Transcription
FghtFMARATHONBRAEBrae Bravo Topsides, Flare Bridge, FlareTower and Flare Jacket/Sub-structureDecommissioning ProgrammesJuly 2018 Final Version
Brae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureDecommissioning Programmes9010-MIP-99-PM-RP-00008-000, I02July 2018 Final Versionwww.marathonoil.com/braedecomThe illustrations and drawings in this document are for information only. Marathon Oil U.K. LLC does notwarrant or represent that it is complete or accurate and will not be liable for any person’s reliance on theseillustrations for any purpose.2 of 52
Brae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureDecommissioning ProgrammesContents1.Installation PipelineExecutive Summary . 71.1Decommissioning Programmes . 71.2Requirement for Decommissioning Programmes . 81.3Introduction . 81.4Overview of Installations Being Decommissioned . 101.5Summary of Proposed Decommissioning Programmes . 121.6Field Locations Including Field Layouts and Adjacent Facilities . 131.7Industrial Implications . 192. Description of Items to be Decommissioned . 202.1Installations: Surface Facilities – Topsides and Jacket/Sub-structure . 202.2Installations: Subsea Including Stabilisation Features . 202.3Pipeline(s) Including Stabilisation Features . 202.4 Wells . 202.5Drill Cuttings . 222.6Inventory Estimates. 223. Removal and Disposal Methods. 243.1Topsides . 243.2Jacket/Sub-structure . 283.3Subsea Installations and Stabilisation Features . 303.4 Pipelines . 303.5Pipeline Stabilisation Features . 303.6 Wells . 303.7Drill Cuttings . 303.8Waste Streams . 304. Environmental Impact Assessment . 324.1Environmental Sensitivities (Summary) . 324.2 Potential Environmental Impacts and their Management . 335. Interested Party Consultations. 356. Overall Programme Management . 366.1Project Management and Verification. 366.2Post-decommissioning Debris Clearance and Verification . 366.3 Schedule . 366.4 Long Term Facilities Management . 386.5 Costs. 386.6 Close Out . 396.7Post-Decommissioning Monitoring and Evaluations . 396.8 Management of Residual Liability . 397. Supporting Documents . 408. Partners’ Letters of Support . 41Appendix 1 Statutory Consultees Correspondence . 47Appendix 2 Estimated Material Inventory . 484 of 52
FiguresFigure 1.1: Brae Bravo Facilities to be Decommissioned . 9Figure 1.2: Brae Area Field Locations within UKCS . 13Figure 1.3: Brae Area Facilities Layout . 14Figure 1.4: Brae Area Adjacent Facilities . 18Figure 2.1: Estimated Inventory. 23Figure 3.1: Brae Bravo Topsides. 25Figure 3.2: Brae Bravo Flare Jacket/Sub-structure . 28Figure 6.1: Overall Brae Area Decommissioning Schedule . 37TablesTable 1.1: Installations Being Decommissioned.10Table 1.2: Brae Bravo Section 29 Notice Holders . 11Table 1.3: Summary of Decommissioning Programmes. 12Table 1.4: Adjacent Facilities . 16Table 2.1: Surface Facilities Information .20Table 2.2: Wells Information. 21Table 2.3: Material And Waste Management . 22Table 3.1: Topsides Cleaning Methods. 26Table 3.2: Topsides Removal Methods. 27Table 3.3: Jacket/Sub-structure Attributes . 28Table 3.4: Jacket/Sub-structure Decommissioning Methods . 29Table 3.5: Well Plug and Abandonment . 30Table 3.6: Waste Stream Management Methods . 30Table 3.7: Inventory Disposition . 31Table 3.8: Reuse, Recycling and Disposal of Material Returned to Shore (By Weight) . 31Table 4.1: Environmental Sensitivities Summary . 32Table 4.2: Environmental Impacts and Management . 33Table 5.1: Summary of Stakeholder Comments . 35Table 6.1: Provisional Decommissioning Costs . 38Table A2.1: Estimated Material Inventory .485 of 52
Brae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureDecommissioning ProgrammesTerms and EPASFFSLVSSIVTeUKUKCSWGS84WWF6 of 52Buoyancy Tank AssemblyCanadian Natural ResourcesCessation of ProductionDepartment of Energy and Climate Change (Role now performed by OPRED)Environmental Impact AssessmentEnvironmental StatementFirst Point Assessment LimitedGiga JoulesHazardous (waste)Heavy Lift VesselHealth and Safety ExecutiveJoint Nature Conservation CommitteeLimited Liability CorporationInternational Convention for the Prevention of Pollution from ShipsMarine & Coastal Access Act 2009Module Support FrameNot ApplicableNaturally Occurring Radioactive MaterialOil and Gas AuthorityOil Pollution Emergency PlanDepartment of Business, Energy and Industrial Strategy Offshore Petroleum Regulator forEnvironment and DecommissioningOslo Paris ConventionPipe Line (as in PL Number)Power Management SystemScottish Area Gas Evacuation (Gas export system)Scottish Environment Protection AgencyScottish Fishermen’s FederationSingle Lift VesselSubsea Isolation ValveTonnesUnited KingdomUK Continental ShelfWorld Geodetic System 1984World Wide Fund for Nature
