Kraken Development

EnQuest Heather Limited Kraken Field Development Environmental Statement

DECC Document Ref: D/4155/2013

EnQuest Heather Limited Document Ref: ENQ-KRA-HS-00-STA-0002

Issued 14th February 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 be investigated as an alternative source of fuel when the infrastructure is available.

All production wells will require artificial lift and Hydraulic Submersib le 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 Environmental Documents

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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Table of Contents

STANDARD INFORMATION SHEET ........................................................................................................................ i

NON-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 ..............................................................................................................................................xxxvii

Glossary ...........................................................................................................................................................xli

1 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 ..................................................................................................................... 2-1

2.1 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 ............................................................................................................................................. 3-1

3.3 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


4.8 Environmental Impact Assessment of Marine Discharges ....................................................................... 4-44

4.8.1 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


4.9 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


4.10 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 OPERATIONS SUPPORTING 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 J WEATHERING OF SPILT OIL .......................................................................................................... J-1

APPENDIX K COMMITMENT 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 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 be investigated as an alternative source of fuel when the 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 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.

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The Existing Environment

The environmental impact assessment process requires a comprehensive review of the existing environment 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 to very 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 planned development 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 on mainland 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 N

Hake 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 dumping

Offshore 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.

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xiv

Environmental Interactions, Impacts and Mitigation Measures

The environmental assessment carried out on the development of the Kraken field, as proposed by EnQuest, indicates that the key interactions, resulting environmental impacts and measures to mitigate those effects are as follows:

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xv

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 ERRV 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 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 the SFF and other fishing 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 MODU anchors 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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xvi



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


Minimise quantities of oil and gas flared.

Medium (power generation)

Low (other)

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xvii



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 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 assessment of the proposed chemicals will be undertaken. Where practicable chemicals with substitution warnings will be replaced with those with an improved environmental profile.

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 brine 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. All discharges will be treated and discharged 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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xviii



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 landfill 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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xix

ROUTINE HAZARDS Installation and Commissioning


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 reasonably practicable.

All installation vessels will be dynamically positioned to minimise disturbance 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)

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xx



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 activities 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 minimising the area impacted.

FEPA consent with a comprehensive Marine Mammal Monitoring Programme. This will include Marine Mammal Observers and Passive Acoustic Monitoring 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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxi



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


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 be replaced 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 requirements of the MARPOL convention prior to being discharged to sea.

All discharges will be treated and discharged 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 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 for treatment and will not be discharged overboard

Low

Solid Wastes

Wastes will include scrap metal, garbage waste 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 waste recycled 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 for 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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxii

ROUTINE HAZARDS Production


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)

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxiii



Noise

Noise from production and oil export operations and helicopter and support vessel movements may 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 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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxiv



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 subject 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 each 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 export. All piping connections into the tanks within the water phase to prevent loss of oil containment. Leak detection system in place.


Black (sewage) and grey water will be collected, treated (macerated) to meet the requirements 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 for treatment and will not be discharged overboard. Hazardous drain system will be equipped with trip 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 contain any leaks; these will be routed to the open drains and then return to the process.

Low

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxv



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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxvi

NON ROUTINE HAZARDS Drilling


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


Emission of CO2/N2 from 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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxvii



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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxviii



Marine Discharges

Uncontrolled well flow during drilling


Drilling will follow established drilling safety standards to minimise the risk 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 careful ly 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, possible relief well locations and time frames to drill a relief well.

Low to Medium depending upon environmental receptor

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxix



Marine Discharges

Loss of hydrocarbons/ chemicals during bunkering, refuelling and general operations

Loss of supply material to sea


Environmentally critical equipment will be identified and specifically highlighted in the MODUs maintenance procedures and plans.

Crews will be adequately trained, supervised and regularly 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





Audits of all equipment brought onto, and takenoff, 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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxx

NON ROUTINE HAZARDS Installation & Commissioning


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 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, OPEP and equipment will be in place. Will also include details of available capping devices, possible relief well locations and time frames to drill a relief well.

Low to Medium

NON ROUTINE HAZARDS Production





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


Emission of CO2/N2 from firefighting

Atmospheric pollution 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

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxxi



Marine Discharges

Potential for hydrocarbon and chemical spills during supply, bunkering and refuelling. 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 regular 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


Liquid storage areas and areas that might be contaminated with oil are segregated from other deck areas.

Permanent drip trays will be located under process plant, pumps and vessels (on grated decks).

Bunding will be provided around plated areas beneath 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 bunding and 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 place with specific emphasis on environmentally critical equipment.

Low to medium depending upon receptor

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxxii



Marine Discharges

Uncontrolled well flow during production

Potential for a significant spill of heavy crude oil.

Physical oiling and toxicity impacts.

Indirect impacts could include: habitat loss, impact on tourism and fisheries, issue of waste disposal, transboundary issue.

Accumulation of oil and chemicals in the food chain and in sediments. Loss of biodiversity and revenue.


Crews will be adequately experienced, trained in well control techniques and supervised. Emergency drills will be held regularly.

Ongoing well verification 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.

Permanent downhole pressure and temperature gauges will be installed in each well to monitor downhole conditions throughout the well life.

Emergency Response Plans, OPEP and spill response equipment will be in place.

The OPEP will include details of available capping devices, possible relief well locations and time frames to drill a relief well.

Low to medium depending upon receptor

EnQuest


Doc Ref No: ENQ-KRA-HS-00-STA-0002 xxxiii



Marine Discharges

Loss of flowline or umbilicals integrity

Small or larger leaks from flowlines may result in release of reservoir hydrocarbons and or production chemicals into the marine environment and directly at the seabed which may have toxicity effects on flora and fauna


Flowlines protected from corrosion through a combination of a protective coating and cathodic protection system and a margin for corrosion is built into the flowline design.

All flowlines and risers pressure tested to above the planned operating pressure.

Flowlines protected from physical damage by fishing gear or anchors by being trenched and backfilled and with other suitable protective measures (rockdump, mattresses etc) in trench transitions.

Routine monitoring of flowline pressure and temperature will be undertaken. Automatic and manual shutdown systems in place.

Regular ROV inspection of all flowlines will be undertaken.

Medium

Kraken Development

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Transcript of Kraken Development