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AOEC 14 Mooring Integrity & FUMA Why is it needed? How is it achieved? Sept 2014
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Mooring Integrity & FUMA Why is it needed? How is it …€¦ · Mooring Integrity • Moorings are Safety Critical Components, inherently protecting the vulnerable subsea architecture

Apr 23, 2018

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  • AOEC 14

    Mooring Integrity & FUMA

    Why is it needed?

    How is it achieved?

    Sept 2014

  • Mooring Integrity

    Moorings are Safety Critical Components, inherently protecting the vulnerable subsea architecture (risers, umbilicals, flowlines etc), together with hydrocarbon production and adjacent assets

    Mooring Failure is regarded as a Class 1 Hazard, the highest rating by the UK Health & Safety Executive

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  • Mooring Systems Typical Field Infrastructure

    3

  • Mooring Systems Typical Field Infrastructure

    4

  • Mooring Systems FPSO Expanding market

    Source EMA 6/14 & Infield 6/13

    264 FPS at 6/14, 60%

    are FPSOs

    Compound annual growth of 18% to 2017, increasing in size, value & complexity

    95% increase in 10 years to 2017

    Drivers - monetise gas at remote locations & focus on deep water

    Dominated by Africa, Latin America & Australasia

  • Mooring Systems FPSO Expanding market

    Prelude FLNG:

    488m by 74m hull

    600,000 tonne weight

    Kizomba A FPSO is 285m by 63m

    90m high turret

    250m water depth

    Cat 5 cyclones (>156 mph)

    24 legs, 15.1 & 11.6 miles of chain & wire

    Source: The Engineer 09 & ship technology.com

    7-8 additional Asia-Pacific FLNG projects proposed

    Source: Upstream 5/11

    6

  • Mooring Systems FPSO Expanding market

    Prelude LNG Terminal Kanowit LNG Terminal Abadi Bonaparte Scarborough

    Operator Shell Exmar Petronas Excelerate Inpex Masela GDF

    Suez/Santos ExxonMobil

    Status (as of Feb 14)

    Under construction

    Under construction

    Under construction

    FEED completed

    FEED in progress

    FEED in progress

    pre-FEED completed

    Location 200 km W of

    Australia Caribbean coast

    of Colombia 180 km N of

    Bintulu, Malaysia Lavaca Bay, Texas

    coast 350 km E of East

    Timor 170 km N of

    Australia 220 km NW of

    Western Australia

    Water Depth 250 m Unknown 80 m Unknown 350-1000 m 85-100 m 900-970 m

    L x B 488 x 75 m 144 x 32 m 365 x 60 m 338 x 62 m ~500 x 80 m ~400 x 70 m 495 x 75 m

    Environment (Typhoon)

    Hs: 11.0 m - Hs: 13.6 m - Hs: 5.5 m Hs: 11.0 m Hs: 13.0 m

    Expected First Production

    2017 2015 2015 2018 2019 2019 2020-21

  • Mooring Systems Hardware

    8

    Mooring make up:

    Chain, mostly studless, up to 6.5 inch

    Wire unsheathed or sheathed spiral or 6 strand

    Polyester rope unsheathed or sheathed

    Connecting shackles

    Buoyancy support modules (buoys)

    Anchors or piles

  • Mooring Systems Hardware

    Spread mooring Single point mooring - external turret Source: API RP 2SK

    9

  • Mooring Systems Vulnerability inherent design

    Limited redundancy in mooring system, chain as strong as its weakest link

    Difficult to inspect & maintain, degradation & retirement issues

    Rapid incident escalation (eg cascading failure) in hostile environments

    Consequences lead to major loss including damage to subsea & seabed architecture and adjacent infrastructure

    10

  • Mooring Systems Vulnerability - Codes

    Issues:

    Various codes on mooring design, less on installation, operation, inspection & retirement

    Differences in technical standards between Societies

    Regional differences within Societies how good is the surveyor?

    Standards only periodically updated (behind the curve, e.g. new failure modes)

    Societies recognise that existing rules do not ensure FPSO mooring integrity

    Source: Oil & Gas UK Report OP023 (2008)

    11

  • Mooring Systems Vulnerability - Codes

    Class Rules evolving from seafaring background

    Existing developments: Class - Ageing, many legacy systems in place (eg SPMs & offloading tankers). Equipment replacement considered as repairs, obsolete Class codes utilized

    Tanker conversions to FPSOs, change in duty

    New developments Speedier, smaller operators, remote & unpredictable environments, deeper water, more subsea infrastructure, increased asset values

    12

  • Main Factors Influencing Long-Term Mooring Integrity including inspection and maintenance, mooring jewellery

