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Risk Control @ Lower Cost
Asset catagory: Land pipelines
Unwanted event: Pinhole
Copyright PIMS International B.V.
Felland Noord 3
9753 TB HAREN
Bowstar diagram Sasol GasO‐000/PIMS INTERNATIONAL‐SASOL GAS/07
© 2014 by PIMS International B.V., Haren, Nederland. All rights reserved. No part of this publication may be reproduced, copied, modified or adapted, without the prior written consent of PIMS International B.V., unless explicit permission has been given by PIMS International B.V. PIMS International B.V. accepts no liability for any loss or damage or expense of any kind, caused by the use of the information and data in this document.
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 3 of 40
Acknowledgement This article presents a full bowtie diagram resulting from a risk assessment that has been carried out by PIMS International by making use of the Bowstar methodology. It is published to assist pipeline operators in the optimization of their risk management practice. Application of this methodology will be a big step forward in risk control and will enable the asset manager to control both safety and operational risk at maximum transparency for all stakeholders. Once implemented Bowstar will be used to monitor any unexpected change in operational risk level, give early warnings, enables Life Cycle Cost optimization and supports all related investment decisions. The bowtie diagram that is presented in this document is based on the risk assessment that has been carried out in Sasol Gas pipeline operations (SA). Part of the data is fictitious and has been added by the author to clarify some special features of the Bowstar methodology. Rob Bos gratefully wants to thank Sasol Gas and in particular Neo Modise, Divisional Manager Pipeline Integrity, for his kindness to use their bowtie diagram data to clarify the methodology of Bowstar that has been developed by PIMS International B.V. Rob Bos Neo Modise Director PIMS International B.V.
Divisional Manager: Pipeline Integrity Sasol Gas
Felland Noord 3 9753 TB Haren Netherlands Rob.Bos@pims‐international.com Tel: +31 6 24 20 24 52
146 Houtbaai Street,Culverwell Park, Elandshaven Germiston South Africa [email protected]
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Origin data Sasol – modified / fictitious
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Content 1 Introduction ............................................................................................................................ 7 2 Bowtie methodology ............................................................................................................... 8 2.1 Basic model ............................................................................................................................. 8 2.2 Bowstar bowtie model ............................................................................................................ 9 2.3 Escalation factors .................................................................................................................. 11
3 Bowtie Analyse: Pinhole ........................................................................................................ 15 3.1 Main diagram ........................................................................................................................ 15 3.2 Threat 1 of 9: External corrosion ........................................................................................... 16 Life cycle barriers ........................................................................................................................... 16 Design barriers .............................................................................................................................. 16 Construction barriers .................................................................................................................... 17 Commissioning barriers ................................................................................................................. 18 Operations barriers ....................................................................................................................... 18 Maintenance barriers .................................................................................................................... 19 3rd Party interference prevention barriers ................................................................................... 20 Mothballing / removal barriers ..................................................................................................... 21
3.3 Threat 2 of 9: 1std Party interference ................................................................................... 21 Life cycle barriers ........................................................................................................................... 21 Design barriers .............................................................................................................................. 21 Construction barriers .................................................................................................................... 21 Commissioning barriers ................................................................................................................. 21 Operations barriers ....................................................................................................................... 21 Maintenance barriers .................................................................................................................... 22 3rd Party interference prevention barriers ................................................................................... 22 Mothballing / removal barriers ..................................................................................................... 22
3.4 Threat 3 of 9: 2nd Party interference (contractors etc) ........................................................ 22 Life cycle barriers ........................................................................................................................... 22 Design barriers .............................................................................................................................. 22 Construction barriers .................................................................................................................... 22 Commissioning barriers ................................................................................................................. 22 Operations barriers ....................................................................................................................... 22 Maintenance barriers .................................................................................................................... 23 3rd Party interference prevention barriers ................................................................................... 23 Mothballing / removal barriers ..................................................................................................... 23
3.5 Threat 4 of 9: 3rd Party interference (digging etc)................................................................ 23 Life cycle barriers ........................................................................................................................... 23 Design barriers .............................................................................................................................. 23 Construction barriers .................................................................................................................... 24 Commissioning barriers ................................................................................................................. 24 Operations barriers ....................................................................................................................... 24 Maintenance barriers .................................................................................................................... 25 3rd Party interference prevention barriers ................................................................................... 26 Mothballing / removal barriers ..................................................................................................... 26
3.6 Threat 5 of 9: Operational error(high P) ............................................................................... 27 Life cycle barriers ........................................................................................................................... 27 Design barriers .............................................................................................................................. 27
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Construction barriers .................................................................................................................... 27 Commissioning barriers ................................................................................................................. 28 Operations barriers ....................................................................................................................... 28 Maintenance barriers .................................................................................................................... 28 3rd Party interference prevention barriers ................................................................................... 28 Mothballing / removal barriers ..................................................................................................... 29
3.7 Threat 6 of 9: Internal corrosion ........................................................................................... 29 Life cycle barriers ........................................................................................................................... 29 Design barriers .............................................................................................................................. 29 Construction barriers .................................................................................................................... 29 Commissioning barriers ................................................................................................................. 29 Operations barriers ....................................................................................................................... 30 Maintenance barriers .................................................................................................................... 30 3rd Party interference prevention barriers ................................................................................... 30 Mothballing / removal barriers ..................................................................................................... 30
