Alma Field Development Environmental Statement

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EnQuest Heather Limited

Alma Field Development

Environmental Statement

DECC Document Ref: D/4110/2011

Intertek METOC Document

Ref: P1459BA_RN2525_Rev0

EnQuest Heather Limited Document

Ref: ENQ-KN501-HS-001-ENS-0001

ISSUED:

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ENQUEST HEATHER LIMITED ENQUEST HEATHER LIMITED ALMA FIELD DEVELOPMENT ALMA FIELD DEVELOPMENT

STANDARD INFORMATION SHEET

Project Name

Project Name Alm Alma Fia Field eld DevDeveloelopmepmentnt DECC Reference

DECC Reference Number

Number D/4110/2011D/4110/2011

Type of Project

Type of Project Small oil field developmentSmall oil field development Undertaker Name

Undertaker Name EnQuest Heather LimitedEnQuest Heather Limited Undertaker Address

Undertaker Address 5 Floor Consort House, Stell Road, Aberdeen, AB11 5QF, United Kingdom5 Floor Consort House, Stell Road, Aberdeen, AB11 5QF, United Kingdom Licencees / Owners

Licencees / Owners EnQuest Heather Limited (100%)EnQuest Heather Limited (100%)

Short Description Short Description

EnQuest Heather Limited wishes to redevelop the Ardmore field in the UK Central North Sea (CNS). The EnQuest Heather Limited wishes to redevelop the Ardmore field in the UK Central North Sea (CNS). The field, to be renamed Alma, will be developed through two drill centres tied-back via new oil production field, to be renamed Alma, will be developed through two drill centres tied-back via new oil production and water injection flowlines to the Uisge Gorm floating production, offloading and storage facility and water injection flowlines to the Uisge Gorm floating production, offloading and storage facility (FPSO). The development will consist of six production wells and two water injection wells (which will be (FPSO). The development will consist of six production wells and two water injection wells (which will be used to drive production due to low reservoir pressures).

used to drive production due to low reservoir pressures).

Wells will be drilled using a combination of water and oil based muds. Cuttings and water based muds Wells will be drilled using a combination of water and oil based muds. Cuttings and water based muds will be discharged to sea both at the seabed and from the drilling rig approximately 10m below the sea will be discharged to sea both at the seabed and from the drilling rig approximately 10m below the sea surface. Oil based mud and cuttings will not be discharged and will be skipped and shipped back to surface. Oil based mud and cuttings will not be discharged and will be skipped and shipped back to shore for disposal.

shore for disposal.

Due to the relatively short expected field life of the Alma development (ten years), the Uisge Gorm FPSO Due to the relatively short expected field life of the Alma development (ten years), the Uisge Gorm FPSO will be used instead of installing a platform. Produced crude will be collect by shuttle tanker once every will be used instead of installing a platform. Produced crude will be collect by shuttle tanker once every two weeks. The majority of the produced gas will be used for power generation, however there may be a two weeks. The majority of the produced gas will be used for power generation, however there may be a short period early part of field life where excess gas is produced that cannot be burned, this will be flared. short period early part of field life where excess gas is produced that cannot be burned, this will be flared. All

All proproducduced ed watwater er wilwill bl be re re-ie-injenjectected.d.

Production flowlines will be surface laid and protected.

Production flowlines will be surface laid and protected. The water injection flowline will be trenched andThe water injection flowline will be trenched and buried, but where trenching is not possible it will be surface laid and protected. Concrete mattresses and buried, but where trenching is not possible it will be surface laid and protected. Concrete mattresses and rock material will be used for protection.

rock material will be used for protection.

Current estimates are that based on a 10 year field life the base case recovery from the Alma field will be Current estimates are that based on a 10 year field life the base case recovery from the Alma field will be 20.7 million barrels (2.8 million tonnes) and a high recovery case of 32.5 million barrels (4.4 million 20.7 million barrels (2.8 million tonnes) and a high recovery case of 32.5 million barrels (4.4 million tonnes). Peak production in the first year will be in the region of 4.5 million barrels (0.61 million tonnes) for tonnes). Peak production in the first year will be in the region of 4.5 million barrels (0.61 million tonnes) for the base case and 7.8 million barrels (1.06 million tonnes) for the high recovery case.

the base case and 7.8 million barrels (1.06 million tonnes) for the high recovery case.

Construction is scheduled to start in January 2012 with the drilling of the first producer wells.

Construction is scheduled to start in January 2012 with the drilling of the first producer wells. First oil isFirst oil is anticipated in August 2013.

anticipated in August 2013. Antic

Anticipated Start ofipated Start of Works

Works January 2012January 2012

Previous / Other Previous / Other Statements Related to Statements Related to this Project this Project N/A N/A Significant Significant Environmental Environmental Impacts Identified Impacts Identified

EnQuest is aiming to limit environmental effects to low impact through project design, mitigation EnQuest is aiming to limit environmental effects to low impact through project design, mitigation

measures and operational controls. No impacts associated with the development have been categorised measures and operational controls. No impacts associated with the development have been categorised as Major or Critical, meaning that the majority of the impacts were assessed as having no or minor as Major or Critical, meaning that the majority of the impacts were assessed as having no or minor residual impact (i.e., impacts can be managed through effective standard opera

residual impact (i.e., impacts can be managed through effective standard operating procedures). ting procedures). A fewA few impacts were assessed as Moderate (i.e., the residual impact has been subject to feasible and cost impacts were assessed as Moderate (i.e., the residual impact has been subject to feasible and cost effective mitigation and no further measures are practicable).

effective mitigation and no further measures are practicable).

During construction and production it is considered that the following activities may have an impact: on During construction and production it is considered that the following activities may have an impact: on the environment; atmospheric emissions from power genera

the environment; atmospheric emissions from power generation; tion; anchoring ; discharge of chemicals andanchoring ; discharge of chemicals and drill cuttings; positioning of structures, rock material and concrete mattressing on the seabed; and the drill cuttings; positioning of structures, rock material and concrete mattressing on the seabed; and the accidental spill of hydrocarbons and/or chemicals. However in all instances the severity of the impact is accidental spill of hydrocarbons and/or chemicals. However in all instances the severity of the impact is limited by the nature and composition of the environment and by the fact that these activities are limited by the nature and composition of the environment and by the fact that these activities are short-term and affect a localised area.

term and affect a localised area.

