1
3.2 Site Survey ......................................................... ................................................................ .................... 3-13.3 Geography ......................................................... ................................................................ .................... 3-3
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3.4 The Seabed and Bathymetry ............................................................... .................................................... 3-4
3.4.1 Bathymetry ........................................................... ................................................................ ......... 3-4
3.4.2 The Seabed ........................................................... ................................................................ ......... 3-4
3.5 Oceanography .............................................................. ................................................................ ........ 3-26
3.5.1 Waves ....................................................... ................................................................ ................... 3-26
3.5.2 Tides and Water Circulation ................................................................. ......................................... 3-26
3.5.3 Temperature and Salinity ........................................................... ................................................... 3-28
3.6 Air and Climate ............................................................. ................................................................ ........ 3-29
3.6.1 Wind............................................................................................................... .............................. 3-29
3.6.2 Air Quality ........................................................... ................................................................. ........ 3-30
3.7 Flora and Fauna ............................................................ ................................................................ ........ 3-30
3.7.1 Plankton ............................................................... ................................................................ ........ 3-30
3.7.2 Seabed Communities ................................................................ .................................................... 3-31
3.7.3 Fish...................................................................................................... ......................................... 3-38
3.8 Offshore Seabird Distribution ............................................................. ................................................... 3-48
3.8.1 Introduction ......................................................... ................................................................ ........3-48
3.8.2 Key Offshore Seabird Species ............................................................... ......................................... 3-48
3.8.3 Seabird Vulnerabilities ............................................................... ................................................... 3-51
3.9 Marine Mammals .......................................................... ................................................................ ........ 3-54
3.9.1 Cetaceans ............................................................. ................................................................ ........ 3-54
3.9.2 Pinnipeds .............................................................. ................................................................ ........ 3-55
3.9.3 Marine Reptiles .............................................................. ..............................................................3-58
3.10 Protected and Sensitive Coastal Habitats ................................................................. ..............................3-59
3.10.1 Overview .............................................................. ................................................................ ........ 3-59
3.10.2 Candidate Marine Special Areas of Conservation ........................................................ ...................3-60
3.10.3 Annex I Habitats in the Vicinity of the Proposed Development .......................................................3-60
3.10.4 Annex II Species in the Vicinity of the Proposed Development .......................................................3-62
3.10.5 Coastal Habitats .............................................................. ..............................................................3-63
3.10.6 International Protected Sites ................................................................ ......................................... 3-65
3.11 Human Environment ............................................................... ..............................................................3-66
3.11.1 Commercial Fisheries ................................................................ .................................................... 3-66
3.11.2 Shipping and Ports .......................................................... .............................................................. 3-74
3.11.3 Pipelines, Wells and Submarine Cables ............................................................ ..............................3-77
3.11.4 Military Activity .............................................................. ..............................................................3-77
3.11.5 Wind Farms .......................................................... ................................................................ ........ 3-77
3.11.6 Archaeology .......................................................... ................................................................ ........ 3-77
3.11.7 Tourism and Leisure ........................................................ .............................................................. 3-77
3.12 Key Environmental Sensitivities .......................................................... ................................................... 3-81
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4 ENVIRONMENTAL ASPECTS, IMPACTS AND MITIGATION MEASURES ........................................................... 4-1
4.1 Introduction ...................................................... ................................................................ .................... 4-1
4.2 Environmental Impact Assessment Methodology ................................................................ .................... 4-2
4.2.1 Aspect Identification ................................................................. ..................................................... 4-2
4.2.2 Potential Impact Identification and Description .......................................................... .................... 4-2
4.3 Risk Assessment ............................................................ ................................................................ ......... 4-4
4.3.1 Combining Likelihood and Consequence To Establish Significance ................................................... 4-6
4.3.2 Developing Mitigation Measures .......................................................... .......................................... 4-6
4.3.3 Evaluating Residual Impacts ................................................................. .......................................... 4-6
4.3.4 Environmental Aspects ............................................................... .................................................... 4-6
4.4 Environmental Impact Assessment of Physical Presence ................................................................ ......... 4-9
4.4.1 Introduction ......................................................... ................................................................ ......... 4-9
4.4.2 Potential Interaction With Other Marine Users ........................................................... ................... 4-10
4.4.3 Planned Mitigation Measures ............................................................... ......................................... 4-11
4.4.4 Residual Impacts of Physical Presence ............................................................. ..............................4-12
4.5 Environmental Impact Assessment of Seabed Disturbance ............................................................. ........4-13
4.5.1 Introduction ......................................................... ................................................................ ........4-13
4.5.2 Seabed Disturbance From Anchoring Operations ........................................................ ...................4-14
4.5.3 seabed Disturbance From Pipeline and Umbilical Installation Operations .......................................4-15
4.5.4 Seabed Disturbance From Flowline and Subsea Facilities Installation .............................................4-16
4.5.5 Seabed Disturbance from Decommissioning ............................................................... ................... 4-20
4.5.6 Planned Mitigation Measures ............................................................... ......................................... 4-20
4.5.7 Residual Impacts ............................................................. ..............................................................4-20
4.6 Environmental Impact Assessment of Noise ............................................................ ..............................4-21
4.6.1 Introduction ......................................................... ................................................................ ........4-21
4.6.2 Types of Noise Generated .......................................................... ................................................... 4-21
4.6.3 Potential Impacts From Noise ............................................................... ......................................... 4-24
4.6.4 Assessing The Likelihood of an Offence Under Offshore Marine Regulations ..................................4-33
4.6.5 Planned Mitigation Methods ................................................................ ......................................... 4-34
4.6.6 Residual Impacts of Noise .......................................................... ................................................... 4-35
4.7 environmental Impact Assessment of Atmospheric Emissions ........................................................ ........4-35
