DET NORSKE VERITAS TM

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2 DET NORSKE VERITAS TM Report ENVIRONMENTAL RISK ANALYSIS (ERA) FOR EXPLORATION WELL 6507/10-2 NOVUS IN THE NORWEGIAN SEA AGR PETROLEUM SERVICES AS REPORT NO./DNV REG NO.: / 16EIG9K-6 REV 0,

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4 Table of Contents Page EXECUTIVE SUMMARY... 1 DEFINITIONS & ABBREVIATIONS INTRODUCTION Background Scope Regulation framework Faroe Petroleum s acceptance criteria for acute pollution Report structure ACTIVITY AND AREA DESCRIPTION DEFINED SITUATIONS OF HAZARD AND ACCIDENT (DSHA) Introduction Probability for DSHA Blowout rates and probabilities Blowout durations and probabilities OIL CHARACTERISTICS OIL DRIFT RESULTS Hit probabilities Topside release Subsea release Single simulation scenario Hit probabilities by mass category Water column concentrations Topside release Subsea release Coastal habitats Topside release Subsea release ENVIRONMENTAL RESOURCES Valued ecosystem components (VECs) Selected VECs Seabirds Marine mammals Shoreline habitat Fish ENVIRONMENTAL RISK ANALYSIS RESULTS Possible consequences from a blowout Possible consequences for pelagic seabirds Revision No.:0 Date : Page ii of iii

5 7.1.2 Possible consequences for coastal seabirds Possible consequences for marine mammals Possible consequences for coastal habitats Possible consequences for fish Environmental risk Pelagic seabirds Coastal seabirds Marine mammals Coastal habitats Summary of environmental risk REFERENCES ENVIRONMENTAL RISK ANALYSIS METHOD ENVIRONMENTAL RESOURCES Revision No.:0 Date : Page iii of iii

6 EXECUTIVE SUMMARY Faroe Petroleum AS plans drilling of exploration well 6507/10-2 Novus in PL645 and the Halten Terrace hydrocarbon province the during the second half of The drilling site is located southwest of the Heidrun field and approximately 168 km from the nearest point along the Norwegian shoreline, Vikna in the county of Nord-Trøndelag. Water depth at the location is 297 m. AGR Petroleum Services, the subcontractor for Faroe Petroleum regarding the planning of the activities concerning drilling, has requested DNV to perform a damage-based Environmental Risk Analysis (ERA) according to the industry standard (Norwegian Oil and Gas, 2007). The oil spill modelling has already been performed by DNV in a separate project (DNV, 2013) and serves as input to the ERA. A wide range of relevant resources have been included in the analysis including seabirds (using data sets of both open sea and coastal seabirds), marine mammals and coastal habitats. The highest probability of population loss among seabird and marine mammal components was identified as: 1-5 % population loss: 67 % probability (Razor-billed Auk in the open sea during the winter season; topside blowout) 5-10 % population loss: 24 % probability (Razor-billed Auk in the open sea during the winter season; subsea blowout) % population loss: 14 % probability (Razor-billed Auk in the open sea during the winter season; subsea blowout) % population loss: 3 % probability (Little Auk in coastal waters during the spring season; subsea blowout) >30 % population loss: 0.5 % probability (Little Auk in coastal waters during the spring season; subsea blowout) Regarding environmental risk, pelagic seabird populations pose the highest risk of environmental damage with approximately 22 % of the acceptance criterion for moderate environmental damage (1-3 years restitution time (autumn season) being dimensioning for the analysis. The risk level is comparable for pelagic and coastal sea birds during spring and summer. During autumn and winter pelagic seabirds exhibit a significantly higher risk level, also reflecting that several coastal seabird resources migrate to open sea, or move further south during the cold months. Marine mammals and coastal habitats exhibit lower risk levels. For marine mammals the highest risk is seen during autumn and winter, reaching 12 % in the winter season and calculated for Grey Seal. For coastal habitats the risk level is comparable throughout the year and never exceeds 6 % of the acceptance level, calculated for moderate damage during the spring season. The environmental risk is within Faroe Petroleum s risk acceptance criteria during the whole year. Based on this it is concluded that the environmental risk related to drilling of exploration well 6507/10-2 Novus is low in relation to Faroe Petroleum s defined risk acceptance criteria. Date : Page 1 of 44

7 DEFINITIONS & ABBREVIATIONS Acceptance criteria ALARP Analysis area BOP cp DNV DSHA ERA GOR Hit probability ICES IMR Influence area The criteria defines the maximum allowed occurrence of accidents that can cause an environmental damage with a given recovery time. The classification is in line with the industry standard for environmental risk analysis (Norwegian Oil and Gas, 2007). As low as reasonably practicable. ALARP expresses that the risk level is reduced (through a documented and systematic process) so far that no further cost effective measure is identified. Area that make the basis for environmental risk analyses and that are larger than the influence area (influence area is a result of oil drift modelling). The resource description is carried out in the analyses area to make sure the size of the area is sufficient. Blowout preventer Centipoise, measure for viscosity Det Norske Veritas AS Defined situations of hazard and accident. DSHA is a selection of hazardous and accidental events that will be used for the dimensioning of the emergency preparedness for the activity and for the environmental risk assessment. Environmental risk assessment Gas to oil ratio. The probability that a given km grid is hit by oil from a potential oil spill. International council for exploration of the sea Institute of marine research (Bergen) A defined area with 5 % or more probability for pollution within a km grid if an oil discharge has taken place. MIRA Method for environmental risk assessment (Norwegian Oil and Gas, 2007). NCS OLF ppb ppm RAC Recovery time THC VEC Weathering Norwegian continental shelf Oljeindustriens landsforening, previous name of the Norwegian Oil and Gas Association (Norsk olje og gass) Parts per billion (µg/l) Parts per million (mg/l) Risk acceptance criteria Recovery is achieved when the original animal- and plant life in the affected environment is present on the same level as before the oil spill (natural variation considered), and the biological processes works normally. Recovery time is the time from an oil spill occurs until the recovery is achieved. Total hydrocarbon Valued ecosystem component. Recourses with high vulnerability and conservation value. VECs are chosen as dimensioning resources in the assessment due to high vulnerability to oil pollution and/or high degree of presence in the analytic area. VECs are species that are likely to be affected in the assessment. Degradation of oil in the environment. The weathering analysis measures the physical and chemical characteristic of the oil present in the environment. Date : Page 2 of 44