With mitigation measures in place, the Alma field developme

With mitigation measures in place, the Alma field development wilnt wil l have a minor il have a minor i mpact on tmpact on t hehe environment.

environment. Statement Prepared

Statement Prepared By

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NON-TECHNICAL

SUMMARY

I

NTRODUCTION

EnQuest Heather Limited wishes to redevelop the Ardmore field in the

EnQuest Heather Limited wishes to redevelop the Ardmore field in the UK Central North SeaUK Central North Sea (CNS). The field, to be renamed Alma, will be developed through two drill centres tied-back (CNS). The field, to be renamed Alma, will be developed through two drill centres tied-back via new oil production and water injection flowlines to a floating production, offloading and via new oil production and water injection flowlines to a floating production, offloading and storage facility (FPSO). Export will be through the use of a shuttle tanker from the FPSO. storage facility (FPSO). Export will be through the use of a shuttle tanker from the FPSO. The proposed Alma development will be located in United Kingdom continental shelf (UKCS) The proposed Alma development will be located in United Kingdom continental shelf (UKCS) Blocks 30/24 and 30/25, approximately 274km east of the nearest landfall on the Blocks 30/24 and 30/25, approximately 274km east of the nearest landfall on the Northumberland coastline and approximately 18.5km from the Norway/UK international Northumberland coastline and approximately 18.5km from the Norway/UK international boundary (median line).

boundary (median line).

In compliance with regulatory requirements, and to responsibly manage any impacts from the In compliance with regulatory requirements, and to responsibly manage any impacts from the development, EnQuest has carried out an Environmental Impact Assessment (EIA) of the development, EnQuest has carried out an Environmental Impact Assessment (EIA) of the proposed development.

proposed development.

The EIA process establishes the environmental baseline in the area of the proposed The EIA process establishes the environmental baseline in the area of the proposed development and identifies environmental sensitivities, particularly with relevance to the development and identifies environmental sensitivities, particularly with relevance to the concerns of stakeholders and regulatory bodies. It also evaluates relevant environmental concerns of stakeholders and regulatory bodies. It also evaluates relevant environmental impacts and their significance, and finally proposes mitigation measures which the operator impacts and their significance, and finally proposes mitigation measures which the operator will implement to minimise t

will implement to minimise these impacts.hese impacts. This document reports on the EIA

This document reports on the EIA process, its findings and conclusions.process, its findings and conclusions.

GOVER

NING

LEGISLA

TION

Offshore oil and gas developments are governed by a collection of international, European Offshore oil and gas developments are governed by a collection of international, European Community (EU) and UK laws, policies and guidelines. These dictate the management goals Community (EU) and UK laws, policies and guidelines. These dictate the management goals and objectives which an environmental assessment may aim to achieve. The main UK and objectives which an environmental assessment may aim to achieve. The main UK regulations that apply to the project are:

regulations that apply to the project are:

Petroleum Act 1998 – Requires all offshore oil and gas development to apply for Petroleum Act 1998 – Requires all offshore oil and gas development to apply for consent to undertake the project.

consent to undertake the project.

Offshore Petroleum Production and Pipelines (Assessment of Environmental Effects) Offshore Petroleum Production and Pipelines (Assessment of Environmental Effects) (Amendment) Regulatio

(Amendment) Regulations 2007 – ns 2007 – These regulations implemenThese regulations implement the t the EC EIA and EC EIA and PublicPublic Participation Directive, and require an ES to be submitted for offshore oil and gas Participation Directive, and require an ES to be submitted for offshore oil and gas projects and public participation in the

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Offshore Marine Conservation (Natural Habitats, &c.) Regulations 2007 (as amended Offshore Marine Conservation (Natural Habitats, &c.) Regulations 2007 (as amended in 2009 and 2010) – These regulations implement in the UK the EC Habitats Directive in 2009 and 2010) – These regulations implement in the UK the EC Habitats Directive (92/43/EC) and the EC Birds Directive (79/409/EC) and aim to protect marine species (92/43/EC) and the EC Birds Directive (79/409/EC) and aim to protect marine species and wild birds from environmentally damaging activities. It is now

and wild birds from environmentally damaging activities. It is now an offence under thean offence under the Regulation

Regulations to s to deliberately disturb wild animals of a deliberately disturb wild animals of a European Protected Species.European Protected Species. Offshore Petroleum Activities (Conservation of Habitats) Regulations 2001 (amended Offshore Petroleum Activities (Conservation of Habitats) Regulations 2001 (amended in 2007) – The

in 2007) – The regulations apply the EC Habitats and EC Birds regulations apply the EC Habitats and EC Birds Directives in relation toDirectives in relation to oil and gas projects on the

oil and gas projects on the UKCS.UKCS.

PROJECT JUSTIFICATION

Oil is the UK’s second largest source of primary energy, supplying over 30% of the country’s Oil is the UK’s second largest source of primary energy, supplying over 30% of the country’s total energy nee

total energy needs (OGUK 2009). ds (OGUK 2009). In 2008, the UKCS oil prIn 2008, the UKCS oil production was enoduction was enough to satisfyough to satisfy 97% of domestic consumption, produced mainly from fields in the Central North Sea (CNS) 97% of domestic consumption, produced mainly from fields in the Central North Sea (CNS) basin, with some pro

basin, with some production in the NNS and Souduction in the NNS and Southern North Sea (SNS). thern North Sea (SNS). In 2000, the UKIn 2000, the UK Government identified the need to stimulate oil and gas investment and activity to ensure Government identified the need to stimulate oil and gas investment and activity to ensure that indigenou

that indigenous production of oil ans production of oil and gas remained at signid gas remained at significant levels into the futureficant levels into the future. . TheThe Promote UK campaign is designed to attract

