Joint Rig Committee. Integrity Management of Permanent Mooring Systems

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1 Joint Rig Committee Integrity Management of Permanent Mooring Systems

2 Commissioning Design rate Performance Test Initial Start-up Mock Operation Trouble Shooting Operation Construction Completion Construction Mechanical Completion Specification Product Plant Acceptance < Picture to go here >

Integrity Management of Permanent Mooring Systems 4 rd October

5 Introduction Discipline responsibilities within SBM Design of Mooring Systems Fabrication of Mooring Systems In-Service load monitoring Installation In-service Inspection Summary Contents

6 Introduction Passive versus active systems 6

7 Introduction

8 Introduction

9 Introduction

10 Introduction Shallow water mooring 10

11 Introduction Deep water mooring 11

12 Introduction 12

13 Introduction Definition of failure: Component failure Loss of one mooring line. This is a design case which does not impact riser integrity. System failure Loss of multiple mooring lines. Potentially leading to damage to risers and subsea system. 13

Introduction 2 papers summarising mooring failures were presented at OTC 2013: Clear trend of infant mortality with over half of the subject failures

14 Introduction 2 papers summarising mooring failures were presented at OTC 2013: Clear trend of infant mortality with over half of the subject failures occurring in the first 5 years ie driven by fabrication faults and installation damage. Other failures concentrated towards end of design life ie driven by fatigue. 14

Discipline responsibilities within SBM Mooring system design is the responsibility of the dedicated Hydrodynamics discipline (35 engineers, all staff).

15 Discipline responsibilities within SBM Mooring system design is the responsibility of the dedicated Hydrodynamics discipline (35 engineers, all staff). Fabrication and delivery of a mooring system is managed jointly by Supply Chain Management and Hydrodynamics (Package Engineers). Installation means are developed jointly by Engineering and the Installations group. 15

16 Limit states A limit state is a condition of a structure beyond which it no longer fulfills the relevant design criteria. Moorings are checked against three limit states: Ultimate Limit State (ULS) Accidental Limit State (ALS). Fatigue Limit State (FLS). 16

17 Limit States Checked on all segments of anchoring line Based on dynamic tension (includes inertia) Factors of Safety for ULS and ALS are defined as: Minimum Breaking Load/Maximum Tension Ultimate Limit State (ULS) 1.67 Accidental Limit State (ALS) 1.25 The Minimum Breaking Load is computed at the end of the design life. Factor of Safety for FLS is defined as: Calculated Fatigue Life/Design Life is 10 17

18 Metocean conditions Site specific (unlike trading tankers) Client-provided (minimum requirements and consistency checks by SBM) All encompassing (wind, waves, current & swells) Extensive Extreme environments (1-year, 10-year, 100-year, 10,000-year return periods) Hindcast time 3-hour intervals with environment magnitude & direction (over tens of years..) 18

19 Design - Rules & Regulations SBM design approach is based on in-house Corporate Engineering Standards (CES): ABS approved Continuously updated Consistency in engineering Additionally, class notation sought from one of the 4 leading Classification Authorities: ABS, BV, DNV and LRS. ABS most often selected for SBM s lease FPSOs. 19

20 Toolbox All software used is validated against model tests: ARIANE (Bureau Veritas) AQWA suite (ANSYS Century Dynamics Ltd) HydroStar (Bureau Veritas) ORCAFLEX (Orcina) In-house developments, particularly for pre and postprocessing. 20 Author's name, DD Month YYYY

21 Toolbox Wind Tunnel Tests Wave Basin Model Tests Testing is now used for calibration rather than directly for design 21

Fabrication responsibilities A Package Manager is assigned responsibility for the fabrication and delivery of each mooring system The design engineer continues during the fabrication phase as the

22 Fabrication responsibilities A Package Manager is assigned responsibility for the fabrication and delivery of each mooring system The design engineer continues during the fabrication phase as the Package Engineer and reviews compliance of vendor documentation with SBM Specifications WP PS408 Kick of Meeting WPF PS Minutes of Kick off Meeting WP PS410 Inspection and Acceptance WPF PS Inspection Test Plan WPF PS Inspection Notification-Confirmation WPF PS Inspection Report WPF PS Inspection Release Certificate WPF PS Outstanding Work List WP PS407 Package Interface Management WPF PS Vendor Variation Request WPF PS Vendor Non-Conformance Report 22

23 In-service load monitoring Anchor Leg Load Monitoring Systems (ALLMS)

24 Installation 24

25 Installation Normand Installer 25

general visual inspections forming the basis The minimum inspection

26 In-service inspection Most units within the SBM fleet operate in significant water depths which limits the practicalities of detailed inspections, with general visual inspections forming the basis The minimum inspection requirement is compliance with class rules, ie full visual inspection twice every 5 years 26

27 In-service inspection The ability to interface directly with the design team allows early identification of potential problems when anomalies are reported during inspection. The inspection regime is modified as required based on feedback from engineering and inspection findings, i.e. it is risk based. The design of the mooring systems in-house allows any potential problems identified by survey to be quickly assessed. Inspection based on Engineering requirements is usually required as input to a life extension study. 27

28 Summary The majority of reported mooring failures are attributed to fabrication defects, installation problems, or fatigue. Integrated teams and clear procedures are needed to ensure fabrication quality and suitable installation means. Understanding of fatigue phenomena has improved and factors of safety have increased. 28

29 Summary Single line failures are component failures and are addressed as a design case. They do not impair the integrity of the riser system, but must not be allowed to escalate into multi-line failures In-service load monitoring can help prevent escalation of single-line failures. In-service inspection is not a substitute for robust design. 29