8 1 INTRODUCTION 1.1 Background Environmental Risk Analysis (ERA) is required by Norwegian law for activities related to exploration and/ or production of oil and gas taking place at the Norwegian Continental Shelf (NCS). The analysis carried out for exploration well 6507/10-2 Novus is a damage-based environmental risk analysis focusing on the potential impact and environmental risk on relevant resources related to a blowout. The resources applied in an ERA are often referred to as Valuable Ecosystem Components (VECs). In order to be defined as a VEC different criteria have to be fulfilled (Section 6.1). Seabirds, marine mammals, fish species and coastal habitats are common VEC categories used on the NCS. The environmental risk contributions from the different activities are eventually calculated as the percentage of Faroe Petroleum s operation specific acceptance criteria and linked to the company s ALARP criteria. The ERA is performed in accordance with the industry guideline for risk analysis on the NCS (Norwegian Oil and Gas, 2007). A brief description of the methodology is available in Appendix 1. For further information it is referred to the guideline. In addition to the herein reported ERA, Faroe Petroleum has also had a habitats assessment and an initial coral risk assessment carried out for the Novus field. For results, evaluation and conclusions reached in these assessments it is referred to Fugro Ltd (2012) and DNV (2012). 1.2 Scope Faroe Petroleum plans drilling of exploration well 6507/10-2 Novus in the during the second half of AGR Petroleum Services (henceforth referred to as AGR), the subcontractor for Faroe Petroleum regarding the planning of the activities concerning drilling, has requested DNV to perform a damage-based ERA for the well. The oil spill modelling has already been performed by DNV in a previous project (DNV, 2013) and serves as input to the ERA. 1.3 Regulation framework The Norwegian Pollution Act state the duty of avoiding pollution. The Framework regulations ( 11) state that principles such as the ALARP principle are required in order to reduce risk. The Framework regulations also state that risk reduction shall follow the cost- benefit principle. In accordance with the Management regulations ( 25-26), all operating companies planning activities related to exploration and/ or production of oil and gas in the Norwegian sector are required to apply for consent from the Norwegian government. In accordance with the Management regulations ( 16-17) an environmental risk assessment and an oil spill contingency assessment for the activity shall be prepared. The Activities regulation ( 73) states a requirement to establish an oil spill response plan which includes a preparedness strategy. The response plan shall be based on the environmental risk- and oil spill contingency assessment, and show a connection between environmental risk and the level of preparedness. The response plan shall protect sea, coast and shoreline. The Framework regulations also set requirements to operators to cooperate for preparedness against acute pollution in regions with shared oil spill response plans and preparedness equipment. Date : Page 3 of 44

9 The Management regulations require that operator shall establish barriers both to avoid an accident, and make actions to reduce consequences. A summary of the analyses mentioned above, together with a description of how the oil spill preparedness against acute pollution is ensured, have to be sent to the government in adequate time before the activity starts, normally along with the application for consent (in accordance with the Management regulations ( 25). Regulations for the petroleum activities are found on: Faroe Petroleum s acceptance criteria for acute pollution Faroe Petroleum has defined acceptance criteria for environmental risk as an integrated part of their management system. For exploration well Novus, the company's operation specific acceptance criteria are used for the environmental risk assessment (Table 1-1). The acceptance criteria set upper limits for what Faroe Petroleum has defined as an acceptable risk to their own activities (probability of a given consequence). These are formulated as a measure of damage to natural resources (VECs), expressed as duration (recovery time) and severity of environmental damage. The ERA captures differences in the environmental vulnerability within a region by taking into account the presence and vulnerability of environmental resources in the assessed area, and by calculating the recovery time of affected resources. This results in a higher, potential environmental risk for an area inhabiting a large portion of a vulnerable population or habitat type. The risk acceptance criteria express Faroe Petroleum s attitude to preserve the nature, stating that as far as possible nature should be unaffected by the company's activities. The criteria specify the maximum allowed frequency of events that may cause damage to the environment. Table 1-1 Faroe Petroleum s operation specific acceptance criteria for environmental damage (Faroe Petroleum, 2011). Severity of environmental damage Duration of damage (recovery time) Intolerable probability (per operation) Negligible probability (per operation) Minor 1 month -1 year 1.0 x x 10-4 Moderate 1-3 years 2.5 x x 10-5 Considerable 3-10 years 1.0 x x 10-5 Serious > 10 years 2.5 x x Report structure The structure of the report is illustrated in Figure 1-1. The chapter references indicate where in the report the different types of information are presented. Date : Page 4 of 44

10 DetNorskeVeritas Reportfor AGR PetroleumServicesAS EnvironmentalRisk Analysis(ERA) for explorationwell 6507/10-2 Novusin the NorwegianSea Figure 1-1 Overviewof the EnvironmentalRiskAnalysis. Thechapterreferencesto the left indicate wheretheinformationis presented. DNV Reg.No.: 16EIG9K-6 RevisionNo.: 0 Date: Page5 of 44