Promote UK campaign is designed to attract new entrants onto the UKCS, and new entrants onto the UKCS, and focused on:focused on: Independent oil companies with the resources to drill wildcat exploration wells and Independent oil companies with the resources to drill wildcat exploration wells and exploit the full value chain from

exploit the full value chain from exploration to development; andexploration to development; and Niche ‘developers’, particularly those with the

Niche ‘developers’, particularly those with the skills to skills to develop previously undevelopeddevelop previously undeveloped discoveries by using technically innovative and best

discoveries by using technically innovative and best cost solutions (DECC 2011a).cost solutions (DECC 2011a). As

As a a result result of of these these initiatives, initiatives, EnQuest EnQuest has has been been active active on on the the UKCS UKCS since since 2010. 2010. ItIt specialises in predominantly mature areas of the NNS and CNS, aiming to maximise the specialises in predominantly mature areas of the NNS and CNS, aiming to maximise the potential from existing field

potential from existing fields and future developmens and future developments in the UKCS. ts in the UKCS. The longer term strategyThe longer term strategy is to

is to become a prominent exploration and development operator.become a prominent exploration and development operator.

The Alma Field development is part of this strategy and fits many of the UK energy policy The Alma Field development is part of this strategy and fits many of the UK energy policy objectives:

objectives:

It would bring on-stream a marginal field that it is now feasible to develop with the It would bring on-stream a marginal field that it is now feasible to develop with the prevailing oil price and the small field allowance applicable to this size of

prevailing oil price and the small field allowance applicable to this size of fieldfield It is

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Current estimates predict that P50

Current estimates predict that P5011 recovery over field life will be 20.7 million barrels of oil recovery over field life will be 20.7 million barrels of oil (2.8

(2.8 million million tonnes). tonnes). P10P1022 recovery is estimated to be 32.5 million barrels (4.4 million recovery is estimated to be 32.5 million barrels (4.4 million tonnes).

tonnes).

PROJECT AL

TERN

ATIVES

EnQuest have con

EnQuest have considered a numsidered a number of developmeber of development options for the Alnt options for the Alma field. ma field. Given theGiven the compact nature of the field and relatively short field life, the decommissioning strategy has compact nature of the field and relatively short field life, the decommissioning strategy has played an imp

played an important role in option ortant role in option selection. selection. Options considOptions considered includeered included the choice ofd the choice of surface facilities (FPSO, floating production facility (FPF), platform or subsea tie-back), the surface facilities (FPSO, floating production facility (FPF), platform or subsea tie-back), the choice of drilling rig (semi submersible or heavy duty jack-up) and the installation philosophy choice of drilling rig (semi submersible or heavy duty jack-up) and the installation philosophy of the flowlines (trenched and buried or

of the flowlines (trenched and buried or surface laid and protected).surface laid and protected). After considerable deliberatio

After considerable deliberation, the n, the FPSO, semi submersible and a FPSO, semi submersible and a combination of trenchingcombination of trenching and surface lay options were selected, based on combination of technical, environmental and surface lay options were selected, based on combination of technical, environmental economic consid

economic considerations. erations. Table 3-3 details all the proTable 3-3 details all the pros and cons of each option.s and cons of each option. FPSO

FPSO

A number of FPSOs a

A number of FPSOs are available fore available for deploymentr deployment Provides an integrated storage and

Provides an integrated storage and offloading systemoffloading system

Modifications required are more economic that other available options e.g. new Modifications required are more economic that other available options e.g. new platform

platform

FPSOs fit for expected field life FPSOs fit for expected field life

Using an existing FPSO is cheaper than a new build Using an existing FPSO is cheaper than a new build FPSOs considered have proven track record in the

FPSOs considered have proven track record in the UKCSUKCS Minimal seabed disturbance from

Minimal seabed disturbance from installationinstallation Can be easily redeployed at end of field life Can be easily redeployed at end of field life Se

Semi mi SubmersibleSubmersible

Less weather dependant during positioning on site Less weather dependant during positioning on site

More scope for moving rig but maintaining same anchor pattern – less seabed More scope for moving rig but maintaining same anchor pattern – less seabed disturbance

disturbance. . For example, For example, moving to allomoving to allow subsea inw subsea infrastructure to frastructure to be installedbe installed,, moving rig if

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ENQUEST HEATHER LIMITED ALMA FIELD DEVELOPMENT

Ability to drill six wells on same anchor pattern – less seabed disturbance Easier to run horizontal xmas trees

Better selection options- at least two rigs are known to be available

Current drilling team has extensive knowledge of semi submersible drilling operations Flowlines

Buried

Greater protection for flowlines – no additional protection such as rock would be required except for mattressing and grouting at trench transition areas

Conventional / proven solution

Option to surface protect spans which cannot be buried due to existing subsurface obstructions

Surface Laid

Ease of installation - range of installation vessels available

Benefit as compact field layout with possible drilling rig on site during installation Lower mobilisation costs for installation

Potential of re-use / decommissioning easier Conventional / proven solution

Minimal seabed disturbance

Lower risk of subsurface obstructions because no trenching

Additional protection such as rock material will be required for certain spans Technically preferred option for production flowlines due to temperature issues

PROJECT DESCRIPTION

S

CHEDULE

Construction is scheduled to start in January 2012 with the drilling of the first production well. Construction activities will continue through to May 2013 with first oil expected in third quarter 2013. A total of six production wells and two water injector wells will be batch drilled and are

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expected to take approximately three months each to drill and complete. Field life is anticipated to be ten years.

C

ONSTRUCTION

The development will consist of:

The drilling of six producers and two water injectors The Uisge Gorm FPSO

Two 10-inch production flowlines, one 10-inch water-injection flowline, two control umbilicals and one power cable

Production wells will target a total of three reservoirs within the Alma Development area: Devonian, Zechstein and Rotliegend. Three production wells will be drilled in five sections using a combination of water based mud (WBM) and oil based mud (OBM), with each section cement cased. The remaining three production wells and the two water injection wells will be drilled in four sections also using a combination of WBM and OBM, with each section cement cased. Cuttings and WBM will either be discharged at the seabed or to sea approximately 10m below sea surface from the drilling rig. All OBM and cuttings will be skipped and shipped to shore for disposal.

