Low Cost Field Development using Hybrid Risers - 2H Offshore · 2020. 5. 21. · between 1986-1999...

OPT 2016 – February 23 & 25, 2016

Advances in Riser & Flexibles Design and Technology Seminar

1

Low Cost Field Development using Hybrid Risers

Prahlad Enuganti Technical Manager

2H Offshore Engineering Ltd., Aberdeen

Learn more at www.2hoffshore.com

OPT 2016 – February 23 & 25, 2016


Typical Field Development Options

Fixed Structure Shallow Water Platform Wells

Floating Production Storage and Offloading (FPSO’s)

Flexible Catenary Risers (FCRs) Modified Steel Catenary Risers (SCRs) Free Standing Hybrid Risers (FSHRs)

Other Floating Production Facilities (Semi-submersibles & Spars)

FCRs SCRs Top Tensioned Risers (TTRs)

Tension Legged Platform (TLP)

TTRs SCRs

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OPT 2016 – February 23 & 25, 2016


Proposed Alternatives

Current drilling rig market is oversaturated – Purchase at low cost compared to new build FPU Free Standing Hybrid risers are installed from the MODUs

Option A

MODU repurposed as FPU to be either minimal or full processing facility Fluid processed at MODU before export to shallow water facility Any future drilling, intervention can be done by a different MODU

Option B

MODU used for pre-drilling wells, FSHR installation Production fluids offloaded to FPSO MODU remains at field to drill future wells, install future risers, intervene on existing wells Solution for fields that would otherwise need a substantial production and drilling host (PDQ)

Long lead-time and expensive TLP/FPU can be avoided Heavy construction vessel can be avoided

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OPT 2016 – February 23 & 25, 2016


Free Standing Hybrid Risers –

Key Components

Buoyancy

Tank

Buoyancy

Tank

Connection

Upper Riser

Assembly

Steel

Linepipe(s)

Flexible

Jumper(s) to

Vessel

Lower

Riser

Assembly Base

Spool(s)

Foundation


OPT 2016 – February 23 & 25, 2016


Free Standing Hybrid Riser Advantages

Design decouples riser from vessel 1st order motions Not highly sensitive to environmental loading Good fatigue performance (F class weld offshore)

Low vessel payload

Pre-installable ahead of production host vessel

Flow assurance flexibility

Large insulation thicknesses Pipe-in-Pipe Can use corrosion resistant alloy lined pipe

Installation flexibility pre or post laying of subsea flowlines and pipelines

Lower the cost ($60MM to $25MM per installed riser) by installing from

the MODU drilling on the field


OPT 2016 – February 23 & 25, 2016


FSHRs – To Date

Type Field Status Owner/Field

Operator Yr.

Installed Region

Water Depth Vessel

(ft) (m)

Bu

nd

le

Green Canyon 29/Garden Banks 388

De-commissioned Placid Oil Company/Ensearch

1988/1994 GoM 1,529/2,096 466/639 Semi-Submersible

Girassol Operating Total Elf 2001 Angola 4,430 1,350 Spread Moored FPSO

Rosa Operating Total Elf 2007 Angola 4,430 1,350 Spread Moored FPSO

BP Greater Plutonio Operating BP 2007 Angola 4,300 1,311 Spread Moored FPSO

Sin

gle

Lin

e Kizomba A & B Operating Exxon 2004/2005 Angola 3,330 to 4,200 1,006 to 1,280

Spread Moored FPSO

Block 31 NE Operating BP 2012 Angola 6,890 2,100 Turret Moored FPSO

P-52 Operating Petrobras 2007 Campos Basin 5,906 1,800 Semi-Submersible

Macondo De-commissioned BP 2010 GoM 5,000 1,515 DP FPSO

Cascade/Chinook Operating Petrobras 2010 GoM 8,531 2,600 Turret Moored FPSO

Block 32 Construction phase Total TBC Angola 4675 - 6315 1425 - 1925 Turret Moored FPSO


OPT 2016 – February 23 & 25, 2016


Potential Applications

Deep water field developments

Remote locations

Marginal fields

But really, can be considered for most applications!