4.7.1 Introduction ......................................................... ................................................................ ........4-35
4.7.2 Atmospheric Impacts Associated with the Drilling Phase ........................................................ ........4-35
4.7.3 impacts Associated with the Installation and Commissioning Phase ...............................................4-37
4.7.4 Impacts Associated with the Production Phase ........................................................... ................... 4-39
4.7.5 Planned Mitigation Methods ................................................................ ......................................... 4-41
4.7.6 Residual Impacts ............................................................. ..............................................................4-42
4.8 Environmental Impact Assessment of Marine Discharges ............................................................... ........4-444.8.1 Introduction ......................................................... ................................................................ ........4-44
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4.8.2 Potential Impacts Associated With Marine Discharges During Drilling Operations ...... ..... ...... ..... ....4-44
4.8.3 Clean-Up and Completion Fluids ........................................................... ......................................... 4-45
4.8.4 other discharges ............................................................. ..............................................................4-46
4.8.5 Potential Impacts Associated with Marine Discharges During Installation and Commissioning
Operations ................................................................ ................................................................ ................... 4-46
4.8.6 Environmental Impacts Associated with Marine Discharges During Production Operations ..... ...... ..4-46
4.8.7 Marine Discharges Mitigation Measures .......................................................... ..............................4-48
4.8.8 Residual Impacts ............................................................. ..............................................................4-50
4.9 Environmental Impacts Associated With Solid Wastes ........................................................ ...................4-51
4.9.1 Introduction ......................................................... ................................................................ ........4-51
4.9.2 Impacts Associated With Solid Wastes Disposal .......................................................... ................... 4-52
4.9.3 Mitigation Measures ................................................................. .................................................... 4-52
4.9.4 Residual Impacts ............................................................. ..............................................................4-53
4.10 Transboundary Impacts of Planned Operations ........................................................ .............................. 4-53
4.11 Cumulative Impacts from Planned Operations ......................................................... ..............................4-53
4.12 Environmental Impacts Associated with Potential Oil and Chemical Spills ..............................................4-56
4.12.1 Introduction ......................................................... ................................................................ ........4-56
4.13 Potential Sources of Spill ......................................................... .............................................................. 4-56
4.13.1 Likelihood of a Spill ......................................................... .............................................................. 4-57
4.13.2 Worst Case Scenario Definition ............................................................ ......................................... 4-60
4.13.3 Predicted Potential Impact on the Coastal Environment ........................................................ ........4-61
4.13.4 Modelling Conclusion ................................................................ .................................................... 4-70
4.13.5 Prevention and Mitigation Measures ............................................................... ..............................4-73
4.13.6 Impact of a Spill .............................................................. ..............................................................4-76
4.13.7 Oil Spill Response Strategy ......................................................... ................................................... 4-77
5 Environmental Management .................................................................................................................... 5-1
5.1 Introduction ...................................................... ................................................................ .................... 5-1
5.2 EnQuests Business Management System (BMS) ..................................................................................... 5-1
5.3 HSEQ Policy ....................................................... ................................................................ .................... 5-1
5.4 Risk Management ......................................................... ................................................................ ......... 5-3
5.5 Contractor Management ......................................................... ............................................................... 5-3
5.6 Environmental Awareness Training.................................................... ..................................................... 5-3
5.7 Emergency Response .............................................................. ............................................................... 5-3
6. Conclusions ............................................................................................................................................ 6-1
6.1 Key Environmental Sensitivities .......................................................... .................................................... 6-1
6.2 Key Environmental Impacts ................................................................ .................................................... 6-1
6.3 Key residual impacts ............................................................... ............................................................... 6-2
7. References .............................................................................................................................................. 7-1
APPENDIX A: ASPECTS TABLES ........................................................................................................................ A-1
APPENDIX B: STATUTORY FRAMEWORK .......................................................................................................... B-1
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APPENDIX C: DRILLING OPERATIONSSUPPORTING INFORMATION ................................................................. C-1
APPENDIX D: PRODUCTION PROFILE TABLES ..................................................................................................... D-1
APPENDIX E: HOCNS & HMCS .......................................................................................................................... E-1
APPENDIX F: SITE SURVEY ............................................................................................................................... F-1
APPENDIX G: SEABED IMAGERY ...................................................................................................................... G-1
APPENDIX H- ATMOSPHERIC DISPERSION MODELLING ...................................................................................... H-1
APPENDIX I - THE BMT OSIS MODEL .................................................................................................................. I-1
APPENDIX JWEATHERING OF SPILT OIL .......................................................................................................... J-1
APPENDIX KCOMMITMENT REGISTER .......................................................................................................... K-1
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Non-Technical Summary
Background
During 2012, EnQuest plc (EnQuest) acquired interests in the licence for the Kraken discovery
(P1027). EnQuest ENS Limited and EnQuest Dons hold a 20% and 40% interest in the Kraken field
respectively, with their partners; First Oil (15%) and Cairn Energy (25%).
The Kraken development will be undertaken in accordance with the EnQuest policy to manage all
company activities such that the environmental impacts of its operations are minimised. To
meet this policy and to ensure compliance with the Offshore Petroleum Production and Pipelines
(Assessment of Environmental Effects) Regulations 1999 (SI No. 1999/360) this Environmental
Statement has been prepared by EnQuest in conjunction with environmental consultants RPS
Energy HSE & Risk Management.
Project Overview
The Kraken development area is in the southern part of the East Shetland Basin in the north ern
North Sea approximately 126km east of the nearest landfall at Noss, the Shetland Islands and
46km west of the UK/Norway trans-boundary median line (Figure 1.1).
EnQuest is planning to develop the Kraken area as three separate fields: Kraken North, Kraken
Central and Kraken South. This will be achieved by drilling fourteen horizontal production wells
and eleven horizontal water injector wells from seven drill centres (see Figure 2.3). The wells will
be drilled in pairs, using two semi-submersible (semi-sub) mobile drilling units (MODU) and will
be suspended pending tie-in to the flowlines and FPSO. All wells will be tied back to an FPSO
(Floating Production, Storage and Offloading) facility which will process and store the producedfluids and then export stabilised crude via shuttle tankers. The FPSO power demands will be met
through the use of associated gas. The short fall in associated gas production will be
supplemented by the use of either crude oil or diesel. It is understood that there may be future
opportunity for gas import from the Vesterled line, this shall be investigated as an alternative
source of fuel when t he infrastructure is available.
