ensign installation decommissioning programme · pdf file the ensign gas field was developed...

Click here to load reader

Post on 12-Apr-2020

5 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • Ensign Installation

    Decommissioning Programme

  • Ensign Installation Decommissioning Programme Page 2 of 30

    DOCUMENT CONTROL

    Document ID: SPT-DCM-SNS0104-REP-0004

    Document Classification: PUBLIC

    Document Ownership: Decommissioning

    Date of Document: 30/08/18 Signature Date

    Prepared by: S. Axon 02 Oct 2019

    Reviewed by: S. Mackenzie 02 Oct 2019

    Approved by: M. Fotheringham M. Fotheringham 02 Oct 2019

    REVISION RECORD

    Revision No. Date of Revision Reason for Issue

    A1 15/03/19 Combined DP issued for Review and Comment

    A2 24/04/19 Issued to OPRED for Review and Comment

    A3 08/10/19 Issued for Statutory Consultation

    DISTRIBUTION LIST

    Company No. of copies

    Offshore Petroleum Regulator for Environment and Decommissioning 1 electronic

    GMG, NFFO, NIFPO, SFF 1 electronic

    Hull Central Library 1 hardcopy

  • Ensign Installation Decommissioning Programme Page 3 of 30

    TABLE OF CONTENTS INST P/L

    1. Executive Summary 7

    1.1 Decommissioning Programme 7

    1.2 Requirement for Decommissioning Programme 7

    1.3 Introduction 7

    1.4 Overview of Installation Being Decommissioned 8

    1.5 Summary of Proposed Decommissioning Programme 8

    1.6 Field Location in UKCS 10

    1.7 Industrial Implications 13

    2. Description of Items to be decommissioned 14

    2.1 Installation: Surface Facilities 14

    2.2 Wells 16

    2.3 Inventory Estimates 16

    3. Removal and Disposal Methods 16

    3.1 Topsides 17

    3.2 Jacket 19

    3.3 Wells 21

    3.4 Waste Streams 22

    4. Environmental Impact Assessment 23

    4.1 Potential Environmental Impacts and their Management 23

    5. Interested Party Consultations 26

    5.1 Informal Consultations 26

    6. Programme Management 27

    6.1 Project Management and Verification 27

    6.2 Post-Decommissioning Debris Clearance and Verification 27

    6.3 Schedule 27

    6.4 Costs 27

    6.5 Close Out 28

    6.6 Post-Decommissioning Liability, Monitoring and Evaluation 28

    7. Supporting Documents 29

    Appendix A PUBLIC NOTICE & CONSULTEE CORRESPONDENCE 30

    Appendix A.1 Public Notices 30

  • Ensign Installation Decommissioning Programme Page 4 of 30

    FIGURES AND TABLES

    Figure 1.6.1: Field Location in UKCS............................................................................................ 10 Figure 1.6.2: Ensign Prior to Decommissioning ............................................................................ 11 Figure 1.6.3: Overview of Ensign Approaches .............................................................................. 12 Figure 2.1.1: Overview of Ensign decommissioning proposals ..................................................... 15 Figure 2.3.1: Pie chart of estimated installation inventory ............................................................. 16 Figure 3.1.1: Ensign Looking North .............................................................................................. 17 Figure 3.1.2: Ensign Looking West ............................................................................................... 18 Figure 3.2.1: Elevations on West & East Jacket Faces ................................................................. 20 Figure 3.2.2: Elevations on North and South Jacket Faces .......................................................... 21 Figure 6.3.1: Gantt Chart of Project Plan ...................................................................................... 27 Table 1.4.1: Installations Being Decommissioned........................................................................... 8 Table 1.4.2: Installation Section 29 Notice Holders Details ............................................................. 8 Table 1.5.1: Summary of Decommissioning Programme ................................................................ 8 Table 1.6.1: Adjacent Facilities ..................................................................................................... 12 Table 2.1.1: Surface Facilities Information .................................................................................... 14 Table 2.2.1: Well Information ........................................................................................................ 16 Table 3.1.1: Cleaning of topsides for removal ............................................................................... 18 Table 3.1.2: Topside Removal Methods ....................................................................................... 19 Table 3.2.1: Jacket Decommissioning Methods ............................................................................ 19 Table 3.3.1: Well Decommissioning ............................................................................................. 21 Table 3.4.1: Waste Stream Management Method......................................................................... 22 Table 3.4.2: Inventory Disposition ................................................................................................ 22 Table 3.4.3: Re-use, Recycle & Disposal Aspirations for Recovered Material .............................. 22 Table 4.1.1: Environmental Impact Management [2] ..................................................................... 23 Table 5.1.1: Summary of Stakeholder Comments ........................................................................ 26

