Clair Ridge Development - Environmental Statement

Clair Ridge DevelopmentEnvironmental Statement

September 2010


Information |September 2010 1

Standard Information Sheet

Project (Installation) Name Clair Ridge Development

DECC Reference number D/4091/2010

Type of Project Field development with two bridge-linked platforms,

wells and tie-in to existing export pipelines

Undertaker name BP Exploration Operating Company Ltd

Undertaker address Farburn Industrial Estate,

Dyce, Aberdeen, AB21 7PB

Licensees/Owners BP Exploration Operating Company Limited _ _ _ _ _ _ _ _ _ 27.6%

Britoil plc _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1.0%

ConocoPhillips (U.K.) Limited _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 24.0%

Chevron North Sea Limited _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 19.4%

Clair UK Limited _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 9.3%

Enterprise Oil Limited _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 18.7%

Short description The project is the second stage of development of the Clair

oil field. It will involve the installation of two bridge-linked

platforms, one supporting drilling and production and the other

supporting accommodation and utilities, on the West Shetland

Continental Shelf in UKCS Block 206/8 (5.6 km northeast of

Clair Phase 1 platform which started production in 2005 and

93 km southeast of the UK/Faroe transboundary line). The Clair

Ridge oil export pipeline will tie into the existing Clair Phase 1

pipeline to Sullom Voe Terminal, Shetland and the gas export

pipeline will tie into the existing West of Shetland Pipeline

System. Of 36 wells to be drilled, several will be drilled from a

semi-submersible drilling rig before the platforms are installed.

The remaining production and water injection wells will be

drilled from the drilling and production platform. The reservoir

fluids will be fully processed on the platform and the produced

water re-injected into the reservoir.

Anticipated commencement of works First oil is targeted for second quarter of 2015.

Signicant environmental impacts identied None

Statement prepared by BP Exploration Operating Company Ltd

Designed and Printed by Tay-CAD Ltd


Contents |September 2010 1

Contents

1 Introduction 1.1 Project background and purpose _ _ _ _ _ _ _ 1 | 1

1.2 Scope and aims of the environmental statement _ _ _ _ _ _ _ _ _ _ _ _ 1 | 4

1.3 Regulatory context _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1 | 5

1.4 BP environmental policy and requirements _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1 | 6

2 Consideration of Alternatives

2.1 Introduction _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2 | 1

2.2 Basis for Clair Ridge Development _ _ _ _ _ 2 | 2

2.3 Concept selection (high level decisions) _ _ 2 | 2

2.4 Second-level decisions _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2 | 6

2.5 Decisions remaining to be made _ _ _ _ _ _ _ 2 | 13

3 The Development

3.1 Development overview _ _ _ _ _ _ _ _ _ _ _ _ _ 3 | 1

3.2 Reservoir characteristics _ _ _ _ _ _ _ _ _ _ _ _ _ 3 | 1

3.3 Fluid characteristics and expected production _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3 | 3

3.4 Wells and drilling _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3 | 6

3.5 Pipelines and subsea infrastructure _ _ _ _ _ 3 | 13

3.6 Jackets and topsides _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3 | 15

3.7 Production _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3 | 17

3.8 Commissioning _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3 | 22

3.9 Decommissioning _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3 | 22

4 The Environment

4.1 Overview _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4 | 1

4.2 The physical environment _ _ _ _ _ _ _ _ _ _ _ _ 4 | 3

4.3 The biological environment _ _ _ _ _ _ _ _ _ _ _ 4 | 12

4.4 Commercial fisheries _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4 | 27

4.5 Other sea users _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4 | 32

4.6 Conservation interests _ _ _ _ _ _ _ _ _ _ _ _ _ _ 4 | 34

5 The Environmental Assessment Process

5.1 Overview _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 5 | 1

5.2 Environmental screening and categorisation _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 5 | 2

5.3 Scoping and consultation _ _ _ _ _ _ _ _ _ _ _ _ 5 | 2

5.4 Environmental issues identification (ENVID) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 5 | 8

5.5 Assessment of residual impacts _ _ _ _ _ _ _ 5 | 14

5.6 EIA integration with overall environmental management _ _ _ _ _ _ _ _ _ _ 5 | 14

6 Physical Presence

6.1 Seabed impacts _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 6 | 1

6.2 Interactions with other sea users _ _ _ _ _ _ 6 | 7

7 Discharges to Sea

7.1 Introduction _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 7 | 1

7.2 Regulatory control _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 7 | 1

7.3 Drilling discharges _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 7 | 2

7.4 Installation, commissioning and operational discharges _ _ _ _ _ _ _ _ _ _ _ 7 | 12

8 Underwater Noise

8.1 Introduction _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 8 | 1


8.3 Hearing and use of sound by species at Clair Ridge _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 8 | 2

8.4 Noise sources and potential impacts _ _ _ _ 8 | 5

8.5 Mitigation measures _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 8 | 14

8.6 Residual impacts _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 8 | 15

8.7 Cumulative and transboundary impacts _ _ 8 | 16

8.8 Assessing the likelihood of an offence _ _ _ 8 | 17


| Contents September 20102

9 Atmospheric Emissions

9.1 Introduction _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 9 | 1


9.3 Sources of potential impacts _ _ _ _ _ _ _ _ _ _ 9 | 4

9.4 Management and mitigation _ _ _ _ _ _ _ _ _ _ 9 | 9

9.5 Residual impacts _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 9 | 12

9.6 Cumulative and transboundary impacts _ _ 9 | 15

10 Risk of Oil and Chemical Spills

10.1 Introduction _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 10 | 1

10.2 Regulatory control _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 10 | 2

10.3 Oil spills _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 10 | 3

10.4 Oil spill response strategy _ _ _ _ _ _ _ _ _ _ 10 | 28

10.5 Cumulative and transboundary risk _ _ _ _ 10 | 31

10.6 Chemical spills _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 10 | 32

11 Waste Management

11.1 Introduction _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 11 | 1

11.2 Regulatory control _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 11 | 2

11.3 Waste management policy _ _ _ _ _ _ _ _ _ _ 11 | 3

11.4 Clair Ridge waste management strategy _ _ _ _ _ _ _ _ _ _ _ _ _ 11 | 3

12 Environmental Management

12.1 Clair Ridge environmental management and commitments _ _ _ _ _ _ 12 | 1

12.2 The BP environmental management process _ _ _ _ _ _ _ _ _ _ _ _ _ 12 | 4

12.3 Environmentally critical equipment (ECE) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 12 | 5

12.4 Environmental monitoring _ _ _ _ _ _ _ _ _ _ _ 12 | 5

12.5 Environmental awareness and training _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 12 | 6

12.6 Interface with contractors _ _ _ _ _ _ _ _ _ _ _ 12 | 6

13 Conclusion

13.1 Approach _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 13 | 1

13.2 Potential environmental issues _ _ _ _ _ _ _ 13 | 1

13.3 Cumulative and transboundary impacts _ 13 | 3

13.4 Protected areas and species _ _ _ _ _ _ _ _ _ 13 | 4

13.5 Environmental management _ _ _ _ _ _ _ _ _ 13 | 4

13.6 Final remarks _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 13 | 4

14 References

Abbreviations and Glossaries

APPENDIX A Summary of environmental legislation

APPENDIX B

Claire Ridge forecast production data

APPENDIX C

Vessel usage

APPENDIX D

Map of environmental surveys

APPENDIX E Summary of informal consultations

APPENDIX F ENVID matrices

APPENDIX G

The DREAM model

APPENDIX H Underwater noise modelling methods

APPENDIX I Emissions quantification data

APPENDIX J Data for appropriate assessments

APPENDIX K Claire Ridge commitments register


Non-Technical Summary |September 2010 1

Introduction

This Environmental Statement (ES) presents the findings of

the environmental impact assessment (EIA) conducted by

BP for the proposed Clair Ridge Development. The project

is the second stage of development of the Clair reservoir

and is located in the northeast Atlantic in UK Continental

Shelf (UKCS) Block 206/8, approximately 55 km west of

Shetland and 93 km southeast of the UK/Faroe median line

(Figure S.1).

