J. Ludwig

1
Title

• Comparision of safety aspects
• oil versus gas pipelines

Jörg Ludwig Den Haag, March 2006
2
Structure

• Preliminary remarks
• Hazard, safety, risk
• Risk management
• Measures to avoid hazards basic design
• Summary and recommendations

3

• The risks from crude oil pipelines are primarily
  those relating to environmental pollution.
• Risks from product pipelines affect both public
  safety and the environment.
• Risk from flammable and toxic volatile liquids
  pipelines as well as gas and liquefied gas
  pipelines primarily concern public safety and
  risk prevention.

4
Safety and hazard as complementary terms
5

1. There is no such thing as absolute safety in the
   sense of zero risk (even the renunciation of
   non-controllable risks bears the risk of lost
   benefits).
2. Different technical products, processes, plants
   and events should preferably not represent
   different risk levels for the objects protected
   by law and regulation (risk equivalence).
3. The scale for the largest and acceptable risk is
   not governed solely by the level of protection
   that the object to be protected needs rather, it
   is derived from the process of weighing up
   between the opportunities (chances) and the risks
   that are linked to the introduction of
   technical/scientific developments (risk
   adequacy).

6

• Risk R can be expressed by a statement of
  probability that links firstly the expected
  frequency of occurrence F (likelihood) of an
  event that leads to damage and, secondly, the
  ex-tent of the damage to be expected when the
  event takes place (L consequence).
• In its most simple form it can be defined as
• R C F

7
Risk-management
Scope Definitions Pipeline, System
Hazard and Failure Identifications

Initial Risk Evaluation Basic Design
Frequency Analysis
Consequence Analysis
Risk Estimation
Pipeline System Related Measures
Substance Related Measures
Risk Acceptance Tolerability Decision
Initiation, Realization Control, Review
8

• Risk analysis attempts to answer three
  fundamental questions
• What can go wrong (by hazard identification)?
• How likely is this to happen (by frequency
  analysis)?
• What are the consequences (by consequence
  analysis)?

9
Simplified scheme for the determination of
potential hazards (deductively determined
hazards)
10
Comment

• The potential hazard of liquified pressurized gas
  is greater than the potential hazard of liquids,
  at all.
• Environmental aspects, particular hazards (e.g.
  earthquake), increasured catastrophe potentials
  etc. have to be taken into account.
• These hazards are not covered by existing
  regulations, in principle.

11
Modalities of transport Aspects and procedures
related to service conditions

• system design
• pipe design
• design of terminal and intermediate stations
• materials and coatings
• corrosion management
• construction
• testing
• commissioning (prior to operation/on the job)
• operation, maintenance, shut-down, scrapping
• supervision procedures
• alarm planning and emergency planning
• reports and documentation

12
Modalities of transport Non-quantifiable
additional conditions I

• batch operation (e. g. gas/liquid)
• particular corrosion conditions caused by the
  substances
• under ground/above ground modes of operation
• special construction and operation conditions
• guarantee of access to pipeline route
• possible working width
• provision of auxiliary material/energy
  requirements
• access to and storage of test water

13
Modalities of transport Non-quantifiable
additional conditions II

• consideration of junctions and narrowing
• difficulties due to geotechnical conditions
• instable conditions (ground faults, fissuring)
• soft, swampy underground
• rocky underground
• flood areas
• earthquake zones
• permafrost zones
• landslide zones

14
Modalities of transport Non-quantifiable
additional conditions III

• areas of cultivation and sanitary fills
• difficulties due to hydrographic conditions
• activities of third parties
• land use
• mining activities
• additional safety aspects
• public safety
• environmental protection
• protection of assets (properties)

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Kind of quantity to be respected

• total amount transported per unit time
• total quantity within the pipeline (stationary)
• quantity in each closable section
• worst-case amount that can be released

16
Chemical properties to be respected I

• explosive
• inflammable
• oxidising
• self reacting
• decomposing
• polymerising
• toxic
• corrosive
• environmentally polluting
• suffocating
• carcinogenic

17
Chemical properties to be respected II

• These properties may affect
• directly
• indirectly
• short-term
• long-term
• the physical integrity of human beings, and may
  damage the environment and properties

18
Environmental safety

• Damage to the environment could relate to
• areas of outstanding natural beauty
• nature reserves
• areas of archaeological importance
• natural resources (reservoirs, usable forest,
  woods, etc.)
• stratified water, water conservation areas
• monuments, works of art, cultural possessions