1.Executive SummaryMarathon Oil has identified an opportunity to bring forward dismantling of the Brae Bravo Topsides,Flare Bridge, Flare Tower, and Flare Jacket/Sub-structure to 2019/2020. This has two advantages; It minimises the period between cessation of production and removal of the facilities. This hassafety and environmental benefits, as it reduces the length of time for which effort must beexpended to maintain the facilities in a safe condition for dismantling Early decommissioning will exploit a predicted lull in offshore decommissioning activity in 2019 –2021. This means that a greater selection of decommissioning vessels, etc. is likely to be availableto Marathon Oil in this period. This in turn leads to a wider choice of technical approaches andleads to lower costs.To support earlier removal of the Brae Bravo facilities, Marathon Oil, in consultation with OPRED, hasreorganised the decommissioning programmes for the Brae Alpha, Brae Bravo and associated subseafacilities into two documents. The reorganised decommissioning programmes are presented in:1.This document, the Brae Bravo Topsides, Flare Bridge, Flare Tower, and Flare Jacket/Substructure Decommissioning Programmes, 9010-MIP-99-PM-RP-00008-000, which covers theBrae Bravo facilities that will be removed early, and2. The Brae Alpha, Brae Bravo, Central Brae, West Brae and SedgwickCombined Decommissioning Programmes, 9000-MIP-99-PM-RP-00003-000, which covers theBrae Bravo main platform jacket/sub-structure, and the Brae Alpha, Central Brae, West Brae, andSedgwick facilities [3].The decommissioning proposals for the Brae Area facilities contained in these documents are the sameas those set out in the previous versions of the decommissioning programmes, with the sole exception ofthe change to the scheduling of Brae Bravo Topsides, Flare Bridge, Flare tower and Flare Jacket / Substructure removal.1.1Decommissioning ProgrammesThis document contains the decommissioning programmes for components of two installations; the BraeBravo and the Brae Bravo Flare. The components covered by the decommissioning programmes are theBrae Bravo topsides, and the Brae Bravo Flare installation in its entirety, comprising the flare bridge, flaretower, and flare jacket/sub-structure. The scope of the decommissioning programmes is shown inFigure1.1As required by the Petroleum Act 1998, amended by the Energy Act 2008, this document contains thedecommissioning programmes for the following facilities:1.Brae Fields Section 29 Notice: Brae Bravo platform topsides Brae Bravo flare bridge, flare tower and flare jacket/sub-structure.The facilities in the scope of these decommissioning programmes are illustrated in Figure 1.1.7 of 52
Brae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureDecommissioning Programmes1.2Requirement for Decommissioning Programmes1.2.1InstallationsIn accordance with the Petroleum Act 1998, as amended, Marathon Oil UK LLC (Marathon Oil) asoperator of the Brae Bravo platform and Brae Bravo Flare and on behalf of the Section 29 NoticeHolders (see Table 1.2 ) is applying to the Offshore Petroleum Regulator for Environment andDecommissioning (OPRED) to obtain approval for decommissioning the components of the Brae Bravoinstallations detailed in Section 2.1 of this document. (See also Section 8 – Partners’ Letters of Support).1.3IntroductionThe Brae Bravo installation lies within UKCS Block 16/7a. The platform stands in 99m of water,approximately 269km north-east of Aberdeen.The Brae Bravo platform facilities include modular topsides and a steel jacket/sub-structure. The BraeBravo flare consists of a second steel jacket/sub-structure, the flare tower and a steel connecting bridgeto the Brae Bravo platform.Brae Bravo started production in 1988. Marathon Oil has extended the life of the Brae Field beyondinitial projections. Other hydrocarbon opportunities have been evaluated and considered non-viable,therefore Marathon Oil made a CoP (Cessation of Production) application for Brae Bravo to the OGA in2015. This