The water injection flowline will be trenched and backfilled. In the event of any undulations in the trench (and subsequently the flowline) a contingency will be in place for the provision of approximately 5,000 tonnes of rock for deposition for protection. The rock will be deployed to mitigate any upheaval buckling (less of a problem with flexible flowlines) or pipeline out of straightness events experienced during the trenching and pipe-lay activities. This may be required for pipeline protection, depth of cover anomalies or dropped object protection. The requirement for rock deposition will be identified during post lay survey and if required the rock will be placed accurately utilising a dynamically positioned fall pipe rock installation vessel. The vessel will be equipped with a fall pipe to deploy rock accurately in the spot location. Where trenching is not possible the water injection flowline will be surface laid and protected where required with concrete mattress to eliminate any pipe-spans or seabed obstructions. The production flowlines will be surface laid and protected. They cannot be trenched as the arrival temperature of the production fluids at the FPSO would be too high. After tie-in, the flowlines will be hydrotested and leak tested before being dewatered and then commissioned. Concrete mattresses and rock material will be used for dropped object protection and stability. The water-injection flowlines will terminate directly in the FPSO. The

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take produced fluids to the FPSO. All flexible risers will be secured by either vertical piled or gravity base anchors and horizontal clump weight anchors.

The Uisge Gorm FPSO will be held permanently on station without any aid from thrusters or other external sources by nine anchors. Modifications and upgrades will be carried out on the FPSO turret to accommodate the new flowline/umbilical riser systems required to receive and process the Alma hydrocarbons and to export injected water. The upgrades will be finished before the FPSO is mobilised to the field.

Note: Image is for illustrative purposes only and does not necessarily reflect exact layout of flowlines and associated infrastructure

P

RODUCTION

Produced crude oil and associated gas will be produced back to the FPSO and oil then offloaded onto shuttle tankers for export.

First oil is currently expected in third quarter 2013. Current estimates are that based on a 10 year field life the base case recovery from the Alma field will be 20.7 million barrels (2.8 million tonnes) of crude oil and a high recovery case of 32.5 million barrels (4.4 million tonnes). Peak production in the first year will be in the region of 4.5 million barrels (0.61

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million tonnes) for the base case and 7.8 million barrels (1.06 million tonnes) for the high recovery case. The reservoir pressure at Alma is such that produced water re-injection is required to ensure that satisfactory quantities of crude oil are produced. Sufficient quantities of gas are expected to be produced with the crude to be used for power generation onboard the FPSO.

Produced water will be passed through a bank of hydrocyclones which will take oil in water (OIW) concentrations from approximately 1000mgl-1 to below 30mgl-1. It will then be routed through a degasser and settling vessel. The produced water then passes through the pumps past an overboard discharge point and into four injection pumps that push the produced water down the water injection flowline to be re-injected. Should any produced water be discharged (due to temporary failure, or routine maintenance of the produced water re-injection system) then OIW concentrations will be below 30mgl-1.

Early in the field life there will be the need to flare gas. This would be due to either insufficient gas production to power the generators on the FPSO or because of an excess of gas produced, over that demanded for fuel.

D

ECOMMISSIONING

Field life is expected to be ten years. Before the end of field life, arrangements for decommissioning will be developed in accordance with the prevailing UK government and international legislation. The development plan is based on the assumption that similar requirements to current legislation will be applicable. These requirements have been considered in the design of the facilities and during project planning. The impacts of decommissioning activities on the environment have not been assessed under the scope of this document as they will be the subject of a separate EIA.

ENVIRONMENTAL IMPACT AND MITIGATION

Mitigation is an integral part of the Alma development. All of the potential interactions between project activities and environmental receptors are subject to either standard recognised best practice mitigation measures or to impact specific, feasible and cost effective mitigation. In general, the mitigation proposed will be sufficient to reduce the effects of activities to below levels which will cause a significant residual impact. For those where mitigation isn’t enough, the residual impacts are detailed below with a discussion of the mitigation that will help to reduce the impact to the acceptable levels identified.

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The following table summarises the findings of the detailed EIA process undertaken in relation to the Alma development and outlines details of the impacts that were considered to have a residual impact on the environment.

Receptor & Type of Impact

Baseline & Impact Assessment Significance

of Residual Impact Mitigation Construction Seabed Conditions: Disaggregation of surface sediments Change in seabed topography

The Alma development area comprises a <1m thickness of very loose to loose silty shelly sands (with a varying degree of gravel and shells) over firm to very stiff sandy gravelly clay. A number of activities have the potential to affect seabed conditions e.g., anchoring and the deposition of drill cuttings. When retrieved, the anchors are expected to leave a small area of residual disturbance on the seabed. Seabed currents (0.42ms-1_{) will ensure}

that all cuttings piles will disperse quickly, although there is the possibility that they may persist for a number of years

Minor The footprint of the development will

be minimised.

Seabed Conditions: Sediment contamination

Site surveys of the Alma field indicate that there is a level of sediment contamination as a result of the historic use of the area for previous oil and gas developments. It is unlikely that further drilling at the site will increase this contamination as chemicals discharged at the seabed are typically environmentally benign. No OBM will be

discharged.

Minor Daily recording of chemical use to

allow more refined and efficient use. Where possible chemicals will be recycled, skipped and shipped or re-injected and not discharged.

Selections of chemicals will be made in accordance with the CEFAS ranked list, where chemicals ranked as lower potential hazards are preferentially chosen.

Only chemicals permitted through the relevant Offshore Chemicals

Regulations chemical permit (i.e. PON15B or PON15C) and that have been subject to a risk assessment will be discharged.

