Mooring Integrity & FUMA. Why is it needed? How is it achieved?

Transcription

1 AOEC 14 Mooring Integrity & FUMA Why is it needed? How is it achieved? Sept 2014

2 2 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

3 Typical Field Infrastructure 3

4 Typical Field Infrastructure 4

5 FPSO Expanding market 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 Source EMA 6/14 & Infield 6/13

6 FPSO Expanding market Prelude FLNG: 6 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

7 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 Lavaca Bay, Texas Bintulu, Malaysia 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 m m 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) Expected First Production Hs: 11.0 m - Hs: 13.6 m - Hs: 5.5 m Hs: 11.0 m Hs: 13.0 m

8 Hardware Mooring make up: 8 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

9 Hardware 9 Single point mooring - external turret Source: API RP 2SK Spread mooring

10 Vulnerability inherent design Limited redundancy in mooring system, chain as strong as its weakest link 10 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

11 Vulnerability - Codes Issues: 11 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)

12 Vulnerability - Codes Class Rules evolving from seafaring background 12 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

13 Vulnerability mooring legs Terminations: 13 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 Main Factors Influencing Long-Term Mooring Integrity including inspection and maintenance, mooring jewellery Source: HSE 2006 study Touchdown - accelerated corrosion (aerobic), chain moves above & below mudline, parent metal exposure

14 Vulnerability fatigue 14

15 Vulnerability fatigue 15

16 Vulnerability fatigue 16

17 Vulnerability corrosion Corrosion comes in many forms 17 Design codes generally allow for <0.8 mm/year SRB Corrosion - In warm, shallow waters, often near river estuaries FPSOs with touchdown zone dynamics (eg draft change due to offloading) Corrosion rates at up to 2-4 mm/year (Welaptega, 2014)

18 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)

19 Losses Cascade Chinook - Loss 3/ 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

20 Losses Gryphon - Loss 2/11 20 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) Recovered Subsea Arches

21 Losses Mooring Loss Statistics: 21 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. ( , 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

22 FUMA 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.

23 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.

24 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.

25 FUMA getting started 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) It s 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 Assured s core philosophy is critical).

26 Risk Screening Moored Risk Screening for FPSOs, FSOs, Spars, TLPs, SPMs & drilling units 26 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 High: Intolerable Risks; mitigation is essential Intermediate: Unacceptable, reduce to ALARP Low: Acceptable: Consider ALARP

27 FUMA assessment levels Level 1: Remote Desktop & Correspondence Review of design limits, operational procedures & history against relevant IACS standards and industry s 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.

28 FUMA when, how, who? 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 Insurer s internal engineering capability, and/or 3 rd party (eg MWS with specialist mooring skills/experience, other specialist engineer). Workscope is applied. Assessor delivers findings to both Assured & Insurers.

29 FUMA - reporting

30 FUMA - reporting

31 FUMA 4 typical tasks 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

32 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

33 FUMA & Integrity Management Ideally a Mooring Integrity Management System exists: 33 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)

34 Analysis of vessel loading conditions and hydrodynamics (Orcaflex) Mooring Systems Tools used - FUMA4 Most likely failure modes Identification of critical components Mooring Extreme & Fatigue Analyses Max. Operational & Survival Conditions Pictures: BPP-TECH,

35 Analysis of structural integrity of critical components based on Welaptega inspection results and FEA Mooring Systems Tools used - FUMA4 FEA (Abaqus) for chain components In-house analysis models for damaged wire ropes Pictures: BPP-TECH,

36 FUMA Identified Risks 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

37 FUMA Recommendations 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 don t rely on Class Societies to do this for you

38 FUMA Benefits 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

39 Lessons Learnt We NEED to know what we really have down there 39 How is it performing currently, how vulnerable is it How much longer is it going to be fit-for-service. We don t know what we don t know and we won t know until We make a conscious effort to go and find out!

40 40 Thanks for your attention and Questions?