OPEN DAY POSTERS - Environmental and advisory … · Toxicity and bioaccumulation ... cuttings Alternative Description Drill site Shell is limiting well drilling to the ... • Discharge

OPEN DAY POSTERS

ENVIRONMENTAL IMPACT ASSESSMENT PROCESS

Project specific activities• 21‐day BID comment period• Advertisements• Notification letters• Meetings held with: MET & MME ‐Windhoek MFMR ‐ Swakopmund Fishing Associations – Walvis Bay Environmental NGOs ‐

Swakopmund Public – Walvis Bay Public – Lüderitz

• 17 written submissions received

• 30‐day DSR comment period• 35 written submissions received

• MET meeting

• FSR approved 4 September 2017

• Drill Cuttings and Oil Spill Modelling • Noise Assessment • Marine and Coastal Ecology Assessment

• Commercial Fisheries Assessment • Socio‐Economic Assessment

• 30‐day Draft EIA Report comment period

• Advertisements• Notification letters

Engagement with the Ministry of Fisheries and Marine

Resources in Swakopmund

Engagement with Fishing Industry in Walvis Bay

PROJECT LOCATION

Place Names

Bathymetry Lines

3D seismic acquired by Shell in 2014

Area of Interest (2 500 km2)

Shell Licence Block (12 299 km2)

Other Licence Blocks

Number of wells 1 ‐ 2

Drilling depth ~ 3 000 m

Drilling duration 2 months per well

ASPECTS AND IMPACTS REGISTERActivity Phase Activity Aspect Potential Impact

1. Mobilisation Phase

Transit of drilling unit and support vessels to drill site

Underwater noise levelsDisturbance of behaviour (foraging and anti-predator) and physiology of marine fauna

Air emissions and local reduction in air quality due to exhaust gases

Potential contribution to cumulative impact on local air quality

Discharge of waste to sea (e.g. deck and machinery space drainage, sewage and galley wastes) and local reduction in water quality

Physiological effect on marine fauna

Increased food source for marine fauna

Increased predator - prey interactions

Exclusion zone around drilling unitDisruption of shipping routes by ships having to make detours

Disruption to fishing activities

Discharge of ballast water Introduction of invasive alien species Loss of biodiversity

Rental of accommodationRequirement for rental and owner-occupied housing

Revenue or income for landlords and rental businesses

Rental of quay spaceRequirement for quay space for onshore facility and support vessels

Revenue or income for Namport

Appointment of local service providersRecruitment for temporary jobs Temporary job creation and earning of salariesBusiness opportunities Income for local service providers

Procurement of equipment / materials from the local market

Business opportunities Income for suppliers

2. Operation Phase

Operation of drilling unit and support vessels

Increase in underwater noise levels

Disturbance / behavioural changes to marine fauna

Fish avoidance of key feeding areas (e.g. Tripp Seamount)

Reduced fish catch and increased fishing effort

Discharge of waste to sea (e.g. deck and machinery space drainage, sewage and galley wastes) and local reduction in water quality



Fish aggregation and increased predator - prey interactions

Exclusion zone around drilling unitDisruption of shipping routes by ships having to make detours

Reduced fishing grounds and catch

Increase in ambient lightingDisorientation and mortality of marine birds


Operation of helicopters Increase in noise levels

Disturbance of coastal and marine fauna

Avoidance of key breeding areas (e.g. coastal birds and cetaceans)

Abandonment of nests (birds) and young (birds and seals)

Seabed survey using a ROV Sediment disturbance Physical damage to and mortality of benthic species / habitats

Well drilling (including spudding)

Sediment disturbancePhysical damage to and mortality of benthic species / habitats

Disturbance of or damage to cultural heritage material (e.g. historical shipwrecks)

Increase in underwater noise levels

Disturbance / behavioural changes to marine fauna

Fish avoidance of key feeding areas (e.g. Tripp Seamount)

Reduction in fish catch and increased fishing effort

Discharge of residual cement during cementing operations

Accumulation of cement on seafloor and sediment disturbance

Toxicity and bioaccumulation effects on marine fauna

Discharge of cuttings and drilling fluidAccumulation of cuttings on seafloor and sediment disturbance

Smothering of benthic fauna

Toxicity and bioaccumulation effects on marine fauna

Increased water turbidity and reduced light penetration


Placement of wellhead on seafloor Increased hard substrate on seafloor Increase in benthic biodiversity and biomass

Well testing (optional for appraisal well only)