3.8 Threat 7 of 9: Internal erosion .............................................................................................. 30 Life cycle barriers ........................................................................................................................... 30 Design barriers .............................................................................................................................. 31 Construction barriers .................................................................................................................... 31 Commissioning barriers ................................................................................................................. 31 Operations barriers ....................................................................................................................... 31 Maintenance barriers .................................................................................................................... 31 3rd Party interference prevention barriers ................................................................................... 31 Mothballing / removal barriers ..................................................................................................... 31
3.9 Threat 8 of 9: Natural disaster .............................................................................................. 32 Life cycle barriers ........................................................................................................................... 32 Design barriers .............................................................................................................................. 32 Construction barriers .................................................................................................................... 33 Commissioning barriers ................................................................................................................. 33 Operations barriers ....................................................................................................................... 33 Maintenance barriers .................................................................................................................... 34 3rd Party interference prevention barriers ................................................................................... 34 Mothballing / removal barriers ..................................................................................................... 34
3.10 Threat 9 of 9: Vandalism, terrorism ...................................................................................... 34 Life cycle barriers ........................................................................................................................... 34 Design barriers .............................................................................................................................. 35 Construction barriers .................................................................................................................... 35 Commissioning barriers ................................................................................................................. 35 Operations barriers ....................................................................................................................... 35 Maintenance barriers .................................................................................................................... 36 3rd Party interference prevention barriers ................................................................................... 36 Mothballing / removal barriers ..................................................................................................... 36
3.11 Consequence 1 of 2: Gas emission ........................................................................................ 36 Life cycle barriers ........................................................................................................................... 36 Design barriers .............................................................................................................................. 37 Construction barriers .................................................................................................................... 37 Commissioning barriers ................................................................................................................. 37 Operations barriers ....................................................................................................................... 38 Maintenance barriers .................................................................................................................... 38
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3rd Party interference prevention barriers ................................................................................... 38 Mothballing / removal barriers ..................................................................................................... 38
3.12 Consequence 2 of 2: Fire ....................................................................................................... 39 Life cycle barriers ........................................................................................................................... 39 Design barriers .............................................................................................................................. 39 Construction barriers .................................................................................................................... 39 Commissioning barriers ................................................................................................................. 39 Operations barriers ....................................................................................................................... 40 Maintenance barriers .................................................................................................................... 40 3rd Party interference prevention barriers ................................................................................... 40 Mothballing / removal barriers ..................................................................................................... 40
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1 Introduction The goal of using the Bowtie method of PIMS International B.V. is to create an overview that includes the risks and organization of policy, the effectiveness of mitigating measures, possible improvements, and the costs involved. The results particularly contribute to asset management in the following ways:
1. They help to ensure the integrity and safety of the assets in place, as well as improving the continuation of operations while focusing on economic optimization.
2. They are utilized to provide input for high‐level investment decisions. 3. They can be used in tender procedures to improve transparency of risk management practice
and to support project execution as they help to monitor the firmness of assumptions made and to mitigate unforeseen issues in time
The Bowtie method is semi‐quantitative, meaning that the data used in the model is based on both expert opinion and casuistry.
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2 Bowtie methodology The Bowtie methodology is applied by implementing the steps mentioned below. Please note that these steps are not always executed in this specific order. Moreover, some of these steps can be executed concurrently. 1. Preparation:
‐ Determining the scope, selecting the members of the expert team, location, and data to be used in the Bowtie workshops.
‐ Defining the objectives in the risk matrix e.g. failure frequency, corporate values and the corresponding severity of the consequences.
During the workshop:
2. Inventory: ‐ Determining the unwanted event in each area relevant to the expert team (during the
workshop) ‐ Create an inventory of the threats that could lead to the unwanted event in each area. ‐ Create an inventory of the consequences that could result from the unwanted event in each
area.
3. Specification: ‐ Identification of the escalation factors of the seven phases of the life cycle. ‐ Identification of the measures (existing and new) in order to mitigate the escalation factors. ‐ Quantification of the mitigating measures (existing and new) by effectiveness and cost (for a
period of five years). ‐ Ranking of the risk matrix.
After workshop:
4. Analysis: ‐ Data analysis ‐ Calculations ‐ Validation of outcome (during a second workshop) ‐ Investigating trends in failure behaviour (frequency of unwanted events), using for instance
maintenance logs from SAP.
5. Reporting and results: ‐ Reporting of the Bowtie results as well as the performance indicators.
2.1 Basic model The general Bowtie model has the following components:
‐ Unwanted event: The unwanted event refers to a hazard that needs to be controlled. In the industry this is sometimes also referred to as the ‘top event’. It is situated in the centre of the bowtie model.
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‐ Threats:There are a number of threats that could cause the unwanted event to occur. They are visualised in the model on the left side and shows a direct relationship between the causes of the unwanted event and the unwanted event itself.
‐ Consequences: The consequences are displayed at the right side of the model. The consequences refer to the possible results in case the unwanted event does indeed occur. This involves a direct relationship between the unwanted event and the consequences of the unwanted event.