    Source: HSE 2006 study

    Also inspection and maintenance, mooring jewellery

    Mooring Systems Vulnerability mooring legs

    Terminations: Hawse tubes - highest tension with

    additional bending, twisting stresses & link contact wear

    Touchdown - heavy contact with sea floor containing rock of comparable hardness to steel -> severe localized wear

    Touchdown - accelerated corrosion (aerobic), chain moves above & below mudline, parent metal exposure

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  • Mooring Systems Vulnerability fatigue

    14

  • Mooring Systems Vulnerability fatigue

    15

  • Mooring Systems Vulnerability fatigue

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  • Mooring Systems Vulnerability corrosion

    17

    Corrosion comes in many forms

    Design codes generally allow for

  • Mooring Systems Vulnerability - Ageing Assets

    18

    Failure trends? recent incidents

    Early life failures, design, manufacture, & installation

    Reduction in mid-life

    Increasing end of life failures; dominated by operational causes

    (OTC 24181)

  • Mooring Systems Losses

    Cascade Chinook - Loss 3/11

    6.25 chain

    Faulty weld repair causes fracture in single chain link

    440T buoyancy tank supporting hybrid riser released

    Chain vulnerable to hydrogen induced stress cracking post heat treatment

    19

  • Mooring Systems Losses

    Recovered Subsea Arches

    Gryphon - Loss 2/11

    winds > 55 knots, ~12m waves, 10 leg mooring, 18 year old chain

    Leading leg fails below design load

    DP loses heading, FPSO turns beam on

    21 degree roll, 3 more legs lost

    180m movement damaging subsea kit (Maersk, 9/11)

    20

  • Mooring Systems Losses

    Mooring Loss Statistics:

    1 in 50 chance of a single line failure per floating asset per year. This equates to a 1 in 2 chance of line failure over a 25 (say) year design life.

    1 in 350 chance of a multiple line failure (and/or infrastructure damage) per asset per year. 1 order of magnitude worse than industry (DNV) guidelines

    Permanently moored assets only. Based on known losses. (2001-11, 23 documented failures inc. 8 system failures, 4 with riser failure).

    Moving forward, these numbers are an underestimate. They do not recognise that all assets have continuously ageing mooring infrastructure.

    Mitigation, to reduce the chance of failure, is essential.

    Source: Mooring Integrity Forum, Monaco, 2014, OTC 24025

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  • Floating Unit Mooring Assessment (FUMA)

    FUMA is an endorsement (not a warranty) for underwriters use.

    Insurers have relied on Class & Operators to ensure adequacy of design & Mooring System integrity.

    JRC mandated Engineering Sub-committee to investigate need for a formal process for Mooring System Assessment.

    Reflects other JRC Assessment Processes, discretionary/voluntary, flexible.

    Mooring Systems FUMA

  • Floating Unit Mooring Assessment (FUMA)

    An underwriting tool, value-adding for assureds.

    Structured consistently with other JRC survey documents eg CAR MWS & Well Plan review (Guidance Notes, Endorsement, Codes of Practice, Workscopes).

    Consideration given to International Standards, Design & Operation Codes, Integrity Management Systems, Industry Best Practice.

    Interaction with industry/operators and Oil & Gas Mooring Integrity Workgroup.

    Mooring Systems FUMA

  • Floating Unit Mooring Assessment (FUMA)

    Promote dialogue between Underwriters and Assureds, without dictating.

    Report becomes Material Information & supports INFORMED underwriting decision making.

    Assist Underwriters in better understanding the Assureds operational practices, integrity management and experience.

    Enhance risk reduction for both Assureds and Insurers.

    Mooring Systems FUMA

  • Intended for Moored Floating Units OTHER THAN MODUs.

    Initial Screening Process (ISP) may indicate FUMA is not required (Generic considerations: Age, Design, Type, Class, Operating Standards)

    Its a tiered process, light touch (Level 1) to full physical (Level 4).

    Entry can be at any level, but with all preceding levels performed (assessing physical condition is important but understanding Assureds core philosophy is critical).

    Mooring Systems FUMA getting started

  • Mooring Systems Risk Screening

    Moored Risk Screening for FPSOs, FSOs, Spars, TLPs, SPMs & drilling units

    Used across a Portfolio of Moored Risks (or Operators) to assist Underwriters with risk mitigation

    Major incident likelihood (frequency) established by Naval Architects based on mooring complexity, age, design code, water depth, operational aspects, extreme environment vulnerability, inspection & monitoring etc

    Risk Consequence considers insured exposure, field infrastructure - subsea architecture, adjacent platforms

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    High: Intolerable Risks; mitigation is essential

    Intermediate: Unacceptable, reduce to ALARP

    Low: Acceptable: Consider ALARP

  • Level 1: Remote Desktop & Correspondence

    Review of design limits, operational procedures & history against relevant IACS standards and industrys best practice.