Increase in air emissions and ambient lightingDisorientation and mortality of marine birds


Discharge of produced water and local reduction in water quality


3. Demobilisation Phase

Abandonment of wellhead on seafloor Increased hard substrate on seafloorObstruction to or damage of fishing gear

Increased benthic biodiversity and biomass

Drilling unit / support vessels leave drill site and transit to port or next destination

Increase in underwater noise levels during transit Disturbance to marine fauna

Discharge of waste to sea (e.g. deck and machinery space drainage, sewage and galley wastes) and local reduction in water quality during transit




4. Unplanned Activities

Dropped objects / Lost equipment Increased hard substrate on seafloorPhysical damage to and mortality of benthic species / habitats

Obstruction to or damage of fishing gear

Loss of fuel from vessel accidentRelease of fuel into the sea and localised reduction in water quality

Effect on faunal health (e.g. respiratory damage) or mortality (e.g. suffocation and poisoning)

Small instantaneous spills

Discharge of fuel into sea during bunkering bunkering and localised reduction in water quality

Discharge of hydraulic fluid into sea due to pipe rupture and localised reduction in water quality

Loss of well control / well blow-out Uncontrolled release of oil / gas from well

Effect on faunal health (e.g. respiratory damage) or mortality (e.g. suffocation and poisoning)

Smothering of coastal habitats

Reduced fishing grounds and increased fishing effort

Reduced catch

PROJECT ALTERNATIVES

DRILLING STAGES

Riserless Drilling Stage

Drill string

Drilling fluid(Water Based Mud)

WBM & cuttings returns

Conductor pipe

Wellhead

Risered Drilling Stage

SBM and cuttings

Blow-out PreventerWellhead

Conductor pipe

Drilling fluid (SBM)

Marine riser Discharge of treated cuttings

Alternative Description

Drill site Shell is limiting well drilling to the northern portion of the licence area. Impacts are of similar significance no

matter where the well is drilled, assuming that localised hard substrates are avoided.

Drill

scheduleAlthough Shell is proposing to drill in a future summer window period, impacts on sensitive receptors

(specifically fishing at Tripp Seamount) remain of similar significance throughout the different seasons of the

year.

Drilling unit Shell is currently considering two alternative drilling units, either a semi‐submersible drilling vessel or a drill‐

ship. There are no additional impacts or differences in impact significance relating to the choice of drilling unit.

Drilling fluid Two types of drilling fluid would be used during drilling, namely water‐based muds (WBM) and synthetic‐based

muds (SBM). The use of WBMs should be maximised at all times, using risered SBMs only when necessary.

Well

completionDuring well abandonment the wellheads would either remain on or be removed from the seafloor. The

proposed abandonment of well(s) would not contribute to a long‐term or cumulative impact on demersal

fishing.

Logistic base An onshore logistics base would be located in either the Port of Lüderitz or the Port of Walvis Bay. The overall

positive impact on the local economy would be greater if the shore base is located in Lüderitz.

No-Go Alternative Lost opportunity to establish the extent of offshore indigenous oil and gas reserves.

Drill ship Semi‐submersible

SUMMARY OF SENSITIVE RECEPTORS

Shipping route

Namibian Islands Marine Protected Area

Area of Interest

Tripp Seamount

Proposed Orange Shelf Edge EBSA

RECEPTOR DESCRIPTION

1. BIO-PHYSICAL

Tripp SeamountTripp Seamount is located 50 km south-east of the area of interest at its

closest point.

Benthic communities

Deep water benthic fauna inhabiting unconsolidated sediments is

comprised of fast-growing species able to rapidly recruit into disturbed

areas.

Namibia Islands Marine

Protected Area (NIMPA)

The NIMPA comprises the coastal strip north-east of the area of interest.

It has an average width of 30 km and includes 16 offshore islands.

Orange Shelf Edge

Ecologically or Biologically

Significant Area (EBSA)

Licence area overlaps slightly with the proposed transboundary Orange

Shelf Edge EBSA.

2. COMMERCIAL FISHERIES

Commercial fisheries

The area of interest overlaps with only the large pelagic long-line sector.

Aggregations of albacore tuna are known to occur in the vicinity of the

Tripp Seamount and are targeted by the tuna pole fishery.

3. SOCIO-ECONOMIC

Lüderitz and Walvis Bay –

Goods and Services

Namibia doesn’t have an upstream oil and gas industry and because of

the highly specialised nature of the project there will be a reliance on

international service companies and technical skills. Opportunities for

local employment and procurement will be identified.