Project background and purpose

The Clair reservoir is the largest known hydrocarbon

resource on the UKCS, occupying an area of some

220 km2. Due to its size and complexity it is being

developed in a series of phases.

The first phase of development included the installation of

the Clair Phase 1 platform and an export pipeline system

in the summer of 2004 (Figure S.1); first oil was achieved

in February 2005. The success of the Clair Phase 1

Development now paves the way for further investment

in the Clair field.

The proposed second phase of development, Clair Ridge,

aims to exploit the oil and gas reserves in the Ridge

section of the reservoir to the northeast of Clair Phase 1

(Figure S.1). The design of the Clair Ridge Development

has built on the environmental and design work

completed for the Clair Phase 1 project and takes

account of BPs operational experience of the

Clair Phase 1 facilities. The new development will

have a greater oil handling capacity than Clair Phase 1

and will be pre-equipped with facilities to support a

number of subsea developments in other parts of the

Clair field, should these be required in the future. Note

that any further phases of Clair development would be

the subject of additional environmental assessment

and approval from the Department of Energy and

Climate Change (DECC).

Non-Technical Summary

Figure S.1 Location of the Clair eld and the proposed Clair Ridge Development


| Non-Technical Summary September 20102 | Non-Technical Summary

Environmental philosophy

BP is committed to conducting activities in compliance

with all applicable legislation and in a manner which contributes to BPs stated goals of no accidents, no harm to people and no damage to the environment. In order to achieve these goals there is a hierarchy of common policies, commitments and expectations that identify policy and regulatory requirements and provide tools to assist in compliance and performance improvements.

During operations, the Clair Ridge Development will conform to the requirements of the Environmental Management System (EMS) established for the BP North Sea Strategic Performance Unit (SPU), which is certified to ISO 14001.

Assessment of alternatives

Throughout concept selection, through initial engineering and going forward into detailed design the Clair Ridge project team is utilising a holistic process of option analysis in order to facilitate and document decisions in a transparent and objective way - utilising criteria such as environmental impact, safety, technical feasibility, cost, ability to meet project needs, and stakeholder concerns. This holistic approach ensures environmental considerations are on an equal footing with other factors such as safety and technical viability.

A number of processing and exporting concepts for the Clair Ridge fluids were considered during early project planning, resulting in selection of twin steel platforms with bridge link, with maximum production of 120,000 barrels of oil per day. Following selection of this concept, 2nd level options were appraised, using operational experience gained from Clair Phase 1. Appraisal included, but was not limited to, the oil export route, the power generation concept and the gas turbine configuration. Some decisions are still to be made, including the method of pipeline installation and the type of flotel to be used; the EIA is based upon the option that would represent the highest environmental impact for each receptor. For example, in considering seabed impacts it has been assumed that an anchored pipelay barge might be used and in considering noise generation and atmospheric impacts it has been assumed that a

dynamically positioned pipelay barge might be used.

Development concept and schedule

The proposed development consists of two installations, one for drilling and production facilities (DP platform) and the other for accommodation and utilities (QU platform), with a bridge-link connection between them. Oil will be exported to Sullom Voe Terminal (SVT) in Shetland via a new pipeline tying into the existing Clair Phase 1 pipeline. Similarly, gas export to SVT will be via a new pipeline tying into the West of Shetland Pipeline System (WOSPS).

In 2011, an eight slot drilling template will be installed and some wells will subsequently be pre-drilled (i.e. drilled from a mobile drilling rig prior to platform installation) and suspended for later tie-in. Export pipelines will be installed in 2012 and the platforms and subsea structures during 2013 and 2014. Following hook-up and commissioning, the current BP schedule is for first oil in 2015, although the timing of activities may change during project development. In total, over 104 million cubic metres of oil are expected to be recovered over the forty-year life of the platform.

Environmental Statement Remit

This ES has been prepared in accordance with applicable legislation and guidelines, including the Offshore Petroleum Production and Pipelines (Assessment of Environmental Effects) Regulations 1999 (as amended) which require evaluation of projects likely to have a significant effect on the offshore environment.

The aim of the EIA is to assess the potential environmental impacts that may arise from the proposed Clair Ridge Development and to identify measures that will be put in place during design and operations to prevent or minimise these impacts. The ES summarises the EIA process and outcomes.

The scope of the EIA was developed and agreed during a scoping consultation process. The EIA has addressed all aspects of this offshore development, from early drilling activities and installation and commissioning, through the operational phase to decommissioning.

Non-Technical Summary |



The Development

Reservoir and uid characteristics

Clair Ridge fluids and conditions are relatively favourable,

i.e. the oil is not at a high temperature or pressure and

does not contain hydrogen sulphide.

Wells and drilling

The development is anticipated to involve the drilling of

36 wells. Of these, 26 will be oil producing wells and 10

will be for water injection to maintain reservoir pressure

and enhance oil recovery. The producing wells are

provided with gas lift facilities.

Between three and seven wells (assumed to be six

for the purposes of the EIA) will be pre-drilled and

suspended for later tie-in by a semi-submersible drilling

rig via a steel seabed template in the two year period

prior to jacket installation. This will allow efficient

production ramp-up on initial platform commissioning.

The platform drilling programme will be continual after

the initial tie-in of the pre-drilled wells and is expected to

last approximately twelve years.

The wells will be drilled in a series of sections of

decreasing diameters. Of the 36 planned wells, it is

expected that approximately 50% will be drilled with

three sections, or strings, with hole diameters of 32,

17 and 12. Five-string wells may be required where

there is a large horizontal distance to the reservoir

target (maximum step-out approximately 6 km), or to

provide extra protection when drilling through the Lower

Cretaceous region of the formation. These wells will

have hole diameters of 32, 23, 17, 12 and 9.

Two further liner strings can be added if required. The

pre-drilled wells include a four-string well design involving

36, 26, 17, and 12 diameter holes.

Drilling uids (muds) and cuttings handling

Drilling muds generally consist of a weighting agent

such as barite suspended in water (water based mud or

WBM) or some type of oil (oil based mud or OBM). Other

chemicals may be added for specific functions depending

on the geological formations being drilled and on the

viscosity and specific characteristics required of the

drilling fluid. Different types of mud are used for different

parts of a well and final fluid selection for each section

will be based on technical requirements for each type of

well (producer or injector).

The top-hole sections of each well (the 36 and 26

sections for the pre-drilled wells and the 32 section

for the platform wells) will be drilled using a seawater

based solution and the inert cuttings generated from

these sections will be deposited directly on the seabed,

around the hole. A riser (pipe) will then be installed which

connects the well to the platform and all other cuttings

can be circulated back up to the drilling rig or platform.

Cleaning and separation systems will enable the recovery

of drilling fluids and partitioning of the drill cuttings for

appropriate disposal.

Well control equipment and well testing

The primary well control barrier is the use of

weighted drilling fluids which are sufficiently heavy to

counterbalance the formation pressure. The secondary

barrier will be the blow out preventer (BOP) system

which exists to prevent uncontrolled flow from the well

by positively closing the well-bore when required.

Testing of the platform-drilled wells will be necessary

for effective reservoir management and assessment

of reservoir performance. This involves the production

of a limited amount of fluid from the well into a test

separator, where metering equipment will monitor the

wells performance. The fluids will then pass into the

main process system and no flaring will be required.

The pre-drilled wells will be cleaned-up and tested

briefly from the drilling rig, with produced crude oil and

gas being flared; there is no plan to include an extended

well test.



DP topsides facilities

The production process facilities are designed to collect

the produced fluids from the wells and deliver crude

oil, gas and water of sufficient quality to meet outlet

specifications. The main process systems, situated

on the DP platform, are illustrated in Figure S.3 and

include the separation system which removes gas and

water from the production fluid to obtain the required

oil product specification. The produced water system

removes residual oil to less than 30 milligrams per litre

(mg/l) from the water separated from the produced

fluids. Produced water can be directed overboard

should the water injection system be unavailable. The

are system provides a safe means of disposal of

hydrocarbon gases during emergency situations, start-up

and maintenance operations. A vapour recovery unit

captures any gases in the flare system during normal

operations and routes these back to the process, rather

than being flared. The hazardous and non-hazardous

drainage systems collect and treat contaminated water,

ensuring that prior to discharge it contains less than

40 mg/l of dispersed oil, in line with legal limits. The

oil export system cools the crude oil and increases

pressure to the specification required for delivery into the

oil export pipeline.

