Post on 18-Apr-2018
Agenda
Introduction
Rambøll
Subsea in the Danish North Sea
‘Danish Subsea’
Example project
Trends in subsea
OCD Subsea Conference 2SlideDecember 5, 2005
Introduction
Henrik Juhl
M.Sc (Civ. Ing.)
Rambøll Oil/Gas
Head Dept. for pipelines and subsea
Phone +45 4598 8772
Fax +45 4598 8624
E-mail hrh@ramboll.dk
OCD Subsea Conference 3SlideDecember 5, 2005
Rambøll Oil/Gas
Part of the Rambøll Group.
Nordic based consulting and Engineering House
More than 4000 employees
90 offices spread in 15 countries
400+ professionals within Oil/Gas
Esbjerg (DK)
Copenhagen (DK)
Doha (Qatar)
Stavanger (N)
Sandefjord (N)
…
OCD Subsea Conference 4SlideDecember 5, 2005
Scene - Danish North Sea
35-70 meters of water depth
Wave and current conditions35 m/s wind (50 yr)21 m Hmax wave heightBreaking waves1 m/s maximum currentSeabed sediments: Sand + Silty clay (Mobility)
OCD Subsea Conference 5SlideDecember 5, 2005
Below the surface…
Pipelines…
Pipeline ’components’
Valve
PLET
Wye
Loading Systems (SAL)
Protection structures/covers
Subsea wells
OCD Subsea Conference 6SlideDecember 5, 2005
OCD Subsea Conference 7SlideDecember 5, 2005
A closer look (Subsea wells)
Stine x 2 (2004, DONG)
Regnar (1993, MOG)
Regnar (Mærsk Oil & Gas)
Marginal field(Expected 3.3 Mill Barrels of oil)
45 m of water
Installed 1993
13 km tie-back to Dan FA
Single well
OCD Subsea Conference 8SlideDecember 5, 2005
Stine – Segment-1 (DONG)
© EPM Consultants
Installed May 2004
60 m of water depth
1 production template + 1 water injection template + 1 PLET
9 km tie-back to Siri platform
© EPM Consultants
OCD Subsea Conference 10SlideDecember 5, 2005
Other subsea installations
SAL Loading systems
Siri (DONG)
South Arne (Hess)
OCD Subsea Conference 11SlideDecember 5, 2005
Other subsea installations
Protection Structures
Valve Stations
Wye
Subsea tie-in
OCD Subsea Conference 12SlideDecember 5, 2005
OCD Subsea Conference 13SlideDecember 5, 2005© Statoil
Characteristics of a subsea well…
Typically consist of:X-mas tree(s)ManifoldValve(s)Control Gear/Instrumentation
No process facilities
Tie-back to field center
Remote operation
Compact lay-outReduced well spacingSmall overall
© MOG
Optimum solution…
2Nos. Wells
Subsea Platform
’Co
st’
CAPEX: Low, OPEX: ’High’ CAPEX: High, OPEX: Low
OCD Subsea Conference 14SlideDecember 5, 2005
Design issues – Danish subsea
Scour development
Foundation
Installation (Shallow water)
Trawl gear interference
OCD Subsea Conference 15SlideDecember 5, 2005
Trawl Interference
Otter trawl
Beam trawl
Clump weight
100 kN
125 kN
150 kN
175 kN
200 kN
225 kN
250 kN
275 kN
300 kN
50 m 100 m 150 m 200 m 250 m 300 m 350 m 400 m
290 kN @ 50 m
119 kN @ 300 m
OCD Subsea Conference 16SlideDecember 5, 2005
Scour Development
© A. Roulund
Global + Local scouris a design case
Consider ’scour repair’ to ’scour prevention’
Avoid accelerated flow field
OCD Subsea Conference 17SlideDecember 5, 2005
Foundation
Large trawl hooking loads (1 MN/100 tonnes)
Scour (around large gravity/suction buckets)
Manageable water depths
Piled structures have been dominating
OCD Subsea Conference 18SlideDecember 5, 2005
Installation
Manageable depth
Diver assisted tie-in has dominated (HSE)
Installation by DSV (< 100 Tonnes)
Jack-up (Regnar)
OCD Subsea Conference 19SlideDecember 5, 2005
Resulting Structures
Inclined to reject trawl gear