was approved in 2016. Brae Bravo is scheduled to cease production and processing in July2018.1.3.1Scope of Decommissioning ProgrammesThe decommissioning programmes contained in this document cover the following facilities: The Brae Bravo platform topsides The Brae Bravo flare bridge, flare tower and flare jacket/sub-structure.The scope of the facilities covered by these decommissioning programmes is shown in Figure 1.1.The jacket/sub-structure of the main Brae Bravo large steel platform is outside the scope of thesedecommissioning programmes. It is included in a separate decommissioning programme [3], andsubject to a derogation application process under OSPAR Decision 98/3.8 of 52
Figure 1.1: Brae Bravo Facilities to be Decommissioned1.3.21.Decommissioning Programmes OutlineThe Brae Bravo platform wells have been permanently abandoned by placing verified barriers toisolate rock formations that have flow potential from the surface, to meet OGA and HSErequirements.2. All topsides process equipment will be flushed and cleaned to an appropriate standard prior todecommissioning.3. The Brae Bravo platform topside modules, and the Brae Bravo flare bridge, flare tower and flarejacket/sub-structure, will be removed and returned to shore for reuse, recycling or disposal.4. Following completion of Brae Area decommissioning, Marathon Oil will conduct a survey to confirmthat the Brae Area is left as described in these decommissioning programmes and the Brae Alpha,etc. decommissioning programmes [3].9 of 52
Brae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureDecommissioning Programmes1.4Overview of Installations Being DecommissionedThe overall layout of the Brae Area facilities, including Brae Bravo, is shown in Figure 1.3.1.4.1InstallationsTable 1.1: Installations Being DecommissionedField(s)BraeProduction th99mUKCS Block16/7aTopside Weight(tonnes)Sub-structure Weight 1(tonnes)Surface InstallationsNumberType1Fixed Large Steel Jacket(Brae Bravo main platform)1Fixed Small Steel Jacket(Brae Bravo Flare)35,000N/A (Decommissioning of BraeBravo Main platform jacket/substructure is described in [3])1,2001,550Number of WellsPlatform WellsSubsea Wells28N/ADrill Cuttings PilesNumber ofPilesTotal EstimatedVolume (m3)N/AN/ADistance toMedian (km)Distance From NearestUK Coastline (km)4187Recoverable steel weight including recoverable piles, but excluding grout, marine growth and additional weight dueto flooded members.110 of 52
Table 1.2: Brae Bravo Section 29 Notice HoldersSection 29 Notice HoldersRegistration NumberEquity InterestMarathon Oil U.K. LLCFC00958740.0%TAQA Bratani Limited597547541.7%Spirit Energy Resources Limited028551518.0%JX Nippon Exploration and Production (U.K.) Limited32886896.3%TAQA Bratani LNS Limited62305404.0%BP Exploration Operating Company Limited3059430.0%ENI UKCS Limited10197480.0%Neptune E&P UK Limited33864640.0%Marathon Oil North Sea (G.B.) Limited9811260.0%Repsol Sinopec Resources UK Limited8258280.0%Repsol Sinopec LNS Limited24831610.0%1.4.2 PipelinesThere are no pipelines included in these decommissioning programmes. (For details of the pipelinesassociated with Brae Bravo see [3]).11 of 52
Brae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureDecommissioning Programmes1.5Summary of Proposed Decommissioning ProgrammesThe selected decommissioning options for the Brae Bravo topsides, flare bridge, flare tower and flarejacket/sub-structure are shown in Table 1.3 below.Table 1.3: Summary of Decommissioning ProgrammesSelected OptionReason for SelectionProposedDecommissioning SolutionTopside removal is mandatory.Marathon Oil will seek to optimisethe benefits that accrue fromremoval of the topsides bymaximising reuse and recycling.Cleaned equipment refurbished forreuse where possible. Equipmentthat cannot be reused will berecycled or processed viaappropriate disposal routes.To leave the seabed clear for otherusers and to meet OSPAR andOPRED requirements.The Brae Bravo flare jacket/substructure will be recycled. Anymaterial that cannot be recycled willbe processed via appropriatedisposal routes.Plugging and abandoning the wellsleaves the wells in a safe and securecondition. This will protect peopleand the environment and meet OGAand HSE requirements.Well equipment that is removed willbe returned to shore for reuse,recycling, or disposal.TopsidesComplete removal of the BraeBravo topsides, flare bridge andflare tower for reuse, recycling orappropriate disposal.Jacket/Sub-structureComplete removal of the BraeBravo flare jacket/sub-structure.WellsThe Brae Bravo platform wells havebeen permanently abandoned byplacing verified barriers to isolaterock formations that have flowpotential from the surface.Drill CuttingsThe Brae Bravo cuttings pile is outside the scope of these decommissioning programmes. (For details ofdecommissioning proposals for the cuttings pile, refer to [3]).InterdependenciesNone12 of 52