31 Integrity Management of Permanent Mooring Systems John MM Awater Department Head Marine & Subsea Support Bluewater TA (Technical Authority) in Operations & Underwater activities Lloyd s Market Association, JRC London 4 October 2013

Bluewater Energy Services BV Privately Owned Company by Hugo Jan Heerema HQ in Hoofddorp, The Netherlands Company was founded (by others) in 1978 We are active in the

32 Bluewater Energy Services BV Privately Owned Company by Hugo Jan Heerema HQ in Hoofddorp, The Netherlands Company was founded (by others) in 1978 We are active in the offshore Energy business We Design or buy, Built & Construct, Install, Operate & Relocate Offshore FPSO systems, all over the Globe. Operating FPSO s is our core business

33 John MM Awater (full profile on LinkedIn) Started in Bluewater 1994, responsible & project leader for the installation of BW FPSO s in the nineties: Uisge Gorm, Fife field Glas Dowr, Durward & Dauntless field Bleo Holm, Ross/Perry & Blake field Main task in Op s after installation: Maximise Availability FPSO (underwater) systems! In 2003 appointed Department Head, responsible for all Bluewater (under) water related activities, World wide.

34 Underwater Infrastructure & new buoy system

35 Bleo Holm, Ross-Perry field (start of design 1997)

36 Mooring systems Bluewater FPSO s System built-up from anchor point towards FPSO Conservative system built-up. We design for wear & tear during lifetime of the system Anchor: Piles or HHP anchors Mooring leg consists of 1 st section chain, mooring wire, catenary section chain & connection to spider or buoy Chain is primarily needed for accepting dynamic loadings and weight in the system to keep the FPSO and the attached systems (Risers) in a predetermined envelop It s a Balanced System!

37 Internal Turret, 3 * 3 mooring legs

38 Uisge Gorm, Fife field UKCS

39 Uisge Gorm, Fife field Design parameters Design life of mooring system 15 years 1 year storm Hs 9.8 mtr Hmax 18.2 mtr 50 year * storm Hs 13.5 mtr Hmax 24.8 mtr UG was taken out of services in 2008, after full life cycle. Inspection of the recovered UG mooring chain from seabed revealed no issues, chain links in good condition

40 Glas Dowr, Durward & Dauntless field Design parameters Design life of mooring system 15 years 1 year storm Hs 9.6 mtr Hmax 17.9 mtr 100 year storm Hs 12.9 mtr Hmax 23.7 mtr GD was taken out of services mid 1999, only 2 years after installation, due to reservoir depletion/economics Onshore inspections of various sections of the GD mooring chain revealed no issues

41 Bleo Holm, Ross/Perry & Blake field Design parameters Design life of mooring system 20 years 1 year storm Hs 8.4 mtr Hmax 15.7 mtr 100 year storm Hs 12.6 mtr Hmax 23.3 mtr Bleo Holm is producing since early 1999 Bluewater does not operate this FPSO! BW analyses and conclusions of the annual mooring inspection reports are OK, no issues!

42 Mooring systems Main function is Station Keeping! In a predetermined area, able to withstand the 100 year storm Designed for Long term (FPSO 15-20y) or Short term (MODU)? Is system: Active, read, thruster assist, power needed or Passive? Bluewater designed mooring systems are Passive systems

43 Large components in System INSTALLATION / HANDLING, surface & underwater Big in size & weight, handling is a challenge, even with correct rigging / sequence offshore Site specific elements and type installation vessels Bending radius, twist & prevent coating damage of some of the mooring component, excluding chain & shackles! Dry runs & simulation tests prior to offshore scope Competency & Commitment (completion & connecting - up) Communication Plan Procedures & Review cycle

44 Uisge Gorm, Fife field UKCS

45 Typ. 3 - point mooring system

46 Offshore Mooring Installation Most crucial part of whole installation project. (A) Timeframe (installation of mooring system far ahead of arrival FPSO?) (B) Contractor & Sub Contractor selection (mind skills) (C) Selection, building and guidance of the offshore Team! Location; pre route survey (e.g. use of side scan sonar) Start at pre-selected location? Interaction with Drilling & Installation Installation & Testing the mooring system, including Class approval Notices to e.g.: Authorities, Mariners & Fishery Surveying, pre- / post installation & secure location (guard vessel on site!)

47 Aoka Mizu, BW Buoy System

48 Parts, to be handled with care

49 Mooring, crucial elements

50 Way forward For the correct installation and operation as well as for the assessment of the integrity of a mooring system and its individual parts you need to go to the designer of that particular mooring system

51 Way forward - 2 In Bluewater we have a good handle on mooring system design and installation, given its complexity. However, there is still scope for further R&D on several areas such as: large diameter chain & wire, shackles, connectors and Factory Acceptance Scope. So: Open dialogue with Peers in the offshore related Industry (Authorities, Oil&GasUK, SUT, SPE, IMCA & OCIMF) Active in relevant JIP s & Seminars Approach & discuss Standards pro-active with Class

53 Q & A

Mooring Capabilities. Angola Brazil Egypt Equatorial Guinea Malaysia Mexico Norway Singapore United Kingdom United States

Mooring Capabilities. Angola Brazil Egypt Equatorial Guinea Malaysia Mexico Norway Singapore United Kingdom United States Headquartered in the United States, InterMoor has facilities across the globe: Angola Brazil Egypt Equatorial Guinea Malaysia Mexico Norway Singapore United Kingdom United States Mooring Capabilities For