Figure S.2 Clair Ridge platforms

(view looking northeast)

Pipelines and subsea infrastructure

The oil and gas pipelines from the Clair Ridge DP

platform will tie into a subsea isolation valve (SSIV)

installed approximately 200 m from the platform. The

Clair Ridge oil will then flow to the Clair Phase 1 SSIV/

Wye assembly via a new 6.5 km oil export pipeline.

The DP platform will also be tied into the WOSPS via a

14.0 km gas export pipeline. The tie-in point will be at

the existing Clair Phase 1 WOSPS Tee. A new tie-in skid

adjacent to this Tee will house isolation valves and allow

gas import from WOSPS to Clair Ridge when required.

The export pipelines will be laid on top of the seabed.

The concrete-coating of the oil pipeline will provide it

with sufficient weight and stability, but the gas export

pipeline will be protected and stabilised with rock along

its entire length. The hard seabed in this area means

that pipeline trenching is not possible. The pipeline tie-in

sections will be covered with concrete mattresses for

stability and protection.

During pipeline commissioning, the pipeline will be

pressure tested using water treated with biocide

and oxygen scavenger (to ensure that the pipeline

is protected from corrosion) and dye (to enable the

detection of any leaks).

Platforms and processing facilities

The twin platform design consists of two jackets

supporting the DP and QU topsides (Figure S.2).

The jackets will be transported onto location and installed

using barges and heavy lift vessels and then piled

into the seabed. The topsides will be transported and

positioned onto the jackets using heavy lift ships and

a heavy lift vessel. A flotel will be used to house the

workforce throughout the hook-up and commissioning

phase of the platforms.




Figure S.3 Simplied process ow diagram

QU topsides facilities

The QU topsides facilities house the utility systems.

These include the main power generation system, i.e.

four dual-fuel gas turbines (one of which is on standby)

with waste heat recovery units (WHRU) which recover

heat from the exhausts to heat the process fluids. Also

included is the LoSalTM unit, a membrane separation

package producing desalinated seawater for injection

into the reservoir (via the DP platform) for improved

oil recovery. Other utility systems include the closed

circuit heating medium, closed circuit cooling medium,

seawater lift, nitrogen generation and instrument air

system. These utilities are distributed across the bridge

link to the DP platform. The living quarters are also

situated on the QU platform, with the fresh-water maker

and sewage system.

Commissioning

The commissioning strategy seeks to minimise offshore

commissioning activities by maximising the amount of

onshore commissioning of process, utility and subsea

systems. This will maximise production ramp-up and

minimise flaring.

Decommissioning

A detailed decommissioning plan will be established

prior to decommissioning to ensure there is minimal

impact on the marine environment and other sea

users. BP will evaluate options for facilities and pipeline

decommissioning and will undertake decommissioning

activities in compliance with regulatory requirements

in force at the time of decommissioning. All technically

feasible options will be considered. The present

regulations for decommissioning require the complete

removal of the Clair Ridge platforms and template to

shore for reuse, recycling or final disposal on land.



Overview of the environment

An understanding of the environment in the vicinity

of the Clair Ridge Development (located on the outer

West Shetland Continental Shelf in the northeast

Atlantic (Figure S.1) in water depths of 140 m), draws

upon regional and site-specific environmental surveys

and on research that has been carried out in the area.

This includes the extensive data collation and review

undertaken as part of the Clair Phase 1 Development

EIA, updated where appropriate. The focus is on the

offshore areas around the platforms and the tie-in

pipeline routes. Consideration has also been given to the

coastal characteristics throughout the area that would be

vulnerable in the unlikely event of a large oil spill.

Water current patterns in this area are often complex

with various non-tidal components of current flow

interacting with relatively weak tidal flow. Water column

stratification occurs during the summer months when

there is a distinct boundary between warmer surface

waters and cooler bottom waters.

Strong winds are characteristic of the northeast

Atlantic, particularly during the winter months, and calm

conditions are rarely recorded. Southerly and westerly

winds tend to predominate for much of the year from

July through to March. In contrast there is a greater

evenness of wind distribution during the spring months

(April to June).

The seabed at the proposed platform locations is

comprised of very gravelly sand with cobbles and

numerous boulders overlain in places by thin ribbons of

sand with occasional megaripples and scattered cobbles

and boulders as shown in Figure S.4, taken in 2009.

Key environmental sensitivities

Based on previous experience, studies and consultation

conducted for both the Clair Phase 1 and Clair Ridge

projects, it has been possible to identify the key

environmental sensitivities to the proposed development.

These are summarised for the offshore environment

in Table S.1. Seasonal ecological sensitivity offshore is

highest between February and July due to high seabird

vulnerability to surface pollution at these times.

The combination of the shelf edge environment and the

influence of the Gulf Stream to the west of Shetland

results in a diversity of habitats and a particularly rich

number of cetaceans. The distribution of cetacean

species is related to oceanographic features such as sea

temperature, salinity, water depth and sea floor relief and

prey distribution and abundance. To the west of Shetland,

different species show a tendency towards shelf, slope

or deep water habitats.

Figure S.4 Seabed in the vicinity of

the Clair Ridge Development




Table S.1 Offshore environmental sensitivities

Plankton Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

A peak in phytoplankton (plant) productivity in late spring is followed by lower, yet constant, productivity until autumn. Zooplankton (animal) productivity follows a similar pattern with a one or two month delay. Zooplankton provides an important source of food for many fish species. Plankton communities are not generally subjected to pressures from human activities.

Seabed animals Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

Surveys showed the seabed to consist of gravelly sands with pebbles and cobbles supporting sparce surface living animal life (epifauna). It is unlikely that any particular seasonal sensitivities exist in the benthic communities present.

Fish Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

The development lies within spawning (March to May) and nursery areas for Norway pout and nursery areas for blue whiting and mackerel, as well as a mackerel migration route. Nonetheless sensitivity is generally low throughout the year since identified spawning and nursery areas extend over much wider areas (throughout UK and European waters).

Seabirds Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

Seabirds offshore are particularly vulnerable to oil spill. Fulmar, northern gannet, herring gull, great black-backed gull, kittiwake, common guillemot, razorbill and puffin are present in the west of Shetland area all year round, with many other species present at certain times of the year. In the vicinity of the Clair Ridge Development, densities of some species can be moderate to high during spring and summer. The European storm petrel (listed under Annex I of the EU Birds Directive) is present in the area in high densities during September and occurs in internationally important numbers. Overall sensitivity to surface oil pollution is greatest during February and March and between May and June.

Cetaceans Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

Large baleen whales migrate through the Faroe-Shetland Channel to summer feeding grounds in the north and winter breeding areas in the south. Long-finned pilot whales, Atlantic white-sided and killer whales also inhabit deep waters of the channel, while minke whales and several dolphin species have been observed over the shelf. Sightings tend to peak during the summer months, although this may be a consequence of seasonality in survey effort.

Conservation Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

There are no designated offshore sites in the vicinity of the Clair Ridge Development. Additionally, there are no potentially protected habitats such as sandbanks, reef structures or pockmarks nearby.

Fisheries Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

Different areas of the continental shelf west of Shetland are important for fisheries throughout the year. Demersal species are generally fished all year round. Pelagic fisheries exhibit some seasonality and exact seasons may change year to year. High-value mackerel are landed in winter months, herring are landed exclusively in July, and saithe are predominantly landed in the first half of the year. The level of demersal fishing effort in the area is moderate and the level of pelagic fishing effort is low, in comparison to the rest of the UK.