Benthic Communities: Potential toxic effects

The benthic community is typical of a sandy biotope with moderate diversity. No rare or protected species were identified in the baseline survey. All seabed chemical discharges will be risk assessed and will be within permitted levels.

Minor Benthic Communities: Physical damage to individuals or habitats and smothering (Anchoring)

The benthic community is typical of a sandy biotope with moderate diversity. No rare or protected species were identified in the baseline survey.

A total of 8 anchors will be deployed within a 1,000m (3,281ft) radius of the rig at each drill site. The total area of seabed impacted by all anchors and chains has been estimated at 4,800m2_.

Communities are expected to recover within two years following cessation of disturbance. Cuttings discharged at the seabed will have a

Minor The development footprint will be

minimised where operationally possible.

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of Residual Impact Mitigation Physical damage to individuals or habitats and smothering (Drill cuttings)

direct impact on the benthic community. Cuttings discharged through the water column could have an impact on the benthic community as they settle out on the seabed. Cuttings will be incorporated in the sediment through bioturbation and general sediment mobility. Significant erosion of cuttings piles starts when the seabed critical velocity reaches 0.35ms-1_{(UKOOA 1999). Seabed}

currents (0.42ms-1_{) will ensure that all cuttings piles}

will disperse quickly, although there is the possibility that they may persist for a number of years. Experience in the CNS region indicates that cuttings piles will persist for 5-10 years.

No mitigation envisaged Fish and Shellfish: Loss or disturbance of spawning and nursery grounds effecting stock viability

Mackerel, lemon sole, sprat, haddock and whiting all spawn and/or nurse in the vicinity of the Alma development. Spawning occurs mainly between April and September, with peaks in May, June and

July. Juveniles may be present in the region all year round.

As the majority of the noise generated by offshore oil installations is low frequency (<1kHz), any impact is likely to be minimal. Noise from piling has the potential to have a greater impact; however, the duration of noise generation from piling will be significantly less than that of general construction (including drilling) and the noise generated by vessels present during the construction period. Cuttings discharged through the water column could have an impact on pelagic fish species and could also have an impact on benthic species, spawning grounds and shellfish as they settle out on the seabed. Seabed currents (0.42ms-1_{) will}

ensure that all cuttings piles will disperse quickly, although there is the possibility that they may persist for a number of years.

Minor No mitigation envisaged

Marine Mammals & Protected Species: Subsea noise

Sightings data suggests that eight species of cetacean are present within and adjacent to Blocks 30/24 and 30/25. All cetacean species are

protected under the EC Habitats Directive. The JNCC risk assessment flowcharts were followed to determine whether subsea noise would cause deliberate injury or deliberate disturbance. The EIA concluded there was a negligible risk of an offence occurring under the Conservation (Natural Habitats &c.) Regulations 1994 (as amended) (HR) and the Offshore Marine

Conservation (Natural Habitats, &c.) Regulations 2007 (as amended in 2009) (OMR).

Minor JNCC guidelines (JNCC 2010) on

‘The protection of marine European Protected Species from Injury and Disturbance’ will be followed. In particular EnQuest are committed to following the mitigation measures outlined in Appendix B – Statutory nature conservation agency protocol for minimising the risk of injury to marine mammals from piling noise (August 2010).

Commercial Fishing:

Impacts on vessels

The project area is not considered to be a

commercially important for fishing. Exclusion from fishing grounds, the potential impact of anchoring on fish spawning areas and stocks and the physical presence of flowlines and concrete mattresses were the only impacts deemed to have

Minor A 500m safety exclusion zone will be

enforced around the drilling rig at each location.

A 500m safety corridor will be established along the route of the

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of Residual Impact

Mitigation

any residual impact after mitigation. production and water injection

pipelines between the FPSO and the production and water injection drill centres

The drilling rig and construction vessels will be appropriately lit and sound warnings will be broadcast in poor visibility.

Users of the sea will be notified of the presence and intended movements of construction vessels via the Kingfisher fortnightly bulletins, Notices to Mariners and VHF radio broadcast.

Shipping and Navigation: Impact on vessel movement

The nearest shipping route is within 2nm of the Alma development. Some shipping will be

displaced from the immediate vicinity of the development; however there is ample sea room to do so. The 500m safety exclusion zone around the drilling rig is intended to prevent potential collisions with any vessels that may be in the area. This will be enforced by a guard vessel.

Minor

Archaeology : Physical damage to undiscovered archaeology

It is unlikely that any remains of archaeological significance exist within the Alma area. However, the proposed mitigation measures would ensure damage to the site would be minimised and the nature of the discovery properly reported. It is therefore likely that any damage would be of minor significance, while the value of the discovery may be of moderate/major (positive) significance.

Minor The British Marine Aggregate

Producers Association (BMAPA) protocol for reporting finds of archaeological significance will be followed Production Commercial Fishing: Exclusion from fishing grounds Potential collision risk

The project area is not considered to be a

commercially important for fishing. The continued presence of development and the exclusion zones around the drill centers and the FPSO will typically preclude fishing in this area due to the small development size.

Minor A 500m safety exclusion zone will be

enforced around the FPSO. The FPSO will be appropriately lit and sound warnings will be broadcast in poor visibility.

Users of the sea will be notified of the presence of the FPSO and new safety exclusion zones via the Kingfisher fortnightly bulletins, Notices to Mariners and VHF radio broadcast.

All vessels will comply with international navigation regulations and codes.

Accidental Events Water Resource: Deterioration in water quality

Water quality is likely to deteriorate in the immediate vicinity of the spill (>10 tonnes) as hydrocarbons are dispersed through the water column. However, it will be naturally biodegraded by microbes within one to two months (NOAA 2006). The concentration and likelihood of natural biodegradation will obviously be dependent on the scale of the incident. However, generally the deterioration in water quality will be short –term.

Minor Accidental spills will be kept to a

minimum through training, good housekeeping and through storage/handling procedures e.g., sumps, drains and bunding should catch accidental spills.

Management controls will be in place to eliminate bunkering spills e.g. only bunkering during day light and in good weather.