The following picture illustrates the basic setup of the bowtie diagram:
2.2 Bowstar bowtie model An attribute is added to the threats that represents the relative contribution of each threat to the unwanted event. The sum of these threat contributions is always 100%. Every threat and consequence has seven barriers (standard). These barriers are being shaped by the seven life phases of the infrastructure. The purpose of these life cycle barriers is to enable differentiation between life cycle specific threats and corresponding mitigations and, as a result, measure the effectiveness and economics of each individual mitigating measure in preventing the unwanted event to happen and/or minimizing the consequence of the unwanted event. With the life cycle barriers included, the basic Bowtie model of PIMS International has the following shape:
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Please note that although the number of threats and consequences may vary, the number of life cycle barriers always remains constant. An attribute is added to each life cycle barriers that represents the relative effectiveness of the barrier in the prevention of the unwanted event. The sum of these life cycle barriers is always 100% for each threat / consequence.
The allocation of the value for effectiveness is conducted by casuistry. Whenever casuistry is not available, each member of the expert team is requested to give an estimate of the effectiveness of each life cycle barrier. The final value of each life cycle barrier is calculated as the average of estimates. A discussion between the members of the expert team will be brought up if the differences in individual scoring is too high.
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2.3 Escalation factors The next step in the development of the Bowtie is to define the so‐called escalation factors. These are sub‐threats which could erode the degree of effectiveness of the life cycle barriers. For instance: insufficient depth of cover (DOC) could lead to serious damage of the pipeline caused by the threat: Third party interference. Hence, in this case, ‘Depth of cover insufficient’ is an escalation factor. This example is illustrated in the following pictures:
Escalation factor incl. percentage contribution to life cycle (total = 100%)
Threat that can result in unwanted event incl. percentage
contribution (total = 100%)
Life cycle barrier incl. percentage of total life cyclebarriers (total barrier value all life cyclus = 100%)
Mitigating measures(2)Green : is implementedBlue : can be improvedRed : newYellow : no mitigation available
Actual life cycle barriereffectiveness (calculated by
software)
Mitigating measures (1)Cost of mitigation mesures (e.g. M€/5 year)Effectiveness of mitigating measure
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Remark: the blue framed boxes elucidate the specific features of the full developed diagram, incl. the results of the calculations of the Bowstar software. The following picture gives the basic diagram including the calculated summed life cycle barriers for each threat / consequence:
Ranking risk matrix:1. Financial consequences2. Employee Safety and Health3. Community Safety and Health4. Environment
Actual summed barrier valueof all life cycle
Maximum summed barrier valueof all life cycles that can be achieved by the
implementation of all improvements
Hazard
Unwantedevent
Consequence
Threat that can result in unwanted event incl. percentage contribution (total = 100%)
Current contributionthreat to unwanted event
Contribution threat tounwanted event after
implementationimprovements
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More information on e.g. risk reduction (visualized in the risk matrix) and life cycle performance, are calculated as well by the Bowstar software. Examples are given in the following pictures:
Option for risk reduction by the implementation of new / improved mitigations are visualized by the arrows.
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The threat contribution (green), the effectiveness of life cycle barriers (red) and the options for improvement (blue) are visualized by the bars.
The reduction of failure frequency resulting from the mitigating measures is visualized by the blue line.