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OPT 2016 – February 23 & 25, 2016


Worldwide Rig Count (Ref: IHS)


OPT 2016 – February 23 & 25, 2016


Option A – MODU Repurposed as FPU

Convert a drilling semi to a production host to reduce CAPEX

Improve schedule to first oil

Use FSHRs from subsea wells for production/injection and a FSHR for export


OPT 2016 – February 23 & 25, 2016


Vessel Field Startup Region Water Depth (m)

Argyll FPU Argyll Oil Field 1975 UK North Sea 150Buchan A Buchan oil field 1981 UK North Sea 160P-09 Corvina Oil Field 1983 Brazil 230P-15 Pirauna 1983 Brazil 243

P-12 Linguado / Badejo Oil Field 1984 Brazil 100

P-21 Badejo / Salema Oil Fields

1984 Brazil 112

Deepsea Pioneer FPU Argyll & Duncan Oil Fields 1984 UK North Sea 150

P-22 Morela 1986 Brazil 114P-07 Bicudo Oil Field 1988 Brazil 207Veslefrikk B Veslefrikk Oil Field 1989 Norwegian Sea 175

AH001 Ivan Hoe Rob Roy Oil Field

1989 UK North Sea 140

P-20 Marlim 1992 Brazil 625P-08 Marimba Oil Field 1993 Brazil 423

P-13 Bijupira / Salema Oil Field 1993 Brazil 625

P-14 Coral / Esrela / Caravela Oil Fields

1993 Brazil 195

Nan Hai Tiao Zhan Luihua 1995 South China Sea 300P-25 Albacora II Oil Field 1996 Brazil 252P-27 Voador 1996 Brazil 533Tahara PY-3 1997 Indian Ocean 339P-19 Marlim 1997 Brazil 770Janice A Janice Oil Field 1999 UK North Sea 80P-36 Roncador 2000 Brazil 1360SS-11 Coral 2003 Brazil 145P-40 Marlim Sul 2004 Brazil 1080ATP Innovator Gomez Oil Field 2006 Gulf of Mexico 914

Northern Producer FPF

Originally Galley Oil Field now at Don Oil Field

2009 UK North Sea 350

Option A – Historical Precedent

15 conversions were carried out in last major oil downturn between 1986-1999

Mostly semi-submersibles

Water depths < 1000m

Subsea developments using flexible risers

Ref: Deegan, Loffman, Odufuwa, “The conversion of Mobile Offshore Drilling Units to Floating Production System – Issues, Opportunities and Challenges”, DOT 2014


OPT 2016 – February 23 & 25, 2016


A larger % of future developments will be in very deep and ultra deepwater (5,000ft +)


OPT 2016 – February 23 & 25, 2016


Riser Selection for DW and UDW Applications

Flexibles > 5000ft WD have several challenges Needs heavy construction vessel for installation Large payload FPU Temperature limit of ~130oC Limit on diameter Expensive

Use of freestanding risers instead of flexibles

Field proven compliant hybrid steel/flexible riser

system suitable for high motion vessel

Low riser payload to allow more for processing and/or drilling equipment


OPT 2016 – February 23 & 25, 2016


Option B - Permanent Moored Drilling Semi with FPSO

Drilling semi would have the same functionality as a TLP:

Permanent installation over field life (requiring permanent mooring system and offshore inspection)

Drill grass root wells

Workover / intervene on existing wells to maximum reservoir recoverability of the field life

Install production risers to avoid use of a costly heavy lift installation vessel

Subsea tree and riser configuration are designed to accommodate the following constraints:

The motions of the drilling semi do not allow for dry trees risers so a system of subsea trees and a compliant production riser system is needed

The use of a freestanding production riser and the transfer of production fluid to the FPSO minimizes additional payload and allows the drilling rig to be maintained


OPT 2016 – February 23 & 25, 2016


Deepwater W Africa and Asia solution

Alternate to new build TLWP with drilling rig

Produce through subsea trees located under drilling vessel to enable through life drilling/workover access to maximise recovery

Offloads to leased FPSO providing overall low CAPEX solution

Freestanding riser in deepwater for fluid transfer to FPSO


OPT 2016 – February 23 & 25, 2016


Liuhua Field Development

300m water depth

South China Sea

Ref: Hall, Sheng, Krenek, Douglas, Macfarlane, “Liuhua 11-1 Development – Subsea Production System Overview”, OTC 1996, Paper 8175


OPT 2016 – February 23 & 25, 2016


Preliminary Schedule Comparison 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

X

X

X

FSHR Installation (1 off)

Install flexibles and umbilicals (w flex

lay vessel)First oil (with 3 wells)

1st Batch 3 off Subsea Trees Delivery

(w manifold, well jumpers and 1st Batch 1 off Riser Delivery (w

surface and seabed jumpers)Mooring Pre Installation

Semi Installation

Drilling and completion from Semi (3

wells)

Integrated Rig With TLP

FEED

Sanction & Detailed Design

Puchase semi and conversion (w

permanent moorings)

