Risk management and
management of uncertainty
Torleif Husebø
Petroleum Safety Authority Norway
PTIL/PSA
PTIL/PSA
Major accidents
© US Coast GuardPTIL/PSA
What is the risk?
http://merchantmarinejobs.org/
Question:
• What is the risk associated with drilling?
• What is the probability of a blowout on a particular installation during the next operation/year?
• Impossible to answer?
- Yes (for most of us)
- Why?
- An enormous amount of factors and conditions that, directly and indirectly, influence the risk and our
assessment of the question – competence, time of day, procedures, experience, leadership, equipment,
reservoir conditions, attitude, safety culture, instruments, ………….
- Most of the factors are dynamic
- We can identify a lot of factors we believe are of importance, but it is not an easy task to describe and assess
the whole picture.
- Does it provide any meaning to “find” the probability?
PTIL/PSA
What is the risk?
http://merchantmarinejobs.org/
Still:
QRA of a (any) drilling rig:
“The probability of a blowout occurring during this operation is
equal to 5,2345 x 10-6 (or any similar small number)”
PTIL/PSA
Risk Acceptance Criteria
Frequency based
10-4
RAC
Potential consequences
Uncertainty
Expected value
PTIL/PSA
Balance
Development and protection
Weight given to E
Take risk
E[NPV], cost-benefit analyses
Reduce the risks
and uncertainties
ALARP
Cautionary-precautionary
Risk acceptance criteria
Source : Aven
PTIL/PSA
Piper Alpha
July 6th 1988 – 167 fatalities
PTIL/PSA
© PTTEP / NOPSEMA
PTIL/PSA
‘Description of uncertainty’
Assumption from an analysis
• Pressure relief- and emergency shut down valves are assumed to be
fail safe in relation to signal and power. It is assumed that the gas
detection system operates as expected. Confirmed detection of gas
will give an ESD 1 and the ESD valves will close and the Blowdown
valves will open.
0,18
0,16
0,14
0,12
0,08
0,06
0,04
0,02
0,00
D 141
F 48
G 75
M4
N3
P 317
S 15
T3
U 14
V 18
W 14
X3
Y8
AA 112
AB 120
AD 47
AE 23
AF 36
AG 48
AH 38
AI 12
AJ 48
AK 30
AL 27
AM 35
AN 164
AP 50
AQ 28
AR 26
AU 76
AV 28
AW 230
AX 186
AY 42
AZ 24
BA 28
BB 45
BC 119
BE 7
BF 1
BH 17
BJ 192
BK 78
BL 150
BM 48
BQ 12
BU 192
BV 11
BW 31
BX 15
BZ 5
BØ 27
CA 188
CB 40
CC 368
CE 28
Andel feil
0,10
2013
Gjennomsnitt 2004-2013
Bransjekrav
PTIL/PSA
BDV, RNNP
2013
Risk management and risk assessment
Some rhetorical issues
• Does the current risk evaluation practice contribute to
more than acknowledgment of already established
knowledge
• To what degree is uncertainty communicated to the users
of the analysis
• Is the use of Risk Acceptance Criteria's and ALARP
compatible
• Is the purpose of the risk management process to save
money
PTIL/PSA
Risk
- We (the whole industry) has to change our approach to risk
- We need to change focus form:
What is the risk?
Is it acceptable or not?
One general or universal risk picture
(which everyone has to understand and
relate to in all situations)
What can we do to make each person (on all
levels) more capable of understanding and
managing their own risk picture, including how
their choices and actions influence the risk.
Presenting information that is relevant, useful
and suitable for the purpose in each
situation/decision.
We have to make everyone more capable of understanding and managing risk
*This requires humility and honesty regarding what we know and what we don’t
know
*It requires a better communication and management of uncertainty
*It requires that our search for, and satisfaction, when we have generated some risk
related numbers rarely is a sufficient solution.
PTIL/PSA
12
Risk
• ‘New approach’ (Norwegian petroleum industry)
- Risk = uncertainty related to consequences of the activity
- Based on ISO 31000
PTIL/PSA
Thank you!
PTIL/PSA