A location specific OPEP will be in place for the drilling rig and an Addendum to the North Cormorant

OPEP will be applied for to cover Plankton:

Potential toxic effect

Marine ecology is typical for the NNS with no rare or protected benthic species identified in the baseline survey. Nine cetacean species may occur in the area, all of which are protected under the EC Habitats Directive. The region is also

Minor

Benthic Communities:

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of Residual Impact

Mitigation

Potential toxic effect

important for seabirds.

Biological receptors are vulnerable to the accidental release of hydrocarbons and/or chemicals. Accidental events are extremely unlikely to occur. A small spill of diesel of crude will rapidly disperse and dilute in the energetic marine environment but a large spill as a result of a loss of containment on the export tanker and FPSO has the potential to have wider reaching impacts. Modelling suggest that under typical

meteorological conditions, there is the potential for a oil slick as a result of the loss of the FPSO and export tanker inventory to beach along the

coastlines of the majority of countries bordering the North Sea (total probability of beaching is 1%). Numerous protected areas could potentially be impacted as shown in Figure 8-4.

production operation. The OPEPs will detail all emergency procedures that will be in place to minimise any spill.

EnQuest has access to Tier 1, 2 and 3 oil spill response capabilities through Oil Spill Response (OSR). EnQuest is a member of OSPRAG which will provide support in a well blow out event.

Control measures will be in place to ensure rapid response to loss of flowline containment. These will be outlined in the Alma OPEP.

Fish and Shellfish: Potential toxic effect Minor Seabirds: Smothering Moderate Marine Mammals and Protected Species: Smothering Minor Commercial Fishing: Damage to vessels and decrease in catch

A major crude oil spill has the potential to cause damage to the fishing industry by long-term effects on fish stocks and damage to market confidence and could potentially exclude shipping from a number of key shipping lanes. However, the likelihood of such an event occurring is extremely rare. Minor Shipping and Navigation: Impact on vessel movement Minor Other Marine Users: Damage to vessels Minor

CUMULATIVE AND INDIRECT IMPACTS

The main concerns regarding the potential for cumulative and indirect impacts from the proposed development relate to impacts from activities at Alma interacting with:

Other activities within the project

Other oil and gas developments (past and future)

Other marine users, such as windfarms, commercial fishing, marine aggregate extraction areas etc

Climate change

The EIA drew the following conclusions:

The project will not have any significant cumulative or indirect effects with any other oil and gas developments

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The project will not have any significant cumulative or indirect effects with any other The project will not have any significant cumulative or indirect effects with any other seabed users

seabed users

The project will not exacerbate the changes predicted to occur as a consequence of The project will not exacerbate the changes predicted to occur as a consequence of climate change.

climate change.

The EIA identified the Alma development will not have any residual impacts on water depth, The EIA identified the Alma development will not have any residual impacts on water depth, wind speed

wind speed or wave conditioor wave conditions. ns. Residual impResidual impacts on the enviacts on the environment will bronment will be short-term,e short-term, predominan

predominantly affecting marintly affecting marine ecology. e ecology. As climate changAs climate change has the potene has the potential to affect thetial to affect the biological baseli

biological baseline it is ne it is possible that the project can act possible that the project can act in combination with climate change toin combination with climate change to exacerbate this imp

exacerbate this impact. act. However, the EIA concludHowever, the EIA concludes that, following conses that, following construction, biologicatruction, biologicall communities are anticipated to recover to pre-impact levels/structures or similar within five communities are anticipated to recover to pre-impact levels/structures or similar within five years (see Section 9.2.4.1

years (see Section 9.2.4.1). ). Given the relatively shoGiven the relatively short timescale of the construction impart timescale of the construction impacts,cts, it is considered unlikely that any cumulative impacts from the project and climate change will it is considered unlikely that any cumulative impacts from the project and climate change will have significant impacts on marine

have significant impacts on marine ecology.ecology.

ENVIRONMENTAL MANAGEMENT SYSTEMS

EnQuest’s corporate policies and environmental management system (EMS) provide a fit for EnQuest’s corporate policies and environmental management system (EMS) provide a fit for purpose framework to implement the mitigation measures proposed in the ES.

purpose framework to implement the mitigation measures proposed in the ES.

EnQuest is a socially responsible employer, committed to maintaining high standards in EnQuest is a socially responsible employer, committed to maintaining high standards in health, safe

health, safety and ety and environmentanvironmental performanl performance. ce. EnQuest impEnQuest implements anlements and operates d operates anan integrated Health, Safety and Environmental Management System (HS&EMS) and a Quality integrated Health, Safety and Environmental Management System (HS&EMS) and a Quality Management System (QMS) which has been accepted and endorsed by the Board, and Management System (QMS) which has been accepted and endorsed by the Board, and embedded in th

embedded in the overall businee overall business culture. ss culture. The HS&EMS is an inteThe HS&EMS is an integral part of the overagral part of the overallll manageme

management system. nt system. It is laIt is laid dowid down in n in policies, policies, procedures, procedures, standards standards and workand work instructions.

instructions. Its general purpIts general purpose is to prevent Enose is to prevent EnQuest’s activities froQuest’s activities from putting peoplm putting people, thee, the environmen

environment, property or t, property or the reputation of the the reputation of the company at risk.company at risk. The HS&EMS is designed to

The HS&EMS is designed to match the requirements of ISO-14001:2004 and is match the requirements of ISO-14001:2004 and is based on thebased on the requiremen

requirements of the Health and Safets of the Health and Safety OHSAS 18001 standty OHSAS 18001 standard. ard. The QMS is certified to BThe QMS is certified to BSS EN ISO 9001.

