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WASHEQ 2015
Ella Agbettor
SHEQ Foundation
Process Safety Engineering
Mitigating Risks
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EVERYONE is responsible for safety
From the lab technician to the cleaner to the managing director
• Nobody wants to be involved with a major accident
• Nobody wants to see their fellow coworkers injured or killed as a result of their work
• Nobody wants to see their jobs or business destroyed
EVERYONE IS RESPONSIBLE FOR SAFETY
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TWO ASPECTS OF SAFETY
There are two aspects of safety
• Process Safety
• Personal Safety
Personal Safety:
Incidents that have the potential to injure
one person and generally occur due to
individual work habits.
Occupational incidents – slips/trips/falls,
struck-by incidents, physical strains,
electrocution.
Generally OHS are avoided by wearing
PPEs & following procedures.
An effective personal safety
management system DOES NOT
prevent major accidents events!
Process Safety:
Process safety hazards can give rise to major
accidents involving the release of potentially
flammable, reactive, explosive or toxic materials,
the release of energy (such as fires and explosions),
or both. These are events that have the potential to
lead to multiple fatalities and/or major
environmental damage. Process safety management
ensures there are Adequate Barriers to MAE’s.
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PROCESS SAFETY VS PERSONAL SAFETY
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Increasing Likelihood of Event
In
cre
asin
g C
on
se
qu
en
ce
s of E
ve
nt
Occupational Health
& Safety Risks
Major Accident
Hazard Risks
Potentia
l
Losses increasin
g
Possib
le E
scala
tion
Increasing Likelihood of Event
In
cre
asin
g C
on
se
qu
en
ce
s of E
ve
nt
Occupational Health
& Safety Risks
Major Accident
Hazard Risks
Potentia
l
Losses increasin
g
Possib
le E
scala
tion
PROCESS SAFETY PERSONAL SAFETY
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INCIDENTS THAT DEFINE PROCESS SAFETY
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PSM REGULATION FROM THE UK AND USA
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Employee Participation
Training
Process Hazard Analysis
Mechanical Integrity
Process Safety Information
Operating Procedures
Hot Work Permit
Management Of Change
Pre Start-up Review
Emergency Planning &
Response
Incident Investigation
Contractors
Compliance Audits
Trade Secrets
OSHA 1910.119 (USA)
Platform Description
Reservoir Description
Management System
Policy
Organisation
Processes
Risk Assessment
Permit To Work
Management of Change
Performance Measurement
Audit & Review
Major Hazard Identification
Major Hazard Risk Assessment
Demonstration Of:
Prevention
Control
Mitigation
Evacuation Rescue & Recovery
Safety Case
SAFETY CASE (UK)
Policy
Organisation
Processes
Risk Assessment
Permit To Work
Management of Change
Performance Measurement
Audit & Review
Major Hazard Identification
Major Hazard Risk Assessment
Safety & Environment
Demonstration Of:
Prevention
Control
Mitigation
Emergency Response Plans
Onsite & Offsite
Safety Report
SEVESO II (COMAH) UK
Does this look familiar? How do these compare? Differences?
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RISK MANAGEMENT PROCESS – SUMMARY
Risk Potential Matrix
New/ Major Facilities
Brownfield / Sites
Workgroup Non-Routine Activity
Routine Activity by Individuals and Workgroups
Task Risk Assessment -Qualitative
Health Risk Assessment
Safety Cases, Hazard Registers, Site
Standards, Procedures, PTW
HSE Bulletins, Toolbox meetings
Risk Management Process
HAZARD IDENTIFICATION [HAZOP][HAZID][LAYOUT REVIEW] [BOWTIE][ FMEA]
[HRA]
HAZARD ASSESSMENT [[FRA][EETRA][QRA][ALARP][DO][LOPA]
HAZARD MITIGATION [F&G][[IGNCONTROL][AFP][PFP][BLOWDOWN][FLARE]
[DOP]
Legislation & Regulations
International Codes & Standards,
Industry Standards, Company Standards
Sources of Information
Inspection checklists,
Induction handbooks,
Incident Report feedback,
Job Start meetings
QUANTITATIVE
QUALITATIVE
PROCESS SAFETY IMPLEMENTATION
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Provide rapid and reliable indication of the occurrence of a hazardous event involving fire and/or
loss of containment of flammable or toxic inventories to :
• Emergency Shutdown (ESD 1) of affected Fire Zone
( on confirmed gas detection or fire detection )
• Initiate Alarms
• Trigger emergency isolation and
depressurisation of hydrocarbon inventories
• Initiate fire water deluge system
(fire, sometimes toxic or flammable gas)
• Initiate CO2 or INERGEN or FMC 200 fixed fire
extinguishing systems
• Trip power generation and electrical equipment
• Increase ventilation in enclosures
• Close dampers in HVAC air intakes
HAZARD MITIGATION – FIRE & GAS DETECTION 1
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HAZARD MITIGATION – FIRE & GAS DETECTION 2
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Types of detectors
• Smoke Detectors (Optical/ Ionisation)
• Heat Detectors ( FT/ RoR)
• Flame Detectors (UV/ UVIR/ IR/IR2/IR3)
• Hydrocarbon Gas Leak Detectors ( Line of sight , ultrasonic)
• Toxic Gas Detectors
• Open Path Gas leak Detectors
• VESDA
The use of fire and gas mapping to ensure coverage is adequate
http://www.thegreenbook.com/products/details/fire-and-gas-detection-system/
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HAZARD MITIGATION – FIRE PROTECTION 1
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Active fire protection objectives are achieved by
reduction of the fire effects through:
•cooling of the hydrocarbon equipment
•shielding against radiation
•fire suppression
Active fire protection is activated:
•By Fire and Gas detection logic (automatically)
•manually (local and remote)
Active fire protection ( fire pumps, ringmain, deluge
valves and nozzles). Type of protection depends on
required duty – this may be to extinguish the fire,
control the fire or provide exposure protection.
