3. Strictly Confidential 2
OBJECTIVES
To determine the major hazard on EWT Facilities.
To identify the threats and consequences of the Top Event
To construct Bowtie Risk Analysis of EWT facilities.
To get better understanding of process and operation
in upstream operation.
4. Strictly Confidential 3
1. Extended well test (EWT) facilities was installed on the Floating
Storage Unit (FSU) Nautica Muar for KMSE & AJK field.
2. Applying bowtie risk analysis for FSU Nautica Muar.
(only focusing on EWT Facilities)
INTRODUCTION
5. Strictly Confidential 4
• Risk Evaluation method used to analyze and demonstrate causal relationships in
HIGH risk scenarios.
• Capture Easily in Visual
• Name from the shape of the diagram-looks like a men’s bowtie.
WHAT IS BOWTIE?
6. Strictly Confidential 5
HISTORY OF BOWTIE
Piper Alpha Incident 1988, 6 July
Cause by
explosion
167 men died,
61 survivors
Nov 1988,
Cullen Inquiry
set an
investigation
Lack of
understanding
of hazards &
risks
Urge rose as
lesson learn to
gain more
understanding
and insight
causality
7. Strictly Confidential 6
METHODOLOGICAL PARENTS OF BOWTIE
1) Fault Tree Analysis
logical structure displaying the
relationship between an undesired
potential event (top event) and all its
probable causes
2) Event Tree Analysis
identifies and quantifies the possible
outcomes following an initiating event
8. Strictly Confidential 7
COMBINATION OF FAULT TREE AND EVENT TREE
UE 1
UE 3
UE 4
UE 5
UE 7
IE
IE
IE
IE
IE
IE
TE
SCE
SCE
DP
DP
DP
ME
ME
ME
ME
ME
ME
Fault Tree Event Tree
Barriers
Prevention Mitigation
DPAnd
And
OR
OR
OR
OR
OR
UE 2
UE 6
UE 8
SCENARIO
Initiating events Major Events
Unwanted Events
9. Strictly Confidential 8
BARRIER THINKING - SWISS CHEESE MODEL
• Early 90’s, James Reason develop the Swiss Cheese Model.
• It is a metaphor that made barrier thinking popular for the past two decades.
• Hazards are contained by multiple protective barriers.
• Barriers are needed to prevent loss.
HAZARD
INCIDENT
Barriers
10. Strictly Confidential 9
• Barriers may have weaknesses.
• Holes represent the weaknesses.
HAZARD
INCIDENT
Barriers
BARRIER THINKING - SWISS CHEESE MODEL
11. Strictly Confidential 10
BARRIER THINKING - SWISS CHEESE MODEL
HAZARDS
INCIDENT
Barriers
• Once the holes (barrier’s flaws)are aligned, Hazard will pass through the holes
in all slices leading to incident to occur./ failure.