The drill centres are located approximately 3.5km apart. The wells will be drilled using a
combination of water based drilling mud (WBM) and low toxicity oil based mud (LTOBM). All
cuttings from the wells which might be contaminated with LTOBM in addition to any used LTOBM
will be returned to the MODU and skipped and shipped to shore for further processing and
appropriate reuse or disposal. All production wells will require artificial lift and Hydraulic
Submersible Pumps (HSPs) have been selected as the preferred technology. The HSPs will be
powered from the FPSO; the power fluid is treated seawater as there will be little or noformation water produced from the reservoir. The spent power fluid will be combined with the
well production fluids and returned to the FPSO. All produced water will be re-injected and
seawater will be used for water injection to replace the oil and maintain reservoir pressure,
voidage replacement and to sweep the oil to the producers.
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The Existing Environment
The environmental impact assessment process requires a comprehensive review of the existingenvironment to provide a basis for assessing the potential for interactions with the proposed
development. For the Kraken development, the existing environment has been characterised
using existing data for the general northern North Sea, supplemented by a set of site specific
survey data.
During 2012, EnQuest conducted a combined geophysical and environmental baseline survey at
the proposed Kraken Field site, undertaken between February-March 2012 by Fugro Survey Ltd.
The geophysical survey was commissioned to provide seabed, sub-seabed and anchoring
conditions for the location. It consisted of an 11km by 7km geophysical survey area and centred
on the proposed location (Figure 3.1). Data were acquired via side scan sonar and multi beam
echo sounders and a sub-bottom profiler, this was to define any potential hazards or factors of
operational significance prior to the development (Fugro, 2012). The environmental survey
comprised acquisition of seabed video and still photographic data, and grab samples. A grid
sampling strategy was adopted to assign sampling stations at regular intervals (1360 m)
throughout the survey area, although some flexibility in station locations was allowed to ensure
full coverage of all sediments and habitats interpreted from the side scan sonar (SSS) and
bathymetry data. Sampling effort was also concentrated in the immediate vicinity of the
proposed development and across a total of 44 environmental sampling stations within the 11 km
by 7 km survey area, providing sufficient coverage for characterisation of all seabed sediment
types.
Site specific data from the Kraken geophysical and environmental baseline survey (Fugro, 2012)
has been incorporated, where relevant, throughout section 3 of the ES. However, a summary of
the key aspects of the current environment within the proposed Kraken development area is
identified below.
Physical Environment
The Kraken development is located in the southern part of the east Shetland basin, referred as
the northern North Sea, approximately 126km east of the nearest landfall at Noss, on the
Shetland Islands and approximately 46km west of the UK/Norway trans-boundary median line.
Water depth within the proposed Kraken development location varies between 108m and 125m.
Surveys indicated that the seabed was deepest in the west reaching a maximum of approximately
123.8 m below LAT, and shoaling gradually towards the east to a minimum of approximately
108.0 m below LAT. A negligible gradient (
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Biological Environment
In the waters of this area, the variability of the average daily quantity of light through the seasons
and changes to the nutrient and mixing regimes result in blooms of plankton. The largest of these
blooms occurs in spring and the second in autumn. The phytoplankton community is dominated
by dinoflagellates whilst calanoid copepods, tiny crustaceans, are the main component of the
zooplankton in the area.
In the northern North Sea, to the north of the 58th
parallel, in water deeper than 100m, the water
mass stratifies strongly in summer, effectively insulating the bottom water and seabed fauna
from the large scale temperature changes that occur in the upper water column.
The site specific surveys indicated that species diversity, richness and abundance of the seabed
fauna (benthos) in the proposed development area are comparable to those in other parts of the
northern North Sea with similar depth. The Kraken survey indicated that the epifuanal
community was typically sparse, with many patches displaying no visible fauna. The most
dominant taxa recorded within the survey area belonged to the polychaetes.
There are a number of fish spawning areas and nursery areas in the development blocks,
including spawning areas for haddock, whiting, saithe, Norway pout, cod and sandeel, with
nursery areas for haddock, whiting, Norway pout, mackerel, blue whiting, herring, sandeel, ling,
hake and anglerfish.
The Kraken development is some 126km from the adjacent coastline at its nearest point.
Although this represents a considerable distance from the internationally important colonies
present in the Shetlands (Fetlar, North-east Unst etc.), foraging seabirds may travel 150km from
their habitat and therefore may be present at sea in the development area. While interactions
between seabirds and oil and gas developments are usually low, the potential for impact if
hydrocarbons are spilt is significant. Vulnerability to an oil spill in the vicinity of the Kraken
development is moderate to low for more than half the year in February, from April to June, from
August to October and December. However, seabird vulnerability to oiling is generally high tovery high during January, March, April, and July whilst at its highest during November.
Available data show that the most commonly occurring cetacean species sighted in the offshore
waters in and surrounding the Kraken development are harbour porpoise, minke whales and
white-beaked dolphins, with increased densities of harbour porpoise in July and August. Both
grey and harbour seals may be found in the area but in relatively low numbers and are unlikely to
spend any significant time in the vicinity due to the distance from shore.
There are no protected sites or unique habitats in the Kraken development area and the site
survey did not identify any species or habitats of conservation protected under the UKs Offshore
Marine Conservation (Natural Habitats, &c.) Regulations 2010. The nearest protected sites are
located along the adjacent coastlines of the Shetland Isles, some 126km distance from Kraken.
These protected sites will not be at risk from normal operations associated with the planneddevelopment or production activities.
Socio-Economic Environment
The Kraken development lies in an area that ranks fishing effort as low and consistent with fishing
effort for large areas of the northern North Sea. Pelagic and demersal species comprise the bulk
of the catch, and to a lesser extent, shellfish. However, annual catch, in terms of tonnage landed
and its monetary value is considered as relatively low.
The Kraken development lies in an area that ranks fishing effort to catch demersal species (cod,
haddock, ling, megrim, monk fish, saithe, whiting etc.) as moderate, effort to catch pelagic
species (herring and mackerel mainly) low and effort to catch shellfish very low (squid, lobster
and Nephrops) in relation to the other UK waters. The highest fishing effort is during March and
September and the lowest effort occurs during December.