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3 Bowtie Analyse: Pinhole
3.1 Main diagram
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3.2 Threat 1 of 9: External corrosion
Life cycle barriers
Design barriers
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Construction barriers
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Commissioning barriers
Operations barriers
No barriers
[T1] ‐ External corrosion
50%
[T1.1] ‐ Design
Actual: 15%
22%
[T1.2] ‐ Construction
Actual: 8%
14%
[T1.3] ‐ Commissioning
Actual: 14%
20%
[T1.3.1] ‐ Insufficient attention for CPefficiency
big pipelines
15,5%
[T1.3.1.1] ‐ Check on proper functioning CP‐system
1,6 MEur
80%
[T1.3.2] ‐ Insufficient attention for CPefficiency
small pipelines
15,5%
[T1.3.2.1] ‐ Check on proper functioning CP‐system
0,1 MEur
80%
[T1.3.3] ‐ As built drawing poor quality, spread all over
the place
23%
[T1.3.3.1] ‐ CP drawings need to be stored on a
central place
0,1 MEur
90%
[T1.3.3.2] ‐ Check by commissioning team
0,38 MEur
40%
[T1.3.4] ‐ Maintenance concept not correct
implemented
15%
[T1.3.4.1] ‐ Check by commissioning team
0,38 MEur
40%
[T1.3.5] ‐ Coating not in good condition
31%
[T1.3.5.1] ‐ DCVG / PCM standard practice
3 MEur
90%
[T1.4] ‐ Operations
Actual: 0%
0%
[T1.5] ‐ Maintenance
Actual: 18%
21%
[T1.6] ‐ 3rd Party interference prevention
Actual: 17%
22%
[T1.7] ‐ Mothballing / removal
Actual: 1%
1%
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Maintenance barriers
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3rd Party interference prevention barriers
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Mothballing / removal barriers
3.3 Threat 2 of 9: 1std Party interference
Life cycle barriers
Design barriers
No barriers
Construction barriers
Commissioning barriers
No barriers
Operations barriers
No barriers
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Maintenance barriers
3rd Party interference prevention barriers
Mothballing / removal barriers
No barriers
3.4 Threat 3 of 9: 2nd Party interference (contractors etc)
Life cycle barriers
Design barriers
No barriers
Construction barriers
No barriers
Commissioning barriers
No barriers
Operations barriers
No barriers
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Maintenance barriers
3rd Party interference prevention barriers
No barriers
Mothballing / removal barriers
No barriers
3.5 Threat 4 of 9: 3rd Party interference (digging etc)
Life cycle barriers
Design barriers
[T4] ‐ 3rd Party interference (digging etc)
20%
[T4.1] ‐ Design
Actual: 16%
18%
[T4.1.1] ‐ Mechanical strength transmission
pipelines not appropriate
12,5%
[T4.1.1.1] ‐ Application code ASME B318 and BS
0,5 MEur
90%
[T4.1.1.2] ‐ Quantitative Risk Assessment transmission
pipelines has been executed / area classification has been
applied
0 MEur
60%
[T4.1.2] ‐ Mechanical strength distribution
pipelines not appropriate
12,5%
[T4.1.2.1] ‐ Application code ASME B318 and BS
0,5 MEur
90%
[T4.1.2.2] ‐ Quantitative Risk Assessment distribution
pipelines has been executed / area classification has been
applied
0 MEur
60%
[T4.1.3] ‐ Insufficient protective measures against
3rd party interference
75%
[T4.1.3.1] ‐ Route selection
0 MEur
10%
[T4.1.3.2] ‐ Buried pipeline to protect against 3rd party
activities
0 MEur
70%
[T4.1.3.3] ‐ Marker signs to indicate pipeline position
0 MEur
10%
[T4.1.3.4] ‐ Protective slabs (concrete, PE etc) remark Barrier only applicable at places where slabs are
installed
1 MEur
9%
[T4.1.3.5] ‐ Add sensors to pipeline (cable etc) to detect vibrations that
indicate 3rd party activities
10 MEur
90%
[T4.1.3.6] ‐ Warning tape 300 mm above top of pipe
0 MEur
30%
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Construction barriers
Commissioning barriers
Operations barriers
No barriers
[T4] ‐ 3rd Party interference (digging etc)
20%
[T4.1] ‐ Design
Actual: 16%
18%
[T4.2] ‐ Construction
Actual: 12%
19%
[T4.2.1] ‐ Material bad quality
30%
[T4.2.1.1] ‐ Inspection by Inspection Authority TUV, Moody International etc)
0 MEur
95%
[T4.2.2] ‐ Welding bad quality
20%
[T4.2.2.1] ‐ NDT‐inspection welds are present (radiography)
0 MEur
99%
[T4.2.2.2] ‐ Inspection by Inspection Authority TUV, Moody International etc)
0 MEur
95%
[T4.2.3] ‐ Depth of Cover insufficient, not meeting
design
20%
[T4.2.3.1] ‐ DOC has been measured, deviation from design are marked with
