Flexible Pipe Optical Sensing Across Turret Swivel Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical sensor systems integrated in unbonded flexible pipes fail to detect strain and temperature changes accurately on floating vessels equipped with turret mooring systems due to signal distortion through swivel devices, particularly affecting analog signal transmission.
Innovation Solution
The flexible pipe system incorporates an optical fibre integrated in the armouring layer of the unbonded flexible pipe, with interrogating equipment placed on the turret to transmit and receive signals without distortion, allowing for wireless signal transfer to monitoring equipment on the floating vessel, using fibre Bragg gratings and distributed temperature sensing for accurate strain and temperature measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical sensor systems are integrated in unbonded flexible pipes for strain and temperature detection, then monitoring capability is improved, but signal distortion occurs when signals pass through swivel devices on turret mooring systems
Solution Approach 1:
The patent introduces an intermediary optical fibre connection between the interrogating equipment on the turret and the swivel device, allowing optical signals to be transmitted without passing through the swivel device's mechanical components. This intermediary optical connection mediates between the sensor system in the flexible pipe and the monitoring equipment on the vessel, eliminating signal distortion while maintaining measurement capability.
Solution Approach 2:
The patent replaces mechanical signal transmission through the swivel device with an optical fibre-based signal transmission system. By substituting the mechanical connection path with an optical path that bypasses the swivel device, the system eliminates the signal distortion caused by mechanical movement and friction in the swivel mechanism while maintaining continuous monitoring capability.
2Adaptability or versatility
If interrogating equipment is placed on the floating vessel to monitor pipe parameters, then monitoring coverage is improved, but signal distortion occurs due to the swivel device between the turret and vessel
Solution Approach 1:
The patent changes the signal transmission dimension by moving the interrogating equipment to the turret and using optical fibres that run independently of the mechanical swivel connection. This dimensional separation allows the signal path to exist in a different spatial and functional dimension than the mechanical rotation path, eliminating signal distortion while maintaining full monitoring coverage of the flexible pipe.
Solution Approach 2:
The optical fibre connection acting as an intermediary carries the measurement signals from the flexible pipe through the turret to the monitoring equipment on the vessel, bypassing the signal-distorting swivel mechanism. This intermediary optical path preserves signal integrity while maintaining the adaptability and monitoring coverage provided by the vessel-based equipment.
3Reliability
If optical fibres are integrated in armouring layers for continuous monitoring, then detection reliability is improved, but the complexity of the pipe system increases
Solution Approach 1:
The patent merges the optical sensing function with the existing armouring layers of the flexible pipe by integrating optical fibres into the armouring structure. This consolidation combines structural support and sensing functions into a single integrated system, improving detection reliability while minimizing the increase in overall system complexity through functional integration rather than additive components.
Solution Approach 2:
The optical fibres integrated in the armouring layers serve multiple functions: providing structural reinforcement as part of the armouring while simultaneously acting as sensors for strain and temperature detection. This multi-functionality reduces the need for separate sensing components, thereby improving detection reliability without proportionally increasing system complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables reliable detection of strain and temperature changes in unbonded flexible pipes even on vessels with turret mooring systems, ensuring continuous monitoring and preventing potential pipe failures by maintaining signal integrity through the swivel device.
Implementation Method 1
Each one of these armouring elements has integrated therein at least one optical fibre comprising a plurality of optical fibre sensors. The optical fibre sensors extend along a monitoring length section of the flexible pipe, and they are arranged to measure or determine a change in strain of the respective armouring elements by transmitting a light signal from an optical transmitter in the interrogating equipment into the optical fibre and measuring in an optical detector light that is reflected from the fibre to the interrogating equipment.
Implementation Method 2
In the optical detector, or a computing unit to which it is connected, the reflected optical signals are processed for determining changes in e.g. intensity, phase, polarization, wavelength, or transit time of light in the fibre, which indicate a change in the strain and/or temperature along the fibre or at one of the sensors.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A flexible pipe system comprises an unbonded flexible pipe (15) connected to a floating vessel (1) and a sensor system with an optical fibre integrated in the unbonded flexible pipe. Interrogating equipment (20) transmits optical signals into the fibre, receives optical signals reflected from the fibre and detects a parameter of the unbonded flexible pipe. A turret (4) connects the flexible pipe rotationally to the floating vessel via a swivel device (22) that provides a fluid transfer passage between the turret and the vessel. The interrogating equip- ment is arranged on the turret and is further configured to transfer signals indicative of the detected parameter to receiving equipment (27) on the floating vessel. In this way, optical signals reflected from the fibre can reach the interrogating equipment without distortion in the swivel, so that parameters can be detected with sufficient quality also for floating vessels equipped with a turret mooring system.