1.6Field Locations Including Field Layouts and Adjacent FacilitiesThe locations of the Brae Area fields within the UKCS are shown in Figure 1.2. Figure 1.3 shows the BraeArea facilities layout in more detail. The facilities adjacent to the Brae Bravo installation are listed inTable 1.4 and shown in Figure 1.4Figure 1.2: Brae Area Field Locations within UKCS13 of 52
Figure1.3: Brae Area FacilitiesLayoutDecommissioningProgrammesBrae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureNOT TO SCALESchematic representation only14 of 52
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Brae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureDecommissioning ProgrammesTable 1.4: Adjacent FacilitiesOwnerNameTypeDistance/Direction FromBrae BravoInformationStatusMarathon OilBrae AlphaPlatform12kmSouth-south-westConnects to BraeBravo via PMScable andpipelinesOperationalMarathon OilEast BraePlatform14kmNorth-eastConnects to BraeBravo via PMScable eastRedundantproductionplatformBeing DecommissionedBPPL1971 Millerto edBPPL722 Millerto BraeAlpha18” edRepsolSinopecEnochWellheadSubsea well19kmSouth-eastSubsea tie-backto Brae AlphaOperationalRepsolSinopecPL2336Enoch toBrae AlphaFlowline8” Flowline in12” RepsolSinopecPL2337 BraeAlpha toEnoch GasLift Line3” Flowline in12” RepsolSinopecPLU2338Brae Alphato CNRPL872Tiffany toPL360 GasExport Line10” l16 of 52
Table 1.4: Adjacent FacilitiesOwnerNameTypeDistance/Direction FromBrae BravoInformationStatusCNRPL873Tiffany toPL64 OilExport Line12” OilPipeline35kmSouthPipelineOperationalSpirit EnergyBirch, Larch,SycamoreSubseamanifolds perationalSpirit EnergyPL1161 Birchto stPipelineOperationalSpirit EnergyPL1162 BraeAlpha toBirch12” WaterInjection Line12kmSouth-south-westPipelineOperationalSpirit EnergyPL1531 BraeAlpha toLarch4” Gas rit EnergyPL1163 BraeAlpha toBirch4” Gas rit EnergyPL1527 Larchto elineOperationalSpirit EnergyPL1528 LarchWYE toLarch6” WaterInjection Line20kmSouth-south-westPipelineOperationalSpirit EnergyPL1529Larch WYEto Larch4” Spirit EnergyPL1530Larch tionalApachePL762 SAGEPipeline13kmNorth-westConnects to EastBrae via PL896and theSSIV/CrossoverstructureOperational17 of 52
Brae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureDecommissioning ProgrammesTable 1.4: Adjacent FacilitiesOwnerNameTypeDistance/Direction FromBrae d alTable 1.4: Adjacent FacilitiesImpacts of Decommissioning ProposalsMarathon Oil has been, and will continue to be, in contact with operators and owners of adjacent facilities. Theadjacent third party facilities have no known impacts on the Brae Bravo Topsides, Flare Bridge, Flare Tower andFlare Jacket/Sub-structure decommissioning programmes.All third party facilities that tie-in to, or are supported by, the Brae Bravo facilities are engaged under normalcommercial agreements and are part of the CoP application process to OGA.Figure 1.4: Brae Area Adjacent Facilities18 of 52
1.7Industrial ImplicationsMarathon Oil is developing the Brae Bravo decommissioning contract and procurement strategy onbehalf of the Section 29 Notice Holders. Marathon Oil has, and will continue to:1.Publish Brae Decommissioning project information, including the project schedule, on the MarathonOil decommissioning website: www.marathonoil.com/braedecom.2. Publish project information and contact details on the OPRED website.3. Engage with the OGA and the decommissioning supply chain on issues relating to the Brae Bravodecommissioning programmes and schedule.4. Use the FPAL database as the primary source for establishing tender lists for contracts andpurchases with a value of 250,000 or more.19 of 52