red/blue
0,1 MEur
80%
[T4.2.3.2] ‐ DOC is checked with laser on excavating
machine
0,1 MEur
90%
[T4.2.4] ‐ Damage of pipeline during construction
30%
[T4.2.4.1] ‐ Inspection onsite by 1st party to
secure proper performance of the 2nd party, only until
pipeline is exposed
3 MEur
70%
[T4.3] ‐ Commissioning
Actual: 11%
11%
[T4.4] ‐ Operations
Actual: 0%
0%
[T4.5] ‐ Maintenance
Actual: 12%
24%
[T4.6] ‐ 3rd Party interference prevention
Actual: 25%
28%
[T4] ‐ 3rd Party interference (digging etc)
20%
[T4.1] ‐ Design
Actual: 16%
18%
[T4.2] ‐ Construction
Actual: 12%
19%
[T4.3] ‐ Commissioning
Actual: 11%
11%
[T4.3.1] ‐ Poor quality documentation
99%
[T4.3.1.1] ‐ Check of documentation at handover
Accurate monitoring pipeline position impossible
0 MEur
80%
[T4.3.1.2] ‐ Measurement pipeline defect status and position with intelligent pig,
determine frequency, currently 1/7 year
20 MEur
85%
[T4.3.2] ‐ Development subcritical defects resulting
from hydrotest
1%
[T4.3.2.1] ‐ Maximize hydrotest duration to 15 minutes to prevent the
development of subcritical defects
0,1 MEur
60%
[T4.4] ‐ Operations
Actual: 0%
0%
[T4.5] ‐ Maintenance
Actual: 12%
24%
[T4.6] ‐ 3rd Party interference prevention
Actual: 25%
28%
[T4.7] ‐ Mothballing / removal
Actual: 0%
0%
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Maintenance barriers
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3rd Party interference prevention barriers
Mothballing / removal barriers
No barriers
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3.6 Threat 5 of 9: Operational error(high P)
Life cycle barriers
Design barriers
Construction barriers
[T5] ‐ Operational error(high P)
4%
[T5.1] ‐ Design
Actual: 22%
24%
[T5.1.1] ‐ Design not capable to withstand higher
pressurer
50%
[T5.1.1.1] ‐ Application code ASME B318 and BS
0,5 MEur
90%
[T5.1.2] ‐ Pipeline has not the right classification
50%
[T5.1.2.1] ‐ Application code ASME B318 and BS
0,5 MEur
90%
[T5.2] ‐ Construction
Actual: 2%
4%
[T5.3] ‐ Commissioning
Actual: 18%
18%
[T5.4] ‐ Operations
Actual: 25%
30%
[T5.5] ‐ Maintenance
Actual: 22%
24%
[T5.6] ‐ 3rd Party interference prevention
Actual: 0%
0%
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Commissioning barriers
Operations barriers
Maintenance barriers
3rd Party interference prevention barriers
No barriers
[T5] ‐ Operational error(high P)
4%
[T5.1] ‐ Design
Actual: 22%
24%
[T5.2] ‐ Construction
Actual: 2%
4%
[T5.3] ‐ Commissioning
Actual: 18%
18%
[T5.3.1] ‐ Test pressure control system hasnt been
executed
45%
[T5.3.1.1] ‐ Hydrotest procedure should prevent
hydrotest not to be executed
0 MEur
99%
[T5.3.2] ‐ Hydrotest pessure too low
0,1%
[T5.3.2.1] ‐ Hydrotest procedure should prevent hydrotest to be executed at wrong pressure (too low)
0 MEur
99%
[T5.3.3] ‐ Emergency Shut Down hasnt been tested
54,9%
[T5.3.3.1] ‐ HIPPS system check Commissioning procedure guarantees
proper execution ESD test
0,1 MEur
99%
[T5.4] ‐ Operations
Actual: 25%
30%
[T5.5] ‐ Maintenance
Actual: 22%
24%
[T5.6] ‐ 3rd Party interference prevention
Actual: 0%
0%
[T5.7] ‐ Mothballing / removal
Actual: 0%
0%
[T5] ‐ Operational error(high P)
4%
[T5.1] ‐ Design
Actual: 22%
24%
[T5.2] ‐ Construction
Actual: 2%
4%
[T5.3] ‐ Commissioning
Actual: 18%
18%
[T5.4] ‐ Operations
Actual: 25%
30%
[T5.5] ‐ Maintenance
Actual: 22%
24%
[T5.5.1] ‐ Insufficient maintenance testing
pressure control system
40%
[T5.5.1.1] ‐ Proper execution of Maintenance concept should prevent overdue maintenance in pressure control system (leak
test etc)
0 MEur
90%
[T5.5.1.2] ‐ Surveillance of Safety Department and PTV Inspection program should guarantee the execution of the maintenance program
0,1 MEur
60%
[T5.5.1.3] ‐ Disassembling and renovation safety
valves 1/3 year
1,25 MEur
95%
[T5.5.2] ‐ Changes in system configuration are not
implemented in maintenance concept
60%
[T5.5.2.1] ‐ MOC procedure should guarantee correct implementation of changes
0,1 MEur
85%
[T5.6] ‐ 3rd Party interference prevention
Actual: 0%
0%
[T5.7] ‐ Mothballing / removal
Actual: 0%
0%
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 29 of 40
Mothballing / removal barriers
No barriers
3.7 Threat 6 of 9: Internal corrosion
Life cycle barriers
Design barriers
Construction barriers
Commissioning barriers
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 30 of 40