EN ISO 9001. The purpose The purpose of the HS&EMS of the HS&EMS and QMS is and QMS is to enhance hto enhance health, safety,ealth, safety, environmental and quality (HSEQ) performance and provide a framework for HSEQ environmental and quality (HSEQ) performance and provide a framework for HSEQ manageme

management for all of the activities carried out thnt for all of the activities carried out throughout the comparoughout the company. ny. The managemeThe managementnt systems are designed to cover HSEQ aspects which EnQuest can control and directly systems are designed to cover HSEQ aspects which EnQuest can control and directly manage and those it does not

manage and those it does not control or directly manage, but can be control or directly manage, but can be expected to influence.expected to influence. EnQuest requires all contractors, their subcontractors and suppliers to have their own EnQuest requires all contractors, their subcontractors and suppliers to have their own HS&EMS and QMS.

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scope of work and will operate according to their own HS&E Management System. scope of work and will operate according to their own HS&E Management System. However, contractors HS&EMS must be compatible with EnQuest’s HS&EMS and they are However, contractors HS&EMS must be compatible with EnQuest’s HS&EMS and they are required to align the

required to align their HS&E managemeir HS&E management with EnQuest’s goals and obnt with EnQuest’s goals and objectives. jectives. Their QMSTheir QMS must meet the applicable requirements of the BS EN ISO 9000 series of standards or an must meet the applicable requirements of the BS EN ISO 9000 series of standards or an agreed equivalent.

agreed equivalent. A

A project specific project specific HS&E HS&E plan plan will will be be developed for developed for the the Alma Alma developmendevelopment t which which will will definedefine how EnQues

how EnQuest will managt will manage HS&E risks e HS&E risks and activities. and activities. The Project HThe Project HSEQ EngineeSEQ Engineer isr is responsible for maintaining and implementing the plan, and for providing HSEQ controls responsible for maintaining and implementing the plan, and for providing HSEQ controls within the project to ensure that the requirements of the EnQuest HSEQ management within the project to ensure that the requirements of the EnQuest HSEQ management systems are met.

systems are met.

It is expected that the mitigation measures identified in the EIA process and reported in this It is expected that the mitigation measures identified in the EIA process and reported in this ES will be adopted and bridged into EnQuest’s HSEQ Management System through the ES will be adopted and bridged into EnQuest’s HSEQ Management System through the PLANC register.

PLANC register.

CONCLUSIONS

E

XISTINGXISTING

E

NVIRONMENTNVIRONMENT

Existing conditions at the Alma development were established through an environmental Existing conditions at the Alma development were established through an environmental baseline and habitat assessment survey, which

baseline and habitat assessment survey, which revealed that:revealed that:

The benthic habitat typically comprised of sparse sandy sediments with low benthic The benthic habitat typically comprised of sparse sandy sediments with low benthic diversity. The majority of benthic taxa were polychaete worms. Stations sampled diversity. The majority of benthic taxa were polychaete worms. Stations sampled where historical drilling activity was prevalent were

where historical drilling activity was prevalent were characterised by more disturbancecharacterised by more disturbance and hydrocarbon contamination tolerant species and lower numbers of sensitive and hydrocarbon contamination tolerant species and lower numbers of sensitive species.

species.

No habitats or species of conservation significance under the UK’s Offshore Marine No habitats or species of conservation significance under the UK’s Offshore Marine Conservation (Natural Habitats, &c.) (Amendment) Regulations 2010 were observed Conservation (Natural Habitats, &c.) (Amendment) Regulations 2010 were observed during seabed surveys

during seabed surveys

The environmental baseline is similar to other regions of the CNS where oil and gas activity The environmental baseline is similar to other regions of the CNS where oil and gas activity is prevalent.

is prevalent. MeteorologicMeteorological conditions aroual conditions around the project suppond the project support a dilution and dispersirt a dilution and dispersionon regime which will rapidly reduce the impact significance of emissions to air, water and regime which will rapidly reduce the impact significance of emissions to air, water and seabed (i.e. winds are sufficient to

seabed (i.e. winds are sufficient to disperse atmospheridisperse atmospheric emissions, tidal currents refresh thec emissions, tidal currents refresh the water column within an estimated 1.5 hours, currents are generally sufficient to disperse drill water column within an estimated 1.5 hours, currents are generally sufficient to disperse drill cuttings or sediment piles on the

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I

MPACTSMPACTS

The potential effects of the project on the environment were identified and quantified by The potential effects of the project on the environment were identified and quantified by reviewing the existing baseline environmental conditions with the potential to be affected by reviewing the existing baseline environmental conditions with the potential to be affected by the project and identifying and evaluating the effect of any activities associated with the the project and identifying and evaluating the effect of any activities associated with the project on these conditions.

project on these conditions.

It should be noted that the majority of

It should be noted that the majority of activities were assessed as having no or minor residualactivities were assessed as having no or minor residual impact on the receiving environment, with a few identified as having a residual impact of impact on the receiving environment, with a few identified as having a residual impact of moderate si

moderate significance. gnificance. This ES reaThis ES reached the folched the following conlowing conclusions wclusions with regards ith regards to theto the project’s impacts on the

project’s impacts on the environment:environment: Benthic Environment

Benthic Environment : The total seabed footprint of the development is 0.04km: The total seabed footprint of the development is 0.04km22. Due. Due to fishing activities and previous oil and gas industry activities, the benthos in the to fishing activities and previous oil and gas industry activities, the benthos in the project area is typical of

project area is typical of a moderately disturbed habitat and consequently species thata moderately disturbed habitat and consequently species that inhabit the area ten

inhabit the area tend to recover quickly after distud to recover quickly after disturbance. rbance. The proposed deThe proposed developmentvelopment is located

is located within an awithin an area of prevrea of previous drillinious drilling activity. g activity. The develoThe development area pment area isis sufficiently homogenous that any localised losses are unlikely to affect the integrity of sufficiently homogenous that any localised losses are unlikely to affect the integrity of the community a

the community as a whole. s a whole. The placemenThe placement of protective struct of protective structures such as contures such as concretecrete mattresses will create new habitat for those species that require hard substrate for mattresses will create new habitat for those species that require hard substrate for anchoring.