Types include:
•water deluge
• foam
•water mist / steam
•dry powder
•inert gas (Inergen), CO2
http://www.google.com/imgres?imgurl=http://www.haltd.co.uk/images/firewater-system.png&imgrefurl=http://www.haltd.co.uk/firewater-systems.html&usg=__fL0-gxYcjmGWhwO8iGsvibHVQOI=&h=260&w=240&sz=132&hl=en&start=13&sig2=LFLmaC2ZzWxf7wZjuWrO-A&zoom=1&tbnid=2R-suutG9YRqZM:&tbnh=112&tbnw=103&ei=8kVbT46kCafI0QWFoYG5DQ&prev=/search?q=FIREWATER+SYSTEM&hl=en&sa=N&gbv=2&tbm=isch&itbs=1http://www.google.com/imgres?imgurl=http://www.darlingmuesco.com/images/delugevalve_big.png&imgrefurl=http://www.darlingmuesco.com/deluge_valve.htm&usg=__egQiPABMn0t-ioT_FxJulCuQ2Jk=&h=352&w=350&sz=29&hl=en&start=7&sig2=_9aPdIsC1MGAn7qpIQk_yg&zoom=1&tbnid=WB-Sku78o2WGFM:&tbnh=120&tbnw=119&ei=KUZbT-LaH-rO0QW9usztDQ&prev=/search?q=deluge+valve&hl=en&sa=N&gbv=2&tbm=isch&itbs=1
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1 200
1 000
800
600
400
200
010
°C
minutes20 30 40 50 60
Standard Fire CurvesTemperature vs. Time
Jet fire
Hydrocarbon fire
Cellulosic fire
Fire Barriers / Partitions between areas e.g. Process /
Non Process :
• Coatings on Bulkheads - For A / H / JF ( with wire
mesh )
• Prefabricated GRP Panels - For A / H / JF
• Prefabricated Panels with insulation - For A / H /
Not JF
Critical Structural Members / Risers / Flare Structure /
Supports
Intumescent or Cementious coatings - For H / JF ( with
wire mesh)
Risers / ESDV's / Equipment / Panels
GRP Cast Sections for risers and boxes for ESDV
Intumescent half shells
Penetrations :
Seals suitable
for For A / H / JF
Passive fire protection -Fireproofing to prevent failure of
structures and equipments. Coating applied to the wall of
vessel (mineral or organic-based).
Resist to flames and slow down heat transfer to the wall ( fire
walls, chartek, blast wall, fire blankets)
Design for blast – possible explosion overpressure
The duration of the required stability and integrity
A = 60 minutes
H = 120 minutes
J = J-class is not a standard fire rating. SEV specification
retains H capabilities of 120 minutes
HAZARD MITIGATION – FIRE PROTECTION 2
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J 45/ H60, 0.3
bar Blast wall
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HAZARD MITIGATION – EMERGENCY SHUTDOWN 1
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In the event of a process upset that can lead to loss of containment or hydrocarbon leak we need to
shutdown the process unit and sometimes the platform immediately so the event does not escalate to other
areas of the Platform.
ESD0 Total Black-Out
ESD1-1 Emergency Shut-
Down Fire Zone 1
SD2-1.1 Functional Unit Shut
Down Unit 1.1
SD3-1.1.1 Individual Shut-Down
Equipment 1.1.1
SD3-1.1.k Individual Shut-Down
Equipment 1.1.k...