Semi-submersible with FSHR

Tendon Installation

TLP Installation & Commissioning

(Ready to drill or complete)First completion and first oil (1 well)

Producing (3 wells)

MODU Drilling (Batch set conductors

and drill 4 wells)

FEED - 20 Slot TLP


TLP Construction & Integration

TLP Tendon Fabircation

1st Batch Riser Delivery (3 production

and 1 drilling)

Year 1 Year 2 Year 3 Year 4 Year 5


OPT 2016 – February 23 & 25, 2016


Preliminary CAPEX Comparison

Costing Assumptions West Africa

Day rate Mob/Demob

J-lay vessel $500,000 $3,500,000

Flex-lay MSV $250,000 $5,000,000

5th Gen MODU $250,000 $2,000,000

Crane Barge $175,000 $3,000,000

ROV survey vessel $150,000 $2,000,000

Anchor Handler $75,000 $500,000

Field Support Vessel $50,000 $500,000

Note: costs do not include day rate for drilling crew and consumables

$417,250,000Total

Mooring Pre Installation

Semi Installation

Drilling and completion from Semi (3 wells)

FSHR Installation (1 off)

Install flexibles and umbilicals (w flex lay vessel)

First oil (with 3 wells)

FEED

$35,000,000

$290,000,000

$35,500,000

Semi-submersible with FSHR


Puchase semi and conversion (w permanent

moorings)1st Batch 3 off Subsea Trees Delivery (w manifold,

well jumpers and umbilical)1st Batch 1 off Riser Delivery (w surface and seabed

jumpers)$25,000,000

$5,250,000

$6,500,000

$12,500,000

$7,500,000

$1,377,250,000

Integrated Rig With TLP

TLP Installation & Commissioning (Ready to drill or

complete)

First completion and first oil (1 well)

Producing (3 wells)

MODU Drilling (Batch set conductors and drill 4 wells)

FEED - 20 Slot TLP


TLP Construction & Integration

TLP Tendon Fabrication

1st Batch Riser Delivery (3 production and 1 drilling)

Tendon Installation

$90,000,000

$1,000,000,000

$90,000,000

$40,000,000

$25,000,000

$39,000,000

$93,250,000

Total


OPT 2016 – February 23 & 25, 2016


Option B - Key Advantages over TLP/Spar

Significant CAPEX saving - up to 50% vs. TLWP/Spar

Faster schedule to first oil by one year or more

Lower installation RISKEX compared with TLP and Spar installations

Maintain life of field workover capability for maximum reservoir recoverability

Conventional subsea recoverability lower than dry tree fields based on long term North Sea and Norway offshore experience

Similar advantage provided by TLP, Spar or FDPSO vessels

Manage reservoir uncertainty

Maximum end of life well count is not a driver for drilling vessel selection

Can initially be an early production system

Subsea architecture is organically expandable using the drilling vessel and a MSV to install more trees, risers, flowlines and jumpers

Vessel and riser system can be readily retrieved and relocated


OPT 2016 – February 23 & 25, 2016


FSHR Rig Installation…..1


OPT 2016 – February 23 & 25, 2016




OPT 2016 – February 23 & 25, 2016


MODU Conversion Considerations

Study of candidate vessel semi vs. drill ships W Africa swells, heave response, vessel heading older vs. newer generation vessels

Establish production characteristics, riser payload range and export options Mooring design configuration and loads - global performance analysis Retrofit mooring structural design Structural and fatigue analysis for long term permanently moored service Weight control and damage stability Corrosion and fatigue survey and assessment Any remedial structural work at dry dock Long term offshore inspection and maintenance requirements Level and stage of processing required (if any) Chemical injection storage Deck space allocation for drilling and production equipment Riser hang-off structures Change in vessel designation under class rules


OPT 2016 – February 23 & 25, 2016


Summary

Surplus rigs in the drilling market is an opportunity to reduce CAPEX by up to 50% and time to first oil by one year compared to an equivalent TLWP

There have been many drilling rig conversions over the last 35 years, mostly to production platforms, except for Luihua which is a drilling and WO semi in 300m water depth moored over a cluster of subsea trees

Subsea trees and freestanding risers enable a MODU to be repurposed as a permanent moored drilling and workover vessel for deepwater

Arrangement provides expansion flexibility to minimize upfront CAPEX and protect against reservoir uncertainty

Risers and vessels can be retrieved and relocated

The drilling vessel and a light construction vessel can be used to install the freestanding risers to avoid the use of an expensive heavy lift installation vessel


Low Cost Field Development using Hybrid Risers - 2H Offshore · 2020. 5. 21. · between 1986-1999...

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