11 2 ACTIVITY AND AREA DESCRIPTION Faroe Petroleum plans drilling of exploration well 6507/10-2 Novus in PL645 in the Halten Terrace hydrocarbon province in the. The drilling site is located southwest of the Heidrun field and approximately 168 km from the nearest point along the Norwegian shoreline, Vikna in the county of Nord-Trøndelag (Figure 2-1). Water depth at the location is 297 m. Faroe Petroleum is the operator of PL645 after the license was awarded in the 2011 APA licensing round. Faroe Petroleum holds 50 % of the equity in the Novus prospect while partners Centrica Resources (Norge) AS and Skagen 44 AS hold equities of 40 % and 10 %, respectively. The operation will target the Novus West prospect, comprising the (from top to base) Garn/Ile, and Tilje formations. In the case of a discovery in Novus West, a sidetrack may be drilled into the Novus East prospect, comprising the Garn/Ile, Tilje and Åre formations. Oil filled reservoirs are probable in both Novus East and Novus West reservoirs (Add Wellflow, 2012). Figure 2-1 The location of exploration well 6507/10-2 Novus in the. The Novus well will be drilled by the drillship West Navigator from Seadrill (Figure 2-2) during the second half of West Navigator has been operating in Norway, UK, West of Shetland, Ireland, Greenland, Canada, Faeroes, Egypt and Mauritania in water depths ranging from 280 m to 1920 m, conducting exploration drilling, development drilling, subsea completion and well testing. For technical specifications refer to Date : Page 6 of 44

12 Hydrocarbons in the Garn/Ile and Tilje formations are located in the lower to middle Jurassic sandstones. The reservoir sandstones are dominated by fine grained and well to very well-stored sub arkosic arenites. The sandstones are buried at a deep of m and are affected by diagenetic processes. Mechanical compaction is the most important process which reduces reservoir quality. Still, most of the sandstones are good reservoir rocks. The porosity is in the range of percent while permeability varies from 20 to 2500 md. The source rocks are believed to be the Spekk formation from late Jurassic and coal bedded Åre formation from early Jurassic. The cap rock which seals the reservoir and keeps the oil and gas in place is the Melke formation. The Not formation behaves as a sealing layer, preventing communication between the Garn and Ile formations (Verlo and Hetland, 2008). Figure 2-2 The drillship West Navigator from Seadrill which is contracted to drill exploration well 6507/10-2 Novus in the during the second half of Date : Page 7 of 44

13 3 DEFINED SITUATIONS OF HAZARD AND ACCIDENT (DSHA) 3.1 Introduction Defined situations of hazard and accident are the activities/scenarios that have the greatest potential to cause harm to the environment. The environmental risk associated with an uncontrolled release of oil is related to its frequency (for a release to take place), intensity and duration. Scenarios selected for the ERA are those with the highest contribution to the environmental risk level. Incidents with the greatest potential to harm the surrounding environment are uncontrolled releases of oil from the well during drilling (blowouts). A blowout from exploration well 6507/10-2 Novus is considered dimensioning for the environmental risk of the planned activity. In order to determine which scenarios that should be a part of the ERA modelling, an identification of potential oil spill blowout and release scenarios has been assessed by Add Wellflow (2012). The possible blowout scenarios are: blowout through drill pipe, blowout through annulus or blowout through open/ cased hole. 3.2 Probability for DSHA Exploration well 6507/10-2 Novus is considered a normal risk level exploration well with the probability of encountering oil in penetrated formations. A standardized blowout frequency for exploration drilling in oil reservoirs of 1.43 x 10-4 (Scandpower, 2012) was therefore used. The drilling operation will be performed from the drillship West Navigator, and the BOP will be at the seabed. The probability split between a topside (18 %) and subsea (82 %) release was established based on the SINTEF database (Scandpower, 2012) for drilling operations from floating installations. 3.3 Blowout rates and probabilities A total of 12 different blowout rates were used in the oil drift modelling, six rates for a topside release, and six rates for a subsea release. Blowout rates and probabilities taken from Add Wellflow (2012) are presented in Table 3-1. The weighted blowout rate for a topside and subsea release is 5119 Sm 3 /day and 4973 Sm 3 /day, respectively. Date : Page 8 of 44

14 Table 3-1 Discharge rates with probability distribution for each blowout scenario. Numbers are taken from Add Wellflow (2012). Blowout location Rate (Sm 3 /day) Probability 2, % 4, % Topside 6, % (18 %) 8, % 13, % 18, % Weighted rate 5,119 Subsea (82 %) Weighted rate 4,973 2, % 4, % 6, % 8, % 12, % 17, % 3.4 Blowout durations and probabilities The longest duration for a blowout is determined by the time it takes to drill a relief well. For Novus the longest duration is estimated to 52 days, which includes mobilization of the rig, drilling time and ranging runs and homing in (Add Wellflow, 2012). The oil drift modelling was performed for the whole year using release durations 2, 15 and 52 days, with probabilities for the release durations according to Add Wellflow (2012). The weighted blowout durations for a topside and subsea blowout are 6.1 days and 19.1 days, respectively (Table 3-2). Table 3-2 Discharge duration with probability distribution for each blowout scenario. Numbers are taken from Add Wellflow (2012). Probability Probability Duration (days) (Topside) (Subsea) % 47.3 % % 25.0 % % 27.8 % Weighted duration (days) Date : Page 9 of 44