Lüderitz and Walvis Bay –

Tourism

Ocean and desert-based tourism in Lüderitz and Walvis Bay contributes

significantly to these local economies.

DISCHARGE OF CUTTINGS AND DRILLING FLUIDS

Issue:Physical disturbance of seabed sediments and accumulation of cuttings on the seabed, as well as the increase of sediment in the water column. Impacts include:• Smothering.• Toxicity and bioaccumulation effects.• Physiological and biochemical effects.

Key receptors:Deep water benthic fauna inhabiting unconsolidated sediment, i.e. fast‐growing species that are able to rapidly recruit.

Project Controls:• Pre‐drilling seabed survey with ROV.• Treatment of cuttings to reduce residual SBM content.• Discharge cuttings > 15 m below surface.

Impact Assessment:

Mitigation:Well to avoid identified vulnerable benthic habitats by >500 m.

Residual Impact:Insignificant to Very Low Significance.

Illustration of cuttings discharge from an offshore drilling unit

A seabed survey will be conducted prior to drilling to avoid impacts on deep water corals

September discharge scenario December discharge scenario

17 km2

20 km2

Max. thickness: 71 mm

Max. thickness: 68 mm

UNDERWATER NOISE

Issue:Project activities would increase the ambient noise levels in the vicinity of the drill site . Impacts include:• Physical injury to hearing or other organs.• Masking or interfering with other biologically important sounds.• Behavioural changes or displacement from important feeding areas.

Key receptors:Pelagic seabirds, turtles, large migratory pelagic fish and cetaceans, some of which are ‘Critically Endangered’, ‘Endangered’ or ‘Vulnerable’, specifically at Tripp Seamount.

Project Controls:The size of the area of interest was reduced to increase the distance between the drill site and Tripp Seamount.

Impact Assessment:• Ambient noise level range: 80 – 120 dB re 1 μPa.

(In underwater sound “dB re 1 µPa” is the standard reference unit of sound pressure level in decibels (dB) relative (re) to 1 µPa (micro Pascal or one‐millionth of a Pascal).

• Project noise range: 184 – 190 dB re 1 μPa. • Project noise levels decrease back to below the median ambient noise level

within 32 km.• Project noise decreases to below the upper boundary of ambient background

level of 120 dB within a distance of less than 5 km from the drill site.

Mitigation:Vertical seismic profiling: Pre‐start scan and “soft‐start” procedure.

Residual Impact: Insignificant to Very Low Significance.

Noise level attenuation with distance

Median ambient level

32 km

Distance back to the median ambient noise level

FISHING – IMPACT OF EXCLUSION ZONE AND NOISE

Issue:Reduced catch and/or increased fishing effort due to exclusion zone around drilling unit and operational noise.

Key receptors:• Sector affected by exclusion zone: Large pelagic long‐line sector. • Sectors affected by noise: demersal trawl, demersal long‐line, large pelagic

long‐line and tuna pole fisheries.

Project Controls:The size of the area of interest was reduced to increase the distance between the drill site and Tripp Seamount.

Impact Assessment:• Exclusion zone: 500 m around drilling unit.• Project noise levels will reduce back to below the

median ambient noise level within 32 km.

1. Large pelagic long‐line:

• Effort overlaps with exclusion zone and predicted 32 km project noise zone.

• Less than 1% of total long‐line effort and catch recoded within area of interest (2005 – 2015).

2. Demersal trawl:

• No overlap with exclusion zone.• Western extent is located within 32 km

of area of interest.

Shell licence bock

Initial EIA area

Revised EIA area

Original and revised area of interest

FISHING – IMPACT OF EXCLUSION ZONE AND NOISE (cont.)

Impact Assessment:3. Tuna pole: 4. Demersal long‐line:

• No overlap with exclusion zone.• Minor effort located within

32 km of area of interest.

5. Pelagic purse‐seine: 6. Mid‐water trawl:

• No overlap with exclusion zone.• No effort located within


Mitigation:• Stakeholder notification: Radio Navigation Warnings and Notice to Mariners.• Vertical seismic profiling: Pre‐start scan and “soft‐start” procedure.

Residual Impact:

• No overlap with exclusion zone.• Minor effort located within


• No overlap with exclusion zone.• No effort located within


Sector Significance Sector Significance Sector Significance

Large pelagic long‐line : Very Low Tuna pole: Insignificant Pelagic purse‐seine: No impact

Demersal trawl: Insignificant Demersal long‐line: Insignificant Mid‐water trawl: No impact

SOCIO‐ECONOMIC ‐ PROJECT SPENDING AND TOURISM

Issue:The project would result in a temporary spending injection that would benefit the local economy. All expenditures would lead to increased economic activity in Namibia.

