Gemini – Offshore Wind Farm - Geo-Informatie Nederland · PDF file1 Gemini –...
Transcript of Gemini – Offshore Wind Farm - Geo-Informatie Nederland · PDF file1 Gemini –...
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Gemini Gemini –– Offshore Wind FarmOffshore Wind Farm
Positioning beyond the horizonPositioning beyond the horizon
Dredging and Marine Contractors
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Company profile
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Leading international contractor
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Large state of the art fleet
Introduction
Dredging and Marine Contractors
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Company profile
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Leading international contractor
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Specializing in:
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Dredging
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Offshore oil & gas
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Offshore wind
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Innovative partner for clients
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Dutch-based, independent family business
Introduction
Dredging and Marine Contractors
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Wim Kanneworff
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Hydrographic Surveyor
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28 years with Van Oord
2009–2010 - ADCOP (Habshan Fujairah Pipeline & SPM) project
2011 - Arkutun-Dagi Pipelines project
2012 - Arkutun-Dagi GBS Installation project
2013 - SWPL Stingray
2014-2016 - Gemini Offshore Wind Farm
Dredging and Marine Contractors
Introduction
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Gemini Offshore Wind Farm
Gemini Offshore Wind Farm
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Geodetic Parameters
Offshore
•UTM Zone 31 North
•European Terrestial Reference System 1989
•Lowest Astronomical Tide
Dredging and Marine Contractors
Employer Requirements
Installation Tolerances
Monopile / Transition Piece
•XY –
3 m. radius
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After Scour Protection Installation –
1 m. radius
•Z –
0.25 m.
•Verticality –
0.25°
( Deviation ≈
4.3 cm in 10 m.)
•Orientation -
±
5°
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Surface Positioning
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Accurate X, Y and Z
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Real Time
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Low cost / economic
Dredging and Marine Contractors
Construction requirements
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Surface Positioning
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Accurate X, Y and Z
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Real Time
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Low cost / economic
Dredging and Marine Contractors
Construction requirements
Surface Positioning
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RTK-GNSS
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Virtual Reference Station
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Trimble SPS GNSS receivers using vessel internet connection
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Construction requirements
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Construction requirements
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Construction requirements
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Construction requirements
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Network extension
January 2014 –
Join Gemini project, start survey preparations
February 2014 –
Start of communications with GDF Suez, NAM and SAPOS
April 2014 –
Schiermonnikoog (NAM) signal on-line
April 2014 –
Start of Hydrographic survey as part of UXO (Unexploded ordnance) survey campaign, Multibeam Echosounder data is processed using PREMO
14 May 2014 –
Financial Close Gemini project
June 2014 –
Start UXO survey campaign
10 June 2014 –
Fino-1 (SAPOS) signal on-line
August 2014 –
After several meetings with GDF Suez on permission, equipment location and installation details, GNSS reference station is installed on G17d-A (GDF Suez) and on-line
6 November 2014 –
Interference is experienced
December 2014 –
New Trimble antenna (TRM GA830) is installed, no more interference
Dredging and Marine Contractors
Timeline
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Users Offshore
3D Positioning using 06-GPS VRS corrections via NTRIP
•Geo Focus
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Positioning XYZ for MBE survey and ROV Video and ROV TSS
•Aeolus / Pacific Osprey
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Positioning XY for jacking up and monopile positioning
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Positioning Z for establishment of Transition Piece final level
•Nexus / HAM602
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Positioning XYZ for Cable Lay, MBE survey and ROV
•Jan Steen
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Positioning XYZ for MBE survey and Trencher
Dredging and Marine Contractors
VRS operational
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Survey Vessel Geo Focus
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MB survey of Gemini Offshore Wind Farm
ZeeEnergie –
47.5 km--²
BuitenGaats –
48.4 km²
Export Cables to Wester Eems –
23.6 km²
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Checks and controls
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Position Check Objects
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Placed in BuitenGaats and ZeeEnergie
Regular checks by:
Survey vessel
Flexible fall pipe vessel (ROV-MBE)
Cable lay vessel (MBE)
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VRS Location
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BPQ (Base Position Quality) message
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distance to virtual base
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Local Reference Station(s)
Installed on MP R1 (BG) and D3 (ZE),
operational since 13th
August
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Quality Control
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BuitenGaats Position Check object
A bundle of chain was left on top of the block, after removal of the chain, the depth changed
Dredging and Marine Contractors
Quality Control
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ZeeEnegie Position Check object
During April 2015, the depth changed significantly. Erosion ?
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Quality Control
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Dynamic mode vs Static mode
Aeolus measurements while jacked up
Dredging and Marine Contractors
GNSS mode Comparison
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Base station on TP
In July 2015 two local reference stations were installed
Base positions were calculated by 06-GPS from logged raw data
Stations run on batteries charged by solar panels
Dredging and Marine Contractors
Installation of Local Reference station
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VRS to Local Base
Static comparison Trimble/Hydrins + VRS to Trimble/Hydrins + Local base station
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Aeolus comparison
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VRS to Local Base
Dynamic comparison POS MV + VRS to Trimble + Hydrins + Local base station
Dredging and Marine Contractors
Geo Focus comparison
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Verticality monitoring during installation
Monitoring –
IHC PIME, Fugro InclinoCam and Leica Total Stations
As-Built verticality –
Level instrument measurements inside the ATPIA
As-Built flange level –
Total Station measurement from calculated offset point
Dredging and Marine Contractors
MP-TP installation
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Positioning for Gemini Offshore Wind Farm
The 06-GPS network extension has proven successful
Accuracy / repeatability as expected (in X,Y and Z)
Real time, stop survey is start data processing
Use of Van Oord of the shelf equipment and vessel IT infrastructure
Reliable service, no downtime due to outage
Lessons learned
Network extension —› Start well in advance of the works
Involve IT to break down the firewalls on the vessel side
Install a local reference station as back-up as soon as it is possible
A local reference station will provide a more stable position in the OWF
Dredging and Marine Contractors
Conclusions
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Score board
Export Cables
200 km installed and buried (95%)
Monopiles
and Transition Pieces
146 out of 150 installed
OHVS ZE, OHVS BG and LHVS
Installed, commissioning in progress
Inter Array Cables
70 Laid, 58 buried
Surveys executed
2000 +
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Gemini Offshore Wind Farm construction status
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??
Dredging and Marine Contractors