SD2-1.j... Functional Unit Shut
Down Unit 1.j...
SD3-1.j.1 Individual Shut-Down
Equipment 1.j.1
SD3-1.j.k... Individual Shut-Down
Equipment 1.j.k...
ESD1-i... Emergency Shut-
Down Fire Zone 2...
SD2-i.1 Functional Unit Shut
Down Unit i.1
SD3-i.1.1 Individual Shut-Down
Equipment i.1.1
SD3-i.1.k... Individual Shut-Down
Equipment i.1.k...
SD2-i.j Functional Unit Shut
Down Unit i.j...
SD3-i.j.1 Individual Shut-Down
Equipment i.j.1
SD3-i.j.k... Individual Shut-Down
Equipment i.j.k...
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HAZARD MITIGATION – OVERPRESSURE
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Most of the plant is pressurised so what happens during an over pressure event. Design of relief disposal dependent on relief
requirements (e.g. fire, overpressure by gas , overfilling by liquid, reaction runaway).
Relief devices are installed and during an overpressure event they open and allow the gas to go to the flare
thus preventing over pressure of equipment. Process engineers have to size these devices for the
equipment they are protecting.
A flare or vent system consists of:
• Relieving devices in the Process systems
(PSV, BDV, Bursting discs,…)
•Headers for collection of relieved effluents
•Knock out (KO) Drum to segregate gas and
liquid phases
•Sealing devices to prevent air ingress (purge
gas, seals) or Designed to
•sustain internal explosion (15 barg as a
result of internal generic study)
•Disposal devices for the gas and liquid
(Flare tip, liquid burners, burn pit,…)
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Function Of Drainage Systems
SAFETY
• Minimise uncontrolled spillage
• Minimise the risk of ignition (evacuation of flammable liquids away from ignition sources)
• Prevent escalation of a fire across the installation (containment and evacuation of flammable liquids)
ENVIRONMENT
• Minimise direct discharge of polluted streams by channelling to appropriate treatment units
Key Features For Safety Of Drainage
• Architecture of network to prevent cross-contamination
• Gas seals and fire breaks to prevent migration
Closed Drains Are Connected To:
• Hydrocarbon equipment under PRESSURE
• Equipment handling TOXIC fluids (intentional release to atmosphere not acceptable)
Open drains are ATMOSPHERIC systems
HAZARD MITIGATION – DRAINAGE
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HAZARD MITIGATION – IGNITION CONTROL 1
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Due to the flammable nature of oil and gas ignition control is very important because if there
is no ignition source there will be no explosion or fires.
Precautions:
> Avoiding flammable substances (replacement technologies)
> Inerting (addition of nitrogen, carbon dioxide etc.)
> Limitation of the concentration by means of ventilation
Ignition sources identification:
Apparatus which, separately or jointly, are intended for the
generation, conversion of energy capable of causing an
explosion through their own potential sources of ignition
Measures to limit the effect of explosions to a safe degree:
> Explosion pressure resistant construction
> Explosion relief devices
> Explosion suppression by means of extinguishers, deluge, etc
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Hazardous Area Classification
Zone 0.
In which ignitable concentrations of flammable gases or vapours are present continuously, or in
which ignitable concentrations of flammable gases or vapours are present for long periods of
time.
• Zone 1.
In which ignitable concentrations of flammable gases or vapours are likely to exist under
normal operating conditions. (for a full definition refer to API RP 505).
• Zone 2.
In which ignitable concentrations of flammable gases or vapours are not likely to occur in
normal operation, and if they do occur will exist only for a short period (for a full definition
refer to API RP 505).
Reduce to an acceptable level the probability of coincidence of a flammable atmosphere and
an ignition source, by means of:
• Segregation of hydrocarbon sources and ignition sources,
•Selection of equipment with the potential to cause ignition:
HAZARD MITIGATION – HAZ. AREA CLASSIF.
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HVAC unit usually is placed between the
helideck and the roof of the quarters for
offshore units.
The living quarters and electrical switch
rooms also requires a ventilation system , in
the event of a gas release or fire the HVAC
damper shut off preventing gas ingress.
Note normally you will have fire and gas
detectors at HVAC inlets to detect gas and
shutdown damper especially if HVAC inlet is
in close proximity to the process area.