Boost to tourism in the project area(s) through its facilitation of increased business tourism.

Key receptors:The communities living in and businesses operating out of Lüderitz and Walvis Bay.

Project Controls:• Shell’s HSSE & SP Control Framework standards for Social Performance.• Shell’s supplier principles for contractors and suppliers.

Impact Assessment:• Employment:

• Project spending:

• Total project spending:

Mitigation:• Inform local stakeholder of project timing and

opportunities for jobs and procurement.

Residual Impact:

Port support activities

Total personnel requirements 170 – 290 people

Opportunities for local Namibians 15 – 50 people

Employment duration 1 – 12 months

Cumulative local income ± N$ 1 ‐ 2 million

Spending by non‐local personnel ± N$ 2 ‐ 5 million

Spending on food and other supplies ± N$ 3 ‐ 5 million

± N$ 6 million ‐ N$ 12 million

Business tourism:

Historical sites

Water sports

Recreational fishing

Accommodation

Impact Significance

Project spending: Low (+ve)

Tourism: Very Low (+ve)

SOCIO‐ECONOMIC – MARINE TRAFFIC

Issue:The presence of the drilling unit and associated exclusion zone present a potential risk of interference with key shipping routes.

Key receptors:The area of interest is located on the eastern boundary of the main traffic route to and from Cape Town.

Project Controls:• 500 m exclusion zone.• Support vessels to enforce exclusion.

Impact Assessment:• Drilling unit would be stationary and is therefore easily avoidable with minimal

adjustment to a vessel’s course.

Mitigation:• Radio Navigation Warnings.• Notice to Mariners.

Residual Impact:Insignificant.

Maritime traffic

Area of Interest

50 km

Key shipping route

500 m exclusion zone

LARGE OIL SPILL: WELL BLOW‐OUT

Issue:Oil spilled in the marine environment would have an immediate detrimental effect on water quality, resulting in mortality of marine fauna or affecting faunal health. An oil spill would also result in several indirect impacts on fishing.

Key receptors:Namibia Islands Marine Protected Area (NIMPA), Tripp Seamount and associated marine fauna. Fishing sectors operating in southern Namibia.

Project Controls:• Technical and HSSE standards and procedures.• Equipment testing and certification.• Multiple barriers, e.g. Blow‐out Preventer, casings and wellbore pressure.• Oil Spill Response Plan and Well Control Contingency Plan.

Impact Assessment:• The probability of a well blow‐out occurring is highly unlikely.• There is a low probability of oil extending into key fish spawning/nursery areas.

Mitigation:• Implement emergency plans.• Use low toxicity dispersants only with the permission of MET/MFMR.

Residual Impact: Medium Significance.

Stochastic analysis – 8‐day blow‐out (400 000 bbl) Stochastic analysis – 90‐day blow‐out (4 500 000 bbl)

Spill orientation North‐West

Shoreline oiling None

Zone of highest oiling (75‐100% probability)

125 km




200 km

SMALL OIL SPILL: LOSS OF MARINE DIESEL

Issue:Small instantaneous spills would have an immediate detrimental effect on water quality, with the toxic effects potentially resulting in mortality of marine fauna or affecting faunal health. There may also be potential indirect impacts on fishing.

Key receptors:• Pelagic seabirds, turtles, large migratory pelagic fish and cetaceans. • The area of interest overlaps with the large pelagic long‐line sector.

Project Controls:• Technical and HSSE standards and procedures.• Equipment testing and certification.• Competent staff.

Impact Assessment:

Mitigation:• Implement Shipboard Oil Pollution Emergency Plan.• Use low toxicity dispersants only with the permission of MET/MFMR.• Inspect and maintain all chemical / fuel containers.

Residual Impact:Impact Significance

Marine fauna: Insignificant

Fishing: Very Low




1 km

Zone with probabilities >1% of oiling

12.5 km

Instantaneous release of 10 000 litres of diesel

EIA CONCLUSIONS

• Ecological integrity:• The area of interest is far removed from

sensitive coastal receptors.• Atlantic Offshore Bioregion is classified as

Least Threatened.• Deep water benthic fauna inhabiting

unconsolidated sediments is less susceptible to the effects of smothering.