Low Moderate HighGeneral sensitivity

With regards to the coastal environment, the ecological

sensitivity of the Shetland coastline ranges from low

to moderately high with numerous specific areas with

an elevated level of local sensitivity, usually related to

bird and marine mammal breeding and nesting areas.

The most sensitive period is during the summer months

when most species are breeding and rearing young.

The winter months are also important due to the

presence of overwintering seabird and wildfowl

populations. Spring appears to be the least sensitive time

of the year.

Other potential sensitivities to oil spills in coastal areas

include fishing, mariculture, tourism and amenity value of

the coastal landscape.



Conservation interests

The proposed development area does not lie within or

close to any designated offshore conservation sites

under Annex I of the EU Habitats Directive. An area of

potential Annex I habitat (stony reef) lies along the shelf

break downslope from the Clair Ridge Development.

However, seabed surveys indicate that the proposed

development area does not support stony reef habitat

according to criteria developed by JNCC.

The JNCC is currently working to identify important

hotspots for seabirds in the offshore area, including

several areas around Shetland, with a view to designating

marine Special Protected Areas (SPAs). However, as yet

no offshore SPAs have been identified for feeding or

overwintering.

A number of marine species in UK waters have been

identified for protection under Annex II of the European

Habitats Directive. The harbour porpoise is the only listed

species likely to occur with any frequency in the vicinity

of the proposed development. Although the JNCC is

seeking to identify areas suitable for designation for

harbour porpoise, the species is widely distributed in

UK waters, and the area to the west of Shetland is not

considered unique. European storm petrels, listed on

Annex I of the Birds Directive, are widely distributed over

the whole shelf break west of Shetland between May

and November.

The Shetland coastline supports internationally and

nationally important populations of breeding seabirds. The

coastline also has numerous boggy areas, which support

approximately half of the British breeding population

of red-throated diver. The west coast of Orkney is

characterised by high cliffs and supports internationally

important breeding seabirds.

Shetland and Orkney also support internationally important

breeding populations of common seal and Shetland

supports one of the densest otter populations in Europe.

Assessment of potential impactsThe main aim of the Clair Ridge project environmental

strategy has been to design out, or reduce, issues

believed to impact on the environment or on users of

the environment.

Project design and operational planning has succeeded

in the removal or reduction of many of the key

environmental issues. Using data and understanding

relating to the proposed design, the sensitivity of the

environment and consultation feedback, the core task of

the EIA process has been to:

Assess potential residual issues from the project, both from routine operations and possible accidents

Define mitigation and management measures to be addressed during the detailed design phase and

subsequent operations

The following sections of the non technical summary

present the findings of the EIA for the residual

environmental issues remaining following design and

operational planning. The issues are addressed under the

following categories:

1 Physical Presence 3 Underwater Noise

2 Discharges to Sea 4 Atmospheric Emissions

Operational issues

5 Risk of Oil and Chemical Spills

Accidental events

The potential for cumulative or transboundary impacts

is also addressed.




1 Physical presence

The anchoring of the drilling rig, flotel and other vessels,

and the installation and presence of the drilling template,

jackets, pipelines and other subsea structures, have the

potential to affect the seabed and associated animals.

In addition, offshore activities associated with all stages

of the development, and the physical presence of

structures, could interact with other users operating

within the same area of the marine environment.

Seabed impacts

Mechanisms for direct impact include disturbance of

sediments and damage to seabed species; as well

as localised loss or change of habitat through the

introduction of novel substrata. Indirect impacts may

be caused by the re-suspension and re-settlement

of sediments.

The total area of seabed directly impacted, including

all anticipated anchor placements, rock dumping and

mattressing, is estimated to be approximately 0.3 km2.

This represents approximately 0.002% of the total West

Shetland Continental Shelf area. Considering the small

area likely to be impacted, the ability of some species

to move out of the area and the absence of rare or

protected species, the residual impact of direct physical

injury or habitat loss to seabed fauna will be minor. The

pipeline and other seabed structures will provide new

stable hard substrata, equivalent to natural rock outcrops,

in the already mixed substratum environment, which are

expected to be colonised by any epifaunal animals (those

living on the surface of the seabed) present in the area.

Any anchor mounds that are generated will be eroded by

the relatively strong bottom currents. Recovery of seabed

affected by transient operations such as anchoring is

expected to be rapid (less than five years) via sediment

mobility and faunal re-colonisation.

Any re-suspension of sediments will be localised and

restricted to the installation phase, i.e. temporary,

therefore the majority of species present will not be

adversely affected and impacts are likely to be negligible.

Interactions with other sea users

The marine environment within which the Clair Ridge

Development will be located is utilised by a number

of other sea users, primarily the fishing and shipping

industries. The increase in vessel traffic during installation

and the physical presence of the structures potentially

increases the risk of collisions. In addition, the proposed

activities, vessels and structures will exclude fishermen

and shipping from the Clair Ridge location and potentially

increases the risk of gear and catch being damaged

through interaction with subsea structures.

Increased vessel traffic

The increase in the number of vessels in the area during

drilling, and installation and commissioning, is of limited

duration. Standard communication and notification

measures will be in place to ensure that all vessels

operating the area are aware of the activities. Since a low

number of vessels frequent waters within a 10 nautical

mile radius of the Clair Ridge Development, and given

the fact that the presence of the existing Clair Phase 1

platform means that shipping and fishing interests are

aware of field-specific vessel movements in the area,

the temporarily increased vessel presence around the

Clair Ridge Development is expected to have little or no

significant residual impact.



Fishing interference

Snagging risks cannot be eliminated entirely and a

number of mitigation measures will be in place to reduce

them significantly, including the use of overtrawlable

subsea infrastructure, consultation and notices to

mariners. The measures BP will adopt are standard

across the industry and have previously assisted in

reducing the impact of oil and gas associated activities to

other sea users.

A specialist fishing study commissioned for the EIA

noted higher vessel sightings occurring along the 200 m

contour to the north and lower vessel sightings occurring

towards the southwest of the Clair field.

The presence of long-term exclusion zones around the

drilling rig and subsequently the platforms, will prevent

fishing vessels from operating in 0.009% of potential

fishing grounds in the West Shetland Continental Shelf.

Pipelines can interfere with demersal fishing activities

due to the increased risk of snagging and damage. The

fishing study indicated that pipelines, which can act as

fish aggregation devices, may be preferentially targetted

for fishing and concluded that the risks inherent in fishing

over and along fishing friendly untrenched pipelines are

within acceptable limits.

Anchor mounds may pose a risk to fishing vessels.

However, due to the small numbers of anchor

placements and the temporary nature of the anchor

mounds (as discussed above), it is likely that the threat to

fishing in the Clair Ridge area is minor.

2 Discharges to sea

BP aims to reduce the impact of discharges on the

environment, with emphasis placed upon pollution

prevention and impact minimisation at source. Key

design features of the Clair Ridge Development, such

as a re-injection target of 98% of produced water and

its associated chemicals, reduce residual levels of

discharges to sea.

The residual discharges from the Clair Ridge

Development and the management and mitigation

measures employed in order to adhere to legislation and

achieve BPs goals are discussed below.

Drilling discharges

Discharge to sea of OBM cuttings is prohibited and these

will be re-injected or, if cuttings re-injection (CRI) is not

available, shipped to shore for onshore processing.

Cuttings from the tophole sections of the wells, drilled

with a seawater-based fluid, will be deposited on the

seabed adjacent to the well. Where WBM are used for

the lower sections of the wells, WBM cuttings will also

be re-injected when CRI facilities are available, otherwise

they will be discharged to sea through a caisson. As the

precise quantity of WBM cuttings which can be

re-injected is unknown, assessment assumed that WBM

is used for all 23 and 17 well sections and no CRI

is available for WBM. The worst-case quantity of WBM

cuttings that would therefore be discharged ranges from

238 tonnes for a pre-drilled well to 1,172 tonnes for a

5-string, long platform well.

Due to rapid dilution soon after release, and settlement

of particles to the seabed, the impacts in the water

column from these discharges will be negligible.