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The intensity of shipping traffic east of the Shetlands is relatively light with one to two vessels
crossing the Kraken development area per day, many associated with other oil and gas facilities
in the northern North Sea. A total of 8 routes pass within 10nm of the proposed Kraken well
location, with a total of 510 vessels per year. The nearest large port for this area is Lerwick onmainland Shetland.
The route for vessels travelling between Sognefjorden (Norway) and Firth of Clyde and between
Milford Haven and Sognefjorden (Norway), pass within less than 3nm of the Kraken well
locations, constituting approximately 21% and 10% of the traffic respectively. However, while
the development will affect these routes there is sea room available in the surrounding area for
the vessels on these routes to achieve an adequate clearance from the installations. Any impact
on other routes is expected to be negligible.
The closest surface platform to the Kraken development, lies approximately 28km to the south
east, at the Bruce gas field.
Charts and local surveys indicate that there are no charted wrecks in the area.
Key Sensitivities
In summary, the key environmental sensitivities, summarised in Table 1.1 at the proposed Kraken
development location are:
The blocks of interest include fish spawning areas for haddock, saithe, whiting, cod,
sandeel and Norway pout. The blocks are also nursery areas for haddock, whiting, Norway
pout, blue whiting, mackerel, herring, ling, hake, anglerfish and sandeel.
In the blocks of interest, seabird vulnerability to oiling is generally low for more than half
the year (3 to 4 on the Joint Nature Conservation Committee (JNCC) scale) in February,
May, during April to June, August to October and December. However, seabird
vulnerability to oiling is generally high (1 to 2 on the JNCC scale) during January, March,
April, July and November.
Cetacean numbers overall are low. The most common occurring species are harbour
porpoise, minke whales and white-beaked dolphins, with increased densities of harbour
porpoise during July and August.
Grey seal (listed in Annex II of the Habitat Directive) may be found in the area. There is also
potential for Harbour seals.
No protected habitats as listed in Annex I of the Habitat Directive have been identified in
the proposed development area.
The nearest coastal environmentally designated sites are all on the Shetland Islands and
include:
- North Fetlar Special Area of Conservation (SAC) dry coastal heathland (200km);
- Hascosay(SAC) sensitive coastal habitats (200km);
- Yell Sound (marine SAC) with two Annex II species including otter and common seal
approximately 212km from the development;
- The nearest seabird colonies are the North-east Unst, Crussa field and West Unst;
- In addition, there are a number of coastal protected sites adjacent to the blocks of
interest on the Shetland Islands, including Fetlar, Hermaness, Saxa Vord and Valla Field
and Otterswick and Graveland.
Potential restrictions to seismic operations (Marine Scotland Period of concern):- Block 9/02 between January and June.
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The overall fishing effort is low throughout the year; the highest fishing effort is noted in
March and September. Catch is primarily of demersal and pelagic species, with very few
mollusc and shellfish targeted.
Moderate to low levels of shipping traffic pass through the area.
There are a number of abandoned wells within the vicinity of the proposed development.
There are currently no proposed offshore wind farms in the near vicinity of the proposed
development.
The planned Kraken development lies approximately 46 kilometres west of the trans-
boundary line.
Table 1.1. Seasonal Environmental Sensitivities
Activity in Block 9/02b surrounding waters and adjacent coast
Component Abundance/Activity J F M A M J J A S O N D
Plankton Phytoplankton and zooplankton
Benthic Fauna Benthic faunal communities
Fish Haddock N N N N
Whiting N N N N N
Saithe
Norway pout N N N N
Mackerel N N N N N
Blue Whiting N N N
Herring N N
Sand eel N N N N
Ling N N N NHake N N N N N
Anglerfish N N N N
Cod
Seabirds Block 9/02b Offshore Vulnerability 2 4 2 3 4 4 2 4 3 3 1 3
Cetaceans Harbour porpoise
Minke whale
White beaked dolphin
Resource Users Commercial fishing (ICES rectangle 48F1)
Shipping and ports
Military Activity
Oil and gas activity (inc. pipelines / cables)
Dredging and dumpingOffshore windfarms
Marine SACs
Coastal protected sites
Tourism, recreation & leisure activities
Numbers refer to the seabird vulnerability index used by JNCC (1999) ranging from highest vulnerability (1) to
lowest (4).
Coastal occurrence Activity in Block 9/02b and surrounding waters
Peak Low None Peak High Low None N Nursery
* Seabird vulnerability - High sensitivity: 1, Low sensitivity: 4, blank: no data (JNCC, 1999)
** Data compiled from the JNCC atlas, 2003. However, sightings by MMOs during surveys conducted in 2004 & 2006 have also
been included for completeness.
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Environmental Interactions, Impacts and Mitigation Measures
The environmental assessment carried out on the development of the Kraken field, as proposedby EnQuest, indicates that the key interactions, resulting environmental impacts and measures to
mitigate those effects are as follows:
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ROUTINE HAZARDS - DRILLING
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Physical Presence
Disruption to other
sea users
Shipping, Commercial Fishing A safety exclusion zone will be designated extending to 500m from the MODU.
An ERRV will be on stand-by and monitor vessels within the area to assist in keeping
vessels away from the MODU.
AIS and radar systems shall assist the ER RV and MODU in identifying approaching
vessels.
Notifications shall be made to the MCA and Hydrographic Office. Notices to
Mariners, NAVTEX and NAVAREA warnings will be circulated and changes to
schedule shall be advised.
Regular runners in the r outes identified as being potentially impacted by the
MODU location shall be notified prior to MODU arriving on s ite.
Operators of radar systems installed at onshore bases will be made aware of the
proposed activity so they can inform ves sels transiting in the area of the pre sence of
the MODU.
A Collision Risk Management Plan will be in place.
Early and ongoing liaison with the SFF and other f ishing groups shall be maintained.
Locations and safety zones shall be marked on appropriate charts.
Good communications with local fishermen shall be maintained with the
appointment of an onshore FLO to coordinate activities throughout the drilling and
installation phase. Vessels will be contacted by VHF radio with regular broadcast to
all vessels operating in the area.
