South East Greenland 2015 Seismic Survey Scope of Works

Transcription

1 South East Greenland 2015 Seismic Survey Scope of Works Prepared for: -NOPEC Geophysical Company ASA

2 Document: J3269 (SEG15 Scoping) v3 Version Date Description Prepared by Checked by Approved by 1 01/12/14 Issued Draft IGP MC/KN/TG IGP S 2 01/12/14 Minor Clarification IGP SO IGP 3 22/12/14 Updated Survey Data Tables. Confirmation of EIA requirement. PO IGP IGP This report has been prepared by Centre for Marine and Coastal Studies Ltd (CMACS). Contact Details: CMACS Ltd 80 Eastham Village Road Eastham Wirral CH62 0AW UK Company No Tel: +44 (0) info@cmacsltd.co.uk Lensmannslia 4 N-1386 Asker, Norway Tel: Fax: Postal Address: P.O. Box 154, N-1371 Asker, Norway CMACS: J3269 (SEG15 Scoping) v3

3 Contents 1. INTRODUCTION DESCRIPTION OF THE PROPOSED ACTIVITY Licence number and licencee Overview of vessels... 4 Seismic survey vessel... 5 Support Operations Seismic survey PURPOSE OF OPERATION AND PROPOSED SPECIFICATION Purpose Proposed Specifications Operation period Placement of construction/equipment Logistics of operation ENVIRONMENTAL ASSESSMENT Overview Identification of Potential Impacts Appendix 1. Survey Data Tables CMACS: J3269 (SEG15 Scoping) v3

4 Figures Figure 1. Proposed SEG15 Survey Area and indicative survey lines Figure 2. SEG15 in relation to previous surveys by Figure 3. Typical 2-D seismic survey arrangement (source: The Open University, 2014) Figure 4. Layout of the 3,350 cubic inch airgun array Figure 5. Layout of the 1,675 cubic inch airgun array Figure 6. Signal duration and associated pressure change: top, 3,350 cubic inch array; bottom, 5,025 cubic inch array as used to inform underwater noise modelling Figure 7: Comparison of smaller (blue) and larger (red) airgun array Figure 8: Cumulative energy flux per pulse (larger array) Figure 9. Example of noise modelling sound exposure level (SEL) map for: top, one airgun array shot, where the SEL is shown using colours, warm colours being a high SEL, and cold colours represent a low SEL; bottom, cumulative noise exposure modelling (sound exposure level for pinnipeds in water) Tables Table 1. Contact details for vessel owners Table 2. Summary vessel details... 6 Table 3. Seismic survey parameters Table 4. Key dates in survey program Table 5. Built-in mitigation Table 6. Provisional list of potential impacts CMACS: J3269 (SEG15 Scoping) v3

5 1. INTRODUCTION -NOPEC Geophysical Company ASA () propose to undertake a seismic survey off South East Greenland between 1 July and 31 October, 2015 (inclusive). The survey is named SEG15. will submit an application for a Survey Licence to the Mineral Licence and Safety Authority (MLSA). This Scope of Works provides information on the proposed surveys and planned environmental assessment work requested by MLSA in guidelines for application, execution and reporting of offshore hydrocarbon exploration activities (BMP, ). Based on the previous version of this Scope of Works, MLSA have advised that an Environmental Impact Assessment (EIA) will be required. This version of the Scope of Works addresses comments received from MLSA and is issued for public consultation. The Scope of Works also includes information requested in supplementary guidelines for EIAs concerning seismic surveys (BMP, ). Data Tables presented in Appendix 1. Survey Data Tables are structured in line with this guidance. The proposed survey is small in scale; up to approximately 1,000 line kilometres of 2D survey will be shot. The data will be acquired over a short period of days to weeks at most, within the survey period identified above. There will be no seabed sampling but in addition to the use of airguns to acquire seismic data (further details in Section 3) it is planned to use the following equipment to support the survey: o multibeam echo sounder o sub-bottom profiler The Survey Area is presented in Figure 1 along with indicative survey lines. Survey lines will be fully within the Survey Area indicated and will not enter any of the closed areas where seismic survey is prohibited. The presence of Seismic Regulation Areas for marine mammal species (closed areas for narwhal and areas of concern for this species and bowhead whale) will be a key focus of the EIA. completed a limited amount of survey in the region in This is summarised in Figure 2. is planning to conduct the SEG15 survey using a single acquisition vessel and up to two support vessels. Further information on the vessels is provided in Section 2. 1 BMP (2011). Guidelines for application, execution and reporting of offshore hydrocarbon exploration activities (excluding drilling) in Greenland. 2 BMP (2012). Supplementary guidelines for EIAs concerning seismic surveys in Greenland CMACS: J3269 (SEG15 Scoping) v3 Page 1