15 4 OIL CHARACTERISTICS Heidrun Fangst (SINTEF, 2004) was chosen as model oil to represent the oil encountered in the Novus well. Some characteristics of Heidrun Fangst are given in Table 4-1. At normal summer conditions (10 m/s wind and 15 C water temperature) approximately 30 % of the oil evaporates after one day at sea. For both topside and subsea releases an initial oil film thickness of 2 mm has been used. Table 4-1 Properties of Heidrun Fangst, the model oil used in oil drift simulations (SINTEF, 2004). Parameter Value Oil density (kg/m 3 ) 883 Maximum water content at 15 C (% volume) 70 Viscosity at 13 C (cp) 19 Wax content (% weight) OIL DRIFT RESULTS Statistical oil drift modeling for both topside and subsea blowouts for e exploration well 6507/10-2 Novus has recently been delivered to AGR (DNV, 2013). For an extensive introduction to the OSCAR model it is referred to that report. The results from the oil drift modeling are used for exposure calculations in the environmental risk analysis. 5.1 Hit probabilities This section presents the hit probability of oil in km grid cells for the different blowout scenarios described in Section The modelled results are based on all blowout rates and durations weighted with the probability for each scenario. The results are presented seasonally for spring (March-May), summer (June-August), autumn (September-November) and winter (December- February). The influence areas are calculated from a total of 5,440 individual simulations for topside and subsea releases, 2,720 simulations for each release point. The horizontal resolution (4 km) of the current data will induce a stronger impact of the Norwegian coastal current and consequently render larger influence areas compared to previous studies. It should be noted that the influence area does not show the extent of a single oil spill, but represents the area affected by >1 ton of oil per 10 x 10 km grid cell in more than 5 % of all single simulations within each season Topside release Seasonal hit probabilities related to a topside blowout from exploration well 6507/10-2 Novus are presented in Figure 5-1. Statistics are generated for each km grid cell and based on 3 durations and 6 release rates and their individual probabilities. The model produces similar influence areas for all four seasons, albeit with a stronger tendency for a spill to spread westwards during spring and summer, and a further propagation northwards beyond Lofoten during autumn and winter Subsea release Seasonal hit probabilities related to a subsea blowout from exploration well 6507/10-2 Novus are presented in Figure 5-2. Statistics are generated for each km grid cell and based on the 3 durations and 6 release rates and their individual probabilities. The model produces similar results as for a topside release (see above), reflecting similar blowout rates and their individual probabilities for both a topside and subsea release. Date : Page 10 of 44

16 Figure 5-1 Seasonal hit probabilities in km grid cells given a topside blowout from exploration well 6507/10-2 Novus. The influence area is based on all release rates and durations and their individual probabilities. Note that the influence area does not show the extent of a single oil spill, but the area affected by > 1 ton of oil per 10 x 10 km grid cell in more than 5 % of all single simulations within each season. Date : Page 11 of 44

17 SPRING SUMMER AUTUMN WINTER Figure 5-2 Seasonal hit probabilities in km grid cells given a subsea blowout from exploration well 6507/10-2 Novus. The influence area is based on all release rates and durations and their individual probabilities. Note that the influence area does not show the extent of a single oil spill, but the area affected by > 1 ton of oil per 10 x 10 km grid cell in more than 5 % of all single simulations within each season. Date : Page 12 of 44

18 5.1.3 Single simulation scenario Figure 5-3 illustrates a single oil spill simulation. Different shades of grey mark the propagation of the spill after 2, 5, 10 and 17 days following the most likely topside blowout scenario (4,054 Sm 3 /day for a period of 2 days). The statistical oil spill (influence area) based on 2,720 different single simulations is displayed in the background and indicates the hit probability in individual 10 x 10 km grid cells. The figure thus demonstrates that a single spill scenario may only cover a part of the influence area. In case of a real spill situation, oil drift and influence area will depend on the actual metocean conditions at the time of the spill. Figure 5-3 Simulation of the most likely topside blowout scenario from the Novus spud location (2 days spill duration at a release rate of 4,054 Sm 3 /day). Different shades of grey indicate spill propagation over a time span of 2, 5, 10 and 17 days. In the background is the statistical influence area based on 2,720 different single simulations. Date : Page 13 of 44

19 5.2 Hit probabilities by mass category For seasonal hit probabilities of oil divided in mass categories; tons, tons, tons and >1000 tons in each km grid cell, refer to the oil spill modelling results presented in a separate study (DNV, 2013). 5.3 Water column concentrations This section presents seasonal estimates of average THC concentrations in km grid cells per season. In this regard THC represents the sum of the dispersed and the dissolved oil in the water column. The results are based on all combinations of rates and durations and their individual probabilities for each defined blowout scenario at the Novus well. It should be noted that presented results do not represent the extent of a single oil spill, but the statistical area that is affected by elevated water column concentrations in all simulations within each season. THC concentration 100 ppb is used as a lower limit of potential effects on fish eggs and larvae (DNV, 2007) Topside release For a topside blowout oil components in the (top layer of the) water column will mainly be a result of down-mixing from surface slicks. Water column concentrations are calculated based on the characteristics of the model oil as well as on prevailing wind and current conditions. Seasonal, average water column concentrations related to a topside blowout from exploration well 6507/10-2 Novus are presented in Figure 5-4. Statistics are generated for each km grid cell and based on the 3 durations and 6 release rates and their individual probabilities. Calculated concentrations are conservatively considered representative of the entire water column, from the surface to the seafloor Subsea release For a subsea blowout, oil components in the water column may result both from down-mixing from surface slicks (see above) as well as from direct dispersion/dissolving of the released oil stream. Seasonal, average water column concentrations related to a subsea blowout from exploration well 6507/10-2 Novus are presented in Figure 5-5. Statistics are generated for each km grid cell and based on the 3 durations and 6 release rates and their individual probabilities. Calculated concentrations are conservatively considered representative of the entire water column, from the surface to the seafloor. Date : Page 14 of 44

