PIPELINE QRA SEMINAR PIPELINE RISK ASSESSMENT SOFTWARETOOLS FOR

PIPELINE QRA SEMINAR

PIPELINE RISK ASSESSMENT SOFTWARE/TOOLS FOR RISK ASSESSMENT

SOFTWARE/TOOLS FOR RISK ASSESSMENT • Different software/tools for QRA • Tools (hand calculations) versus software • Tools (hand calculations) – actually manual development of simplified software (typically Excel) • There are software/tools also for qualitative risk assessment (e. g. linked to different methods – HAZID/HAZOP) • Focus on software/tools for QRA

SOFTWARE/TOOLS FOR QRA Advantages of tools (hand calculations) • Simple (understanding and execution) • Flexibility Disadvantages of tools (hand calculations) • Standardization (i. e. do we always calculate in the same way? ) • Size and presentation (i. e. number of documents/sheets)

SOFTWARE/TOOLS FOR QRA Advantages of software • More advanced (often) • Accepted (e. g. could be recommended from authorities) Disadvantages of software • Black-box (often) • Non-flexible (e. g. change of parameters)

SOFTWARE FOR QRA • Software/tools established by consultant companies, authorities, companies (e. g. oil and gas industry and process industry) and software companies Software: SAFETI from DNVGL QRA Open from Taylor Associates Ap. S • Method depending on the situation (e. g. complexity, stage of project and time) Shepherd from Shell Riskcurves from TNO • Economical and technological aspects (e. g. costs for license and knowledge of the software) • No single best software/tool to solve all problems

SOFTWARE FOR QRA • “Same, same. But different!” • Similarities in presentation • Differences in way of calculations/models (exact differences hard to establish, since often “black-box”)

SOFTWARE: SAFETI • Software from DNVGL • Specialized for onshore process facilities and petrochemical facilities • Used frequently in the oil- and gas industry (e. g. BP, Total, Maersk and Shell) • Connected to the PHAST software

SOFTWARE: SAFETI • How does it work? - Accident scenarios (e. g. PHAST and frequencies) - Population - Weather conditions - Ignition sources - Quantification of the risk (i. e. individual risk and group risk) • Compare with presented methodology for quantitative risk assessment

SOFTWARE: SAFETI Advantages of PHAST • Easy to get some quick results from (compared to others) • Interface (i. e. easy to understand present) Disadvantages of PHAST • Black-box (i. e. what happens in the model and change of parameters)

TOOLS FOR QRA • Tools (and guidelines/standards) established by consultant companies, organizations, authorities and companies (e. g. oil and gas industry and process industry) • General difference - two categories of tools: - Scoring systems (i. e. simple ranking of pipeline segments) - Traditional QRA (i. e. general methodology) • Standalone versus included in larger risk management framework Guidelines/standards: Pipeline systems - Steel pipelines on land Guide to the application of pipeline risk assessment to proposed developments in the vicinity of major accident hazard pipelines containing flammables (BS PD 8010 -3: 2009) (part of framework BS PD 8010 -1: 2004) from British Standards Assessing the risks from high pressure natural gas pipelines (IGEM/TD/2) from Institution of Gas Engineers and managers

TOOLS FOR QRA • Detailed difference - three categories of tools: - Generic values for leakages - Possibility to modify values for leakage to account for special properties and situation (e. g. corrosion) - Possibility to modify values for leakage to account for special properties and situation (e. g. corrosion ) as well as including of external hazards (e. g. 3 rd party interference and similar) • What is best? Depending on the situation (e. g. complexity). Most important to be aware of what is included and what is not included.

TOOLS FOR QRA How is a QRA carried out?

EXAMPLE OF QRA

EXAMPLE OF QRA Ringsted, Denmark - 30’’ gas pipeline - 80 bar - 12 mm - exposed - no construction work or agricultural work allowed within 50 meters from the pipeline - shopping centre (opening hours 08. 00 -20. 00) at 100 meters - parking lot between shopping centre and pipeline

EXAMPLE OF QRA • What could go wrong? - Internal corrosion (expected problems with impurities) - External corrosion (noted damages to protection from installation) • As detailed as want (e. g. is the restriction on construction work followed and possible natural hazards)

EXAMPLE OF QRA • What is the frequency for the different scenarios? • Where could we find information? - Riser & pipeline release frequencies from International Association of Oil- and Gas Producers (OGP)

EXAMPLE OF QRA • Riser & pipeline release frequencies from International Association of Oil- and Gas Producers (OGP) - 8. 1 x 10 -5 per km-year (12 mm wall thickness) - 18% are medium holes (75 mm hole) • Frequency for specified scenario: - 1. 5 x 10 -5 per km-year • Just one of several scenarios!

