risktec solutions
TRANSCRIPT
Risktec Solutionsrisk management and assessment for business
© 2018 Risktec Solutions Limited
When is enough, enough? Using Bowties to Review Well Control Risks
Andy Lidstone, Principal Consultant, Risktec Solutions, UKSteve Lewis, Director, Risktec Solutions, UK
Risk Management Process
Identify Risks
Analyse Risks
Evaluate Risks
Terminate Transfer Treat Tolerate
Risk
Assessment
Monitor &
Review
Communicate
& Consult
ALARP
When is enough, enough?
Risk assessment should be
an input into a decision
making process NOT a
justification for a decision
already made
Risk
Treatment
Establish Context
Risk Understanding
The better we understand, the better we manage
Reactively, for what we have
Proactively, for audit and review
What is really there, rather than what we wish is there
Basic Bowtie
Hazard
Conseq-
uence
Threat
Top EventThreat
Threat
Conseq-
uence
Conseq-
uence
Prevention Mitigation
Barriers
Bowtie Method - Advantages
Graphical format encourages
Participation
Ownership
Use
Understanding
Clear identification of roles and responsibilities
Can vary level of detail specific to the analysis
Bowtie Method - Pitfalls
Can be difficult to do well
Need to ensure:
Consistency of approach
Pitching at the right level
Involving the right people
Avoiding wish fulfilment
Control dependencies
Doesn’t replace QRA
Example case study
7 Footer
Hydrocarbons in Formation
Fire or
expolsionShallow Gas
Loss of
control
Kick during
drilling
Improper
completions
H2S
release
Oil spill
Shallow gas
release
Kick during
cementing
other threats
What are the preventive controls?
Kick during drilling
Loss of control
Well design and drilling program
Well kill
procedures
– wait and
weight or
circulate out
Primary well
control –
maintain
hydrostatic
head
Secondary
well control
– close BOP
What are the mitigative measures?
Fire or explosion
Personnel alerted by General
Alarm and rig PA
announce-ments
Isolate and control
potential sources of
ignition
Muster and account for personnel
A Class exterior
bulkheads
Multiple escape
routes and muster areas
Escape routes impaired
It’s more than a picture: who is responsible and what must they do?
Fire or explosion
Personnel alerted by General
Alarm and rig PA
announce-ments
Multiple escape
routes and muster areas
Escape routes impaired
Instr. Tech
Isolate and control
potential sources of
ignition
OIM
Muster and account for personnel
Chief
Mate
A Class exterior
bulkheads
Mech. Eng.
Safety Eng.Test and calibrate critical instrumentation, alarms
and communication systems
And what is the critical documentation?
PoB listing and EmgcyResponse Plan
Fire or explosion
Personnel alerted by General
Alarm and rig PA
announce-ments
Isolate and control
potential sources of
ignition
Muster & account for personnel
A Class exterior
bulkheads
Multiple escape
routes and muster areas
Escape routes impaired
Instr. Tech
OIM
Chief Mate Mech. Eng.
Safety Eng.Protective sys. spec. &
performance stds.
Bowtie approach
Generic, e.g. well control
Operations specific
ALARP Fundamental Questions
Is there anything more we can do?
Is it reasonably practicable?
Have we done the basics?
Risk Levels (quantitative and/or qualitative)
Legislative Requirements
Good Practice
Company Standards
Further risk
reduction
The better we understand what we have, the better we can
answer the questions...
Acceptance criteria
Risk levels – may be quantitative and/or qualitative
Number, type and quality of controls
Need to consider what supports the barrier, e.g. people, equipment, documentation
The likelihood of the event
Suitability of the controls
Independence of the controls
Defeating factors
Acceptance Criteria – effective barriers
Simple
e.g. three independent and effective
Semi-complex
Complex
Numerical criteria
SIL
Well Test
Threat
Score Total
Threat 1 2 3 4 5
Overpressure of seperator 0 4 2 3 2 5 16
Internal Corrosion 0 4 4 4 12
Failure of piping / small connections 0 2 3 5
Dropped Objects 2 4 4 2 12
Human Error 0 4 4 6 3 3 20
Barrier Scores
ALARP Assessment
Identify potential risk reduction measures
Improvements on existing controls
Additional controls
Compare Benefit and Sacrifice
Depth of assessment should be proportional
Qualitative
Semi-quantitative
Cost Benefit Analysis
Rigour will depend on e.g.