• Recovery of benthic fauna in 2 – 5 years.• Negligible loss of ecological integrity.

• Economic efficiency:• Project is largely compatible with key

socio‐economic policies and plans.• Only the large pelagic long‐line sector is

directly affected – exclusion from 500 m safety zone.

• Adverse underwater noise impacts at the Tripp Seamount are considered unlikely.

• Limited jobs and local project spending.• Economically efficient, as no other party/ies

would be significantly impacted.

• Equity and social justice:• No unfair discrimination on any one party.• Negative impacts are not unequally

distributed.

The generally INSIGNIFICANT to LOWsignificant impact with mitigation should

support a positive decision and the issuing of an Environmental Clearance Certificate

SUMMARY OF IMPACTS AND SIGNIFICANCE RATINGS – NORMAL OPERATIONS

No. Activities ImpactsProbability with

mitigation

Significance

Without

mitigationWith mitigation

1 Emissions to the atmosphere:

1.1Emissions from vessel operation (incl.

incineration of waste and well testing)

Physiological effect on marine fauna and contribution to global

greenhouse gas emissionsProbable Very Low VERY LOW

2 Discharge of wastes to sea:

2.1 Discharge of cuttings, drilling fluid and cement

Smothering by cuttings, drilling fluid

and cement

Unconsolidated sediments PossibleInsignificant ‐

Very Low

INSIGNIFICANT ‐

VERY LOW

Hard substrates Improbable Low ‐Medium INSIGNIFICANT

Toxicity and bioaccumulation effects on

marine fauna

WBM Possible Very Low INSIGNIFICANT

SBM Probable Very Low VERY LOW

Cement Possible Very Low INSIGNIFICANT

Increased water turbidity and reduced light penetration Possible Insignificant INSIGNIFICANT

Reduced physiological functioning of marine organisms due to

indirect biochemical effectsPossible Insignificant INSIGNIFICANT

3 Physical disturbance of the seabed sediments:

3.1Seabed survey, spudding and wellhead

installation

Physical damage to, mortality of and physiological effects on

benthic faunal communitiesProbable Very Low VERY LOW

Emissions from drilling unit operation and well testing / flaringSeabed disturbance due to infrastructure installation

Drill string and wellhead guide base

SUMMARY OF IMPACTS AND SIGNIFICANCE RATINGS – NORMAL OPERATIONS


mitigation

Significance

Without


4 Noise

4.1Noise emissions from the operation of the

drilling unit and support vessels

Masking of biologically significant sounds Probable Very Low VERY LOW

Behavioural changes or displacement from important feeding or

breeding areasPossible Insignificant INSIGNIFICANT

4.2 Noise emissions from Vertical Seismic ProfilingMasking of biologically significant sounds and behavioural changes or

displacement from important feeding or breeding areasPossible Very Low INSIGNIFICANT

5 Physical presence of subsea infrastructure:

5.1 Abandonment of the well(s) on the seafloor Increased the benthic biodiversity and biomass Definite Low (neutral) LOW (NEUTRAL)

6 Local project spending:

6.1Employment of local staff and purchase of

goods and services

Increased economic activity linked to employment and incomes

(salaries, fees, rentals, etc.)Definite Very Low (+ve) LOW (+VE)

7 Commercial fishing:

7.1Noise emissions from vessels and drilling

operations

Loss of catch and / or increased fishing effort due to behavioural

changes or displacement of fish from important feeding areasPossible Insignificant INSIGNIFICANT

7.2 Discharge of well drill cuttings and cementLoss of catch and / or increased fishing effort due to affect predator–

prey interactions (large pelagic long‐line sector only)Improbable Insignificant INSIGNIFICANT

Key noise sources:

Drilling unit Helicopter operationsSupport vessels Drilling Vertical Seismic Profiling (VSP)

SUMMARY OF IMPACTS AND SIGNIFICANCE RATINGS – UNPLANNED ACTIVITIES


mitigation

Significance

Without


1 Small operational spill

Toxic effect on faunal health (e.g. respiratory damage) and mortality

(e.g. suffocation and poisoning)Possible Low INSIGNIFICANT

Impact on commercial fishing through exclusion from polluted areas

and reduced recruitmentProbable Very Low VERY LOW

Exclusion of sea‐based tourism activities Improbable Low VERY LOW

2 Large well blow‐outs

Effect on faunal health (e.g. respiratory damage) or mortality (e.g.