Low
Seabed Disturbance
Disturbance may
occur from MODUanchors and anchor
chains
Water quality, Sediments, Seabed
fauna
Anchoring patterns will be reviewed to ensure they do not encroach any existing
seabed infrastructure.
Low
Noise
Noise from drilling
operations may
disturb marine
fauna
Marine Mammals, Fish Days on location of the semi-submersible MODU will be kept to a minimum.
Operational and maintenance procedures on the MODU will aim to optimise the
efficiency of equipment and schedule of operations.
Optimise vessel movement by careful planning.
Low
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ROUTINE HAZARDS - DRILLING
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Atmospheric
Emissions
Emissions from
power generation
for the MODU and
support vessels.
Additional
emissions for
maintenance and
flaring during well
clean-up.
Air quality Environmental critical elements (ECE) on the MODU will be identified and subject to
specific maintenance routines. In particular, main power generation equipment will
be well maintained and operated.
Contracted vessels will be required to control processes, maintain equipment,
manage energy and minimise usage wherever possible.
Low sulphur diesel will be used wherever possible.All drilling activities will be planned so as to minimise duration and ensure efficient
operations
Optimise vessel movement by careful planning.
Minimise quantities of oil and gas flared.
Medium (power
generation)
Low (other)
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ROUTINE HAZARDS - DRILLING
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Marine Discharges
Discharge of ballast
water, WBM and
associated cuttings,
cement, drainage
water, sewage,
food waste and
well completion
fluids
Water Quality, Seabed Fauna, Fish,
Shellfish, Offshore seabirds,
Marine mammals
Strict adherence to the rules governing discharge of ballast waters at sea.
Use of a MODU/ vessels coming fr om previous North Sea operations or location for
intake and discharge of ballast water within same region.
A full Chemical Hazard Assessment and Risk Management assessment of the
proposed chemicals will be undertaken. Where practicable chemicals with
substitution warnings will be replaced with those with an improved environmentalprofile.
Only spent WBM and associated cuttings will be discharged to sea; LTOBM and
associated cuttings will be skipped and shipped to shore.
Cuttings / mud cleaning equipment will ensure optimal cuttings cleaning of the
WBM prior to discharge. Recovered WBM will be reused / re-circulated where
practical.
Cement and associated chemicals will be mixed offshore as needed to minimise
quantities used.
Environmental critical elements (ECE) on the MODU will be identified and subject to
specific maintenance routines to ensure compliance with environmental legislation.
The hydrocarbon content of the completion br ine will be monitored. Only fluids
with an oil in water content, which does not produce a surface sheen, will be
discharged to sea. If, oil is visible on the surface of the sea, all discharge shall cease
and the water will be contained and shipped to shore for processing. Good
housekeeping standards will be maintained on the MODU.
Black (sewage) and grey water will be collected, treated (macerated) to meet the
requirements of the MARPOL convention prior to being discharged to sea. Alldischarges will be treated and dis charged according to the MARPOL Convention,
which prohibits discharge of any garbage or solid waster into the North East Atlantic
Ocean.
Good housekeeping standards will be maintained on the MODU to minimise
hydrocarbons or chemicals in the drainage water.
Suitable containment, treatment and monitoring systems for the drainage systems
will be in place. Hazardous streams will be contained for treatment and will not be
discharged overboard.
Low
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ROUTINE HAZARDS - DRILLING
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Solid Wastes
Wastes will include
spent LTOBM and
associated cuttings,
scrap metal,
garbage, waste oil
and chemicals
Land Use, Air quality Procedures will be in place to ensure that filling, storage and removal of the
containers will conform to strict guidelines to minimise the risk of accidental spillage
of LTOBM. Recycling of LTOBM will be undertaken where possible.
Thermal treatment of cuttings associated with LTOBM will be undertaken once at
contractors site. Resulting process water will be used to dampen the dry cuttings
before final disposal at a l andfill site. Drill cuttings that will be disposed of to landfill
will be used for covering other material that has been disposed of at the landfill site.
Auditing of waste management contractors to ensure compliance.
A Waste Management Plan will be in place to ensure:
Minimisation of the amounts generated at source;
Segregation of waste by type;
Storage in covered skips to prevent emissions and leaks.
Recycling or re-use prioritised where possible, in particular for scrap metal,
waste oil and surplus chemicals ;
Waste sent to authorised landfills or incineration facilities, depending on its
precise nature, when no other option is possible;
Use of authorised waste contractors.
Low
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ROUTINE HAZARDSInstallation and Commissioning
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Physical Presence
Disruption to other
sea users from
presence of FPSO and
vessels.
Shipping, Commercial
Fishing
A safety exclusion zone will be designated extending to 500m around the FPSO and drill
centres.
An ERRV will be on stand-by and monitor vessels within the area to assist in keeping vessels
away from the exclusion zones and installation activities.AIS and radar systems shall assist the ERRV and FPSO to identify approaching vessels.
FPSO location and exclusion zones shall be notified to appropriate authorities and marked on
charts.
Continued liaison with SFF, fishing groups, MoD and other industries will ensure that the
physical presence of facilities and vessels has minimum interference with other activities.
All potential, long-term obstructions to fishing vessels will be notified to the appropriate
authorities and marked on charts.
All pipelines will be trenched and backfilled to minimise interference with fishing gear.
Subsea facilities at the drill centres will be designed to be fishing friendly.
Low
Seabed Disturbance
Disturbance may
occur from anchors
and mooring lines,
trenching and
backfilling, subsea
infrastructure and
protective/
stabilisation
materials
Sediments, Seabed fauna Anchoring patterns will be reviewed to ensure they do not encroach on any existing seabed
infrastructure.
Working corridors will be minimised wherever re asonably practicable.
All installation vessels will be dynamically positioned to minimise disturban ce by anchors.
The amount of deposited material and the method of placement will be optimised in order to
achieve stabilisation while minimising the area impacted.
Medium
(flowline
installation)
Low (other)
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ROUTINE HAZARDSInstallation and Commissioning
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Noise
Noise from flowline
installation, piling
activities and vessel
presence may disturb
marine fauna
Fish, Marine Mammals Operational and maintenance procedures on the vessels will aim to optimise the efficiency of
equipment and schedule of operations.