Sturdy Structure
Piled (Funnels removed after driving)
Components hung from above to minimiseacceleration of seabed flow
OCD Subsea Conference 20SlideDecember 5, 2005
Future DK
”Vurdering af Virkningen på Miljøet fra yderligere Brønde” Juli 2005, MOG (EIA Additional Wells, July 2005)
Adda (38 m)
Alma (43 m)
Boje (app. 40 m)
Elly (40 m)
Freja (70 m)
Halfdan development (43 m)
”… installation of new wellhead platforms (STAR) or subseawellheads (Regnar type)…”
OCD Subsea Conference 21SlideDecember 5, 2005
Example project
Statoil – Tyrihans
Discovered 1983/84
Oil/Gas proven by appraisal in 2002
PUD delivered 2005-07-11
ScheduleRambøll pre-engineering of pipelines 2004-05Rambøll awarded design contract July 2005 - Pipelines + StructuresFollow-on 2008On stream 2009
Estimated CAPEX 14 bill. NOK
Estimated reserves182 mill. barresl oil/Condensate35 Bill. m³ gas
OCD Subsea Conference 22SlideDecember 5, 2005
OCD Subsea Conference 24SlideDecember 5, 2005
Tyrihans
Kristin
Åsgard B
10” Gas InjectionLine
3” MEG/Umbilical16”/18” Production
Power CableA
Umbilical
ÅsgardTransport
B
C
D
W
Tyrihans South
Tyrihans North
42”
Åag
ard
Tra
nsp
ort
300 m water depth
HPHT Pipelines
Uneven Seabed
Soft/Stiff clay
Rambøll Detail design (July 05)
Pipelines
Pipeline structures
OCD Subsea Conference 25SlideDecember 5, 2005
Tyrihans (Production Riser)
Kristin
Åsgard B
10” Gas InjectionLine
3” MEG/Umbilical16”/18” Production
Power CableA
Umbilical
ÅsgardTransport
B
C
D
W
Tyrihans South
Tyrihans North
42”
Åag
ard
Tra
nsp
ort
OCD Subsea Conference 26SlideDecember 5, 2005
Tyrihans (Injection Riser)
Kristin
Åsgard B
10” Gas InjectionLine
3” MEG/Umbilical16”/18” Production
Power CableA
Umbilical
ÅsgardTransport
B
C
D
W
Tyrihans South
Tyrihans North
42”
Åag
ard
Tra
nsp
ort
OCD Subsea Conference 27SlideDecember 5, 2005
Tyrihans (In-line tees)
Kristin
Åsgard B
10” Gas InjectionLine
3” MEG/Umbilical16”/18” Production
Power CableA
Umbilical
ÅsgardTransport
B
C
D
W
Tyrihans South
Tyrihans North
42”
Åag
ard
Tra
nsp
ort
OCD Subsea Conference 29SlideDecember 5, 2005
Tyrihans (Hottap tees)
Kristin
Åsgard B
10” Gas InjectionLine
3” MEG/Umbilical16”/18” Production
Power CableA
Umbilical
ÅsgardTransport
B
C
D
W
Tyrihans South
Tyrihans North
42”
Åag
ard
Tra
nsp
ort
OCD Subsea Conference 30SlideDecember 5, 2005
Tyrihans (Spools)
Kristin
Åsgard B
10” Gas InjectionLine
3” MEG/Umbilical16”/18” Production
Power CableA
Umbilical
ÅsgardTransport
B
C
D
W
Tyrihans South
Tyrihans North
42”
Åag
ard
Tra
nsp
ort
Trends in subsea production
Increased length of tie-back (Ormen Lange 120 km)
Advanced production/depletion philosophy (Improved recovery)Flow assurance (e.g. Isolation/Electrical Heating)HPHT fields are ’produceable’
MaterialsPipeline buckling
Coordination design/fabrication/installationComponent based (Designer = Fabricator)
Tie-ins (Hot taping)To ’prepared’ systems/locations
To existing systems
OCD Subsea Conference 32SlideDecember 5, 2005
Conclusion…
Challenges remain…and always will!Deeper watersLonger Tie-backsMaterials and technology
More subsea – in generalSpare capacity in ’field centers’Deeper/more hostile waters’Marginal fields’ less marginal (Oil/Gas prices)
More subsea - in DK watersSingle/Double wells
More ‘Danish Subsea’ - in Norwegian watersSouthern North Sea (Shallow water)
OCD Subsea Conference 33SlideDecember 5, 2005