6 Figure 1. Proposed SEG15 Survey Area and indicative survey lines. CMACS: J3269 (SEG15 Scoping) v3 Page 2

7 Figure 2. SEG15 in relation to previous surveys by. CMACS: J3269 (SEG15 Scoping) v3 Page 3

8 2. DESCRIPTION OF THE PROPOSED ACTIVITY 2.1 Licence number and licencee Prospecting licence for an offshore area in East Greenland Licence: No. 2012/41 for East Greenland Licensee: -Nopec Geophysical Company ASA Licence area: Offshore areas in North Greenland Licence period: Contact details of licence holder: -NOPEC Geophysical Company ASA Lensmannslia 4, N-1386, Asker, Norway Sergej Usov Tel: Fax: Knut Agersborg Tel: Fax: Postal Address P.O. Box 154 N-1371, Asker, Norway 2.2 Overview of vessels plan to use the seismic survey vessel M/V Akademik Shatskiy, or a similar vessel, to undertake 2D seismic survey acquisition. The seismic survey vessel will be a i d e d b y a support vessel (e.g. the M/V Kvitbjørn or similar). The vessels have implemented safety systems that meet all requirements of the leading companies in the oil industry. They are also insured in accordance with the requirements standard for major oil companies. CMACS: J3269 (SEG15 Scoping) v3 Page 4

9 Seismic survey vessel The M/V Akademik Shatskiy is a Russian registered vessel owned by the Russian geophysical company Sevmorneftegeofizika (SMNG). SMNG is the largest marine geophysical company in Russia. It renders a wide range of marine geophysical services worldwide including: 2D/3D marine seismic acquisition, navigation positioning, data processing and integrated interpretation of seismic data. will operate the seismic survey vessel under a charter agreement with SMNG. will be responsible for maritime and seismic operations together with SMNG. Akademik Shatskiy is an 83.5m, 3,211 gross ton vessel (Plate 1); it, or a similar vessel, will be the survey vessel, towing airguns and hydrophone streamer. Plate 1. M/V Akademik Shatskiy. Support Operations A support vessel, provisionally the M/S Kvitbjørn, will be chartered. Contact details for vessel owners are provided in Table 1 and summary vessel details in Table 2. This information is provisional and will be confirmed in the EIA/EMA once the vessel selection process is finalised. CMACS: J3269 (SEG15 Scoping) v3 Page 5

10 Table 1. Contact details for vessel owners. M/V Akademik Shatskiy Sevmorneftegeofizika Trust (SMNG) 17, Karl Marx Str. Murmansk Russia Phone: Int Phone: Fax: Int Fax: smng@smng.murmansk.ru M/V Kvitbjørn Kvitbjørn AS Midnattsolvn Tomasjord Norway Tel signe@kvitbjorn.no NB the information above is provisional and will be confirmed in the EIA/EMA. Table 2. Summary vessel details. Vessel Vessel Type Call sign IMO MMSI Contact number/ number M/V Akademik Shatskiy Seismic Survey UAIR TBC M/S Kvitbjørn Support Vessel LALJ TBC NB the information above is provisional and will be confirmed in the EIA/EMA. 2.3 Seismic survey Offshore seismic survey involves transmitting acoustic energy to the seabed and recording energy reflected back from subsurface boundaries to acquire information on subsurface geology. Airguns towed by a survey ship are used to provide the acoustic energy that is reflected to the towed hydrophone streamer(s) some 5-12km long (Figure 3). Airguns fire repeatedly, typically every 10 seconds, and produce very short duration bursts of sound. Most energy in seismic surveys is produced under 200Hz with a peak typically around Hz. CMACS: J3269 (SEG15 Scoping) v3 Page 6