    Level 2a/2b: Attended Technical Review

    (2a: Attendance Onshore, 2b: Attendance Onshore & Offshore)

    Attendance by Mooring Assessors of onshore facilities and, if required, of offshore location.

    Level 3: Physical Inspection

    Physical inspection of moorings and third-party engineering as required.

    Level 4: Detailed Physical Inspection

    Physical inspection of moorings to higher specification and third-party engineering as required.

    Mooring Systems FUMA assessment levels

  • Can be at any point in moored unit lifecycle (pre or post installation benchmarking, mid-life, if life extension planned).

    Uses competent Mooring Assessors; any party on which Insurers & Assureds mutually agree.

    Assessors may include Insurers internal engineering capability, and/or 3rd party (eg MWS with specialist mooring skills/experience, other specialist engineer).

    Workscope is applied. Assessor delivers findings to both Assured & Insurers.

    Mooring Systems FUMA when, how, who?

  • Mooring Systems FUMA - reporting

  • Mooring Systems FUMA - reporting

  • FUMA Level 4 Mooring Assessment - Tasks :

    Pre-engineering to tailor inspection campaign

    Offshore inspection campaign

    2D/3D high def. focused visual inspections

    Chain/wire/fibre measurement tools, 3D modelling

    Review & report on risks associated with:

    Historic mooring failures and blackouts

    Operator Performance Standards

    Original design analysis and assumed extreme environment

    Operational philosophies and procedures

    Inspection findings

    Mooring Systems FUMA 4 typical tasks

  • FUMA Level 4 Mooring Assessment Tasks:

    Review and report on risks associated with:

    Reported operations & offloading against original design inputs

    Mooring fatigue life re-assessment

    Subsea architecture complexity & vulnerability

    Collision risks & consequences floating, water column & seabed

    Identify & report on gaps in operations, maintenance and inspection procedures

    Recommendations for future inspection campaigns and wider mooring integrity management

    Mooring Systems FUMA 4 typical tasks

  • Mooring Systems FUMA & Integrity Management

    Ideally a Mooring Integrity Management System exists:

    Part of Operator Safety Management System

    Developed, owned & administered by Operator

    Recognition that Moorings are Safety Critical

    Key components:

    System Description. Design, Manufacturing & Deployment

    System Performance Standards (specific, measurable, agreed, realistic & timed)

    Normal & Damaged Operational Procedures

    Component Risk Review (ALARP)

    Monitoring & Inspection driven by Risk Review

    Feedback into Performance Standards

    Suitable Tracking Systems to close out anomalies Source: Oil & Gas UK Report OP023 (2008)

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  • 34

    Most likely failure modes Identification of critical components Mooring Extreme & Fatigue Analyses Max. Operational & Survival Conditions

    Pictures: BPP-TECH, 2012

    Analysis of vessel loading conditions and hydrodynamics (Orcaflex)

    Mooring Systems

    Tools used - FUMA4

  • 35

    FEA (Abaqus) for chain components In-house analysis models for damaged

    wire ropes

    Pictures: BPP-TECH, 2013

    Analysis of structural integrity of critical components based on Welaptega inspection results and FEA

    Mooring Systems

    Tools used - FUMA4

  • Key high risk items identified in previous studies:

    Failure to establish meaningful root causes of historic failures

    Failure to implement recommendations made in internal accident investigations

    Absence of line-tension verification systems

    Lack of coherent emergency plans for mooring failures

    Mooring inspections not conducted deeper than 30m (air diving limit)

    Severe chain degradation known to operator No action taken to manage reduced capacity

    Mooring Systems FUMA Identified Risks

  • Key recommendations made in previous studies:

    Root cause analyses to be completed by competent persons

    Engineering studies to account for real-world condition of system

    Line-tension verification system to be installed as priority

    Mooring line failures to be simulated in drills and findings integrated in emergency procedures

    Comprehensive mooring inspection programme to be implemented

    Take ownership of mooring integrity management dont rely on Class Societies to do this for you

    Mooring Systems FUMA Recommendations

  • Development of effective mooring management strategies leading to:

    Safer mooring systems, less prone to failure

    Better early warning of mooring component degradation

    Rapid identification of failures through improved monitoring

    More efficient response of on-board and shore-based staff to mooring failure

    Minimisation of mooring failure consequences

    Reductions in number and size of insurance claims, improved insurance terms

    Lower downtime and improved productivity

    Improved industry reputation

    Mooring Systems FUMA Benefits

  • Lessons Learnt

    We NEED to know what we really have down there

    How is it performing currently, how vulnerable is it

    How much longer is it going to be fit-for-service.

    We dont know what we dont know

    and we wont know until

    We make a conscious effort to go and find out!

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  • Thanks for your attention and

    Questions?

    d.brown@bpp-tech.com

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