11

Society for Underwater Technology

“The Life-Cycle of Flexible Risers and Flowlines”

(a design and operations awareness course)

22

Presenters

33

Course Structure

• Follows the life-cycle of a flexible:• Design

• Installation

• Damage, Degradation and Failure modes (installation and operation)

• Integrity management (operator’s viewpoint)

• Integrity management (specialist’s viewpoint)

• Decommissioning

• Course Dinner tonight

44

Objectives

• To take you through the life-cycle of flexible risers and flowlines

• To give you an awareness of when and where they might be used

• To give you an awareness of design and operational issues

• To give you enough information for you to be comfortable with your responsibilities

55

Modus Operandi

• This is a course, not a conference

• Please do not hesitate to ask questions

• Please share experience

• At the end, please tell us what you think of the course

66

Flexibles at Work

77

What is a Flexible?

• It is unbonded flexible pipe• It is a flowline or riser made up of a number of metallic and

polymeric elements – fluid containment, pressurecontainment and axial strength functions are separated

• It can be bent to a much smallerradius than the equivalent rigidpipe without suffering plasticdeformation

• It can endure dynamicenvironments with much lessfatigue than the equivalentrigid pipe

• It does not feel flexible if youtry to bend it!

88

Why a Flexible Flowline?

• Fabrication is carried out in controlled conditions ashore, off-line

• Installation is quicker & easier – just unreel it…

• Limited metrology requirements

• Insulating properties

• Resistance to buckling

• Re-useability

• Decommissioning

• Cost/metre higher than rigid

pipe – total package must be

viewed on a case by case basis

99

Why a Flexible Riser?

• All the benefits of flowlines, plus:

• Catenary risers feasible in

shallow water depths

• Decouple surface excitation

from seabed facilities (FPUs)

• Freedom in location of riser bases

• Components of hybrid risers, towers, etc

• Cheaper alternative where all rigid riser slots taken (fixed platforms)

1010

NKT Facility

1111

Technip Facility

1212

Wellstream Facility

1313

Very Brief History1943 PLUTO – fuel pipelines laid across the Channel

1968 flexible flowlines laid between Vestmanna Islands and Iceland to provide drinking water after volcanic eruption

1973 first HP flexible flowline (Elf, Emeraude, Congo)

1974 Le Trait facility opened; first flexible flowline in North Sea (Mobil, Beryl)

1986 first dynamic production riser system installed (Sun Oil, Balmoral, North Sea)

1991 flexibles reach 1000m water depth

2000 flexibles reach 1883m water depth - 6’’ Flowline (Petrobras, Roncador, Brazil)

2002 first line using high insulation profile – 6’’ in 550m water depth (AGIP, Abo, Nigeria)

2005 11” prod riser, 2-section design, fully sour service rated, 1000m (CNR, Baobab, Côte d’Ivoire)

2006 7.5” WI riser, 10,000psi, 1900m (BP Thunder Horse, GoM)

2006 11” Integrated Production Bundle (IPB) risers, 1300m (incl. active electric heating and gas lift tubing) (Total, Dalia, WAf)

1414

What Might The Future Bring?

• Larger diameters?

• Deeper water?

• Higher pressures?

• Hybrid solutions?

• Unexpected failure modes (ageing related)?

• Novel inspection techniques?

• Intelligent pigs for flexibles?

• More general acceptance of re-use?