Current Riser & Subsea Technology Issues being addressed by MCS Dr Patrick O’Brien, Director, MCS

1. PRESENTATION PREPARED FOR SUBSEA SOLUTIONS 06 Current Riser & Subsea Technology Issues being addressed by MCS Dr Patrick O’Brien, Director, MCS 11th May 2005 An ISO 9000 Company

2. Presentation Overview • Fatigue of Flexible Pipe and Steel Tube Umbilical Risers • Progress on recent development work • Upcoming STU Prototype Testing • Subsea Integrity Management • The SCRIM Joint Industry Project • Deepwater Pipelay analysis • MCS Pleased to Sponsor the Technical Seminar Programme for Subsea Solutions 06 • Importance of Paris as a hub for West of Africa business by our recent opening of an MCS Paris office

3. System Architecture: Girassol Subsea

4. Flexible Pipes and Steel Tube Umbilicals Flexible Pipe Integrated Production Bundle Steel Tube Umbilical

5. Flexible Pipes and Steel Tube Umbilicals • All an integral part of the SURF scope of supply • All include helically wound components • Friction between layers or helically wound components • Need to model behaviour of helically wound components on a bent pipeline or umbilical • Fatigue Design important for Risers Flexible Pipe Steel Tube Umbilical

6. Integrated Local-Global Modelling • Stick-Slip Bending • Armour / tube initially sticks on reverse bending • Slip is inline with and transverse to lay-direction • Hysteretic fatigue stress Regular Stress Cycle

7. Flexible Pipe and STU Fatigue Design • MCS managed programmes • Real Life JIP • Emphasis on global analysis • Interface between global and local pipe loads • DTI – Fatigue Analysis Tool for Flexible Pipes • Specifically established to embody methodologies recommended by Real Life JIP • Focus on local pipe stress analysis • Tensile armours • Pressure armours • Fatigue Life Testing of Steel Tube Umbilicals • Jointly between MCS and COPPE • Testing of manufacturer prototypes and model calibration

8. Wire or Tube Equations of EquilibriumHelically Wound Components Tangential 2 Surface Normal 1 3 Transverse • Method of Solution • Incremental curvature determines incremental non-slip axial stress • Incremental non-slip axial stress determines incremental tangential shear, normal interface and tranverse shear stresses • Check Coulomb law and gradually relax stresses while retaining equilibrium • Wire curvatures from loxidromic / geodesic equations

9. Friction-Induced Stress • MCS Structural Model for Friction – Irregular Loading

10. 3D (out-of-plane) Irregular Seas

11. Tensile Armour Stress Validation • MCS stress computed almost instantaneously from global loads

12. Fatigue Analysis Highlights • Closely integrated with global analysis • Takes timetraces directly from the global analysis • Tensions & component curvatures • Regular or irregular responses • Computes stress timetraces that are cycle (rainflow) counted • Local analysis supports 3D bending of pipe / umbilical • Fully accounts for global directionality • Wire stress computed at several locations • Economically processes several loadcases • Validated as part of the Real Life JIP • Hysteresis effects applied to reduce conservatism • In either a semi-local or global analysis

13. Hysteresis: Global Modelling • Global modelling only takes the “plastic” slope

14. Hysteresis

15. Hysteresis • Improves fatigue life by factors of over 5

16. Steel Tube Umbilical X-Section Analysis • Similar Issues to Flexible Pipe Technology • Helically Wound Components (Tubes/Armour Wires) • Slip / No-Slip of Tubes • Hysteresis Effects • Complex 3D Global Motions / Loads • Friction Issues • Identical approach to global fatigue analysis

17. Steel Tube Umbilicals • Some Key Differences to Flexible Pipe Technology • Much Smaller Lay Angles (2º to 10º) • More Complex and varied Cross-Sections • Complex Contact Pressure Scenarios • More Prone to Disorientation

18. MCS STU Technology Development • Research Project – Fatigue Life Testing of Steel Tube Umbilicals • Joint Project between MCS and COPPE • COPPE - Graduate School and Research Institute from the Federal University of Rio de Janeiro • Funding by Petrobras and Brazilian Government • STU Samples from Marine Production Systems (Oceaneering Multiflex) and Prysmian (Pirelli)

19. COPPE Test Rig • Bosch-Rexroth Hydraulic System • Tension Capacity of 225 ton • Max Bending Moment of 200 ton.m • Angle Range from -15° to +30° • Sample maximum length of 12m • Variable Tension Loads • In or Out of Phase Load Combinations • Full Instrumentation • Continuous Monitoring

20. Summary of STU Research Project • Full Scale Dynamic Test of Two Samples • Using COPPE’s test rig in Rio • Global and Local Numerical Modelling of STUs • Calibrate MCS Cross-Section Models against Test Results • Preliminary Guidelines for Fatigue Analysis of STUs

21. Summary of STU Research Project (cont.) • Project Schedule • 12 month schedule • May ’06 to April ‘07 • Deliverables • Qualify Two STU Designs • Gather Full Scale Test Data • Calibrate Models • Preliminary Guidelines

22. Subsea Integrity Management • Integrity management for subsea components evermore important • Deep water, remote locations: cost of intervention • High profile failure incidents around the world (Brazil, GOM) • Gulf of Mexico • Hurricane conditions in excess of 1000 year event • Accelerated growth in use of Steel Catenary Risers (SCRs) combined with uncertainty in design of SCRs • Regulator framework for riser CVA from the MMS • All leading to an increased focus on safety and integrity

23. SCR Integrity Management (SCRIM) JIP • Primary objectives of the SCRIM JIP have been: • to develop a systematic methodology for the risk-based integrity management of SCR field systems. • to investigate best technology in terms of inspection and monitoring methods for SCRs, and identify emerging technologies for SCR inspection and monitoring.

24. SCRIM JIPPARTICIPANT STATUS Operators • BP (Steering Committee Chair) • ExxonMobil • ChevronTexaco • Petrobras • Kerr McGee • Anadarko • Dominion • BHP Billiton Transportation Companies • Williams Contractors • SBM Regulators • Minerals Management Service • Department of Transportation Component Suppliers • Oil States Industries • RTI Energy Systems • Techlam Pipe Mill • Tenaris

25. PipeLay TM Deepwater Pipeline Installation Analysis

26. Developed with the Industry

27. State of the Art User Interface

28. Rollerbox Modelling Options • Range of options provided • Simplest can be used in preliminary studies – extremely fast • Most complex combines realistic model with fast solutions times

29. Applications • Deep and shallow water pipeline installation analysis • Start-up procedures: • Sheave • Stab and hinge over • Dead man anchor • Abandonment & Recovery • In-line structure • SCR transfer • And more …

30. Conclusions • Leading Edge Fatigue Methodology for Flexible Pipe and Steel Stube Umilical Risers • Globally integrated stress methodology • Much improved interface between global and local analyses • Numerically efficient • Generic equations to solve helically wound elements • Ongoing full scale tests to validate and calibrate methodologies • Subsea Integrity Mangement • Industry iniative to develop methods for SCR integrity management • Pipelay analysis • A new generation tool for dynamic pipelay analysis

31. The End www.mcs.com