ocd subsea technology--- - offshoreenergy.dk · agenda introduction rambøll subsea in the danish...

OCD Subsea Technology---December 5th 2005

A Designers Perspective

Rambøll

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 [email protected]


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)

…


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)


Below the surface…

Pipelines…

Pipeline ’components’

Valve

PLET

Wye

Loading Systems (SAL)

Protection structures/covers

Subsea wells



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


Stine – Segment-1 (DONG)


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


Other subsea installations

SAL Loading systems

Siri (DONG)

South Arne (Hess)


Other subsea installations

Protection Structures

Valve Stations

Wye

Subsea tie-in


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


Design issues – Danish subsea

Scour development

Foundation

Installation (Shallow water)

Trawl gear interference


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


Scour Development

© A. Roulund

Global + Local scouris a design case

Consider ’scour repair’ to ’scour prevention’

Avoid accelerated flow field


Foundation

Large trawl hooking loads (1 MN/100 tonnes)

Scour (around large gravity/suction buckets)

Manageable water depths

Piled structures have been dominating


Installation

Manageable depth

Diver assisted tie-in has dominated (HSE)

Installation by DSV (< 100 Tonnes)

Jack-up (Regnar)


Resulting Structures

Inclined to reject trawl gear

Sturdy Structure

Piled (Funnels removed after driving)

Components hung from above to minimiseacceleration of seabed flow


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)…”


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


Tyrihans



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


Tyrihans (Production Riser)

Kristin

Åsgard B



Power CableA

Umbilical

ÅsgardTransport

B

C

D

W

Tyrihans South

Tyrihans North

42”

Åag

ard

Tra

nsp

ort


Tyrihans (Injection Riser)

Kristin

Åsgard B



Power CableA

Umbilical

ÅsgardTransport

B

C

D

W

Tyrihans South

Tyrihans North

42”

Åag

ard

Tra

nsp

ort


Tyrihans (In-line tees)

Kristin

Åsgard B



Power CableA

Umbilical

ÅsgardTransport

B

C

D

W

Tyrihans South

Tyrihans North

42”

Åag

ard

Tra

nsp

ort

Protection covers



Tyrihans (Hottap tees)

Kristin

Åsgard B



Power CableA

Umbilical

ÅsgardTransport

B

C

D

W

Tyrihans South

Tyrihans North

42”

Åag

ard

Tra

nsp

ort


Tyrihans (Spools)

Kristin

Åsgard B



Power CableA

Umbilical

ÅsgardTransport

B

C

D

W

Tyrihans South

Tyrihans North

42”

Åag

ard

Tra

nsp

ort

Tyrihans - Lateral buckling of pipline


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


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)


END OF PRESENTATION


ocd subsea technology--- - offshoreenergy.dk · agenda introduction rambøll subsea in the danish...

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