Positioning Solitaire From surface to seabed

Positioning Solitaire
From surface to seabed
By Marco Kwanten
Hydrographic Society Benelux
Wednesday, 14 October 15
Allseas fleet
Solitaire
Audacia
Lorelay
Tog Mor
Calamity Jane
Pioneering Spirit
Solitaire is the world’s largest pipelayer
5 Boeing 747-400s
Solitaire specification
Length (incl. stinger)
Length (excl. stinger)
Breadth
Stinger length
Minimum radius
Installed power
Maximum speed
Tension capacity
Pipe diameters
Pipe storage
Multi-purpose crane
Accommodation
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397 m
300 m
41 m
140 m
120 m
51,500 kW
13.5 knots
1050 t
2” to 60’’
22,000 t
300 t
420 persons
(1302 ft)
(984 ft)
(135 ft)
(459 ft)
(394 ft)
(69,063 hp)
(2315 kips)
(661 kips)
Tasked to lay pipe from A to B
From beach to fork
From subsea target box to target box
Avoiding ‘danger’ areas
Laying through tiny corridors
Crossing rock berms
Lay around pre-installed counteracts
Displacement initiator
Buckle initiators
Lay inside lay corridor
Requirements
• Hardware
• Software
• Human touch
GNSS antenna locations
Stinger cantilever
Main mast
Gantry mast
Main mast and gantry mast
Two sets of 2x GNSS receivers with:
• 2x L-band corrections (each)
• 1x GNSS antenna (each)
• Input from one of the 2 Inmarsat domes
• QC computer
• NTRIP corrections (Network Transport of RTCM
data over IP)
GNSS setup
Heading
During unguided lay, heading is very important. With a layback of 600 m in shallow waters,
0.4° heading difference (Octans precision of 0.1° seclat at 1σ translated to 60°N at 2σ)
amounts to a 4.2 m difference on the seabed.
In deeper waters the layback may increase to several kilometres, but next to heading, the
current starts playing a role. Corridors are usually wider in deeper waters.
On pipeline
heading
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PPP heading shows 0.1° difference, roll induced as
height difference between antennas is 15 m
LD7 heading is noisier that Octans heading
PPP heading is noisier than LD7 heading
Octans units do not seem to drift >0.05° from LD7
In a curve
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PPP heading shows -0.2° difference, roll induced as
height difference between antennas is 15 m
LD7 heading is noisier that Octans heading
PPP heading is noisier than LD7
All 3 Octans units have different drift, but well
within their specs within this period
Stinger tip monitoring
ROV from support vessel
ROV on board Solitaire
Layback
Layback is calculated from the bead stall to touchdown and is
dependent on lay vessel tension:
•Pipe parameters (wall thickness, coating, steel grade etc.)
•Stinger settings (radius, departure angle)
•Client/DNV criteria
•Depth
•Dynamics (shifting TD point)
Varies from ~400 m to 3500 m
Online display
Helmsman display
ROV over pre-lay during touchdown monitoring
Polarled animation
Questions?