Operations barriers
Maintenance barriers
3rd Party interference prevention barriers
No barriers
Mothballing / removal barriers
No barriers
3.8 Threat 7 of 9: Internal erosion
Life cycle barriers
[T6] ‐ Internal corrosion
4%
[T6.1] ‐ Design
Actual: 15%
15%
[T6.2] ‐ Construction
Actual: 8%
10%
[T6.3] ‐ Commissioning
Actual: 10%
10%
[T6.4] ‐ Operations
Actual: 36%
40%
[T6.4.1] ‐ Unpredictable internal corrosion
mechanisms
60%
[T6.4.1.1] ‐ Measurement pipeline defect status and position with intelligent pig,
determine frequency, currently 1/7 year
20 MEur
85%
[T6.4.2] ‐ Accumulation of liquids in pipeline
40%
[T6.4.2.1] ‐ Application of pig to remove accumulated
water from pipeline
5,67 MEur
90%
[T6.4.2.2] ‐ Gas heaters to prevent condensation of
water
0 MEur
85%
[T6.5] ‐ Maintenance
Actual: 21%
25%
[T6.6] ‐ 3rd Party interference prevention
Actual: 0%
0%
[T6.7] ‐ Mothballing / removal
Actual: 0%
0%
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 31 of 40
Design barriers
Construction barriers
No barriers
Commissioning barriers
No barriers
Operations barriers
Maintenance barriers
No barriers
3rd Party interference prevention barriers
No barriers
Mothballing / removal barriers
No barriers
[T7] ‐ Internal erosion
3%
[T7.1] ‐ Design
Actual: 77%
95%
[T7.1.1] ‐ Dust contaminated gas results in
erosion
80%
[T7.1.1.1] ‐ Filters are applied to prevent erosion resulting from dust in gas
0 MEur
80%
[T7.1.2] ‐ Break through of condensate
20%
[T7.1.2.1] ‐ Fluid catchers are installed to prevent condensate coming in
pipeline
0 MEur
85%
[T7.2] ‐ Construction
Actual: 0%
0%
[T7.3] ‐ Commissioning
Actual: 0%
0%
[T7.4] ‐ Operations
Actual: 0%
5%
[T7.5] ‐ Maintenance
Actual: 0%
0%
[T7.6] ‐ 3rd Party interference prevention
Actual: 0%
0%
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 32 of 40
3.9 Threat 8 of 9: Natural disaster
Life cycle barriers
Design barriers
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 33 of 40
Construction barriers
Commissioning barriers
Operations barriers
[T8] ‐ Natural disaster
3%
[T8.1] ‐ Design
Actual: 27%
31%
[T8.2] ‐ Construction
Actual: 20%
28%
[T8.3] ‐ Commissioning
Actual: 5%
5%
[T8.3.1] ‐ Document and performance control not
properly executed
40%
[T8.3.1.1] ‐ Measuring earthing standard practice during commissioning
0,1 MEur
95%
[T8.3.1.2] ‐ Control of certificates standard
practice during commissioning
0,38 MEur
95%
[T8.3.1.3] ‐ Check as built information standard
practice during commissioning (can be improved up to 95%)
0,5 MEur
95%
[T8.3.2] ‐ Changes are not correctly implemented
60%
[T8.3.2.1] ‐ MOC procedure should guarantee correct implementation of changes
0,1 MEur
85%
[T8.4] ‐ Operations
Actual: 5%
6%
[T8.5] ‐ Maintenance
Actual: 25%
27%
[T8.6] ‐ 3rd Party interference prevention
Actual: 2%
3%
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 34 of 40
Maintenance barriers
3rd Party interference prevention barriers
Mothballing / removal barriers
No barriers
3.10 Threat 9 of 9: Vandalism, terrorism
Life cycle barriers
[T8] ‐ Natural disaster
3%
[T8.1] ‐ Design
Actual: 27%
31%
[T8.2] ‐ Construction
Actual: 20%
28%
[T8.3] ‐ Commissioning
Actual: 5%
5%
[T8.4] ‐ Operations
Actual: 5%
6%
[T8.5] ‐ Maintenance
Actual: 25%
27%
[T8.5.1] ‐ Checking proper function devicesearthing etc not properly executed
50%
[T8.5.1.1] ‐ Checking functioning preventive devices against natural
disaster standard practice
0,1 MEur
90%
[T8.5.2] ‐ Consequence of natural disaster not notified
50%
[T8.5.2.1] ‐ Measurement pipeline defect status and position with intelligent pig,
determine frequency, currently 1/7 year
20 MEur
85%
[T8.5.2.2] ‐ Helicopter inspection incl fixing
(interval 1 time per 2‐4 week)
3 MEur
70%
[T8.5.2.3] ‐ Car / foot patrol incl fixing (1/month)
7,7 MEur
60%
[T8.5.2.4] ‐ PIMS in Space
1,5 MEur
95%
[T8.6] ‐ 3rd Party interference prevention
Actual: 2%
3%
[T8.7] ‐ Mothballing / removal
Actual: 0%
0%
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 35 of 40
Design barriers
Construction barriers
Commissioning barriers
No barriers
Operations barriers
[T9] ‐ Vandalism, terrorism
6%
[T9.1] ‐ Design
Actual: 26%
30%
[T9.1.1] ‐ Rectifiers not vandalism proof
80%
[T9.1.1.1] ‐ Housing of rectifiers in SA is vandalism proof (concrete housing)
0,25 MEur
60%
[T9.1.1.2] ‐ Housing of rectifiers in Mozambique
concrete armoured housing