11 Figure 3. Typical 2-D seismic survey arrangement (source: The Open University, 2014). 2-D seismic survey, as planned for SEG15, involves a single towed streamer (hydrophone array). This contrasts with 3-D seismic survey which use multiple towed streamers. A 2- D survey is typically used to provide a regional dataset that allows many companies and other stakeholders insight to the hydrocarbon potential of a region as a whole rather than smaller areas typically covered by 3D surveys CMACS: J3269 (SEG15 Scoping) v3 Page 7

12 3. PURPOSE OF OPERATION AND PROPOSED SPECIFICATION 3.1 Purpose The overall purpose of the project is to acquire multi-client seismic data to delineate major structural elements of the southeast Greenland margin. Additional geophysical data will be acquired for use by various exploration companies in relation to hydrocarbon resource prospecting. Multibeam and sub-bottom profile data will be acquired if this work is supported by the exploration companies and would aid seafloor mapping of geohazards and marine habitats within the area. The data acquired by the survey will contribute to a more accurate and advanced understanding of the geology and hydrocarbon potential of the area. 3.2 Proposed Specifications The survey is to be undertaken using the parameters set out in Table 3 which are equivalent to previous survey by off SE Greenland since There will be an array of 16 (2 x 8) active guns with a total active volume of 3,350 cubic inches. A smaller array of 1,675 cubic inches is also available and can theoretically be deployed to provide a total volume of 5,025 cubic inches. Although this is not planned for the survey this Scoping Report provides relevant information for both the planned array (3,350 cubic inch) and larger (5,025 cubic inch) array. Where possible, information on the characteristics of the 3,350 cubic inch array has been derived from the acquisition report of the NEG14 survey which used identical equipment and therefore represents real data. Some data for the 3,350 cubic inch array and all comparative values for the 5,025 cubic inch array are maximum theoretical values since no field data are available. In all cases these are expected to be higher than real-world values. Underwater noise modelling has been completed based on the worst-case of the larger array. This may overestimate the magnitude underwater noise generation but there is then less chance of the assessment underestimating the magnitude effects on the marine environment. Airgun array layouts are detailed in figures 4 and 5. The total operating airgun pressure will be a maximum of 2000 PSI and the peak to peak pressure approximately 90 bar-m for the 3,350 cubic inch array (theoretically 151 bar-m for a 5,025 cubic inch array). The duration of each airgun shot and associated pressure change is presented in Figure 6. The smaller and larger arrays have almost identical signal frequency characteristics (Figure 7). Information on the energy transmitted with each pulse is CMACS: J3269 (SEG15 Scoping) v3 Page 8

13 provided in Figure 8. This information is important to understand the characteristics of the underwater noise produced during the survey so that modelling work can be undertaken to support assessments of its likely effects on marine wildlife such as fish and marine mammals. Examples of the output of noise modelling work are provided in Figure 9. The vessel will conduct the survey whilst travelling at around 5 knots with a firing interval of 10 seconds (firing approximately every 25m). The survey vessel is intended to be operational 24 hours a day except in periods when weather or other conditions do not allow for data acquisition. Table 3. Seismic survey parameters. Parameter Typical Value (maximum Number of active air guns attainable) 16 (24) Total active volume (cubic inches) 3350 (5025) Length of array/inline spread (m) 19 Width of array/crossline spread (m) 6 Total pressure (psi) 2000 ±10% Peak to peak Pressure (bar-m) 90 (151) Planned source depth (m) 7-9 Vessel speed (knots) 5 Firing frequency (s) 10 Firing interval (m) 25 CMACS: J3269 (SEG15 Scoping) v3 Page 9

