Oil Spill Modelling
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Annex F Oil Spill Modelling Vessel Spill and 45-day Loss of Well Control REPORT Tamarind Resources - Tui Field Oil Spill Modelling Prepared by: RPS AUSTRALIA WEST PTY LTD Prepared for: ERM NEW ZEALAND Suite E1, Level 4 117 Powderham St 140 Bundall Road New Plymouth 4310 Bundall, QLD 4217 New Zealand Australia T: +61 7 5574 1112 T: +64 (0)9 3034 664 E: [email protected] E: [email protected] W: www.erm.com Author: Nathan Benfer Reviewed: Sasha Zigic Approved: Nathan Benfer No.: MAQ0648J Version: 2 Date: 21/03/18 rpsgroup.com.au REPORT Document Status Version Purpose of Document Approved by Reviewed by Review Date 0 Draft issued to client Nathan Benfer Sasha Zigic 23/02/2018 1 Issued to client Nathan Benfer Sasha Zigic 7/01/2018 2 Issued to Client Nathan Benfer Sasha Zigic 21/03/2018 Approval for issue Name Signature Date Nathan Benfer 21/03/2018 This report was prepared by [RPS Australia West Pty Ltd (‘RPS’)] within the terms of its engagement and in direct response to a scope of services. This report is strictly limited to the purpose and the facts and matters stated in it and does not apply directly or indirectly and must not be used for any other application, purpose, use or matter. In preparing the report, RPS may have relied upon information provided to it at the time by other parties. RPS accepts no responsibility as to the accuracy or completeness of information provided by those parties at the time of preparing the report. The report does not take into account any changes in information that may have occurred since the publication of the report. If the information relied upon is subsequently determined to be false, inaccurate or incomplete then it is possible that the observations and conclusions expressed in the report may have changed. RPS does not warrant the contents of this report and shall not assume any responsibility or liability for loss whatsoever to any third party caused by, related to or arising out of any use or reliance on the report howsoever. No part of this report, its attachments or appendices may be reproduced by any process without the written consent of RPS. All enquiries should be directed to RPS. MAQ0648J | Tamarind Resources - Tui Field | Oil Spill Modelling | 21/03/18 Page II REPORT Contents EXECUTIVE SUMMARY .................................................................................................................................... 1 Background ....................................................................................................................................................... 1 Methodology ..................................................................................................................................................... 1 Oil Properties .................................................................................................................................................... 1 Key Findings ..................................................................................................................................................... 2 1 INTRODUCTION ................................................................................................................................. 4 2 SCOPE OF WORK ............................................................................................................................. 6 3 REGIONAL CURRENTS .................................................................................................................... 6 3.2 Tidal Currents .................................................................................................................................... 8 3.2.1 Grid Setup ........................................................................................................................................... 8 3.2.2 Tidal Conditions ................................................................................................................................. 10 3.2.3 Surface Elevation Validation ............................................................................................................. 10 3.3 Ocean Currents ............................................................................................................................... 15 3.4 Currents at the Release Site .......................................................................................................... 16 4 WINDS .............................................................................................................................................. 18 5 WATER TEMPERATURE AND SALINITY ...................................................................................... 21 6 OIL SPILL MODEL - SIMAP ............................................................................................................ 23 6.1 Stochastic Modelling ...................................................................................................................... 23 6.2 Sea surface, Shoreline and In-Water Thresholds ........................................................................ 24 6.2.1 Sea surface Exposure Thresholds .................................................................................................... 24 6.2.2 Shoreline Contact Threshold ............................................................................................................. 25 6.2.3 Water Column Exposure Thresholds ................................................................................................ 26 6.3 Exposure Calculation...................................................................................................................... 28 7 OIL PROPERTIES ............................................................................................................................ 30 8 MODEL SETTINGS AND ASSUMPTIONS ...................................................................................... 33 9 INTERPRETING MODELLING RESULTS ....................................................................................... 35 9.1 February to May Stochastic Assessment ..................................................................................... 35 9.2 Receptors Assessed ....................................................................................................................... 37 10 RESULTS: AMOKURA-2H LOSS OF WELL CONTROL ................................................................ 38 10.1 Stochastic Analysis ........................................................................................................................ 38 10.1.1 Sea Surface Exposure and Shoreline Contact ................................................................................. 38 10.1.2 In-Water Exposure ............................................................................................................................ 51 11 RESULTS: AMOKURA-2H 200 M3 MDO SURFACE RELEASE .................................................... 58 11.1 Stochastic Analysis ........................................................................................................................ 58 MAQ0648J | Tamarind Resources - Tui Field | Oil Spill Modelling | 21/03/18 Page III REPORT 12 REFERENCES .................................................................................................................................. 66 MAQ0648J | Tamarind Resources - Tui Field | Oil Spill Modelling | 21/03/18 Page IV REPORT Tables Table 1 Location of the wells for the study. ................................................................................................. 4 Table 2 Statistical comparison between the observed and HYDROMAP predicted surface elevations data from the 1st to 31st January 2014. ........................................................................................ 11 Table 3 Predicted average and maximum surface current speeds at the study site. The data was derived by combining the HYCOM ocean data and HYDROMAP tidal data for 2008-2012 (inclusive). .................................................................................................................................... 16 Table 4 Predicted average and maximum winds for the wind node nearest the release site. Data derived from CFSR hindcast model from 2003-2012 (inclusive). ............................................................. 19 Table 5 Monthly average sea-surface temperature and salinity at the study area. .................................. 21 Table 6 The Bonn Agreement Oil Appearance Code. .............................................................................. 24 Table 7 Thresholds used to classify the zones of sea surface exposure. ................................................ 25 Table 8 Thresholds use to assess shoreline contact ................................................................................ 26 Table 9 Dissolved aromatic threshold values applied as part of the modelling study .............................. 27 Table 10 Entrained hydrocarbon threshold values applied as part of the modelling study. Thresholds based on OSPAR guidelines........................................................................................................ 27 Table 11 Physical characteristics. ............................................................................................................... 30 Table 12 Boiling point ranges. ..................................................................................................................... 31 Table 13 Summary of the oil spill