anchoring. This could This could lead to selead to settlement of nettlement of new species w species and the pand the potential for otential for aa localised change in marine ecology. Current speeds are sufficient to erode cuttings localised change in marine ecology. Current speeds are sufficient to erode cuttings piles and these are unlikely to persist for a long period of time.

piles and these are unlikely to persist for a long period of time. Protected Species

Protected Species: No protected species were identified in the marine benthic: No protected species were identified in the marine benthic surveys. Marine mammals are likely to be the only protected species of relevance to surveys. Marine mammals are likely to be the only protected species of relevance to the Alma

the Alma development. development. Assuming the source to Assuming the source to be near be near the seabed, for the seabed, for a receptora receptor 10m below the surface, the noise would have reduced to approximately 153 dB SEL 10m below the surface, the noise would have reduced to approximately 153 dB SEL vertically above the

vertically above the source. source. This is This is 7 7 dB dB below the below the lowest of lowest of the recognisedthe recognised thresholds for strong

thresholds for strong avoidance behaviour (160 avoidance behaviour (160 dB SEL) dB SEL) of marine of marine mammals. mammals. InIn conclusion

conclusion, and , and provided mitigation measures are followed, the provided mitigation measures are followed, the sound experienced willsound experienced will not exceed the inju

not exceed the injury thresholds for marinry thresholds for marine mammals. e mammals. There is therefore a neglThere is therefore a negligibleigible risk of an offence under the Conservation (Natural Habitats &c) Regulations 1994 (as risk of an offence under the Conservation (Natural Habitats &c) Regulations 1994 (as amended) and the Offshore Marine Conservation (Natural Habitats &c) Regulation amended) and the Offshore Marine Conservation (Natural Habitats &c) Regulation 2007 (as amended in 2010).

2007 (as amended in 2010). Protected Areas

Protected Areas: There are no protected sites within 40km of the Alma development.: There are no protected sites within 40km of the Alma development. The nearest protected site is the Dogger Bank potential Special Area of Conservation The nearest protected site is the Dogger Bank potential Special Area of Conservation (pSAC) which is approximately 78km south-east from the Alma southern drill centre. (pSAC) which is approximately 78km south-east from the Alma southern drill centre.

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Due to the distance of the protected site from the development area, it is unlikely that Due to the distance of the protected site from the development area, it is unlikely that there will be any impacts during normal activities.

there will be any impacts during normal activities. Water/Sediment Quality

Water/Sediment Quality: During normal activities, the production activities will have a: During normal activities, the production activities will have a negligible impact on the marine environment.

negligible impact on the marine environment. Commercial Fishing

Commercial Fishing: With consideration of other development activities in the CNS,: With consideration of other development activities in the CNS, the project will have a minor contribution to seabed smothering from cuttings piles, the project will have a minor contribution to seabed smothering from cuttings piles, infrastructure in

infrastructure installation and anstallation and anchoring. choring. However, this is anHowever, this is anticipated to be limticipated to be limited toited to within the imme

within the immediate vicinity of the wdiate vicinity of the wells. ells. Safety exclusioSafety exclusion zones are likeln zones are likely to have ay to have a moderate impact on commercial fishing in the area as this will result in vessels being moderate impact on commercial fishing in the area as this will result in vessels being displaced fro

displaced from their fishing grom their fishing grounds. unds. Overall it is concluOverall it is concluded cumulativded cumulative impacts ande impacts and the in-combination impacts with the fishing industry and other marine users are likely the in-combination impacts with the fishing industry and other marine users are likely to be

to be of negligible significance.of negligible significance. Oil/Chemical Spill Pollution

Oil/Chemical Spill Pollution: In the unlikely event of a major oil spill, a worst case: In the unlikely event of a major oil spill, a worst case scenario loss of containment of 100,000m

scenario loss of containment of 100,000m33 (87,000 tonnes) of crude oil from the (87,000 tonnes) of crude oil from the export tanker has

export tanker has been modelled. been modelled. This indicates that there This indicates that there is a is a 1% chance 1% chance ofof beaching occurring on the majority of coastlines bordering the North Sea. Modelling beaching occurring on the majority of coastlines bordering the North Sea. Modelling also indicates that the spill could reach the UK coastline within 8 days and 10 hours also indicates that the spill could reach the UK coastline within 8 days and 10 hours and the

and the Danish coastline within 5 Danish coastline within 5 days and days and 12 hours. 12 hours. The spill is The spill is likely to havelikely to have completed disper

completed dispersed within 417 days. sed within 417 days. Numerous protected areaNumerous protected areas along the coastliness along the coastlines of those North Sea countries that could be affected by a spill of this magnitude. of those North Sea countries that could be affected by a spill of this magnitude. EnQuest will have an OPEP in place.

EnQuest will have an OPEP in place.

E

NVIRONMENTALNVIRONMENTAL

M

ANAGEMENTANAGEMENT

The EnQuest corporate policies and environmental management system provide a fit for The EnQuest corporate policies and environmental management system provide a fit for purpose fram

purpose framework to impleework to implement the mitigatioment the mitigation measures pn measures proposed in thiroposed in this ES. s ES. The EMSThe EMS also provides adequate control and bridging arrangements for EnQuest to ensure that the also provides adequate control and bridging arrangements for EnQuest to ensure that the contractors imp

contractors implement these mitiglement these mitigation measureation measures. s. During the conDuring the construction and pstruction and productionroduction operations, a set of permits an

operations, a set of permits and consents will be obtaid consents will be obtained from the regulatory boned from the regulatory bodies. dies. PermitPermit conditions under

conditions under these will these will also also be be fed into fed into the EMS the EMS to to ensure compliance. ensure compliance. EMSEMS performance will be regularly benchmarked against recommendations from independent performance will be regularly benchmarked against recommendations from independent verifications, through internal and independent audits and reviews.

verifications, through internal and independent audits and reviews. With mit

With mit igation measures in pligation measures in pl aceace, the Alma Fie, the Alma Field development willd development wil l have a minorl have a minor impact on the environment.

Alma Field Development Environmental Statement

EnQuest Heather Limited

EnQuest Heather Limited