14 Figure 4. Layout of the 3,350 cubic inch airgun array. Figure 5. Layout of the 1,675 cubic inch airgun array. CMACS: J3269 (SEG15 Scoping) v3 Page 10

15 Figure 6. Signal duration and associated pressure change: top, 3,350 cubic inch array; bottom, 5,025 cubic inch array as used to inform underwater noise modelling. CMACS: J3269 (SEG15 Scoping) v3 Page 11

16 Figure 7: Comparison of smaller (blue) and larger (red) airgun array. Figure 8: Cumulative energy flux per pulse (larger array). CMACS: J3269 (SEG15 Scoping) v3 Page 12

17 Figure 9. Example of noise modelling sound exposure level (SEL) map for: top, one airgun array shot, where the SEL is shown using colours, warm colours being a high SEL, and cold colours represent a low SEL; bottom, cumulative noise exposure modelling (sound exposure level for pinnipeds in water). CMACS: J3269 (SEG15 Scoping) v3 Page 13

18 3.3 Operation period The survey programme is summarised in Table 4. Table 4. Key dates in survey program. Activity Date Arrival in Greenland waters (earliest) 01/07/2015 Start of seismic data acquisition (earliest) 01/07/2015 Completion of survey (latest) 31/10/ Placement of construction/equipment No placement of equipment is planned. 3.5 Logistics of operation The initial port of mobilisation is planned to be Tromsø, there will be the option to use Bergen (Norway), Lerwick (UK), Longyearbyen (Svalbard) or Reykjavik (Iceland) if the survey vessels require port facilities or shelter. Crew changes, if required, will be done from either Longyearbyen or Reykjavik using the support vessel. Bunkering and resupply, if required, would be performed by the support vessel, if necessary with the additional support of a specialized bunkering vessel. All waste will be retained and disposed of at facilities onshore. CMACS: J3269 (SEG15 Scoping) v3 Page 14

19 4. ENVIRONMENTAL ASSESSMENT 4.1 Overview A key purpose of the Scoping Report is to identify potentially significant environmental impacts of the proposed survey. Impact receptors, i.e. groups potentially affected, could include marine wildlife such as seabirds or marine mammals, or other users of the survey area such as commercial fishing activity for example. Section 4.2 summarises identified potential impacts which it is intended will be considered in more detail should EIA be requested. As is the case for previous surveys off Greenland by, relevant statutory guidance will be followed to minimise environmental impacts and this represents built-in mitigation which is accounted in any environmental impact assessment. Identified built in mitigation, above and beyond compliance with standard good environmental practice and compliance with national and international environmental legislation, is set out in Table 5. CMACS: J3269 (SEG15 Scoping) v3 Page 15