Cuttings dispersion modelling predicted that, for a

5-string platform well, deposition would occur on the

seabed in a thin oval-shaped area lying predominantly to

the northeast of the drilling centre. Any adverse risk as

defined by the environmental impact factor (EIF) will be

limited to a central area up to 300 m from the discharge

location in the direction of the predominant current and

approximately 50 m in other directions.




These impacts will be largely attributable to grain size

alteration and thickness of deposition.

The environmental impact factor (EIF) is an estimate

of the area of seabed within which there exists a

possibility of injury to 5 % of the most sensitive

species.

The environmental impact of the drilling discharges is

expected to be loss of benthic community near the

wellhead due to complete burial, and limited changes

in the communities further from the discharge location.

Available information for the Clair Ridge site suggests

that no species were particularly sensitive to increased

suspended solids or limited deposition and that

recoverability of the species was high or very high.

Further modelling considered the discharges from

all platform drilled wells (30), to investigate potential

cumulative impacts. As a worst case the discharges

were assumed to occur immediately after each other

with no time interval incorporated between modelling

of individual well discharges to allow for recovery of

the sediment. In this case the area of adverse risk, as

defined by the EIF, extends to approximately 3.5 km from

the discharge location in the direction of the dominant

current and 250 m in other directions.

In reality, the 30 wells are planned to be drilled over a

12-year period. This will extend the duration of impacts,

but reduce the scale of impact at any point in time, and

reduce the likely recovery time following cessation of the

drilling programme. A combination of sediment transport

and redistribution, and recolonisation and bioturbation

of the sediment, is expected to return the sediment to

its natural state within a few years of completion of the

drilling programme.

Commissioning discharges

The Clair Ridge pipelines will be flooded with seawater

containing chemicals (eg biocides, oxygen scavengers

and scale inhibitors) and hydrotested. Before start up,

the pipelines will be dewatered. Although there will be

discharges associated with each of these operations,

they will be short-term and have only a localised effect.

The risk to the environment was assessed as negligible.

Produced water

Following treatment of the produced water to ensure it

contains an oil-in-water concentration of less than

30 mg/l, a target of 98 % will be re-injected into the

reservoir. The re-injection of produced water will limit the

quantities of oil discharged and will also ensure minimal

discharge of other chemicals added during processing.

The impacts of any produced water discharges to sea

during periods of produced water re-injection down-time

were assessed as being negligible.

Discharges from LoSalTM unit

Use of the LoSalTM unit results in the discharge of

high salinity water containing added chemicals such

as biocide and anti-scalant. Predictive modelling

indicates that the plume sinks rapidly to the seabed

and that its concentration decreases to less than

1 % above background salinity levels within 35 m of

the discharge point.

The risk to the environment from the LoSalTM discharge

is predominantly from the batch discharge of a biocide

which will be dosed on a weekly basis. However, this

potential impact is very localised to within approximately

1 km of the discharge point and short-term, lasting for

approximately 24 hours after dosing.



3 Underwater noise

This EIA has utilised up-to-date scientific information and

applied the most recent JNCC guidelines in an attempt to

assess the significance of any potential impacts from the

Clair Ridge Development.

Sources of noise generation from activities associated

with the development which have the potential to impact

upon marine species in the vicinity of the development

include pile driving, drilling, vessel activity and offshore

pipelay activities. The potential impacts of most noise

sources on marine mammals were assessed as being

negligible or minor.

A specialist modelling study was commissioned to

inform the assessment of the impacts from the noisiest

operations, the piling of the drilling template and jackets.

The study indicated that the entire range in which injury

may be caused will be contained within the marine

mammal mitigation zone, i.e. within the area where

measures can be taken that seek to ensure no marine

mammals are in the area of impact prior to pile driving

being initiated.

Considering the very short time period during which pile

driving will actually occur, and the nomadic behaviour of

cetaceans (which imply that they will actively avoid loud

noise sources), it is unlikely that any will be exposed to

sound which would cause significant behavioural effects.

Assessing the likelihood of an offence

The EIA also includes an assessment of whether or

not the proposed operations will cause disturbance of

European Protected Species (EPS) under the Habitat

Regulations and Offshore Marine Regulations.

The nature of the piling activity and the proposed

mitigation measures mean there will be a negligible risk

of injury or disturbance offence as a result of the Clair

Ridge activities. BP therefore considers that application

for an EPS licence is not required.

4 Atmospheric emissions

The use of energy optimisation and BAT studies for

power generation, and key design decisions regarding

flaring, have minimised the atmospheric emissions

associated with the development. The ES details

the expected residual levels of emissions from the

installation and operation of the Clair Ridge Development

and models the dispersion of emissions from the major

operational sources, i.e. the gas turbines and

safety-related flaring.

To reduce the total level of flaring from Clair Ridge

operations, the development includes a vapour recovery

unit. This means that vapours that would otherwise be

flared can be recovered and processed.

The naturally low driving force of the Clair reservoir

means that the Clair Ridge Development starts from a

position of considerable disadvantage when comparing

energy required per barrel of oil production against many

other BP assets. Notwithstanding, energy efficiency

and minimisation of atmospheric emissions has been

evaluated as part of the decision-making process when

assessing options around the main energy consumption

items e.g. power generation, gas compression, artificial

lift, water injection and oil export.

Local impacts

Throughout the installation, commissioning, and

operation of the Clair Ridge Development there will be

additional levels of NOX, SO2, and VOCs released into the

environment. However, the effects from these pollutants

will be very localised and, due to the dispersive nature of

the offshore environment and the remote location, they

will have a negligible effect on the nearest receptors

on Shetland.

Contribution to global greenhouse gases

The average annual CO2 equivalent emissions from

the Clair Ridge Development, including both direct and

indirect greenhouse gases have been estimated to be

approximately 377 kte which represent approximately

0.85% of the total offshore UKCS CO2 emissions.




5 Risk of oil and chemical spills

The ES describes the measures that will be put in place

during the Clair Ridge Development to prevent spills, and

proposed contingency measures that will be employed

to ensure an effective response in the unlikely event

of a spill.

It is BPs aim to cause zero damage to the environment,

minimising the risk of spills using measures relating to

plant, people and processes. Therefore in light of the

Deepwater Horizon incident in the Gulf of Mexico, the

ES incorporates emerging, relevant information from the

incident while recognising that the Clair Ridge drilling

programme consists of development drilling in 140 m of

water into a reservoir which does not contain fluids at

high pressure or temperature and in which more than 30

wells have been drilled since the 1970s.

Oil spills

Analysis of industry spill frequency indicates that the

most probable spills from the Clair Ridge Development

are small spills of < 1 tonne and focus has been given to

prevention of these spills through design, specification

and implementation of agreed operational procedures.

Larger blowout and pipeline spills that could reach the

coastline are considered to be remote or extremely

remote events, i.e. low probability.

The consequences of a significant release of

hydrocarbons from the Clair Ridge Development will vary

depending on factors such as wind speed and direction

and sea state, as well as the time of year and the length

of coastline affected. For example, after the breeding

season ends in June, moulting auks (guillemot, razorbill

and puffin) disperse from their coastal colonies into

offshore waters and kittiwake, gannet and fulmar are

present in significant numbers, making high numbers of

birds particularly vulnerable to oil pollution.

As the probability of spills of this magnitude occurring

is considered remote or extremely remote, the overall

risk of an oil spill from the Clair Ridge Development

adversely impacting Shetland is very low. To address

the small residual risk of spill which remains, even

with comprehensive prevention measures in place, BP

implements a range of response/mitigation measures, as

detailed in the spill response strategies.

Spill response strategy

Procedures and protocols have been implemented for the

Clair Phase 1 oil export pipeline to prevent and minimise

the risk of an oil spill from the pipeline, and respond in

the unlikely event of a spill. These will be updated, as

appropriate, to incorporate the Clair Ridge oil export

pipeline tie-in.

The BP Onshore Oil Spill Plan was implemented for the

Clair Phase 1 Development in addition to immediate

offshore response. As part of this plan, BP have

contracted OSR to have strategically located mobile

response packages, and trained response personnel,

that can be engaged to combat oil spills approaching

inshore areas of Shetland. This plan will be reviewed

and modified to incorporate any changes required for the

inclusion of the Clair Ridge Development.