17. Strictly Confidential 16
STEP 1: IDENTIFY HAZARDS
• Anything which is a source of potential loss or damage
HYDROCARBON
OIL UNDER
PRESSURE
Hazard
18. Strictly Confidential 17
STEP 2: IDENTIFY TOP EVENT
• A point in time which describes the release or loss of control over a Hazard
LOSS OF
CONTAINMENT
HYDROCARBON
OIL UNDER
PRESSURE
Hazard
Top Event
19. Strictly Confidential 18
Top Event
STEP 3: IDENTIFY THREATS
Threats
Human Error
Blockage of Piping due to
waxy crude resulting in
Piping Breakage
Corrosion
(Internal)
Corrosion
(External)
LOSS OF
CONTAINMENT
HYDROCARBON
OIL UNDER
PRESSURE
Hazard
20. Strictly Confidential 19
STEP 4: EVALUATE CONSEQUENCES
Human Error
Blockage of Piping due to
waxy crude resulting in
Piping Breakage
Corrosion
(Internal)
Corrosion
(External)
Fire without personnel
injury but Damage to
Facilities
Personnel injury
(HC release with fire)
Environmental Impact /
Hydrocarbon Spill
Fire (Multiple fatalities)
LOSS OF
CONTAINMENT
HYDROCARBON
OIL UNDER
PRESSURE
Threats
Consequences
Top Event
Hazard
21. Strictly Confidential 20
CONSTRUCTING THE BARRIERS
Function of barriers: to:
1. Control Threats
2. Determine the Recovery Measure
3. Controlling Escalation Factors
22. Strictly Confidential 21
CONSTRUCTING BARRIERS
Human Error
Blockage of Piping due to
waxy crude resulting in
Piping Breakage
Corrosion
(Internal)
Corrosion
(External)
Fire without personnel
injury but Damage to
Facilities
Personnel injury
(HC release with fire)
Environmental Impact /
Hydrocarbon Spill
Fire (Multiple fatalities)
LOSS OF
CONTAINMENT
HYDROCARBON
OIL UNDER
PRESSURE
Threats
Consequences
Top Event
Hazard
Threat Barriers Recovery Measure
23. Strictly Confidential 22
STEP 5: THREAT BARRIERS
Human Error
Blockage of Piping due to
waxy crude resulting in
Piping Breakage
Corrosion
(Internal)
Corrosion
(External)
LOSS OF
CONTAINMENT
HYDROCARBON
OIL UNDER
PRESSURE
Threats
Top Event
Threat Barriers
24. Strictly Confidential 23
Threats Barrier 1 Barrier 2 Barrier 3 Barrier 4 Barrier 5 Barrier 6 Barrier 7
Corrosion (internal) Piping (corrosion
allowance, corrosion
coupon in design)
(Piping system)
Anode in Tank
(design)
(Tanks)
Annual Class
Survey
(Inspection)
Crude & gas
sampling to
develop crude
assay and MSDS
(to ensure the
compatibility of
the crude)
(inspection)
Corrosion (Eternal) Painting & Coating Spec
for piping, corrosion
allowance
(Piping system)
Painting & Coating
Program
(Maintenance)
Annual Class
Survey
(Inspection)
Human Error Rest hour policy to
mitigate fatigue
(Procedural)
Competent personnel
(Administrative)
Correct tools
(Procedural)
Compliance to
PTW and
conducting tool
(Procedural)
Safety passport
requirement ,
Health declaration
form to be fill up
(Procedural)
Pre-joining medical
check and marine
medical check every 2
years.
(Procedural)
Stop work policy
(Procedural)
Blockage of Piping
due to waxy crude
resulting in Piping
Breakage
Steam System
(Fired Heaters)
Steam heating coil in
tank
(Tanks)
Chemical
Injection at FSU
(Chemical
Injection
Systems)
Threats Barriers (Left Side of Bowtie)
25. Strictly Confidential 24
STEP 6: RECOVERY MEASURES
Fire without personnel
injury but Damage to
Facilities
Personnel injury
(HC release with fire)
Environmental Impact /
Hydrocarbon Spill
Fire (Multiple fatalities)
LOSS OF
CONTAINMENT
HYDROCARBON
OIL UNDER
PRESSURE
Consequences
Top Event
Hazard
Recovery Measures
26. Strictly Confidential 25
Barrier 1 Barrier 2 Barrier 3 Barrier 4 Barrier 5 Barrier 6 Barrier 7 Barrier 8 Consequences
Routine operation
on main deck
(Operation and
maintenance)
Emergency Shutdown
System (ESD) for
pump
Process Emergency
Shutdown Valves
(ESDVs)
Oil Spill
Response Plan
(Oil Spill
Contingency)
Emergency
Response
Procedures
(ERP) and
Emergency
Control
Centre (ECC)
(Safety)
Communication
during spill
(Communication
system)
Alarm to be
activated during
oil spill
(Process control
& Alarms)
Safety Standby
Vessel
(Rescue
Facilities)
Environmental
Impact /
Hydrocarbon
Spill
Routine operation
on main deck
(Operation and
maintenance
Emergency Shutdown
System (ESD) for
pump
Oil Spill Response
Plan (Oil Spill
Contingency)
Safety Standby
Vessel
(Rescue
Facilities)
First Aid/
Medical
response
Manual Fire
Fighting Equipment
Fire water pump Hazardous Area
Ventilation
Personnel injury
(HC release with
fire)
Routine operation
on main deck
(Operation and
maintenance
Emergency Shutdown
System (ESD) for
pump
Oil Spill Response
Plan (Oil Spill
Contingency)
Safety Standby
Vessel
(Rescue
Facilities)
Personal
Survival
Equipment
(PSE),
lifejackets.
