Comparison of Safety Aspects: Oil vs Gas Pipelines

1. Title Comparision of safety aspects: oil versus gas pipelines Jörg Ludwig Den Haag, March 2006 J. Ludwig Sheet no.1

2. Structure • Preliminary remarks • Hazard, safety, risk • Risk management • Measures to avoid hazards; basic design • Summary and recommendations J. Ludwig Sheet no.2

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. J. Ludwig Sheet no.3

4. Safety and hazard as complementary terms J. Ludwig Sheet no.4

5. 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). • Different technical products, processes, plants and events should preferably not represent different risk levels for the objects protected by law and regulation (risk equivalence). • 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). J. Ludwig Sheet no.5

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 J. Ludwig Sheet no.6

7. NO NO YES Scope Definitions Pipeline, System Risk-management 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 J. Ludwig Sheet no.7 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)? J. Ludwig Sheet no.8

9. Simplified scheme for the determination of potential hazards (deductively determined hazards) J. Ludwig Sheet no.9

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. J. Ludwig Sheet no.10

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 J. Ludwig Sheet no.11

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 J. Ludwig Sheet no.12

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 J. Ludwig Sheet no.13

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) J. Ludwig Sheet no.14

15. 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 J. Ludwig Sheet no.15

16. Chemical properties to be respected I • explosive • inflammable • oxidising • self reacting • decomposing • polymerising • toxic • corrosive • environmentally polluting • suffocating • carcinogenic J. Ludwig Sheet no.16

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 J. Ludwig Sheet no.17

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 J. Ludwig Sheet no.18

19. 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 J. Ludwig Sheet no.19

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) J. Ludwig Sheet no.20

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. J. Ludwig Sheet no.21

22. „Morphological box” - the Safety Cube J. Ludwig Sheet no.22

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) J. Ludwig Sheet no.23

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 J. Ludwig Sheet no.24

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. J. Ludwig Sheet no.25

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 J. Ludwig Sheet no.26

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. J. Ludwig Sheet no.27

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. J. Ludwig Sheet no.28

29. 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. J. Ludwig Sheet no.29

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. J. Ludwig Sheet no.30

31. Impressum BAMDivision III.2 Unter den Eichen 87 D-12205 Berlin Dr.-Ing. Jörg Ludwig Phone: +49 (0) 30/8104-1320 Fax: +49 (0) 30/8104-1327 E-Mail: joerg.ludwig@bam.de J. Ludwig Sheet no.31