Detailed and fully tested oil spill response strategies,

appropriate to local environmental sensitivities will be

developed and finalised for both drilling and production

prior to the commencement of operations. These will

be documented in the Oil Pollution Emergency Plans

(OPEPs) for the drilling rig and the Clair Ridge platforms.

In light of the Deepwater Horizon incident in the Gulf of

Mexico. The OPEPs will consider, and where appropriate

incorporate information gained from the Deepwater

Horizon incident in the Gulf of Mexico. The OPEPs will be

submitted for approval by the regulator in sufficient time

to allow full consideration of the proposals.



6 Cumulative and transboundary issues

Cumulative effects are those that impact on the

environment outside the local scale and those that add to

existing or reasonably foreseeable future impacts. Clair

Phase 1 was the third oil and gas field to be developed

in the area to the west of Shetland, following Foinaven

and Schiehallion. Approval has also been granted for

the combined subsea development of the Laggan and

Tormore gas fields.

Transboundary environmental impacts originate in one

country but have an effect on the environment in another

country. Clair Ridge is located approximately 93 km (58

miles) from the UK/Faroes boundary and

236 km (147 miles) from the UK/Norwegian boundary

(Figure S.1).

The main aim of the Clair Ridge environmental philosophy

has been to design out, or reduce, issues believed to

present significant risk to the environment or users of

the environment. Project planning and operational design

has removed or substantially reduced key issues such as

the discharge to sea of drill cuttings, produced water and

associated chemicals and certain atmospheric emissions.

Modelling of residual discharges to sea and atmospheric

emissions, and consideration of interference of the

development with other sea users indicated that the

potential for cumulative or transboundary environmental

impacts attributable to these is limited.

As indicated by historical data, the likelihood of one major

spill occuring is remote or extremely remote, limiting the

potential cumulative oil spill impact from Clair Ridge and

other existing installations. Detailed contingency plans

are in place for each installation, outlining the response

measures to be implemented in the event of any spill.

Oil spill modelling undertaken - which assumed no

response measures were implemented - indicates

some probability that, in the event of a worst case

spill, oil could move across international boundaries,

particularly into Norwegian waters. The assessment of

spill likelihood, based on historical UKCS and international

incident data, demonstrates that the likelihood of a spill

large enough to lead to such a transboundary impact

is remote extremely remote, i.e. low probability.

Therefore BP believes that consultation under the

Espoo convention is not required as a result of the Clair

Ridge Development, the Espoo convention requiring

notification and consultation only on projects likely to

have a significant adverse environmental impact across

boundaries.

The risk of oil spill having transboundary impact,

particularly from the North Sea operations, is recognised

by the UK Government and other governments around

the North Sea. Agreements are in existence for dealing

with international oil spill incidents with states bordering

the UK. In the event of a major spill which is predicted

to drift into Norwegian waters the NORBRIT plan will be

activated. The NORBRIT plan is a joint UK/Norway oil

spill contingency plan operating within the framework of

the 2006 National Contingency Plans; the plan is oriented

towards major spills resulting from, for example,

blow-outs. It becomes operational when agreement

to the request for its implementation is reached.

Responsibility for implementing joint action rests with

the Action Co-ordinating Authority (ACA) of the country

on whose side of the median line a spill originated. The

UKs ACA is the Counter Pollution Branch of the Maritime

and Coastguard Agency (MCA).




The way forward

Environmental considerations have played, and will

continue to play, an important role in the decision-

making process throughout the Clair Ridge project.

Throughout the project, considerable efforts have been

made to remove or significantly reduce issues that could

lead to possible impacts on the environment. Where

this has not been possible, detailed attention has been

given to defining residual issues and seeking ways of

minimising any potential impacts.

Several key decisions led to removal or major reduction

in activities considered likely to have significant impacts

onto the environment, in particular:

Oil/Gas pipeline oil and gas exported to shore via short tie-ins to existing pipelines, thus reducing the

environmental impact that would result at landfall and

to the seabed from new export pipelines.

Routine flaring the flaring philosophy for the Clair Ridge Development is not to flare gas routinely

during normal operations, and to have a closed flare

system with flare gas recovery in order to reduce

atmospheric emissions such as CO2, NOx, SOx and

unburnt hydrocarbons.

CRI OBM drill cuttings and drilling slops will routinely be re-injected into the formation. WBM drill cuttings

and drilling slops (other than those of the top hole

sections drilled riserless) will be considered for CRI.

Each well will be reviewed on a case-by-case basis to

assess if re-injecting such materials would significantly

reduce the availability of CRI wells for re-injection of

OBM cuttings. CRI will reduce any potential impacts

on seabed and fauna.

PWRI and LoSalTM produced water and its associated chemicals will be re-injected into the

reservoir, thus reducing potential impacts on the

water column. Low salinity water injection using

LoSalTM will reduce the risk of reservoir souring and

sulphate scaling. This will reduce the overall chemical

requirement, reducing potential impacts on the water

column.

Power generation the selection of a centralised electrical power generation system allows for recovery

of the waste heat from Gas Turbines as useful heat to

meet the process requirements, removing the need

for separate fired heaters or large electrical heaters.

Key Residual Issues

Overall it is considered that, following application of

management and mitigation measures identified in

this ES, the Clair Ridge Development will not cause

significant environmental impacts.

However, there are aspects of the project that will need

to be managed sensitively in order to minimise potential

environmental effects. These include the following key

residual issues:

Underwater noise pile driving is seen as the Clair Ridge Development activity generating the greatest

underwater noise levels. BP will implement a number

of measures to mitigate noise impacts based on the

principles of the JNCC guideline for piling activities

to address any potential for injury and non-trivial

disturbance. As the most commonly sighted marine

mammals species in the development vicinity are

considered less susceptible to low frequency sounds,

and that pile driving noise will be emitted over a

short period of time, significant, residual injury or

disturbance impacts occurring as a result of the piling

activities at Clair Ridge are considered unlikely.

Risk of oil spills the focus of the Clair Ridge project has been on spill prevention. The highlighted

prevention methods will considerably reduce the risk

of oil spill. However, a residual risk of oil spill remains

and therefore an oil spill response strategy has been

developed. This strategy will be taken on into detailed

OPEPs which will include further consultation with the

statutory authorities and appraisal of existing response

arrangements.


1 |September 2010 1

Introduction1

1.1 Project background and purpose1.1.1 History of the Clair eld

The Clair field, discovered in 1977 and extending over an

area of about 220 km2, is the largest known hydrocarbon

resource on the UKCS. It is a challenging fractured

sandstone reservoir of Devonian to Carboniferous age,

which is being developed in a series of phases.

Ten appraisal wells were drilled into the reservoir (by four

different operator groups) from field discovery through

to 1990. The information obtained demonstrated that

the reservoir covered a large geographical area but failed

to confirm the presence of economically recoverable

reserves. Between 1990 and 1995 the operators with

an interest in the Clair field drilled a further five appraisal

wells and commissioned a 3D seismic survey. Although

not sufficient to establish commercial viability, this

activity did demonstrate that one geological segment

of the reservoir known as the Core was the focal area

for any possible development. In 1996 an extended well

test demonstrated that the Core area was capable

of sustained production performance. A further two

appraisal wells drilled in 1997 into other areas of the

This Environmental Statement (ES) presents the findings of the environmental impact assessment (EIA) conducted

by BP for the proposed Clair Ridge Development. The project is the second stage of development of the Clair oil

reservoir and is located in the northeast Atlantic in UK Continental Shelf (UKCS) Block 206/8, approximately 55 km

west of Shetland and 93 km southeast of the UK/Faroe median line, in water depths of 140 m (Figure 1.1).

The proposed development consists of two installations, one for drilling and process facilities (DP platform) and the

other for accommodation and utilities (QU platform), with a bridge-link connection between them. Oil will be exported

to Sullom Voe Terminal (SVT) in Shetland via a new 22 diameter 6.5 km pipeline tying into the existing Clair Phase 1

pipeline. Similarly, gas export to SVT will be via a new 6 14 km pipeline tying into the existing West of Shetland Pipeline

System (WOSPS).