Fixed Foam system
for pump room,
engine room, main
deck, cargo area,
etc.
Hazardous Area
Ventilation
Emergency Stop
Button
(ventilation
system/quick
closing valve to
stop oxygen
from going into
engine room,
pump room
Fire without
personnel injury
but Damage to
Facilities
Routine operation
on main deck
(Operation and
maintenance
Emergency Shutdown
System (ESD) for
pump
Oil Spill Response
Plan (Oil Spill
Contingency)
Safety Standby
Vessel
(Rescue
Facilities)
First Aid/
Medical
response
Emergency/Escape
Lighting
Helicopter
Facilities
Manual Fire
Fighting
Equipment
Fire (Multiple
fatalities)
Recovery Measures (Right Side of Bowtie)
27. Strictly Confidential 26
STEP 7: IDENTIFY ESCALATION FACTORS
A condition that leads to increase risk by defeating or reducing the effectiveness
of controls
Human
Factors
Mechanical
Failures
Abnormal
Conditions
Loss of Critical
Services
28. Strictly Confidential 27
Not Familiar with
Facility’s ERP
Environmental Impact /
Hydrocarbon Spill
LOSS OF
CONTAINMENT
HYDROCARBON
OIL UNDER
PRESSURE
Consequences
Top Event
Hazard
Recovery Measures
Emergency Response
Procedures (ERP) and
Emergency Control
Centre (ECC)
(Safety)
Escalation Factor
STEP 7: IDENTIFY ESCALATION FACTORS
A condition that leads to increase risk by defeating or reducing the
effectiveness of controls
29. Strictly Confidential 28
STEP 8: CONTROLLING ESCALATION
A control that manages the conditions which reduce the effectiveness of other controls.
1. Controlling Human Factors
• Training and Induction
• Supervision and mentoring
• Qualification and Certifications
• Auditing and Verification
2. Controlling Mechanical Failures
• Maintenance and Repairs
• Inspection and Testing
• Redundancy and Spares
• Design and Specification
30. Strictly Confidential 29
Loss of Critical
Services
COMPLETE BOWTIE
Human Error
Blockage of Piping due to
waxy crude resulting in
Piping Breakage
Corrosion
(Internal)
Corrosion
(External)
Fire without personnel
injury but Damage to
Facilities
Personnel injury
(HC release with fire)
Environmental Impact /
Hydrocarbon Spill
Fire (Multiple fatalities)
LOSS OF
CONTAINMENT
HYDROCARBON
OIL UNDER
PRESSURE
Threats
Consequences
Top Event
Hazard
Threat Barriers Recovery Measures
Inspection and Testing
Mechanical Failures
Maintenance and Repairs
32. Strictly Confidential 31
BOWTIE ADVANTAGES
1. BARRIER EFFECTIVENESS - Barrier effectiveness gives instant visual insight into the
strength of Barriers.
2. BARRIER TYPE - Having different Barrier types will increase the strength of the
organization, by decreasing the likelihood of common mode failures.
3. BARRIER ACCOUNTABILITY - Making people responsible for Barriers, makes it
transparent what everybody is supposed to do to operate safely.
4. Suggest Bowtie to be applied seriously for Risk Analysis.
5. Mitigation strategies can be identified easily – So the concept *ALARP can be
achieved.
*As Low As Responsible Practicable
33. Strictly Confidential 32
CONCLUSION
Major hazard can
be identified
Threats can be
determined.
Consequences of
The Top Event can
be evaluated
Barriers and
mitigation strategies
can be measured.