20 Figure 5-4 Seasonal average water column THC concentrations ( 100 ppb) in km grid cells given a topside blowout from exploration well 6507/10-2 Novus. Estimates are based on all combinations of rates and durations and their individual probabilities. Note that the highlighted area does not show the extent of a single oil spill, but the statistical area that is affected by elevated THC water column concentrations on average over all simulations within each season. Date : Page 15 of 44

21 Figure 5-5 Seasonal average water column THC concentrations ( 100 ppb) in km grid cells given a subsea blowout from exploration well 6507/10-2 Novus. Estimates are based on all combinations of rates and durations and their individual probabilities. Note that the highlighted area does not show the extent of a single oil spill, but the statistical area that is affected by elevated THC water column concentrations on average over all simulations within each season. Date : Page 16 of 44

22 5.4 Coastal habitats This section presents the hit probability of oil in km coastal grid cells for the different blowout scenarios described in sections The results are based on all combinations of rates and durations and their individual probabilities for each defined blowout scenario at the Novus well, and presented seasonally for spring (March-May), summer (June-August), autumn (September-November) and winter (December-February). The influence areas are calculated from a total of 5,440 individual simulations for topside and subsea releases, 2,720 simulations for each release point. It should be noted that the influence area does not represent the extent of a single oil spill, but the area affected by > 1 ton of oil per 10 x 10 km grid cell in more than 5 % of all single simulations within each season Topside release Seasonal hit probabilities of coastal grid cells related to a topside blowout from exploration well 6507/10-2 Novus are presented in Figure 5-6. Statistics are generated for each km coastal grid cell and based on 3 durations and 6 release rates and their individual probabilities Subsea release Seasonal hit probabilities of coastal grid cells related to a subsea blowout from exploration well 6507/10-2 Novus are presented in Figure 5-7. Statistics are generated for each km coastal grid cell and based on 3 durations and 6 release rates and their individual probabilities. Date : Page 17 of 44

23 Figure 5-6 Seasonal hit probabilities of more than 1 ton of oil in km coastal grid cells given a topside blowout from exploration well 6507/10-2 Novus. The influence area is based on all release rates and durations and their individual probabilities. Note that the influence area does not show the extent of a single oil spill, but the area affected by > 1 ton of oil per 10 x 10 km grid cell in more than 5 % of all single simulations within each season. Date : Page 18 of 44

24 Figure 5-7 Seasonal hit probabilities of more than 1 ton of oil in km coastal grid cells given a subsea blowout from exploration well 6507/10-2 Novus. The influence area is based on all release rates and durations and their individual probabilities. Note that the influence area does not show the extent of a single oil spill, but the area affected by > 1 ton of oil per 10 x 10 km grid cell in more than 5 % of all single simulations within each season. Date : Page 19 of 44

25 6 ENVIRONMENTAL RESOURCES 6.1 Valued ecosystem components (VECs) Environmental resources analysed in the ERA are briefly described in the following sections, with a more thorough description given in Norwegian language in Appendix 2. An extensive description in English language of the environmental resources, conditions and ecosystems in the can be obtained from the Norwegian government report Integrated Management of the Marine Environment of the (Norwegian Ministry of Environment, 2009). The potential damage to specific Valued Ecosystem Components (VECs) creates the basis for the assessment of the environmental risk level. These components are used as risk indicators in the environmental risk analysis. 6.2 Selected VECs According to Norsk olje og gass (Norwegian Oil and Gas, 2007) a VEC is defined as a resource or an environmental characteristic that: is important to local human populations, or has a national or international interest, and if changed from the present state, it will have importance for how the environmental impact is considered, and for which mitigating measures is chosen The selection of VECs within an influence area is based on the following priority criteria: VEC must represent a population, a society or a habitat, VEC must be vulnerable to oil contamination in the relevant season, VEC population must be represented by a high proportion of the population within the influence area, VEC population must be present most of the year, or in the relevant season, and VEC habitat must have a high probability for being exposed to oil The selection ensures that the ERA is carried out for the type of resources with a high probability of being affected by oil pollution. In such an analysis it is vital that the best available population data is used, and separate studies should be acquired when necessary. Based on the criteria listed above seabirds, marine mammals, fish and coastline (habitat) are included in the ERA. In the following sections species used in the ERA in each of the VEC categories are listed Seabirds Seabirds are divided in two different datasets, pelagic and coastal seabirds which are listed in Table 6-1. Pelagic and coastal seabirds may be part of the same populations, but are distributed in different areas throughout the year, as most of the pelagic species move towards coastal areas for breeding/nesting in the spring/summer period. This is for most species also regarded as the most vulnerable period. Date : Page 20 of 44