This chapter explains the background and purpose of the proposed development and describes the scope and aims of the EIA process carried out. The underlying regulatory and BP environmental requirements are also outlined.

reservoir supported initiation of development concept

studies for a first phase of development.

Initial development (Clair Phase 1) of the Clair field

centred on the Core, Graben and Horst reservoir areas

in the central part of the reservoir (Figure 1.1). An EIA

was completed for Clair Phase 1 and the resultant ES

was submitted and approved in 2002 (BP, 2001; DTI

reference number: D/1228/2001).

The Clair Phase 1 platform and export pipelines were

installed offshore during the summer of 2004 and the

field achieved first oil in February 2005. Oil from Clair

Phase 1 is exported to SVT via a 105 km pipeline, whilst

gas is exported through a 10 km spur line into the

WOSPS (Figure 1.1). Oil production from Phase 1 built up

to a plateau of around 50 thousand barrels per day (mbd

ca 7,950 m3 per day) in 2007. By the end of 2010 the Clair

Phase 1 Development will have produced 70 million stock

tank barrels (mmstb) of oil (approximately 11.5 million

m3) from the Lower Clair Group reservoir. The success of

the Clair Phase 1 Development now paves the way for

further investment in the Clair field.


| 1 September 20102 | 1

1.1.2 The Clair Ridge Development

The second phase of the development, Clair Ridge

(originally named Clair Phase 2), commenced with a

programme of appraisal drilling involving three wells

drilled between 2005 and 2007. These wells, together

with an ocean bottom cable (OBC) seismic survey

acquired in 2006, have given sufficient confidence to

proceed with the Clair Ridge project. This aims to exploit

the oil and gas reserves in the Ridge section of the

reservoir (the elongated up-thrown part of the field

to the northeast of Clair Phase 1; Figure 1.1).

Figure 1.1 Location of the Clair eld and the proposed Clair Ridge Development

1 |


1 |September 2010 3

Table 1.1 Ownership of the Clair eld

The design of the Clair Ridge Development has built

on the environmental and design work completed for

the Clair Phase 1 project and takes account of BPs

operational experience of the Clair Phase 1 facilities.

The Clair Ridge facility will have 36 well slots, compared

to the 28 of Clair Phase 1; a higher process capacity

(ca 19,000 m3 or 120 mbd oil handling capacity compared

to ca 11,000 m3 or 67 mbd) and will be pre-equipped with

facilities to support a number of subsea developments

in other parts of the Greater Clair field, should these

be required in the future. Any further activities and

development related to possible further phases of

Clair development would be the subject of additional

environmental impact assessment and submission

of statutory environmental documentation to the

Department of Energy and Climate Change (DECC).

Concept selection for the Clair Ridge Development

occurred during 2008 and 2009. In 2011, an eight slot

template will be installed and a number of wells are

expected to be pre-drilled (i.e. drilled before installation

of the DP platform), cleaned, completed and suspended.

The subsea pipelines will be installed in 2012. This will

be followed by installation of the platforms and subsea

structures during 2013 and 2014. Following hook-up

and commissioning (HUC), the current BP schedule

is to achieve first oil in 2015 (Figure 1.2), although the

proposed timing of activities may change during project

development. In total, over 104 million m3 (638 mmstb)

of oil are expected to be recovered over the forty-year life

of the platform.

BP is the nominated operator of the Clair field

partnership (Table 1.1).

Figure 1.2 Preliminary schedule for development of Clair Ridge

Unit Owner Interest %1

BP Exploration Operating Company Limited2 27.6

Britoil plc2 1.0

ConocoPhillips (U.K.) Limited 24.0

Chevron North Sea Limited 19.4

Clair UK Limited3 9.3

Enterprise Oil Limited3 18.7

1 Unit Interests are rounded to one decimal place.2 BP Exploration Operating Company Limited and Britoil plc

are wholly owned subsidiaries of BP plc.3 Enterprise Oil Limited and Clair UK Limited are wholly

owned subsidiaries of Royal Dutch Shell plc.


| 1 September 20104 | 1

1.2 Scope and aims of the environmental statementThe aim of the EIA is to assess the potential

environmental impacts that may arise from the proposed

Clair Ridge Development and to identify measures that

will be put in place to prevent or minimise these impacts.

The EIA process is integral to the project, assessing

potential impacts and setting design and operational

challenges to ensure that the final impacts of the project

are minimal. The process also provides for the potential

concerns of stakeholders to be identified and addressed

as far as possible at an early stage, and ensures that the

planned activities comply with environmental legislative

requirements and with BPs Environmental Policy.

The ES is a report summarising the EIA process and

outcomes. It also includes details of how the project

decision-making was undertaken and how environmental

criteria were incorporated into that process. The scope

of the EIA was developed and agreed during the

scoping consultation process (see Chapter 5). The ES is

submitted to DECC to inform the decision on whether or

not the project may proceed, based on the acceptability

or otherwise of the residual levels of impact, and is

subject to formal public consultation.

The EIA process has addressed the following

components of the Clair Ridge Development:

Template installation and drilling prior to

jacket installation

Jackets and topsides installation and presence;

New pipelines and subsea infrastructure installation

and presence

Hook-up and commissioning

Operational phase activities including fluids processing

and export, platform drilling, waste management and

subsea activities

Decommissioning

The assessment has included both routine and abnormal

events (such as production upsets) and considered the

risk of accidental events with possible environmental

implications.

The following project components were not within the

scope of the EIA and are therefore not addressed within

this ES:

Existing pipeline infrastructure, e.g. WOSPS and the

Clair Phase 1 oil export line

Clair Phase 1 topsides modifications required for the

Clair Ridge tie-in to the existing export pipelines

Any modifications at SVT that may be required

as a result of receiving, storing and exporting

Clair Ridge fluids

Potential, future subsea tie-backs1

Offsite fabrication of jackets, topsides, utility

packages, pipes, etc. (BP implements an assurance

process to verify the environmental management

systems and processes adopted by project

contractors, including those contracted to complete

offsite fabrication)

Full details of the methodology applied during the EIA

process is described in Chapter 5. This ES reports the

outcome of the process and includes the following:

A non-technical summary of the whole ES

Justification for the field development and the role

of the EIA (Chapter 1)

Description of the options considered for the

Clair Ridge Development and how environmental

considerations were integrated into the decision-

making process (Chapter 2)

Description of the selected concept (Chapter 3)

Description of the environment in the vicinity of

Clair Ridge and the key sensitivities of the nearest

coastlines (Chapter 4)

Methods used to identify and evaluate the

environmental issues associated with the proposed

field development (Chapter 5)

1 However, calculations and modelling included in this ES for the operational phase of the development are based on the full production profile for which the Clair Ridge platforms has been designed, incorporating potential future subsea tiebacks. Further explanation is provided in Section 3.3.

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Detailed assessment of each issue, including the

potential for any cumulative or transboundary

impacts (Chapters 6 to 10)

Environmental management and control measures

that will be in place during the development,

including waste management procedures

(Chapters 11 and 12)

Conclusions (Chapter 13)

1.3 Regulatory context

1.3.1 Requirement for an EIA

The EIA reported in this ES has been carried out in

accordance with the requirements of the Offshore

Petroleum Production and Pipelines (Assessment of

Environmental Effects) Regulations 1999 (as amended).

These regulations require the undertaking of an

environmental assessment and production of an ES for

certain types of offshore oil and gas projects likely to

have a significant effect on the environment. Approval

of the ES is required before approval can be granted to

the Field Development Plan under the Petroleum Act

1998. An environmental assessment is mandatory for

any development that is expected to produce more than

500 tonnes (ca. 3.1 mbd) of oil per day and more than

500,000 m3 (ca. 17.4 mmscf) gas per day. The proposed

development will exceed these threshold quantities and

therefore an EIA is mandatory for Clair Ridge.