HAZARD MITIGATION – HVAC & VENTILATION 1
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TECHNICAL INTEGRITY
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8 Dimensions of Integrity Monitoring
Shutdown Systems
Risk Control Dimensions Hydrocarbon
Leak
Safe
Operation
Major
Accident
H
A
Z
A
R
D
S
Prevention Barrier
• Mech
Integrity
• Ignition
Control
• Fire & Blast
walls location
Plant
Design
A
Plant
Design
A
• Thickness
m’ment
• PM checks
Equip. online
•Condition
monitoring
Inspection
and
Maintenance
B
Inspection &
Maintenance
B
• Defined &
understood
scope of
work
• Hazards
identified,
risk assessed
& Controls
in place
• Work
authorised
Permit to
work
C
Permit to
Work
C
• Risk
assessment
for potential
impacts
• Authorised
management of
change
• Case to
operate
Plant change
management
D
Plant Change
Management
D
• Standard’sd
Operating
Procedures
• Periodical
review done
• Temporary
procedures
for changed
situations risk
assessed.
Operational
Procedures
E
Operations
Proedures
E
• Role specific
competency
criteria for
process safety
• Periodic inputs
for updating
• Periodic
assessment
Staff
Competence
F
Staff
Competence
F
• Fire & Gas
alarms
• Routine
monit’ng
of alarms / trips
• Defined
procedure
for
management
of inhibits /
overrides
Alarms &
Instruments
G
Alarms &
Instruments
G
• Periodic
testing of ESD /
trips and
emergency
systems
• Periodic Mock
drills of ERP
• Emergency
procedures
updated
Emergency
arrangements
H
Emergency
Arrangements
H
Mitigation Barrier
C
O
N
S
E
Q
U
E
N
C
E
S
• Each Barrier is important
• Concurrent failure in barriers can result in Near Miss or MAE
• Significant Failing in just one critical barrier sometimes is sufficient to cause incident
• Continuous monitoring & testing of Barriers is needed through suitable tools
Technical Integrity (TI) is all about management of SCE ( HAZARD MITIGATION
MEASURES)
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ESTABLISH DESIGN INTEGRITY
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Technical Integrity Management
Hazid Hazop
Studies
PERFORMANCE
STANDARDS
SMS and
Procedures
Operations Safety Case
Work
Orders
Risk Based
Inspection /
Reliability
Centred
Maintenance
Major Health Hazards and
Major Accident Events
Hazard
Register
All HSE
Hazards
Formal Safety
Studies
SAPIntegrity
ReportsMAXIM
O
Project Phase Establish Integrity by identifying MAE, SCE ( Safety Critical Elements) producing Performance Standards(PS) all contributing to the establishment of Technical Integrity (TI).
In the operation phase, safeguard integrity by maintaining equipment, reviewing, verifying and assuring integrity using
performance standards, corrective action should be closed out appropriately all leading to maintaining TI.
MAJOR ACCIDENT EVENTS
(MAE)
Establish Design Integrity and Safeguard it during Operations
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INHERENT SAFETY
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THE BASICS •Fewer hazards •Fewer causes •Reduced severity •Fewer consequences
1 . Minimise – use smaller quantities of hazardous substances
2 . Substitute – replace a material with a less hazardous substance
3 . Moderate – use a less hazardous condition, a less hazardous form of a material, or facilities that minimise the impact of a hazardous material or energy
4 . Simplify – design facilities that eliminate unnecessary complexity and make operating errors less likely and that are more forgiving of errors which are made
barg barg
Gas Hot Oil
Gas Hot Water
But are design should be Inherently Safe in the first place
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INHERENT SAFETY RISK REDUCTION MEASURES
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Physical protection
– Safety valves to flare
– Rupture disks to flare
– Vacuum breakers
– Blowdown systems
Reduction of Leak
Frequencies
– Enhanced inspection plan (mechanical integrity)
– Full containment design
– Corrosion allowance
– Corrosion risk management
– Safety Critical Procedures (with high reliability level in execution)
Process Design
– Alternative chemical process (chemicals used, …)
– Reduction of operating pressure
– Reduction of operating temperature
– Reduction of area congestion
– Selection of construction materials
– Some critical cooling systems
Automatic action SIS
– Interlocks independent from DCS
• PCV to flare
• Heat cutout interlock
• Feed cutout interlock
– UPS systems
– Emergency power generator
– HIPPS
Limitation of Released Quantity
– Reduction of product inventory
– Remote operated isolation valves (ESD system)
– Blowdown system
– Flow orifices
– Excess flow valves
Mitigating & Protective measures
– Diking
– Water curtains
– AFP (Sprinkler/deluge systems)
– Foam application systems
– Restricting flow orifices
– Excess flow valves
– PFP(Blast/fire resisting structures blast/fire walls, reinforced control rooms)
– Control of ignition sources
– Emergency shutdown systems
– Containment systems (containment inside building)
– Flange protection
– Devices influencing the direction of leaks.
– Explosion suppression systems
– Inhibitor or killing agent injection systems
– Detection systems (gas, liquid, smoke, fire,...) with operator intervention