Vessels engaged in pipelay and installation a ctivities will be either stationary or operating at
slow speeds during work activities.
The method of placement will be optimised in order to achieve stabilisation while minimisingthe area impacted.
FEPA consent with a comprehensive Marine Mammal Monitoring Programme. This will include
Marine Mammal Observers and Passive Acoustic M onitoring package stationed offshore
throughout the piling programme.
Low (other)
Medium (piling)
Atmospheric
emissions
Emissions from
power generation on
installation vessels
and FPSO during
commissioning
Air quality Environmental critical elements (ECE) on the FPSO will be identified and subject to specific
maintenance routines. In particular, main power generation equipment will be well maintained
and operated.
Contracted vessels will be required to control processes, maintain equipment, manage energy
and minimise usage wherever possible.
Low sulphur diesel will be used wherever possible.
All operations will be planned so as to minimise duration and ensure efficient operations.
Optimise vessel movement by careful planning
Medium
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ROUTINE HAZARDSInstallation and Commissioning
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Marine Discharges
Will include discharge
of ballast water from
FPSO and vessels,
flowline testing and
commissioning fluids,domestic sewage, food
waste and drainage
water.
Water Quality, Plankton,
Seabed fauna, Fish/Shellfish,
Offshore seabirds, Marine
mammals
Strict adherence to the rules governing discharge of ballast waters at sea.
Where possible the use of vessels coming from previous North Sea operations or location for
intake and discharge of ballast water within same region.
A full Chemical Hazard Assessment and Risk Management (CHARM) assessment of the proposed
chemicals will be undertaken. Where practicable chemicals with substitution warnings will bereplaced with those with an improved environmental profile. All chemicals shall be approved by
the OCNS.
Good housekeeping standards will be maintained onboard vessels.
Black (sewage) and grey water will be collected, treated (macerated) to meet the re quirements
of the MARPOL convention prior to being discharged to sea.
All discharges will be treated and dis charged according to the MARPOL Convention, which
prohibits discharge of any garbage or solid waste into the North East Atlantic Ocean.
Good housekeeping standards will be maintained on th e FPSO and vessels to minimise
hydrocarbons or chemicals in the drainage water.
Suitable containment, treatment and monitoring systems for the drainage systems will be in
place.
Hazardous streams will be contained for treatment and will not be discharged overboard
Low
Solid Wastes
Wastes will include
scrap metal, garbagewaste oil chemicals
Land Use, Air quality Minimisation of waste generated.
Bulk waste (e.g. Garbage, scrap, etc) generated on the installation vessels will be segregated by
type and stored in covered skips. Periodically these will be transported to shore and the wasterecycled or disposed of in a controlled manner through authorised waste contractors.
A waste management programme will be implemented to minimise the amounts generated and
to ensure material such as scrap metal, waste oil and surplus chemicals are sent f or recycling or
re-use as far as practicable. Other waste will be sent to authorised landfills or incineration
facilities, depending on its precise nature.
Low
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ROUTINE HAZARDSProduction
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Physical Presence
Disruption to other
sea users
Shipping, Commercial
Fishing
A safety exclusion zone will be designated extending to 500m around the FPSO and drill
centres.
An ERRV will be on stand-by and monitor vessels within the area to assist in keeping vessels
away from the exclusion zones and installation activities.
AIS and radar systems shall assist the ERRV and FPSO identify approaching vessels.
FPSO location and exclusion zones shall be notified to appropriate authorities and marked on
charts.
Continued liaison with SFF, fishing groups, MoD and other industries will ensure that the
physical presence of facilities and vessels has minimum interference with other activities.
All potential, long-term obstructions to fishing vessels will be notified to the appropriate
authorities and marked on charts.
All pipelines will be trenched and backfilled to minimise interference with fishing gear.
Subsea facilities at the drill centres will be designed to be fishing friendly.
Low
Seabed Disturbance
Disturbance may
occur from anchors
and mooring lines,
subsea infrastructure
and protective/stabilisation
materials
Sediments, Seabed fauna The amount of deposited material will be optimised in order to minimise the area impacted. Medium (marine
fauna colonising
hard structures)
Low (other)
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ROUTINE HAZARDSProduction
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Noise
Noise from production
and oil export
operations and
helicopter and support
vessel movementsmay disturb marine
fauna
Fish, Marine Mammals Operational and maintenance procedures on the FPSO and vessels will aim to optimise the
efficiency of equipment and schedule of operations.
Equipment maintenance schedules will include minimisation of mechanical noise, e.g. pump
cavitation.
Tankers will be either stationary or operating at slow speeds in the Kraken area.Optimise vessel movement by careful planning.
Optimise vessel and helicopter movement by careful planning.
Low
Atmospheric
Emissions
Emissions from
power generation on
the FPSO, support
vessels and export
tanker, Flaring during
engine shutdown,
tanker offloading,
cleaning and
maintenance
Air quality Environmental critical elements (ECE) on the FPSO will be identified and subject to specific
maintenance routines. In particular, main power generation equipment will be well maintained
and operated.
All machines to include Dry Low Emissions (DLE) technology, which minimises production of NOx
and CO.
Variable speed drives on pumps will allow to tailor speed (and associated energy consumption)
to actual need.
Fuel consumption and flaring on the FPSO will be regularly monitored to allow analysis of the
efficiency of the systems and effectiveness of procedures.
Contracted vessels will be required to control processes, maintain equipment, manage energy
and minimise usage wherever possible.
Low sulphur diesel will be used wherever possible.
A vapour recovery unit will be installed to recover vapours from the separators and other oil
processing equipment to minimise vapours routed to the flare system.
Use of high combustion efficiency burners.
Minimisation of emergency blow-down as a safety mitigation for confirmed fire and gas
detection and not on process or compressor shutdown
Low loss fittings. High integrity compressor and pump seals for high pressure systems.
Closed drains for the hydrocarbon system.
Loss of VOC during offloading will be minimised by the preferential selection of shuttle tankers
with a VOC capture facility or VOC reduction capability.