Nature of hazard
Extent of risk
Societal concerns etc.
The more systematic the approach, the more rigorous and transparent it is to stakeholders
Semi-Quantitative - Matrices
High Impact / Low Cost High Impact / High Cost
Ris
k C
on
tro
l Im
pa
ct
Implement Immediately Implement if Practicable*
Implement as part ofContinuous Improvement
Don't Implement
Low Impact / Low Cost Low Impact / High Cost
Cost of Risk Control
High Impact / Low Cost High Impact / High Cost
Ris
k C
on
tro
l Im
pa
ct
Implement Immediately Implement if Practicable*
Implement as part ofContinuous Improvement
Don't Implement
Low Impact / Low Cost Low Impact / High Cost
Cost of Risk Control
Risk Reduction
Level Value Risk Matrix Value
HIGH 1 Risk reduction from High to Low
MEDIUM 2 Risk reduction from High to Medium
LOW 3 Risk reduction from Medium to Low
Cost
Level Value $ Cost of implementation
LOW 1 <50k
MEDIUM 2 50k – 500k
HIGH 3 >500k
Effort
Level Value Effort
LOW 1 Quick Fix, simple to achieve, e.g. install new valve
or conduct training
MEDIUM 2 Simple fix, relatively easy to achieve, e.g. replace
item of equipment or revise simple layouts
HIGH 3 Complex fix, technically feasible but not easy to
achieve, e.g. major equipment or layout changes
Allows for consistent and transparent decision making
Need to calibrate axes
Effort
Level Value Effort
LOW 1 Quick Fix, simple to achieve, e.g. install new valve
or conduct training
MEDIUM 2 Simple fix, relatively easy to achieve, e.g. replace
item of equipment or revise simple layouts
HIGH 3 Complex fix, technically feasible but not easy to
achieve, e.g. major equipment or layout changes
Low Medium High
Low ConsiderConsider, if
risk high
Do not
implement
Medium Implement ConsiderConsider, if
risk high
High Implement Implement Consider
Benefit (risk
reduction)
Sacrifice (time, cost, effort)
ALARP process assessment
Is
RRM ‘easy’ to
implement?
Assess benefit and
sacrifice for RRM
Implement RRM
Follow recognized industry good
practice for hazard management?
or
Have significant impact on
reducing potential for multiple
fatality events?
or
Result in inherently safer design?
YES
NONO
Does RRM?
YES
NO
Low Medium High
Low ConsiderConsider, if
risk high
Do not
implement
Medium Implement ConsiderConsider, if
risk high
High Implement Implement Consider
Benefit (risk
reduction)
Sacrifice (time, cost, effort)
Matrix Assessment for
Implementation of RRM based
on Benefit vs Sacrifice
Example ALARP review items
Potential Measure Benefit Sacrifice Decision
Install a riser fill valve Low Medium Reject
Mark all 6⅝" drill pipe to ensure it can be
properly identifiedMedium Low Implement
Install water curtain on aft face of
accommodationMedium Medium Review
Provide gas detection in accommodation
HVAC inletsMedium High Reject
Provide well test equipment inventory and
certification prior to arrivalMedium Low Implement
ALARP Process Summary
- Equipment- People- Procedures
Develop the Bowtie
Identify and question the barriers
How good are the barriers?
Could we do more?
Is it reasonably practicable?
Implement in good time
Document the process
- Are there enough?
- Of the right quality?
- Improve existing?
- Add more?
- Monitor
- Review
Low Medium High
Low ConsiderConsider, if
risk high
Do not
implement
Medium Implement ConsiderConsider, if
risk high
High Implement Implement Consider
Benefit (risk
reduction)
Sacrifice (time, cost, effort)
Conclusions
To improve, we need a clear view of where our weaknesses are
Bowties have gained wide usage as an excellent understanding and communication tool
ALARP reviews need to question
Have we done enough?
Could we do more?
Is it reasonably practicable to do so?
A simple matrix can aid clarity and transparency of decision making