26 Table 6-1 Selected seabird VECs applied in the environmental risk analysis for exploration well 6507/10-2 Novus. Red list information from Artsdatabanken, Name (English) Name (Norwegian) Name (Latin) Red list Razor-billed Auk Alke Alca torda VU Little Auk Alkekonge Alle alle - Common Gull Fiskemåke Larus canus NT European Herring Gull Gråmåke Larus argentatus LC Northern Fulmar Havhest Fulmarus glacialis NT Northern Gannet Havsule Morus bassanus LC Black-legged Kittiwake Krykkje Rissa tridactyla EN Common Guillemot Lomvi Uria aalge CR Atlantic Puffin Lunde Fratercula arctica VU Brünnich's Guillemot Polarlomvi Uria lomvia VU Glaucous Gull Polarmåke Larus hyperboreus - Great Black-backed Gull Svartbak Larus marinus LC Razor-billed Auk Alke Alca torda VU Little Auk Alkekonge Alle alle - Common Gull Fiskemåke Larus canus NT European Herring Gull Gråmåke Larus argentatus LC Long-tailed Duck Havelle Clangula hyemalis LC Northern Fulmar Havhest Fulmarus glacialis NT Northern Gannet Havsule Morus bassanus LC Black-legged Kittiwake Krykkje Rissa tridactyla EN Goosander Laksand Mergus merganser LC Common Guillemot Lomvi Uria aalge CR Atlantic Puffin Lunde Fratercula arctica VU Brünnich's Guillemot Polarlomvi Uria lomvia VU King Eider Praktærfulg Somateria spectabilis - Red-breasted Merganser Siland Mergus serrator LC Velvet Scoter Sjøørre Melanitta fusca NT Great Black Cormorant Storskarv Phalacrocorax carbo LC Great Black-backed Gull Svartbak Larus marinus LC Black Guillemot Teist Cepphus grylle VU European Shag Toppskarv Phalacrocorax aristotelis LC Dataset Pelagic seabirds (Norwegian Sea) Coastal seabirds (Norwegian Sea) Common Eider Ærfugl Somateria molissima LC LC Least concern; NT Nearly threatened; VU Vulnerable; EN- Endangered; CR Critically endangered Date : Page 21 of 44

27 6.2.2 Marine mammals For marine mammals the species listed in Table 6-2 are identified as potentially affected given an oil spill in the Halten Terrace region. Grey seal and Harbour seal are most vulnerable during their birthand moulting periods when they gather in colonies in coastal areas. The Grey seal forms colonies in September-December (birth), with delayed mating with increasing latitude, and in February-March (moulting). The Harbour seal forms colonies in June-July (birth) and in August-September (moulting). The common otter is considered equally vulnerable all year. Table 6-2 Selected marine mammal VECs applied in the environmental risk analysis for the exploration well 6507/10-2 Novus. Red list information from Artsdatabanken, Name (English) Name (Norwegian) Name (Latin) Grey seal Havert Halichoerus grypus LC Harbour seal Steinkobbe Phoca vitulina VU Common otter Oter Lutra lutra VU LC Least concern; VU Vulnerable Red list Dataset Shoreline habitat There is a potential that an oil spill from the Novus well will reach the Norwegian shoreline (Section 5.4). Based on this the shoreline habitat is included in the damaged based environmental risk analysis Fish The effect of oil on organisms in the water column (fish and plankton) is dependent on the oil type, the degree of natural dispersion, as well as the release rate and duration of an oil spill. Due to their limited mobility and hence inability to concentrate in designated spawning areas and transatlantic distribution, plankton (phyto- and zooplankton) are generally less vulnerable to oil pollution. The focus of the environmental risk analysis is therefore on fish, whose eggs and larvae can be very vulnerable to oil pollution. Juveniles greater than about 2 cm and adult fish are considered having sufficient mobility to avoid an oil spill (DNV, 2007). This is consistent with field observations that have shown little mortality of adult fish in relation to real oil spill incidents. Fish species which spawn in a limited area and during a restricted time period have the highest potential for impact from an oil spill. In the studied area only coastal populations of Atlantic cod (Gadus morhua) and Norwegian, spring-spawning herring (Clupea harengus) have spawning areas which potentially overlap with the influence area given an oil spill from the Novus well. The environmental risk analysis of water column resources is therefore restricted to (early life stages of) these two fish species. Coastal populations of Atlantic cod spawn along the entire Norwegian coast. The spawning stock of Atlantic cod exhibited a negative trend and is according to the ICES not harvested in sustainable amounts (IMR, 2012). The major spawning areas of the Norwegian, spring-spawning herring are concentrated to the counties of Møre-Romsdal and Nordland. Spring-spawning herring is currently harvested in sustainable amounts but the spawning stock is expected to drop in the years to come (IMR, 2012). Both Atlantic cod and Norwegian, spring-spawning herring have red list status Least Concern (Artsdatabanken, 2010). Date : Page 22 of 44

28 7 ENVIRONMENTAL RISK ANALYSIS RESULTS 7.1 Possible consequences from a blowout Possible consequences for seabirds and marine mammals are estimated as the probability for a given loss proportion (respectively <1 %, 1-5 %, 5-10 %, %, % and > 30 %) of a population. The calculations are based on monthly population distributions of chosen species, and the results are presented per season averaged over the months within each season (spring: March-May; summer: June-August; autumn: September-November; winter: December-February) Possible consequences for pelagic seabirds Calculated probabilities for population loss of pelagic seabirds are presented in Figure 7-1 for a topside blowout and in Figure 7-2 for a subsea blowout from exploration well 6507/10-2 Novus. Given a topside blowout there is less than 1 % probability of population losses exceeding 20 %. Razorbilled Auk and Atlantic Puffin stand out as the two species with highest probabilities for population loss up to 20 %, reaching 5 % for Atlantic Puffin in summer and autumn, and 6 % for Razor-billed Auk in autumn and winter. During winter and spring Razor-billed Auk has the highest probability for population loss up to 10 % as well as up to 5 %, reaching 6 % in spring (up to 10 %) and 67 % in winter (up to 5 %), respectively. During summer and autumn Common Guillemot is among the species with highest probability for population loss up to 10 % as well as up to 5 %, reaching 9 % (up to 10 %) and 72 % (up to 5 %) both in the autumn season. Given a subsea blowout there is again less than 1 % probability of population losses exceeding 20 %. Razor-billed Auk has up to 14 % probability for population loss up to 20 % during autumn, winter and spring. The same species stand out as the species with highest probability for population loss up to 10 %, reaching 24 % in the winter season. Date : Page 23 of 44