Medium
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ROUTINE HAZARDSProduction
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Marine Discharges
Will include discharge
of produced water
during re-injection
pump unavailability,
production chemicals,displaced water,
cooling water, ballast
water, sewage, food
waste and drainage
water.
Water Quality, Plankton,
Seabed fauna,
Fish/Shellfish, Offshore
seabirds, Marine mammals
Environmental critical elements (ECE) on the FPSO will be identified and s ubject to specific
maintenance routines to ensure compliance with environmental legislation and EnQuest goals.
Produced water will be re-injected into the reservoir except during short periods for maintenance
or upset conditions. Any discharge of produced water will be treated to meet oil-in-water
standards of < 30 mg/l and will be monitored and sampled in accordance with an approved OPPC
permit.
Independent storage management and monitoring systems in place in e ach oil storage tank.
Coatings of storage tanks designed to inhibit bacterial growth and rag layer development.
High and low oil level alarm systems in each of the storage tanks. Automatic shutdown
sequence to prevent transfer of oil to a tank or shutdown oil ex port. All piping connections into
the tanks within the water phase to prevent loss of oil containment. Leak detection system in
place.
Strict adherence to the rules governing discharge of ballast waters at sea.
Black (sewage) and grey water will be collected, treated (macerated) to meet the r equirements
of the MARPOL convention prior to being discharged to sea
Good housekeeping standards will be maintained on the FPSO, and vessels to minimise
hydrocarbons or chemicals in the drainage water.
Suitable containment, treatment and monitoring systems for the drainage systems will be in
place. Hazardous streams will be contained f or treatment and will not be discharged overboard.
Hazardous drain system will be equipped with tr ip and alarm systems in place.
Recovered oil from the open and closed drainage systems is returned to the process and waste
water will be treated and monitored to ensure that the oil content is in line with appropriate
standards prior to discharge overboard.
A full Chemical Hazard Assessment and Risk Management assessment of the proposed chemicals
will be undertaken. Where practicable chemicals with substitution warnings will be replaced
with those with an improved environmental profile. Areas where chemicals may be laid down or
stored will have bunding to c ontain any leaks; these will be routed to the open drains and then
return to the process.
Low
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ROUTINE HAZARDSProduction
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Solid Wastes
Wastes will include
scrap metal, garbage
waste oil chemicals
Land Use, Air quality A Waste Management Plan will be in place to ensure:
Minimisation of the amounts generated at source;
Segregation of waste by type;
Storage in covered skips to prevent emissions and leaks.
Recycling or re-use prioritised where possible, in particular for scrap metal, waste oil and
surplus chemicals ;
Waste sent to authorised landfills or incineration facilities, depending on its precise
nature, when no other option is possible.
Use of authorised waste contractors.
Low
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NON ROUTINE HAZARDS Drilling
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Physical presence /
Seabed disturbance
Debris dropped at
sea
Sediments, seabed fauna, seabed
infrastructure
Audits of all equipment brought onto, and taken off, the site.
Debris is identified during the post work surveys or if dropped objects occur then
these will be appropriately reported and procedures will be in place to ensure their
recovery, wherever possible.
Low
Atmospheric
emissions
Emission of CO2/N2from firefighting
equipment.
Atmospheric
pollution from
uncontrolled gas
release from well
Air quality Fire fighting equipment not to be used in exercise scenarios.
A shallow gas survey has been undertaken.
Crews will be adequately experienced, trained in well control techniques and
supervised. Emergency drills will be held regularly.
Well design and construction reviewed by an independent well examiner.
Weighted drilling fluids will provide the primary barrier and the well will be carefully
controlled and monitored.
The secondary barrier will be the BOP, which will be regularly maintained and
tested.
Production isolation valves will be included on the subsea Xmas tree and all safety-
critical subsea valves will be ROV or diver operable.
Emergency Response Plans, OPEP and equipment will be in place.
Low
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NON ROUTINE HAZARDS Drilling
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Marine Discharges
Loss of
containment on
the MODU due to
ship collision or
other major event
Water Quality, Land use,
Sediments, Plankton, Seabed
fauna, Fish/Shellfish, Offshore
seabirds, Marine mammals,
Coastal seabirds, Fishing, Tourism
A safety exclusion zone will be designated extending to 500 metres from the MODU.
An ERRV will be on stand-by and monitor vessels within the area to assist in keeping
vessels away from the MODU.
AIS and radar systems shall assist the ERRV and MODU to identify approaching
vessels.
Notifications shall be made to the MCA and Hydrographic Office. Notices to
Mariners, NAVTEX and NAVAREA warnings will be circulated and changes to
schedule shall be advised.
Regular runners in the routes identified as being potentially impacted by the
MODU location shall be notified prior to MODU arriving on site.
Operators of radar systems installed at onshore bases will be made aware of the
proposed activity so they can inform vessels transiting in the area of the presence of
the MODU.
A Collision Risk Management Plan will be in place.
Early and ongoing liaison with SFF and other fishing groups. Locations and safety
zones shall be marked on appropriate charts.
The appointment of a FLO to maintain communication and coordinate activities.
Regular contact with vessels operating in the area via VHF radio broadcasts.
Low
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NON ROUTINE HAZARDS Drilling
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Marine Discharges
Uncontrolled well
flow during drilling
Water Quality, Land use,
Sediments, Plankton, Seabed
fauna, Fish/Shellfish, Offshore
seabirds, Marine mammals,
Coastal seabirds, Fishing, Tourism
Drilling will follow established drilling safety standards to minimise the r isk of well
control loss.
A shallow gas survey will be undertaken.
Crews will be adequately experienced, trained in well control techniques and
supervised. Emergency drills will be held regularly.
Well design and construction reviewed by an independent well examiner.Weighted drilling fluids will provide the primary barrier and the well will be carefully
controlled and monitored.
The secondary barrier will be the BOP, which will be regularly maintained and
tested.
Production isolation valves will be included on the subsea Xmas tree and all safety-
critical subsea valves will be ROV or diver operable.
Emergency Response Plans, OPEP and equipment will be in place.
The OPEP will include details of available capping devices, poss ible relief well
locations and time frames to drill a relief well.
