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TRANSCRIPT
Reeled Installation of EHTF
Electrically Heat Traced Pipe-in-Pipe
J. Mair Subsea7S. Vernageau ITP InTerPipeC. Geertsen ITP InTerPipe
2Page 6-Oct-11
Presentation content
• Subsea 7 Pipe-in-Pipe program
• Why trace Pipe-in-Pipe?
• ITP Electrically Heat Traced Pipe-in-Pipe
• Reeled Installation of an ITP Electrically Heat Traced PiP
• Tests, analysis and certificate
• Conclusions
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Subsea 7 & ITP – PIP Program
• Subsea 7 has an extensive track record in the construction and installation of pipelines in Bundles, REEL Lay, S. Lay and J. Lay.
• In order to qualify pipe-in-pipe technology for its REEL LAY vessels, Subsea 7 started an intensive investigation of possible solutions early 2005.
• ITP’s Pipe in Pipe was selected as the most efficient technology overall.
• Further development with ITP was conducted under the impetus of Total to qualify the option of trace heating.
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Phase 1 – Mechanical Trials
• Establish:
– Centraliser Effects
– Flowline residual curvature
• Data recorded for input to model
– Deformations during bending
– Stresses & strains
– Potential for crushing insulation
• Calibrate analysis tools
• Confirm acceptable behaviour & preferred product arrangement
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Phase 2 – Thermal tests
Measuring OHTC (Overall Heat Transfer Coefficient) for PiP applications
Measure and record OHTC empirically for CFD model input
• Validate insulation materials available i.e. K values
• Measure and record Thermal performance post reeling
• Generate and calibrate a CFD model
CFD vs. Test Cooldown
0
10
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30
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60
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100
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00
Time (Hours)
Tem
pera
ture
s (°
C)
Test (Pre bending)CFD
CFD COOLDOWN:T = 95.659e-0.0401t
(Valid only in range T = 50°C to T = 95°C)
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Cooldown 3 times longer for similar cost in same cross-section
Post Bending Cooldown Test Results
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Enhanced Thermal Performance PIP
ITP PiP : the most energy efficient system in the most compact configuration
Continuous annulusIzoflex acts as a continuous spacer supporting reeling loads
Flowline
Sleeve Pipe
Thermal loss at spacers (30 to 50W/spacer)
Insulation material less efficient than Izoflex
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DnV Qualification
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Time
WAT; HAT
T°C
Shutdown
Why trace Pipe-in-Pipe ?
• The market driver:– Longer reach
– Lower cost of development (single line tie-back)
– More satellite developments to existing facilities
– More difficult oils (wax, etc)
• Traced Pipe-in-Pipe is the solution for:– Preventative action during operation (Low flow rate, Varied effluent
composition, Longer shutdown)
– Restart capacity (After long shutdown and wax melt out)
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ITP Electrically Heat Traced Pipe-in-Pipe
• Combines Thermal performance of PiP design with Electrical heating
• High thermal performance = low power requirement(Elect power drawn = heat losses)
• Advantages for the Operator– Lower CAPEX and OPEX (Low consumption)
– More flexible in operation
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EHTF – main features
• Joule heating (resistive effect) P = RI²
• High thermal performances U-Value = < 0.5 W/m²K
• Low power 3 to 10 W/m (1 to 3 W/ft)
• Electricals:
– Low voltage less than 1KV required
– Current type AC – 3-phase
– Power factor ~1
– Distance Unlimited20-50km/power inlet
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Construction & Installation
• EHTF PiP are assembled in stalks, welded together and reeled
• The final installation is as a standard reeled pipeline, with electrical connections to be done between each reel
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Glycol Jacket at Humble (TX)EHTF fabrication
ITP Full scale test• Joint Industry Project : 2000/2001
• Achievements : Validation of the concept (PREVENTION & RESTART conditions)U-value = 0.45 W/m2K7 W/m required for temperature maintenance above typical HAT 10 W/m required for restart conditions
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Certification
• Recent DNV Certificate of Fitness for Service for Reeled EHTF PiP with Subsea 7
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Conclusion
• Reeled installation of EHTF is– A solution qualified by Total
– A solution based on proven technologies and fabrication/installation methods
– A tested concept & solution, by modeling and physical tests
– A DNV Certified of Fitness for Service
– The most energy efficient system in the most compact configuration
18Page 6-Oct-11
John [email protected]
+44 (0)1224 526463
Sylvain [email protected]
+33 1 80 10 80 95
Christian [email protected]
+33 1 80 10 80 90
Any Questions?