EXAMPLE OF QRA • What is the consequence from the different scenarios? • Choice: human safety – fatalities • What do we need to consider? - Gas cloud - flash fire (extent and radiation from) - Jet fire (radiation from) - Pin hole - Rupture - Large hole

EXAMPLE OF QRA • As detailed as want (e. g. are there some of the combinations we can exclude? ) • What do we need to consider? - Gas cloud - flash fire (extent and radiation from) - Jet fire (radiation from) (excluded) - Pin hole (excluded) - Rupture - Large hole • Remember – all scenarios quantified (increasing effort)!

EXAMPLE OF QRA • What scenario? - Gas cloud - flash fire (extent) - Large hole (75 mm) - LFL and ½ LFL - All inside a cloud would be fatalities (>37. 5 k. W/m 2) • Just one of several scenarios!

EXAMPLE OF QRA • Combine the frequency for the scenario and the consequence for the scenario to get the actual risk • What do we know? - With the frequency 1. 5 x 10 -5 per year there will be a release of gas from the pipeline and the cloud will enclose the parking lot

EXAMPLE OF QRA • What do we not know? - Exposure (e. g. how often are there people in the parking lot and how many people are there in the paring lot) - Ignition (i. e. what is the probability of ignition of the gas) - Weather conditions (e. g. how often wind towards the parking lot)

EXAMPLE OF QRA • What do we not know? - Exposure – in average 50 persons in the parking lot from 08. 00 to 20. 00 every day and a parking guard there 5 days a week between 07. 30 and 20. 30 - Ignition – 50% probability of ignite the gas due to the cars at the parking lot and the electrical signs on the shopping centre - Weather conditions – 10% probability of wind towards the parking lot (defined as south) due to prevailing wind east

EXAMPLE OF QRA • Combine the frequency for the scenario and the consequence for the scenario to get the actual risk (considerations for the parking guard) - Frequency x ignition x wind x exposure (individual) - 1. 5 x 10 -5 x 0. 1 x 0. 39 per year - 2. 9 x 10 -7 per year

EXAMPLE OF QRA • What does this mean? - With the frequency 2. 9 x 10 -7 per year there will be a release of gas from the pipeline, the cloud will enclose the parking lot, the cloud will ignite and the parking guard will be present (fatality) - The individual risk (for the parking guard) from this scenarios is 2. 9 x 10 -7 per year • Just one of several scenarios!

EXAMPLE OF QRA • What about the group risk? - With the frequency 2. 9 x 10 -7 per year there will be a release of gas from the pipeline, the cloud will enclose the parking lot, the cloud will ignite and in average 50 persons will be present (fatalities)

EXAMPLE OF QRA • Is the risk (from this scenario) acceptable? • Risk acceptance criteria for individual risk - 1. 0 x 10 -6 (Danish legislation) – YES! • Risk acceptance criteria for group risk - (see figure) (Danish legislation) – MAYBE! - Separate presentation on ALARP - Most likely not given contribution from other scenarios

EXAMPLE OF QRA • QRA is a tool to evaluate and support what in the end are political decisions whether to proceed with construction/design (or similar) within questionable, high-risk and/or consequence areas • Could have a high consequence and a high frequency, but anyway an acceptable risk

EXAMPLE OF QRA • Even the smallest QRA has large complexity • What has been simplified in this QRA? - Wind directions (e. g. 4 or 16? ) - Wind speed (i. e. consequences different) - Ignition probabilities (e. g. models or ignition sources) - Frequency (i. e. just considered one scenario) - Consequence (i. e. just considered one scenario) - Simplified population (e. g. cars on the road and residents) - Release frequency given per kilometre (e. g. not all releases within kilometres would give consequences within 1 kilometre)

EXAMPLE OF QRA How is a QRA carried out?

EXAMPLE OF QRA • What is the challenges of quantitative risk assessment? - Uncertainty (i. e. the risk could be something that has never happened before) - Statistic (i. e. availability) - Assumptions – big effect (e. g. sensitivity analysis) - Complexity (i. e. how much could/should be included? ) - Ideal model (e. g. would people move from a release? ) 32

QUESTIONS? 33