Low to Medium
depending upon
environmental
receptor
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Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxix
NON ROUTINE HAZARDS Drilling
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Marine Discharges
Loss of
hydrocarbons/
chemicals during
bunkering,
refuelling andgeneral operations
Loss of supply
material to sea
Water Quality, Land use,
Sediments, Plankton, Seabed
fauna, Fish/Shellfish, Offshore
seabirds, Marine mammals,
Coastal seabirds, Fishing, Tourism
Environmentally critical equipment will be identified and specifically highlighted in
the MODUs maintenance procedures and plans.
Crews will be adequately trained, supervised and r egularly hold exercises to contain
and clean up deck spills.
If feasible, the drilling rig will arrive on site fully bunkered.
Where practicable, re-fuelling and transfer of LTOBM, lubricants and other utility
fluids will be undertaken during daylight and in good weather conditions.
Non-return valves will be installed on LTOBM and fuel transfer hoses. Hoses will be
tested and inspected as a part of a regular maintenance programme.
Volumes of LTOBM will be reduced by drilling all top hole sections with WBM.
Special containers will be used to store and ship the LTOBM and associated cuttings
to shore for treatment and appropriate disposal.
Transfer operations will be supervised at all times from both the supply boat and
semi-submersible.
Clean up materials will be available on the drilling rig and vessels to manage small
deck spills.
Minimisation of chemical transfers and loading operations.
Operational controls for loading, unloading, and movement of materials.
Double-checking containment of all materials for transfer to/from the drilling rig.
Emergency response procedures available in the event of a chemical spill.
Low to medium
depending upon
environmental
receptor (others)
Low (loss of
supply material)
NON ROUTINE HAZARDS Installation & Commissioning
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Physical presence /
Seabed disturbance
Debris dropped at
sea
Sediments, seabed fauna, seabed
infrastructure
Audits of all equipment brought onto, and taken off, the site.
Debris is identified during the post work surveys or if dropped objects occur then
these will be appropriately reported and procedures will be in place to ensure their
recovery, wherever possible.
Low
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Kraken Field Development Area Environmental Statement
Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxx
NON ROUTINE HAZARDS Installation & Commissioning
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Marine Discharges
Uncontrolled well
flow during
commissioning,
potential for spill of
heavy crude
Water Quality, Land use,
Sediments, Plankton, Seabed
fauns, Fish,/Shellfish, Offshore
seabirds, Marine mammals,
Coastal seabirds, Fishing, Tourism
Crews will be experienced and tr ained in well control techniques and supervised.
Emergency drills will be held regularly.
Well design and construction reviewed by an independent well examiner.
Production isolation valves will be included on the subsea Xmas tree and all safety-
critical subsea valves will be ROV or diver operable.
Emergency Response Plans, OPEP and equipment will be in place. Will also includedetails of available capping devices, possible relief well locations and time frames to
drill a relief well.
Low to Medium
NON ROUTINE HAZARDS Production
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Physical presence /
Seabed disturbance
Debris dropped at
sea
Sediments, seabed fauna, seabed
infrastructure
Audits of all equipment brought onto, and taken off, the site.
Debris is identified during the post work surveys or if dropped objects occur then
these will be appropriately reported and procedures will be in place to ensure their
recovery, wherever possible.
Low
Atmospheric
emissions
Emission of CO2/N2from firefighting
Atmosphericpollution from
uncontrolled gas
release from well
Air quality A shallow gas survey has been undertaken.
Crews will be adequately experienced, trained in well control techniques and
supervised. Emergency drills will be held regularly.
Well design and construction reviewed by an independent well examiner. Production
isolation valves will be included on the subsea Xmas tree and all safety-critical
subsea valves will be ROV or diver operable.Emergency Response Plans and equipment will be in place
Fire fighting equipment not to be used in exercise scenarios.
Low
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5/28/2018 Kraken Development
33/440
EnQuest
Kraken Field Development Area Environmental Statement
Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxxi
NON ROUTINE HAZARDS Production
Hazard & Effect(s) Environmental receptors Mitigation Measures Residual Impact
Marine Discharges
Potential for
hydrocarbon and
chemical spills
during supply,
bunkering andrefuelling. Loss of
containment of
hydrocarbons during
normal operations
Water Quality, Land use,
Sediments, Plankton, Benthic
communities, Fish, Shellfish,
Offshore seabirds, Marine
mammals, Coastal seabirds,
Fishing, Tourism
Environmentally critical equipment will be identified and specifically highlighted in
the FPSO maintenance procedures and plans.
Crews will be adequately trained, supervised and regularly hold exercises to contain
and clean up deck spills.
Where practicable, re-fuelling and transfer of lubricants and other utility fluids will
be undertaken during daylight and in good weather conditions.
Non-return valves will be installed on fuel transfer hoses, hoses will be tested and
inspected as a part of a reg ular maintenance programme.
Transfer operations will be supervised at all times from both the supply boat and
FPSO.
Clean up materials will be available on the FPSO and vessels to manage small deck
spills
Low to Medium
depending upon
environmental
receptors (others)
Low (loss of
containment
during normal
operations)
Marine Discharges
Loss of containment
on the FPSO due to
ship collision or
other major event .
Release of
hydrocarbons into
the marine
environment
Water Quality, Land use,
Sediments, Plankton, Seabed
fauna, Fish/Shellfish, Offshore
seabirds, Marine mammals,
Coastal seabirds, Fishing, Tourism
Liquid storage areas and areas that might be contaminated with oil are segregated
from other deck areas.
Permanent drip trays will be located under pr ocess plant, pumps and vessels (on
grated decks).
Bunding will be provided around plated areas bene ath equipment with significant
hydrocarbon inventories.
On all levels with grated decks any operational tasks requiring breaking of
hydrocarbon containment will make use of portable drip trays, temporary bundingand other absorbent materials.
Utility and fuel storage tanks will be equipped with trip and alarm systems and
procedure will be in place to minimise and prevent spills overfilling these storage
tanks.
Special training will be given to personnel with the responsibility for the operation
of valves, particularly dump valves.
Routine equipment maintenance programme will be in pla