  • Ensign Installation Decommissioning Programme Page 5 of 30

    TERMS AND ABBREVIATIONS

    ABBREVIATION EXPLANATION

    CPUK Conoco Phillips UK Limited

    CSV Construction Support Vessel

    DCA Decommissioning Operations (Master Application Template)

    DSV Diving Support Vessel

    Ensign Installation comprising small topsides and jacket held in location using 4x piles

    ESDV Emergency Shutdown Valve

    GMG Global Marine Group

    HSE Health and Safety Executive

    Installation Installation as defined by the Section 29 Notice, comprising topsides and jacket

    “ Inch; 25.4 millimetres

    JNCC Joint Nature Conservation Committee

    JUWB Jack Up Work Barge

    km Kilometre

    LAT Lowest Astronomical Tide

    LOGGS Lincolnshire Offshore Gas Gathering System

    m Metre(s)

    MAT, SAT Master Application Template, Supplementary Application Template

    MCV Monohull Crane Vessel

    MSV Multipurpose Support Vessel

    N,S,E,W, ESE North, South, East, West, East-South-East

    n/a Not Applicable

    NFFO National Federation of Fishermen's Organisations

    NIFPO Northern Ireland Fish Producers Organisation

    NORM Naturally Occurring Radioactive Material

    NPAI Not Permanently Attended Installation

    NUI Normally Unattended Installation

    OPEP Oil Pollution Emergency Plan

    OPRED Offshore Petroleum Regulator for Environment and Decommissioning

    OSPAR Oslo-Paris Convention

    Piggybacked Smaller pipeline is adjacent and clamped to a larger pipeline throughout its length

    Pipeline Pipeline or umbilical

    PL Pipeline Identification numbers

    PLA Pipeline Operations as defined in MAT Operation Types

    Platform Installation, typically comprising topsides and jacket

    PON Petroleum Operations Notice

    ROVSV Remotely Operated Vehicle Support Vessel

  • Ensign Installation Decommissioning Programme Page 6 of 30

    ABBREVIATION EXPLANATION

    SFF Scottish Fishermen’s Federation

    SLV Shear Leg Vessel

    Spirit Energy Spirit Energy North Sea Limited

    SSCV Semi-Submersible Crane Vessel

    UK United Kingdom

    UKCS United Kingdom Continental Shelf

    WGS84 World Geodetic System 1984

  • Ensign Installation Decommissioning Programme Page 7 of 30

    1. EXECUTIVE SUMMARY

    1.1 Decommissioning Programme

    This document contains one Decommissioning Programme for the set of notices under Section 29 of the Petroleum Act 1998. The Decommissioning Programme is concerned with:

    • The Ensign installation, comprising a steel jacket and topsides.

    Although decommissioning of the Ensign installations and pipelines is being treated in this document as a standalone project, Spirit Energy will also continue to explore cost saving synergies with other projects.

    A separate Decommissioning Programme will be prepared for the Ensign pipelines.

    1.2 Requirement for Decommissioning Programme

    Installations: In accordance with the Petroleum Act 1998, Spirit Energy North Sea Limited (as operator of the Ensign field, and on behalf of the Section 29 notice holders (Table 1.4.2), is applying to the Offshore Petroleum Regulator for Environment and Decommissioning (OPRED) to obtain approval for decommissioning the installations detailed in Section 2 of this document.

    In conjunction with public, stakeholder and regulatory consultation, this Decommissioning Programme is submitted in compliance with national and international regulations and