Sikkerhetsforum
Stavanger 8. juni 2017
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DNV GL © 2014
SAFER, SMARTER, GREENER
DNV GL ORGANIZATION
DNV GL FLEET
HORIZONTAL WAVE LOADS
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DNV GL © 2014
DNV GL ORGANIZATION
DNV GL FLEET
HORISONTAL WAVELOADS
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DNV GL © 2014
How Offshore Classification is organized
Group CEO
Remi Eriksen
CEO Energy
CEO Maritime
CEO Oil & Gas
Ditlev Engels
Knut Ø. Nilssen
Elisabeth Tørstad
EVP Offshore Class
Ernst Meyer
Offshore Class Office
SEA
Kevin
Robertson
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DNV GL © 2014
Korea
Ole Harnes
China
Johan
Gardin
North
America
Antony
D’Souza
South
America
Neil Fraser
EU/Africa
ME/India
Scott Jervis
Nair Bijali
Norway
Eirik
Jacobsen
DNV GL ORGANIZATION
DNV GL FLEET
HORIZONTAL WAVE LOADS
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DNV GL © 2014
Record high number of MOUs in our fleet – 349 UNITS
68 in Norway
40 in UK
29 in Brazil
39 in Gulf of Mexico
5 in Canada
36 in West Africa
33 in Middle East Gulf
7 in India
75 FPSO
210 Drilling
59 Service
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DNV GL © 2014
32 in South East Asia
DNV GL ORGANIZATION
DNV GL FLEET
HORIZONTAL WAVE LOADS
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DNV GL © 2014
The two questions….
Freak wave?
yes
No actions needed
yes
Actions on GM4000 only
no
GM4000 only?
no
Industrial
approach
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DNV GL © 2014
OTG 13: Documentation of air gap
OTG 14: Documentation of horizontal wave loads
Can it happen
again?
Freak wave?
From PTIL’s Investigation Report:
On the basis of available data it is PSA’s consideration that the wave was steep.
However, the weather conditions 30.12 was probably within what the unit
should have been designed for.
*)
DNV GL approved units shall in the future have resilience to similar and worse
waves than the one that struck COSL Innovator 30.12.2015
*)Translated to English by DNVGL
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DNV GL © 2014
 92 Semi-Subs classed by DNV GL
 50 units built for UK, Canada and Norway
 38 units plus/minus 2 meter still water air gap relative to COSL Innovator
DNV GL cannot isolate the risk posed by horizontal wave
loads to the GM4000 design only.
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DNV GL © 2014
OTG
13/14
OTG
13/14
DRAFT
1
DRAFT
Industry
input
JUNE
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DNV GL © 2014
Technical
Seminar
OTG
13/14
Rules
2018
FINAL
HEARING
2
SEPT
DEC 1st
JANUARY
Possible Effect on Existing Units
Air Gap Assessment
(OTG13 or model test)
Positive
Negative
Wave Load Assessment
No actions
(OTG14 or model test)
Sufficient
strength
•
•
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DNV GL © 2014
Insufficient
strength
Remove
windows
•
Reinforcement
•
Restricted services
HAZID
•
HAZID
Possible Effect on Existing Units – 2016/17/18
Air Gap Assessment
(OTG13 or model test)
Positive
Negative
Remove
Wave• Load
Assessment
weak
(OTG14points
or model test)
No actions
Sufficient
strength
•
•
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DNV GL © 2014
Remove
windows
HAZID
Insufficient
strength
•
Reinforcement
•
Restricted services
•
HAZID
DNVGL - OS - C103
Offshore Technology Guideline (OTG):
OTG 13: Air gap
OTG 14: Wave Slamming Loads
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DNV GL © 2014
Air Gap Practise – Oil & Gas versus Maritime Safety Regime
•
Oil & Gas Safety Regime
Negative air gap avoided
by philosophy for fixed
installations.
•
Maritime Safety Regime
Negative air gap utilized
in the MOU and industry
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DNV GL © 2014
Status
Out of 35 units operating in Norway, UK and Canada:
 9 units permanent approval
 18 units temporary approval
 5 older and large units with signifcant static air gap
 1 unit has removed windows but not completed the formal documentation
process
 2 units docked
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DNV GL © 2014
Status
DNVGL has approved 27 units based on new documentation
Approval
Number of
units
Basis
Permanent
4 units
Model test
•
•
Blinded windows
Reinforcements
5 units
OTG-13
•
Positive airgap
2 units
Model test
•
•
Blinded windows
Reinforcemen
•
Positive air gap
•
•
•
Blinded windows
Reinforcements
Operational restrictions
Temporary
2 units
14 units
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DNV GL © 2014
OTG-13
Hva med resten (8 stk)
 5 eldre og «store» rigger med betydelig statisk airgap (mulig positivt airgap eller
moderate overskridelser)
 1 stk har lukket vinduer men har ikke formelt avsluttet dokumentasjon
 2 stk ligger ved kai
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DNV GL © 2014
Videre arbeid og oppfølging
 All units need permanent approval before winter 2019
 Stacked units needs documentation before remobilization
 OTG-13/OTG-14 will be further refined through WaDeck JIP
– Reduce conservatism
– Establish simplified methods for slamming load estimations
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DNV GL © 2014
[email protected]
www.dnvgl.com
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DNV GL © 2014