Post on 14-Nov-2021
Fibre Optic Instrumented Pipeline Bundle for HPHT DevelopmentsSUBSEA EXPO February 2017
Mostafa Hendawy – Mechatronics Engineer
2Page 20-Jan-17
• Introduction
• HPHT Theoretical Development
• Bundles HPHT Trial
• Results and Analysis
• Conclusions
Agenda
3Page 20-Jan-17
Introduction • What is a Pipeline Bundle?
4Page 20-Jan-17
Introduction• Why Pipeline Bundles?
– Onshore SIT and pre-commissioning;
– No need for specialist and expensive vessels;
– Less congested field layout;
– Improved flow assurance and thermal solution;
– No need for trenching / rock-dump;
– Fast hook-up and commissioning offshore;
– Year round installation (with enhanced weather criteria).
• Pipelines bundle operating temperature range is currently at 160°C.
5Page 20-Jan-17
HPHT Theoretical Development• Pipeline bundle pre-tensioning advantages:
– Suitable for 220°C, 1379 bar;
– Reduction of compressive axial forces due to high temperature;
– Mitigate the need for expansion spools.
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HPHT Trial – Mechanical Setup
7Page 20-Jan-17
HPHT Trial – Instrumentation Setup
Fibre Optic Instrumentation FBG Chain
Strain gauge Instrumentation
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HPHT Trial – Testing Procedure• Pressure Strength test (1 cycle):
– Hold points: 35bar, 169.2bar, 253.8bar and 287bar.
• Mechanical Pre-tensioning test (3 cycles):– 4 pre-tensioning steps (104mm each; i.e. 416mm total);
– Flowline extends by 253mm;
– Sleeve compresses by 163mm.
• Unrestrained HPHT test (2 cycles):– Temperature applied 220°C;
– Pressure applied 193bar
• Boulder case test (1 cycle):– Temperature applied 220°C;
– 300mm prop bend.
– Pressure applied 193bar
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Results - Pressure Strength Test
Strain gauge results (hoop and axial strains)
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Results - Pressure Strength Test
Strain gauge results (hoop and axial strains)
Hoop strain at pressure hold points
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Results - Mechanical Pre-tensioning Test
Jacks & extension legs installed During Jacking, installing packers
All packers installed Insulation and half shells installed
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Results – Mechanical Pre-tensioning Test
Strain gauge results (hoop and axial strains)
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Results – Mechanical Pre-tensioning TestAxial strain at Pre-tensioning steps
Strain gauge results (hoop and axial strains)
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Results – Mechanical Pre-tensioning Test
Instrumentation technology comparison (axial strain)
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Results – Unrestrained HPHT Test
Strain gauge results (hoop and axial strains)
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Results – Unrestrained HPHT Test
Strain gauge results (hoop and axial strains)
Temperature:Axial strain drop
Pressure:Hoop strain rise
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Results – Unrestrained HPHT Test• Distributed Temperature Sensing Video 3 heating cycles
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Results – Boulder Case Test
Distributed Axial Strain Sensing Results (DSS)
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150
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220
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0
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1000
16:19:12 17:31:12 18:43:12 19:55:12 21:07:12
Tem
per
atu
re (ᴼC
)
Str
ain
(μ
m/
m)
Date and Time
Axial Strain 2 IP (µε)
Axial Strain 3 IP (µε)
Temperature Max. (ᴼC)
Results – Boulder Case Test
Strain gauge results (axial strain)
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Conclusions• Trials performed safely in presence of third party.
• Pre-tensioning system generated strains within 7% of the FEA results.
• Friction coefficient was insignificant (0.17) due to the use of Subsea 7’s low friction HT centralisers (Patent Pending).
• Strain gauges verified the FEA model and the FO instrumentation results.
• Results are all within 90% accuracy of the maximum strain value during the given test.
21Page 20-Jan-17
Conclusions• Subsea 7 demonstrated the technology required to pre-
tension bundles for HPHT applications up to 220ᴼC.
• Subsea 7 demonstrated the technology required to use fibre optic and/or strain gauges for monitoring pipeline bundles during pre-tensioning and operational phases.
• Qualifications according to DNV-RP-A203 almost complete.
22Page 20-Jan-17