1.3.2 Key environmental legislationThe Clair Ridge project will be subject to the

requirements of UK and EU legislation in addition to other

international treaties and agreements such as the Oslo

and Paris Commission (OSPAR). As the development

lies outwith UK territorial waters (ie more than 12 nm

from land), the majority of the activities undertaken will

be governed under the applicable legislation regarding

offshore oil and gas activities, rather than that governing

inshore waters.

The key environmental regulatory drivers applicable

to the Clair Ridge Development, listed below, are

summarised in Appendix A. In addition, key legislation

and guidance relating to the main environmental issues

associated with the development are presented in the

relevant chapters of the ES (Chapters 6 to 11).

Petroleum Act 1998;

Coast Protection Act 1949;

Petroleum Licensing (Production) (Seaward

Areas) Regulations 2008;

Food and Environment Protection Act 1985;

Offshore Petroleum Activities (Oil Pollution

Prevention and Control) Regulations 2005;

Offshore Combustion Installations (Prevention

and Control of Pollution) Regulations 2001;

Offshore Chemical Regulations 2002;

Offshore Petroleum Activities (Conservation of

Habitats) Regulations 2001 (as amended);

Offshore Marine Conservation (Natural Habitats

&c.) Regulations 2007;

Merchant Shipping (Prevention of Pollution by

Garbage) Regulations 1998;

Oil Pollution Preparedness, Response and

Co-operation Convention Regulations 1998,

Emergency Pollution Control

Regulations 2002.


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1.3.3 Evolving environmental legislation

BP recognises that environmental legislation is subject

to change as technology advances and understanding

of the impacts of human activities on the environment

develops. Therefore, an important factor throughout the

EIA process has been the consideration of both known

evolving legislation and other potential future regulation.

A Future Legislation Review (Xodus Group, 2010a) was

conducted to provide an overview of current and evolving

UK environmental legislation that has implications for the

design of the Clair Ridge Development and that should

be considered as part of the detailed design process.

Potential future legislative of relevance to the EIA are

described in the appropriate ES chapter. For example,

EU Emissions Trading Scheme (ETS) requirements are

described in Chapter 9 Atmospheric Emissions.

1.4 BP environmental policy and requirementsBP and its Partners are committed to conducting

activities in compliance with all applicable legislation

and in a manner which contributes to BPs stated goals

of no accidents, no harm to people and no damage

to the environment. In order to achieve these goals

there is a hierarchy of common policies, commitments

and expectations that identify policy and regulatory

requirements and provide tools to assist in compliance

and performance improvements.

In addition to relevant UK and EU legislation and

international standards, the Clair Ridge project is subject

to the following BP environmental requirements:

BP Group Defined Practice (GDP) on Environment

(see Section 12.1) which defines BPs approach

to achieving consistent, environmentally sound

operations in new projects, including the requirement

for environmental assessment of new developments

such as Clair Ridge

The North Sea Strategic Performance Unit (SPU)

HSE policy (see over)

Clair Ridge Environmental principles (see Section 12.1)

as defined in the Clair Ridge Environmental Philosophy

These requirements, together with applicable legislation,

have been applied from the start of the Clair Ridge

project, informing the concept selection and early

design processes with the aim of eliminating or limiting

environmental impact by design.

During operations, the Clair Ridge Development will

conform to the requirements of the Environmental

Management System (EMS) established for the BP

North Sea Strategic Performance Unit (SPU), which is

accredited to ISO 14001 (see Section 12.2).

Details of BPs environmental policy and management

processes, and how they will be applied to the Clair

Ridge Development and implemented during the

operational phase, are provided in Chapter 12.

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2.1 Introduction

The Environmental Impact Assessment (EIA) Directive

(85/337/EEC) requires that where appropriate, an outline

of the main alternatives studied by a developer and an

indication of the main reasons for choice, taking into

account the environmental effects be provided.

DECC Guidance notes on the Offshore Petroleum

Production and Pipelines (Assessment of Environmental

Effects) Regulations 1999 (DECC, 2009) require that

the Environmental Statement (ES) should describe

the main alternatives to the proposed activity that have

been considered. The advantages and disadvantages of

each option should be clearly stated with the specific

environmental implications indicated for each. The main

reasons for the selection of the preferred option should

be described, taking into account the environmental

effects. Other factors influencing the choice of

alternatives should be noted e.g. feasibility, technical

constraints and cost effectiveness. If a formal option

appraisal has been carried out it should be described

and the relevant decision factors noted. Options such

as alternative sites, timing, construction practices, plant

and equipment, operating processes and pipeline routes

should be considered where appropriate.

2.1.1 The decision-making process

From the earliest stages of concept assessment, the

Clair Ridge project team introduced a holistic process

of option analysis in order to facilitate and document

decisions in a transparent and objective way.

The strength of the process is ensured through having

the right people involved which enables experienced and

multi-disciplined input to the decision making process.

Decision evaluation included analysis of five factors

(Figure 2.1) to characterise the concept or technical

options under consideration. During concept selection

consideration was also given to capital expenditure

(CAPEX) and operational expenditure (OPEX). This holistic

approach ensured environmental considerations were

on an equal footing with other factors such as safety and

technical viability.

Consideration of Alternatives2

This chapter outlines the main options considered for the Clair Ridge Development at both the conceptual and Front End Engineering Design (FEED) stages of the project. It describes the evaluation and decision-making process that has been caried out. The decisions made have resulted in the removal or major reduction by design of several sources of potential environmental impact.


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Describethe Issue

Outline options/alternative

Analyse options

Decide

Implementdecision

Flexibility toClair Ridge development

Flexibility toClair field development

Safety

Project deliverability

Environment

This process has been applied by the Clair Ridge project

during concept selection, through FEED and will continue

into detailed design after project sanction. The decisions

taken to date are typically cross-discipline, high impact,

and where transparency was considered essential, i.e.

for DECC, Health and Safety Executive (HSE), partners,

and external stakeholders.

BP has used a variety of tools to support the

decision-making process, including Best Practicable

Environmental Option (BPEO) and Best Available

Technology (BAT) studies, comparative assessment,

and environmental issues identification (ENVID). The

BPEO concept involves assessing the performance of

alternative options against key objectives for various

criteria, including technical feasibility and cost as well

as environmental performance, in order to identify the

option that performs best overall.

2.2 Basis for Clair Ridge DevelopmentAs described in Chapter 1, the first phase of the Clair

field development included the installation of an export

pipeline system and the Clair Phase 1 platform. Clair

Ridge, the second phase of the development, is targeting

the elongated up-thrown part of the field to the northeast

of Clair Phase 1 (see Figure 1.1).

The overall size of the Clair field, the volume of the

available hydrocarbon reserves at Clair Ridge and the

requirement to use dry Xmas trees1 do not allow for

the Clair Ridge area to be developed as a tie-back to the

existing Clair Phase 1 platform. Therefore, a stand-alone

installation is required in order to access and exploit the

hydrocarbon reserves in the Ridge area of the Clair field.

2.3 Concept selection (high level decisions)2.3.1 Concepts considered

A number of potential processing and exporting facilities

for the Clair Ridge fluids were considered during early

project planning. The concept options were centred on

commissioning a new platform (concrete tower/steel

jacket), a jack-up installation or a Floating, Production,

Storage and Offloading (FPSO) facility (Table 2.1).

The facility concept options were screened in

terms of engineering feasibility and practicability,

safety, environment and cost. The options that were

deemed impractical or had an unacceptable level of

environmental risk were not carried forward for further

detailed engineering consideration.

NOTE: Flexibility to Clair Ridge Development: Options potential to adapt to the changes in fluids/conditions brought through production of the Ridge segments of the Clair reservoir.

Flexibility to Clair field development: Options potential to adapt to different fluids/conditions brought by future tie-backs to Clair Ridge or different areas of the Clair reservoir.

Figure 2.1 Decision making process

1 Due to the nature of the Clair reservoir, a requirement for frequent well interventions is anticipated. It is thus deemed impractical to leave Xmas trees on the seabed (Aurora, 2001).

Clair Ridge Development - Environmental Statement

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