20 Table 5. Built-in mitigation. Potential Impact Built-in Mitigation Notes Conflicts with other vessels (e.g. fishing, commercial traffic). Support (chase) vessel to liaise via radio to alert other vessels to activity and avoid conflicts. Disturbance of marine mammals/seabirds by survey vessels. Injury and disturbance to marine mammals from airgun noise. Contamination of waters Survey vessels to avoid marked changes of speed or direction when operating in vicinity of marine mammals, unless avoidance action is required. During and around airgun firing operations guidelines detailed in Kyhn et al. ( ) will be followed. Hydrophone streamer cables to be solid, not fluid filled. Guidelines will be implemented by a team of 4 marine mammal and seabird observers (MMSOs) following guidelines provided by Johansen et al ( ). Passive acoustic monitoring (PAM) will be implemented at all times (by two PAM operators working shifts) and two MMSOs will undertake visual surveillance during daylight hours. 4.2 Identification of Potential Impacts A provisional outline of receptors potentially affected by the survey is provided in Table 6, below. Impact assessments will be completed taking into account that built-in mitigation (Table 5) would be in place. Any additional mitigation necessary will be identified following comprehensive assessment. It is currently unknown whether any other seismic surveys are planned to be conducted at the same time. will wait for advice from the Greenland authorities (via MLSA) and will prepare a cumulative assessment with appropriate mitigation if required. All assessments relating to underwater noise will be supported by detailed modelling of underwater noise that has been completed by NIRAS on behalf of. 3 Kyhn LA, Boertmann D, Tougaard J, Johansen K & Mosbech A (2011) Guidelines to environmental impact assessment of seismic activities in Greenland Waters, 3rd revised edition, Danish Center for Environment and Energy, Dec Johansen KL, Boertmann D, Mosbech A & Hansen TB (2012) Manual for seabird and marine mammal survey on seismic vessels in Greenland. 3rd revised edition, May Aarhus University, DCE Danish Centre for Environment and Energy, 74 pp. Scientific Report from DCE Danish Centre for Environment and Energy No. 38 CMACS: J3269 (SEG15 Scoping) v3 Page 16

21 Table 6. Provisional list of potential impacts. Receptor Fish Anticipated Impacts and Mitigation The key potential impact is underwater noise and sensitivities of fish will be assessed in relation to known distributions, including seasonal considerations in relation to spawning. Underwater noise modelling will support the assessment. The threat to fish from accidental spills, e.g. of oil/fuels, will be assessed. Mitigation commensurate with identified risks will be developed if appropriate. Sea Birds Mammals Analysis of potential sensitivities will be conducted as part of the EMA/EIA process. The survey approaches to within approximately 12km to the shore. The main risk is anticipated to be oil spills which could reach the coast. The potential for birds which forage away from the coast to be affected, including through underwater noise and the influence of vessel lighting, will also be considered. Marine mammals are a particular concern when considering seismic survey impacts. In the extreme, underwater noise from airguns a t c l o s e r a n g e can cause physical harm and hearing damage, and at greater range disturbance and temporary displacement. The survey surrounding areas will be carefully assessed for marine mammal sensitivities during the EIA/EMA. It is expected that with built-in mitigation the risk of physical injury to marine mammals will be minimal but this will be evaluated carefully and additional mitigation identified if appropriate. The assessment will also include consideration of potential long-range disturbance effects as well as the risk of impacts from accidental oil spills and collision with vessels. The assessment will be supported by underwater noise modelling. Human Activities Potential impacts on commercial fisheries (trawlers) will be assessed based on the above mentioned assessment on fish as well as in relation to possible conflict between the survey vessels and fishing vessels using the same waters. The potential impact on small scale subsistence fishing (small boats) and hunting will be considered but it is expected that the survey will be too far offshore for effects to be significant. The impact on tourism is anticipated to be negligible but this will be considered within the assessment in more detail. CMACS: J3269 (SEG15 Scoping) v3 Page 17

22 APPENDIX 1. SURVEY DATA TABLES A. Survey data table (Overview) Specify Description Provided Type of survey (2D, high resolution (3D), well testing, other) 2D Seismic Geophysical (multibeam echo sounder and sub-bottom profiler) Map of the area with all transect lines shown Figure 1 Start and end dates for the survey Start 01/07/2015 End 31/10/2015 Expected duration Up to 4 months Duty cycle of operation (in hours/24 hours) 24 hour operations Number of hours in the dark per 24 hours 15 August = 8hrs of dark 15 October = 15 hours of dark Intended use of icebreakers No Will survey be carried out in ice? No CMACS: J3269 (SEG15 Scoping) v3 Appendix 1, page 1