29 DetNorskeVeritas Reportfor AGR PetroleumServicesAS EnvironmentalRisk Analysis(ERA) for explorationwell 6507/10-2 Novusin the NorwegianSea Figure 7-1 Seasonalprobabilities for populationlossof pelagic seabirdsgiven a topsideblowout from explorationwell 6507/10-2 Novus.Population loss is divided in categories<1 %, 1-5 %, 5-10 %, %, % and> 30 %. DNV Reg.No.: 16EIG9K-6 RevisionNo.: 0 Date: Page24 of 44

30 DetNorskeVeritas Reportfor AGR PetroleumServicesAS EnvironmentalRisk Analysis(ERA) for explorationwell 6507/10-2 Novusin the NorwegianSea Figure 7-2 Seasonalprobabilities for populationloss of pelagic seabirdsgiven a subsea blowoutfrom explorationwell 6507/10-2 Novus.Populationlossis dividedin categories<1 %, 1-5 %, 5-10 %, %, % and> 30 %. DNV Reg.No.: 16EIG9K-6 RevisionNo.: 0 Date: Page25 of 44

31 7.1.2 Possible consequences for coastal seabirds Calculated probabilities for population loss of coastal seabirds are presented in Figure 7-3 for a topside blowout and in Figure 7-4 for a subsea blowout from exploration well 6507/10-2 Novus. Given a topside blowout only the Little Auk has some probability of population loss exceeding 20 % with 3 % probability up to 30 % population loss. The highest probability of population loss up to 20 % is seen for Atlantic Puffin in the summer season with 6 % probability. Little Auk again stands out as the species with highest risk of population loss up to 10 % as well as up to 5 %, reaching 10 % (up to 10 % population loss) and 48 % (up to 5 % population loss), respectively, in spring and summer. Given a subsea blowout there is less than 1 % probability of population losses exceeding 30 %. Little Auk and Atlantic Puffin have 2-3 % probability of population loss up to 30 % in spring and summer, respectively. The same two species stand out as having the highest probability of population loss up to 20 %, reaching 9 % for Little Auk and 11 % for Atlantic Puffin, both in the summer season. Little Auk is again the species with highest probability of population loss up to 10 % (23 % in summer) as well as up to 5 % (58 % in spring). For both topside and subsea blowout scenarios there is less than 1 % probability of population losses exceeding 5 % during autumn and winter. Date : Page 26 of 44

32 DetNorskeVeritas Reportfor AGR PetroleumServicesAS EnvironmentalRisk Analysis(ERA) for explorationwell 6507/10-2 Novusin the NorwegianSea Figure 7-3 Seasonalprobabilities for populationlossof coastalseabirdsgiven a topsideblowout from explorationwell 6507/10-2 Novus.Populationlossis dividedin categories<1 %,1-5 %, 5-10 %, %,20 30 % and> 30 %. DNV Reg.No.: 16EIG9K-6 RevisionNo.: 0 Date: Page27 of 44

33 DetNorskeVeritas Reportfor AGR PetroleumServicesAS EnvironmentalRisk Analysis(ERA) for explorationwell 6507/10-2 Novusin the NorwegianSea Figure 7-4 Seasonalprobabilities for populationloss of coastal seabirdsgiven a subseablowout from explorationwell 6507/10-2 Novus.Populationlossis dividedin categories<1 %, 1-5 %, 5-10 %, %, % and> 30 %. DNV Reg.No.: 16EIG9K-6 RevisionNo.: 0 Date: Page28 of 44

34 DetNorskeVeritas Reportfor AGR PetroleumServicesAS EnvironmentalRisk Analysis(ERA) for explorationwell 6507/10-2 Novusin the NorwegianSea Possibleconsequencesfor marine mammals Calculatedprobabilitiesfor population loss of marine mammalsare presentedin Figure 7-5 for a topsideblowout, andin Figure 7-6 for a subseablowoutfrom explorationwell 6507/10-2 Novus. For both topsideandsubseablowout scenariosthereis lessthan1 % probability of populationlosses exceeding20 % for all species.only Grey Seal hassomeprobability(1 %) of populationlossup to 20 % (autumnseasongivena topsideblowout).thesamespeciesstandsout ashavinghighestprobability of populationlossup to 10 % (5 % probabilityin theautumnseasongivena subseablowout)aswell as up to 5 % (43 % probabilityin thewinter seasongivena subseablowout). The HarbourSeal exhibits similar probabilitiesof populationlossasthe Grey sealduring the summer season,but significantly lower duringtherestof the year.otterhasonly 2 % probability of population lossup to 5 %, givena topsideblowoutduringthesummerseason. Figure 7-5 Seasonalprobabilitiesfor populationlossof marinemammalsgivena topsideblowout from explorationwell 6507/10-2 Novus.Populationlossis dividedin categories<1 %, 1-5 %, 5-10 %,10-20 %, % and> 30 %. DNV Reg.No.: 16EIG9K-6 RevisionNo.: 0 Date: Page29 of 44