0,5 MEur
90%
[T9.1.2] ‐ Pressure reduce station not protected against vandalism
10%
[T9.1.2.1] ‐ Installation detection device on places
that are suspected to unauthorized activities
0 MEur
90%
[T9.1.3] ‐ Easy access to underground pipeline
makes them sensitive to vandalism terrorism
10%
[T9.1.3.1] ‐ Increase of DOC to minimize easy access to underground pipeline (MSP
and GNP pipelines)
5 MEur
99%
[T9.2] ‐ Construction
Actual: 1%
1%
[T9.3] ‐ Commissioning
Actual: 0%
0%
[T9.4] ‐ Operations
Actual: 20%
24%
[T9.5] ‐ Maintenance
Actual: 26%
27%
[T9] ‐ Vandalism, terrorism
6%
[T9.1] ‐ Design
Actual: 26%
30%
[T9.2] ‐ Construction
Actual: 1%
1%
[T9.3] ‐ Commissioning
Actual: 0%
0%
[T9.4] ‐ Operations
Actual: 20%
24%
[T9.4.1] ‐ Vandal entering rectifier station not notified
60%
[T9.4.1.1] ‐ Installation detection device on places
that are suspected to unauthorized activities
0 MEur
90%
[T9.4.2] ‐ Pressure reduce station not protected against vandalism
40%
[T9.4.2.1] ‐ Armoured response to prevent vandals entering the
location
0,5 MEur
70%
[T9.5] ‐ Maintenance
Actual: 26%
27%
[T9.6] ‐ 3rd Party interference prevention
Actual: 9%
18%
[T9.7] ‐ Mothballing / removal
Actual: 0%
0%
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 36 of 40
Maintenance barriers
3rd Party interference prevention barriers
Mothballing / removal barriers
No barriers
3.11 Consequence 1 of 2: Gas emission
Life cycle barriers
[T9] ‐ Vandalism, terrorism
6%
[T9.1] ‐ Design
Actual: 26%
30%
[T9.2] ‐ Construction
Actual: 1%
1%
[T9.3] ‐ Commissioning
Actual: 0%
0%
[T9.4] ‐ Operations
Actual: 20%
24%
[T9.5] ‐ Maintenance
Actual: 26%
27%
[T9.5.1] ‐ Unauthorized excavation and hot tap
30%
[T9.5.1.1] ‐ Installation detection device on places
that are suspected to unauthorized activities
0 MEur
90%
[T9.5.1.2] ‐ Car / foot patrol incl fixing (1/month)
7,7 MEur
60%
[T9.5.2] ‐ Vandalism not notified
70%
[T9.5.2.1] ‐ Measurement pipeline defect status and position with intelligent pig,
determine frequency, currently 1/7 year
20 MEur
85%
[T9.5.2.2] ‐ Helicopter inspection incl fixing
(interval 1 time per 2‐4 week)
3 MEur
70%
[T9.5.2.3] ‐ Car / foot patrol incl fixing (1/month)
7,7 MEur
60%
[T9.5.2.4] ‐ PIMS in Space
1,5 MEur
95%
[T9.6] ‐ 3rd Party interference prevention
Actual: 9%
18%
[T9.7] ‐ Mothballing / removal
Actual: 0%
0%
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 37 of 40
Design barriers
Construction barriers
Commissioning barriers
No barriers
G1 G0 G2 G1
[C1] ‐ Gas emission[C1.1] ‐ Mothballing / removal
Actual: 0%
0%
[C1.2] ‐ 3rd Party interference prevention
Actual: 20%
27%
[C1.3] ‐ Maintenance
Actual: 10%
27%
[C1.4] ‐ Operations
Actual: 32%
34%
[C1.5] ‐ Commissioning
Actual: 0%
0%
[C1.6] ‐ Construction
Actual: 5%
6%
[C1.7] ‐ Design
Actual: 1%
6%
[C1.7.1] ‐ Loss of containment not detected
3%
[C1.7.1.1] ‐ Odorization of gas should increase the
chance of detection of loss of containment
0,3 MEur
35%
[C1.7.2] ‐ Ignition sources too close to the pipeline, eg highway on 10 m distance
from pipeline
40%
[C1.7.2.1] ‐ Application of zoning distance meeting
code requirements
0 MEur
5%
[C1.7.3] ‐ Ignition sources like power lines, railway,
tram etc cant be prevented
40%
[C1.7.3.1] ‐ No measure against ignition gas leak by power lines, railway etc
0 MEur
0%
[C1.7.4] ‐ Ignition by static electricity
1%
[C1.7.4.1] ‐ No measure against ignition gas leak by
static electricity (pd2 criterion)
0 MEur
0%
[C1.7.5] ‐ No vent stack
16%
[C1.7.5.1] ‐ Construction of vent stack with sufficient
capacity
0 MEur
99%
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 38 of 40
Operations barriers
Maintenance barriers
3rd Party interference prevention barriers
Mothballing / removal barriers
No barriers
G1 G0 G2 G1
[C1] ‐ Gas emission[C1.1] ‐ Mothballing / removal
Actual: 0%
0%
[C1.2] ‐ 3rd Party interference prevention
Actual: 20%
27%
[C1.3] ‐ Maintenance
Actual: 10%
27%
[C1.4] ‐ Operations
Actual: 32%
34%
[C1.4.1] ‐ No Emergency Plan
80%
[C1.4.1.1] ‐ Emergency Plan is in place
0,1 MEur
90%
[C1.4.1.2] ‐ Emergency drill on regular time basis
0,8 MEur
90%
[C1.4.1.3] ‐ Safety distance document for fire brigade
0,1 MEur
25%
[C1.4.1.4] ‐ Control room calls the Emergency Control
when a gas leak occurs
0,1 MEur
90%
[C1.4.2] ‐ Leak not detected and if it is, geographic position unknown
5%
