Cost Reduction Opportunities in Deepwater Riser Systems

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2 Opportunities in Deepwer Riser Systems Presented by: Prahlad Enuganti, 2H Offshore Engineering Ltd.

3 Slide 2 Agenda Deepwer Riser Systems Riser s Steel Cenary Risers Freestanding Hybrid Risers Alternive Installion Methods Summary and Conclusions Opportunities in Deepwer Riser Systems Prahlad Enuganti

4 Slide 3 Deepwer Riser Systems Common riser configurions used in deepwer FPS s: Steel cenary and freestanding hybrid Configurion selection driven by: Environment Vessel type Vessel loading Fight or flight extreme condition stregy Figue sensitive structures Riser systems form a major component of the cost of deepwer developments Opportunities in Deepwer Riser Systems Prahlad Enuganti

5 Slide 4 Steel Cenary Risers Opportunities in Deepwer Riser Systems Prahlad Enuganti

6 Slide 5 Free Standing Hybrid Risers Opportunities in Deepwer Riser Systems Prahlad Enuganti

7 Slide 6 Deepwer Riser s 6 off FSHR - $452M SCR - $152M LWSCR - $176M

8 Slide 7 Deepwer Riser s 3 off FSHR - $281M SCR - $98M LWSCR - $110M Opportunities in Deepwer Riser Systems Prahlad Enuganti

9 Slide 8 General Targets for Merials Fabricion Installion Vessel specificion Time Mobilision Opportunities in Deepwer Riser Systems Prahlad Enuganti

10 Slide 9 SCR Drivers Merials and fabricion Pipe manufacture to very tight tolerances / special forged or upset pipe Very small fabricion defects Clad pipe for corrosion resistance ly fabricion and inspection qualificion programs Long installion time to achieve quality requirements Vessel requirements Pre-lay Retrieval and hand-over Opportunities in Deepwer Riser Systems Prahlad Enuganti

11 Slide 10 SCR Figue Damage Opportunities in Deepwer Riser Systems Prahlad Enuganti

12 Slide 11 SCR Potential Savings Is Golden pipe throughout necessary? Localised figue improvement TDP with high specificion pipe, fabricion and inspection Region specific fabricion and inspection requirements Vessel repositioning over field life Spread figue damage in touchdown zone Use of lazy wave arrangement Reduced figue criticality and less critical merial and fabricion specs Reduced extreme vessel loads Opportunities in Deepwer Riser Systems Prahlad Enuganti

13 Implementing Savings - SCRs Slide 12 Limiting high specificion pipe quality to Touch Down Zone Can reduces merial cost by 15% (overall riser cost savings of ~5%) Limiting weld quality requirements to Touch Down Zone area Can reduces installion time in half ( enabling savings of ~15%) Limiting weld quality requirements by using vessel repositioning to ease figue requirements Can limit qualificion and installion time (enabling savings of ~20%) Mechanical connection for riser joints Savings can be significant (can use high strength steel, installion time reduced, installion via MODU) Opportunities in Deepwer Riser Systems Prahlad Enuganti

14 Hybrid Riser Components Buoyancy Tank Buoyancy Tank Upper Riser Assembly (URA) LRA Lower Flexible Joint Upper Flexible Joint Lower Riser Assembly (LRA) Base Foundion Pile/ Gravity Base URA Piping URA Frame Crossover Joint

15 FSHR Top Assembly

16 FSHR Lower Assembly and Jumper

17 Slide 16 FSHR Riser Targets Merials and fabricion Upper riser assembly (URA) structure, forgings, piping Installion complexity/time Buoyancy tank ballasting Flexible riser tachment below buoyancy tank Riser base jumpers Vessel requirements Specialty (URA and buoyancy tank size), mobilisions Opportunities in Deepwer Riser Systems Prahlad Enuganti

18 Slide 17 FSHR Design and Installion Options Distributed buoyancy to reduce air tank size Jumper take-off from above air tank Tow out installion Use of composite pipe for riser base jumpers Opportunities in Deepwer Riser Systems Prahlad Enuganti

19 Slide 18 Distributed Buoyancy and Smaller Air Tank Tank size less than half unbuoyed pipe arrangement Scope to use alternive compartment arrangement Can simplify ballast operion Steel Pipe Faster installion Lower specificion vessel Neutrally Buoyant Opportunities in Deepwer Riser Systems Prahlad Enuganti

20 Slide 19 FSHR Jumper Take-Off from Top Easier installion and operional access with jumper the top Use slotted tank or Pre-installed upper spool with connector below Used for bundles Opportunities in Deepwer Riser Systems Prahlad Enuganti

21 Implementing Savings - FSHRs Slide 20 Reducing buoyancy tank size (enables savings of ~10%) Fabricion cost Lighter installion vessel Installion time Surface jumper taking off from the top of buoyancy tank (enables savings of 5%) URA fabricion URA installion Flexible jumper installion Tow out installion Foundion design changes Opportunities in Deepwer Riser Systems Prahlad Enuganti

22 Slide 21 Installion - Mechanical Coupling Instead of Welding Good connector track record for limited hydrocarbon exposure Current applicions: Top tensioned production risers Completion/well test risers HP drilling risers Types - T&C, interference, collar, breech-block Codes in place (ISO 21329) and qualificion being conducted Faster riser installion Potential for re-use Approach used for Macondo containment risers Opportunities in Deepwer Riser Systems Prahlad Enuganti

23 Slide 22 Installion - Use of Local MODU s High lifting capacity Reduce specialist vessel mobilisions Potential uses SCR pick-up and hand over Foundion installion FSHR installion (using mechanical connectors) Approach used for Macondo containment risers Opportunities in Deepwer Riser Systems Prahlad Enuganti

24 Slide 23 Barriers to Change Contract stregy EPC leaves choices with contractors, preferred vessels Complex liability structure with shared Operor/contractor responsibility Not invented here Operor and contractor reluctance to implemented ideas devised by others New technology Risk averse industry High oil price Current low price should provide a stimulus Opportunities in Deepwer Riser Systems Prahlad Enuganti

25 Slide 24 Summary and Conclusions The current low oil price clime has produced a need for targeting cost reductions, not considered necessary in the last decade Alternive configurions and installion methods for cost reduction in deepwer risers FPS s have been described savings of 20% are feasible with current technology Further savings are feasible with new technology Operor drive and changes to contract stregy are needed to maximise potential benefits Opportunities in Deepwer Riser Systems Prahlad Enuganti

26 Slide 25 Acknowledgements / Thank You / Questions I would like to thank Dr. Hugh Howells, Madhu Hariharan and Alex Rimmer and all personnel in 2H who have contributed to the content of this paper.