suffocation and poisoning)Improbable High MEDIUM

Impact on commercial fishing through exclusion from polluted areas,

reduced recruitment and fishing gear damageImprobable Medium MEDIUM

Impact on tourism through the exclusion of sea‐based tourism

activities Improbable Low VERY LOW

3 Dropped objectsPhysical damage to and mortality of benthic species / habitats Possible Low INSIGNIFICANT

Increased the benthic biodiversity and biomass Possible Insignificant NO IMPACT

Capping stack systemBlow‐out preventer

Project controls for oil spillsImprobable event of an 8‐day blow‐out (400 000 bbl) –

worst case simulation scenario

Oil spill booms

EXTRACT FROM ENVIRONMENTAL MANAGEMENT PLAN – OPERATION PHASE

No. Activities AspectsKey

Receptors

Environmental

and Social

Performance

Objective

Indicators TargetsMitigation and Management

actions

Type of

Mitigatio

n Option

Responsi‐

bility

Frequency

/ timing

Monitoring

and record

keeping

require‐

ments

1 Operation

of drilling

unit at drill

site

Creation of

an exclusion

zone around

drilling unit

which other

vessels

cannot enter

Fishing

industry

and

mariners

Ensure

navigational

safety

All maritime

stakeholders

informed of

project

timing, vessel

information,

transit and

location

Zero maritime

incidents

All maritime

stakeholders

on project

database

notified

Request, in writing, HyrdoSAN to

release Radio Navigation

Warnings via Navigational Telex

(Navtext) and Lüderitz radio.

Avoid /

reduce at

source

Shell 7 days

prior to

establish‐

ment at

drill site

and

throughout

drilling

Confirm that

request was

sent to

HydroSAN

2 Distribute a Notice to Mariners to

fishing companies and directly

onto vessels. The notice should

give notice of:

the co‐ordinates of the well

location;

an indication of the proposed

drilling timeframes;

an indication of the 500 m

safety zone around the drilling

unit; and

provide details on the

movements of support vessels

servicing the drilling operation.

Avoid /

reduce at

source

7 days

prior to

establish‐

ment at

drill site

Copies of all

correspon‐

dence

Fisheries Notification:

Radio Navigation warning and Notice to Mariners

Drill ship:

A 500m safety zone will be established around the drilling unit according to Article 60 of the United Nations Convention of the Law of the Sea

EXTRACT FROM ENVIRONMENTAL MANAGEMENT PLAN – OPERATION PHASE

No. Activities AspectsKey

Receptors

Environmental

and Social

Performance

Objective

Indicators TargetsMitigation and Management

actions

Type of

Mitigation

Option

Respon‐

sibility

Frequency /

timing

Monitoring

and record

keeping

require‐

ments

3 Well

drilling

Discharge of

drill cuttings

Marine

fauna,

specifically

benthic

fauna

Protect

sensitive

seabed

habitats

Smothering

of hard

substrates

Zero

disturbance

of hard

substrates,

which house

sensitive

benthic

communities

Review ROV footage of pre‐

drilling surveys to identify

potential vulnerable habitats

within 500 m of the drill site.

Ensure drill site is located more

than 500 m from any identified

vulnerable habitats.

Avoid /

reduce at

source

Drilling

contractor /

Shell

Prior to

spudding

ROV footage

4

5 Drilling fluid

additives

Use only low‐

toxicity and

biodegradable

additives in

drilling fluid

Ensure only low‐toxicity and

partially biodegradable

additives are used in drilling

fluid.

Avoid /

reduce at

source

Drilling

contractor

Prior to

drilling

Volume

discharged

Additives in

drilling fluid

Oil content

of SBM drill

cuttings

6 Oil content:

≤6.9%

PAH: 0.001

Hg: <1 mg/kg

Cd: <3 mg/kg

Treatment of cuttings to reduce

the:

Oil content to 6.9% or less of

dry cutting weight;

PAH to less than 0.001;

Hg to less than 1 mg/kg; and

Cd to less than 3 mg/kg.

Reduce at

source

Drilling

contractor

Throughout

risered

drilling

Cuttings treatment:

Shale shakers separate solids from liquids. The liquids are pumped back downhole, while the solids are removed and undergo further treatment before disposal

Pre‐drilling seabed survey:

An remotely operated vehicle (ROV) will be used for pre‐drilling seabed survey

OPEN DAY ATTENDANCE REGISTERS

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OPEN DAY POSTERS - Environmental and advisory … · Toxicity and bioaccumulation ... cuttings Alternative Description Drill site Shell is limiting well drilling to the ... • Discharge