Pipeline Engineering - PE

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Pipeline Engineering - PE
Developments in Mechanical Production Cleaning of
Pipelines
Robin Brinham PPSA Aberdeen Nov. 14th
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Agenda

• Why Pig a pipeline?
• Production Cleaning Process
• Data Gathering
• Phase 1 Proving Piggability
• Phase 2 Progressive Cleaning
• Factors Affecting Cleaning Tool Design
• Designing the Right Cleaning Tool
• Case Studies
• Conclusion

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Why Pig A Pipeline?

• Pigging is an operation to remove debris or
• unwanted deposit build up in a pipeline
• Build up of deposit can
• restrict fluid flow/increase pressure
• damage pumps
• prevent chemicals accessing pipe wall
• encourage corrosion
• prevent assessment of pipeline integrity
• Planned pigging program is essential to overcome
  the above

Wax removed from a 14 line using a dual module
tool
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Production Cleaning Process

• Data Gathering
• Develop Pigging Program/Design the Tool
• Implement the Production Cleaning Program
• Phase 1, prove piggability
• Phase 2, progressive cleaning

Solid Works based pig design (computer modelling
can be used to help confirm tool can traverse
the line)
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Data Gathering

• Effective Production Cleaning depends critically
  on gathering the appropriate data
• Nature/quantity of debris
• Handling eg NORM, black powder etc
• Line Conditions
• temperature
• pressure
• flow rates
• product chemistry
• Line Features/Geometry
• Bends, Ys, Ts, valves, id changes,
• Pigging History

Heat damaged PU cup
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Progressive CleaningPhase 1

• For infrequently pigged lines it can be critical
  to prove piggability.
• Low density followed by higher density foams of
  increased diameter
• Risk of wax candle (esp. lt12)
• Once plugged d/p may harden wax consistency
• Consider the use of chemical additives for wax
  dispersion prior to cleaning

Foams of different diameter and coating
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Progressive Cleaning Phase 2

• Progressively increasing the aggressiveness of
  the tool minimises the risk of blockage
• Tool design will generally consist of a metal
  body with discs and/or cups attached or both
• In the final stages they may have studs, pins,
  scraper blades or metal plates attached
• The removal of highly abrasive deposits e.g.
  black powder or sand particularly in gas lines
  often involves the use of pick up gels
• Pingers/Transmitters are often used to help
  confirm tool location
• The art is to remove enough but not too much of
  the debris during any one pigging run

Studded Cups
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Factors Affecting Cleaning Tool Design

• Out of the many factors affecting pig design
  three are especially critical
• Pipe Size
• Effectiveness of attachments eg brushes in small
  IDs
• Higher frictional resistance on the PU for small
  ID tools
• Weight stress for larger ID tools (friction,
  compression set/static stress..)
• Pipe Length
• Additional friction wear and possible heat build
  up
• Bend Radius
• Pig length, body tube diameter, sealing length

56 tools, 54 weight saving using Aluminium.
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Factors Affecting Cleaning Tool Design

• Other factors include
• Medium used to propel tool
• ID changes
• Valves, Ys, Ts etc
• Subsea or Cross Country
• extra sub sea features eg manifolds, pigging
  loops etc
• Pig Trap Design

Dual diameter, unbarred Ts
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Designing The Right Cleaning Tool

• Each pipeline is different, use of standard
  tool designs does not guarantee success
• In many cases a bespoke approach is required
• Gather the data
• Design the tool
• Build the prototype
• Test Loop trial
• Finalise Tool design
• Client witnessed trial
• The overall objective to maximise tool
  effectiveness and to minimise risk

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Whats New?

• Many recent developments are incremental
• Towing module for brushes etc
• Annular cleaning heads
• Brush redesigns
• A new innovation is the Automatic Multiple Pig
  Launching System (AMPL) whereby depressurising
  the launcher will arm the next cleaning tool
  ready for launch

AMPL pigs in launch cassette
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Waxy Crude Oil

• Large trunk line with heavy wax deposits
• Cleaning to be affected along considerable length
  and at elevated temperature
• Substantial sand inclusion
• Tool needed to be robust with careful choice of
  PU grade

Cleaning tool after receipt, low flow, check
valves..
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Mineral Extraction

• Minerals (Zn/Pb) extracted from powdered ore then
  residue mixed with cement and piped underground
  for mine roof support
• 4.5km, 8 line used intermittently
• Residue paste settled/set restricting line
• Used progressive macerating pigs to remove hard
  sludge (5 to 6.5 in 0.5 increments).
• Sludge removed in sections (too much to remove
  all at once)
• Complete removal of all sludge achieved

Metal cutters to break up sludge
Sludge layer breaking up
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Conclusions

• To effectively clean lines it is essential to
  gather the requisite information
• Using a standard pig will frequently give
  unsatisfactory results (every line different)
• The potential cost of inadequate pipeline
  cleaning can be very high