Brae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureDecommissioning Programmes2.Description of Items to be Decommissioned2.1Installations: Surface Facilities – Topsides and Jacket/Sub-structureKey information regarding the Brae Bravo platform topsides, flare bridge, flare tower, and flarejacket/sub-structure is presented in Table 2.1.Table 2.1: Surface Facilities cimal58.792540 NWGS84DecimalMinute58 47.552’NWGS84Decimal58.792540 NWGS84DecimalMinute58 ryNumberWeightof(tonnes) ModulesWeightWeight Number Number of Piles(tonnes) of Legs of Piles (tonnes)1.3470857 E35,000281 20.825’E2The Brae Bravo main platform jacket/substructure does not form part of thesedecommissioning programmes. (Fordetails of the main platform jacket/substructure, see [3]).1.3470857 E1,2001,55033501 20.825’EInstallations: Subsea Including Stabilisation FeaturesThere are no subsea installations or stabilisation features in the scope of these decommissioningprogrammes. (For details of the subsea installation associated with the Brae Bravo see [3]).2.3Pipelines Including Stabilisation FeaturesThere are no pipelines or stabilisation features in the scope of these decommissioning programmes. (Fordetails of the pipelines and stabilisation features associated with Brae Bravo see [3]).2.4WellsThe Brae Bravo wells are listed in Table 2.2. These wells have been permanently abandoned by placingverified barriers to isolate rock formations that have flow potential from the surface, to meet OGA andHSE requirements.Recoverable steel weight, including recoverable piles but excluding grout, marine growth, and additional weight dueto flooded members220 of 52
Table 2.2: Wells 07a-B01 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B02 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B03 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B04 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B05 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B06 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B08 (North Brae)Gas InjectorP&A’dPL 0-0-016/07a-B09 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B15 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B16Z (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B17 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B18 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B19 (North Brae)Not CompletedP&A’dPL 0-0-016/07a-B20 (North Brae)Oil and Gas Condensate ProducerP&A’dPL 0-0-016/07a-B21 (Beinn)Oil and Gas Condensate ProducerP&A’dPL 0-0-016/07a-B22 (North Brae)Oil and Gas Condensate ProducerP&A’dPL 0-0-016/07a-B23Z (Beinn)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B24 (Central)Oil ProducerP&A’dPL 0-0-016/07a-B25 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B26 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B27 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B29 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B30 (Beinn)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B31Z (Central)Oil ProducerP&A’dPL 0-0-016/07a-B32 (North Brae)Not CompletedP&A’dPL 0-0-016/07a-B33 (Beinn)Gas Condensate ProducerP&A’dPL 0-0-0WellPlatform Wells (Brae Bravo)21 of 52
Brae Bravo Topsides, Flare Bridge, Flare Tower and Flare Jacket/Sub-structureDecommissioning ProgrammesTable 2.2: Wells y16/07a-B34 (North Brae)Gas Condensate ProducerP&A’dPL 0-0-016/07a-B35 (Beinn)Not CompletedP&A’dPL 0-0-02.5Drill CuttingsThere are no drill cuttings in the scope of these decommissioning programmes. (For details of the BraeBravo drill cuttings pile see [3]).2.6Inventory EstimatesThe approximate amounts of key materials used in the make-up of the Brae Bravo, topsides, flare bridge,flare tower and flare jacket/sub-structure has been evaluated. These inventories are listed in Table 2.3. Afocused review of the inventories of materials will be conducted during the detailed engineering phaseof decommissioning. The level of detail developed and waste coding of materials will be subject to thereuse, recycling or disposal options selected, and the chosen removal method and destination.Summaries of the material inventories for the Brae Bravo, topsides, flare bridge, flare tower and flarejacket/sub-structure are shown in Figure 2.1.Appendix 2 provides further information on the main waste types on the facilities known at this stage.Table 2.3: Material And Waste Management
SAGE Scottish Area Gas Evacuation (Gas export system) SEPA Scottish Environment Protection Agency SFF Scottish Fishermen's Federation SLV Single Lift Vessel . 9000-MIP-99-PM-RP-00003-000, which covers the Brae Bravo main platform jacket/sub- structure, and the Brae Alpha, Central Brae, West Brae, and .