35 DetNorskeVeritas Reportfor AGR PetroleumServicesAS EnvironmentalRisk Analysis(ERA) for explorationwell 6507/10-2 Novusin the NorwegianSea Figure 7-6 Seasonalprobabilitiesfor populationlossof marinemammalsgivena subseablowout from explorationwell 6507/10-2 Novus.Populationlossis dividedin categories<1 %, 1-5 %, 5-10 %,10-20 %, % and> 30 % Possibleconsequencesfor coastalhabitats Potentialconsequencesfor coastalhabitatsdueto a blowout from explorationwell 6507/10-2 Novus wascalculatedper km of coastalgrid basedon thevulnerability of coastalhabitats(refer to methoddescriptionin Appendix1 andresourcedescriptionin Appendix2). The ten coastalgrid cells (10 10 km grid) with the highestmaximumrisk (the highestpart of acceptancecriteria regardlessof damagecategory)in eachseasonwerechosenfor detailedresultpresentation.thehighestrisk is seen for the outerarchipelagoof the countyof Nordland,south of Lofoten. Thelocationof thesegrid cells arepresentedin Figure 7-7. In grid cellsdominatedby mainlandor largeislandsthequantityof oil is calculatedasaccumulatedoil per simulation.this meansthat all the oil enteringa grid cell in onesingle simulationis summedup andgivesthe strandedquantityof oil in that grid cell. This overestimatesthe quantityof oil, sinceit is likely thatsomeoil will bewashedbackto sea, degradeordrift intootherareas. For grid cells with small islands the averagequantity of oil over time is used rather than the accumulatedquantityto calculatethe volumeof strandedoil. The averageover time meansthat each time lap in which a grid cell containsoil is registeredin eachsinglesimulation. The quantityof oil is thensummedup in thesameway asfor theaccumulatedquantity,howeverdivided by the actualtime for which a grid cell containsoil, andrenderingan averagequantityof oil for eachsinglesimulation. In the context,accumulatedquantities of oil is consideredtoo conservativefor grid cellscontaining small landareas,asit is unlikely thattheentireoil volumeenteringthe grid cell would endup on the shore. DNV Reg.No.: 16EIG9K-6 RevisionNo.: 0 Date: Page30 of 44

36 The oil hit probabilities for each km coastal grid cells divided in oil mass categories (1-100 tons, tons, tons and > 1000 tons) are presented in Table 7-1. Results are presented for the ten coastal grid cells with highest probability for environmental damage (based on probability for oil pollution and vulnerability of the habitat), with topside and subsea blowout scenarios presented separately. The highest probabilities for oil hit in the different mass categories are 37.9 % (1-100 tons), 11.5 % ( tons) and 2.0 % ( tons), all as a result of a subsea blowout. There is no probability for hit by > 1000 tons of oil in individual grid cells. A subsea blowout event would generally increase the probability of oil reaching the shore, and oil hit probabilities are slightly higher in winter and spring than in summer and autumn. Oil hit probabilities were used for calculation of environmental damage to coastal habitats, expressed as restitution time; < 1 year (minor), 1-3 years (moderate), 3-10 years (considerable) and > 10 years (serious). The results of these calculations are presented in Table 7-2 and basically reflect oil hit probabilities in individual grid cells. The highest probabilities of damage to coastal habitats were found to be 34.9 % for minor damage (> 1 year), 11.5 % for moderate damage (1-3 years) and 0.2 % for considerable damage (3-10 years), all as a result of a subsea blowout during spring. There is no probability for serious environmental damage (> 10 years restitution time) in coastal habitats. Date : Page 31 of 44

37 Figure 7-7 The ten km coastal grid cells representing the highest environmental risk given a blowout from exploration well 6507/10-2 Novus. Maximum risk (the highest part of acceptance criteria regardless of damage category) for both topside and subsea blowout scenarios. Date : Page 32 of 44

38 Table 7-1 Probability for oil pollution divided in oil mass categories per 10 x 10 km coastal grid cell given a blowout from exploration well 6507/10-2 Novus. Results are presented as yearly, maximum probabilities for the ten 10 x 10 coastal grid cells with highest probability of oil pollution. Topside Subsea Season Cell nr tons/cell tons/cell tons/cell tons/cell tons/cell tons/cell Winter Autumn Summer Spring % 3.2 % % 11.0 % % 2.5 % 0.7 % 21.2 % 11.5 % 2.0 % % 1.5 % % 5.9 % % 2.6 % % 5.2 % % 1.4 % % 3.4 % % 2.3 % % 5.1 % % 0.6 % % 3.0 % % 2.3 % % 2.3 % % 0.7 % % 5.6 % 0.1 % % 0.2 % % 0.7 % % 6.6 % % 11.0 % % 2.3 % % 3.7 % % 2.4 % % 5.3 % % 3.5 % % 6.8 % % 2.7 % % 3.8 % % 2.9 % 0.4 % 19.6 % 4.0 % 0.1 % % 1.6 % % 2.1 % % 1.7 % % 0.6 % % 3.9 % % 4.9 % % 2.0 % % 2.3 % % 3.8 % % 2.6 % % 3.8 % % 7.9 % % 0.5 % % 1.9 % % 2.0 % % 2.1 % % 2.5 % % 4.4 % % 0.3 % % 0.4 % % 0.6 % % 1.7 % % 1.4 % % 2.9 % % 0.7 % % 1.7 % % 0.7 % % 1.4 % % 4.7 % % 6.4 % % 4.3 % % 4.9 % % 3.8 % % 6.1 % % 1.4 % % 1.1 % % 2.4 % 0.1 % 21.9 % 2.8 % % 1.1 % % 1.6 % % 0.9 % % 1.7 % % 0.5 % 0.8 % 15.1 % 3.7 % 1.4 % % 0.5 % % 1.8 % % 1.0 % % 1.6 % - Date : Page 33 of 44