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Effects related to liquids and gases

• Liquids
• Flammable immediate ignition followed by a pool
  fire or evaporation and delayed ignition of a
  vapour cloud, resulting in a flash fire and/or
  explosion
• Toxic evaporation from pool, formation and
  dispersion of toxic cloud
• Dangerous to the environment entry into the soil
• Gases
• Flammable immediate ignition followed by a
  flare or delayed ignition of the gas cloud,
  resulting in a flash fire and/or explosion
• Toxic formation and dispersion of toxic cloud
• Dangerous to the environment nothing available
• Liquefied pressurised gases
• Flammable immediate ignition followed by a flare
  or a BLEVE / fireball or delayed ignition of
  the vapour cloud, resulting in a flash
  fireand/or explosion
• Toxic partial rain-out, and formation and
  dispersion of toxic cloud
• Dangerous to the environment dispersion in the
  atmosphere, affecting fauna

20
Failure modes and duration

• The failure modes for different kinds of
  pipelines are significantly different , too.
• Additional aspects to consider in this respect,
  besides the properties of the inventories of
  pipelines are
• heavy gas behaviour (cooling down effects)
• third party interference
• corrosion behaviour (internal and external)
• aging (fatigue)

21
Summary I

• Basic safety can be related to regulations, in
  principle.
• Additional safety aspects have to be considered
  in relation to different inventories and their
  characteristics and properties.
• Therefore, initial hazard and failure
  investigation is of fundamental importance for
  the risk management process, regardless if the
  process is of a deterministic or probabilistic
  kind.

22
Morphological box - the Safety Cube

23

• Pipeline design relates initially to the
  pressure-carrying components such as
• piping, pipes
• containers, vessels
• apparatuses, auxiliary facilities
• pumps
• fittings, valves, slide valves (shut-off valves)

24

• The application of modern standards, sets of
  rules and pressure-vessel codes can provide
• a conservative limitation of permissible
  stresses
• avoidance of stress peaks with the help of
  optimised designs
• favourable material properties
• largely optimised manufacturing, construction
  and testing technology
• knowledge of possible damage and its assessment
  (liability)
• consideration of corrosive effects
• elevated impact protection
• leak before break behaviour

25

• This can lead to improvements with respect to
• material coefficients and/or safety coefficients
• increase in safety coefficients generally
• materials-related increase in safety coefficients
• more in-depth consideration of corrosion
• increase in level of welding, manufacturing and
  testing procedures
• application of similar safety levels for pipes
  and equipment components.

26

• Transport conditions can be improved by means of
  the application of a two-barrier-priciple
• underground pipe laying
• increased earth coverage
• laying of cover plates
• provision of double-walled pipes

27
Summary II

• Measures for reducing the consequences cannot be
  taken, easily.
• Methods for reducing the consequence are, e.g.
• limiting the quantity of substances that could be
  released by subdividing the pipeline into
  sections in connection with
• leak monitoring measures and
• remote control for shut-off valves,
• relocation positions of pumping stations etc.,
• changing the routing of the pipeline.

28

• By creating, raising and optimising measures for
• maintenance procedures
• monitoring and supervision procedures
• alarm and emergency planning
• it is also possible to actively or passively
  counteract undesirable events.

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Conclusion

• Regulations, standards, pressure vessel codes
  etc. deal with service conditions and are
  applicable unrestricted for liquid pipelines,
  only. In all cases where additional hazards have
  to be mentioned substance related or pipeline
  system related additional requirements have to
  be elaborated respectively met. Hazards and
  failures have to be identified and measures to
  cover these have to be developed as complete and
  systematically as possible because omissions are
  hardly to be recognised later on.

30
Recommendation

• Because of the importance of the differences of
  characteristics and properties of the pipeline
  inventories in connection with the key role of
  the first steps of each risk preventive strategy
  some recommendations on these items should be
  added to the UN/ECE Draft Safety Guidelines/Good
  Practices for Pipelines.

31
Impressum
BAMDivision III.2 Unter den Eichen 87 D-12205
Berlin Dr.-Ing. Jörg Ludwig Phone 49 (0)
30/8104-1320 Fax [phone] E-Mail
joerg.ludwig_at_bam.de