[C1.4.2.1] ‐ The tool Pipeline Manager can
pinpoint on the geographic position of the leak
0,1 MEur
90%
[C1.4.3] ‐ Excessive release of gas due to high pressure
15%
[C1.4.3.1] ‐ Reduction pressure in pipeline to minimize volume of gas
release
0,1 MEur
60%
[C1.5] ‐ Commissioning
Actual: 0%
0%
[C1.6] ‐ Construction
Actual: 5%
6%
G1 G0 G2 G1
[C1] ‐ Gas emission[C1.1] ‐ Mothballing / removal
Actual: 0%
0%
[C1.2] ‐ 3rd Party interference prevention
Actual: 20%
27%
[C1.3] ‐ Maintenance
Actual: 10%
27%
[C1.3.1] ‐ Loss of containment not detected
50%
[C1.3.1.1] ‐ Loss of containment is detected
during pipeline survey (foot patrol observation crop damage discoloration)
0,1 MEur
5%
[C1.3.1.2] ‐ Loss of containment is detected during pipeline survey by helicopter (observation
crop damage discoloration)
0,1 MEur
1%
[C1.3.2] ‐ Crack propagation results in excessive release
of gas
50%
[C1.3.2.1] ‐ Application of crack arrestors to prevent
crack propagation
1,44 MEur
70%
[C1.4] ‐ Operations
Actual: 32%
34%
[C1.5] ‐ Commissioning
Actual: 0%
0%
[C1.6] ‐ Construction
Actual: 5%
6%
[C1.7] ‐ Design
Actual: 1%
6%
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 39 of 40
3.12 Consequence 2 of 2: Fire
Life cycle barriers
Design barriers
Construction barriers
Commissioning barriers
No barriers
A1 A0 A2 A1
[C2] ‐ Fire[C2.1] ‐ Mothballing / removal
Actual: 0%
0%
[C2.2] ‐ 3rd Party interference prevention
Actual: 12%
16%
[C2.3] ‐ Maintenance
Actual: 7%
19%
[C2.4] ‐ Operations
Actual: 21%
22%
[C2.5] ‐ Commissioning
Actual: 0%
0%
[C2.6] ‐ Construction
Actual: 13%
16%
[C2.7] ‐ Design
Actual: 5%
27%
[C2.7.1] ‐ Loss of containment not detected
3%
[C2.7.1.1] ‐ Odorization of gas should increase the
chance of detection of loss of containment
0,3 MEur
35%
[C2.7.2] ‐ Ignition sources too close to the pipeline, eg highway on 10 m distance
from pipeline
40%
[C2.7.2.1] ‐ Application of zoning distance meeting
code requirements
0 MEur
5%
[C2.7.3] ‐ Ignition sources like power lines, railway,
tram etc cant be prevented
40%
[C2.7.3.1] ‐ No measure against ignition gas leak by power lines, railway etc
0 MEur
0%
[C2.7.4] ‐ Ignition by static electricity
1%
[C2.7.4.1] ‐ No measure against ignition gas leak by
static electricity (pd2 criterion)
0 MEur
0%
[C2.7.5] ‐ No vent stack
16%
[C2.7.5.1] ‐ Construction of vent stack with sufficient
capacity
0 MEur
99%
Documentno: O‐000/PIMS INTERNATIONAL‐SASOL GAS/07
Bowtie: Unwanted event – Pinhole
Origin data Sasol – modified / fictitious
© 2014 by PIMS International B.V Page 40 of 40
Operations barriers
Maintenance barriers
3rd Party interference prevention barriers
Mothballing / removal barriers
No barriers
A1 A0 A2 A1
[C2] ‐ Fire[C2.1] ‐ Mothballing / removal
Actual: 0%
0%
[C2.2] ‐ 3rd Party interference prevention
Actual: 12%
16%
[C2.3] ‐ Maintenance
Actual: 7%
19%
[C2.4] ‐ Operations
Actual: 21%
22%
[C2.4.1] ‐ No Emergency Plan
80%
[C2.4.1.1] ‐ Emergency Plan is in place
0,1 MEur
90%
[C2.4.1.2] ‐ Emergency drill on regular time basis
0,8 MEur
90%
[C2.4.1.3] ‐ Control room calls the Emergency Control
when a gas leak occurs
0,1 MEur
90%
[C2.4.1.4] ‐ Safety distance document for fire brigade
0,1 MEur
25%
[C2.4.2] ‐ Leak not detected and if it is, geographic position unknown
5%
[C2.4.2.1] ‐ The tool Pipeline Manager can
pinpoint on the geographic position of the leak
0,1 MEur
90%
[C2.4.3] ‐ Excessive release of gas due to high pressure
15%
[C2.4.3.1] ‐ Reduction pressure in pipeline to minimize volume of gas
release
0,1 MEur
60%
[C2.5] ‐ Commissioning
Actual: 0%
0%
[C2.6] ‐ Construction
Actual: 13%
16%
A1 A0 A2 A1
[C2] ‐ Fire[C2.1] ‐ Mothballing / removal
Actual: 0%
0%
[C2.2] ‐ 3rd Party interference prevention
Actual: 12%
16%
[C2.3] ‐ Maintenance
Actual: 7%
19%
[C2.3.1] ‐ Loss of containment not detected
50%
[C2.3.1.1] ‐ Loss of containment is detected
during pipeline survey (foot patrol observation crop damage discoloration)
0,1 MEur
5%
[C2.3.1.2] ‐ Loss of containment is detected during pipeline survey by helicopter (observation
crop damage discoloration)
0,1 MEur
1%
[C2.3.2] ‐ Crack propagation results in excessive release
of gas
50%
[C2.3.2.1] ‐ Application of crack arrestors to prevent
crack propagation
1,44 MEur
70%
[C2.4] ‐ Operations
Actual: 21%
22%
[C2.5] ‐ Commissioning
Actual: 0%
0%
[C2.6] ‐ Construction
Actual: 13%
16%
[C2.7] ‐ Design
Actual: 5%
27%