23 B. Array Specification Specify Description Provided Number and names of vessels towing airgun arrays One (provisionally Akademik Shatskiy) For each vessel provide geometric layout of complete airgun array with individual volume specified (in PSI per airgun and in 3 per airgun) See Figure 4 and Figure 5. Size of total array (In 3 and PSI for the entire array) 2 x 8 gun array, 3,350 cubic inch. Theoretical maximum 3 x 8 gun, 5025 cubic inch. 2,000 PSI Firing rate in shots/sec 1 per 10s, 25 m per shot Will sub arrays fire simultaneously or alternate? Operation speed of the vessel in km/hours or knots. Single stream most likely scenario 5 knot towing speed CMACS: J3269 (SEG15 Scoping) v3 Appendix 1, page 2

24 C. Acoustic Properties of Airgun Array Specify Description Provided Far field pressure signature of total airgun output (provide figure) Frequency spectrum of the far field airgun signature (broadband) (provide figure) Source level (source factor) of airgun array on acoustic axis below array, given in all of the following units: db re 1 µpa peak- peak (broadband) Figure 6: Spectrum of far field pressures Figure 7: Frequency spectrum 264 (5,025 cu in) 259 (3,350 cu in) db re 1 µpa rms (Over 90%* pulse duration) (provide duration for rms calculation) *as defined in Malme et al., 1986; Blackwell et al., 2004 db re: 1 µpa 2 s. per pulse 229 (3350 cu inch) 241 (5025 cu inch) Duration for RMS calculation is 280ms for both arrays 235 (5,025 cubic inch array) Pulse length is 280ms (see above) Energy, joule/m 2 per airgun pulse See Figure 8. Signal duration (Define how it is measured) Map showing modelled sound pressure levels (rms*), peak-peak and sound exposure level (µpa 2 s) for the survey area and surroundings (to levels likely to affect marine mammals or nearest land) * rms calculated by the 90% energy approach for derivation of the duration (Malme et al., 1986; Blackwell et al., 2004). 400msec (peak response over less than 30msec) (measured from Figure 6) NB 90% pulse duration 280ms (see above) It is proposed to utilise noise modelling completed in support of the SEG12, SEG13 and SEG14 surveys. (see Figure 6) (see example output from the modelling Figure 9) CMACS: J3269 (SEG15 Scoping) v3 Appendix 1, page 3

25 Provide description of the noise propagation model, including assumptions of sound speed profiles. The noise propagation modelling used, is Bellhop and RAM. Bellhop is a geometric beam implementation, and is mostly used for medium- todeep waters. It supports range-dependent parameters, herein seabed reflection, bathymetry, surface reflection, sound speed profile, volume attenuation. All these parameters are extracted from the databases WOA09, GEBCO, CRUST, each providing precise data for the area in and around the seismic survey zone. RAM is a parabolic equation (PE) model and is mostly used for shallow waters. It supports the same parameter inputs as Bellhop, as well as complex seabed interaction in cases where layered bottom profiles occur. CMACS: J3269 (SEG15 Scoping) v3 Appendix 1, page 4

26 D. Specifications of PAM system Specify Description Provided Number of hydrophones 4 on array Threshold of the recording system 201 dbv re 1 upa based on soundcard and NI card Sample rate of the recording system Up to 500 KS/s on NI card, 96 KS/s on audio interface Where will hydrophones be placed? Will there be duty cycling of recordings? Approximately 200 metres astern of vessel in close proximity to source array Recordings will be made when suspected sightings are made or as per client request In that case when will the PAM system be used? PAM system used in accordance with local guidelines i.e. 60 minutes prior to ramp up at start of line during darkness or periods of poor visibility. Name of software PAMGuard Species covered Estimated range accuracy, m. Broadband hydrophones covering all species will be covered (0 to 150 KHz response) This is dependent on many variables, i.e. frequency, directionality of vocalisation and amplitude of original vocalisation. Typically dolphin species 5000m, whale 10000m, porpoise 200m. Range accuracy 5-10%, direction <5 degrees with Port/Starboard ambiguity Very low frequency and very high frequency vocalisations will have reduced accuracy due to array geometry and rate of change of position respectively. CMACS: J3269 (SEG15 Scoping) v3 Appendix 1, page 5