Subsea Acoustic Sensor Vibration Control
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Solution Overview
Problem
Subsea structures experience flow-induced vibration, leading to reduced equipment lifespan and potential catastrophic failure due to amplified disturbance forces at resonance frequencies, which existing monitoring techniques, such as accelerometers and acoustic sensors, either limit sensor lifetime or require costly and time-consuming maintenance.
Innovation Solution
A method and apparatus utilizing subsea acoustic sensors to detect acoustic energy characteristics and adjust operational parameters like flow rate or fluid composition in real-time through a closed-loop control system, using a Subsea Control Module to vary the choke valve and maintain vibration below a threshold, thereby reducing structural damage and resonance effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If accelerometers are mounted directly onto subsea structures to monitor vibration, then vibration monitoring capability is improved, but sensor lifetime is reduced due to exposure to vibration
Solution Approach 1:
The patent uses acoustic sensors as an intermediary to detect vibration indirectly through acoustic energy in seawater, rather than mounting sensors directly on the vibrating structure. This mediator approach allows vibration monitoring without exposing the sensor to the harsh vibrational environment, resolving the contradiction between monitoring capability and sensor lifetime.
2Reliability
If acoustic sensors are used to monitor vibration remotely, then sensor reliability is improved, but response time for maintenance is increased
Solution Approach 1:
The patent implements a closed-loop feedback control system where acoustic sensors continuously monitor vibration, the controller processes the signals in real-time, and automatically adjusts flow parameters to reduce vibration. This continuous feedback mechanism enables immediate response to vibration events, eliminating the time delay associated with manual intervention while maintaining sensor reliability through remote operation.
Solution Approach 2:
The system performs self-service by automatically detecting vibration through acoustic sensors and adjusting flow parameters without human intervention. The closed-loop control system self-regulates to reduce vibration, enabling immediate response time while maintaining sensor reliability through automated operation.
3Productivity
If flow rate is increased to maximize productivity, then fluid flow output is improved, but flow-induced vibration is amplified at resonance frequencies
Solution Approach 1:
The patent dynamically adjusts flow parameters based on real-time vibration monitoring. The system continuously monitors acoustic energy and automatically modifies flow rate and other parameters to maintain productivity while avoiding resonance conditions. This dynamic adaptation allows the system to optimize flow output while preventing harmful vibration amplification.
Solution Approach 2:
The system changes operational parameters (flow rate, fluid composition) in response to detected vibration levels. By dynamically adjusting these parameters, the system maintains high productivity when vibration is low and reduces flow parameters when approaching resonance frequencies, thereby maximizing output while minimizing harmful vibration effects.
4Device complexity
If manual monitoring and maintenance procedures are used, then system complexity is reduced, but maintenance costs and time consumption increase
Solution Approach 1:
The patent implements automated feedback control where acoustic sensors continuously monitor vibration and the controller automatically adjusts flow parameters. This closed-loop system eliminates manual monitoring and intervention, significantly reducing maintenance time and costs despite the increased automation complexity.
Solution Approach 2:
The system performs self-diagnosis and self-adjustment by automatically detecting vibration through acoustic sensors and modifying operational parameters without human intervention. This self-service capability reduces maintenance requirements and time consumption, offsetting the initial complexity of the automated system.
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
This approach provides continuous feedback for effective vibration control, maximizing fluid flow while keeping vibrational effects within safe limits, reducing maintenance costs and extending equipment life by automatically adjusting operational parameters based on detected acoustic energy characteristics.
Implementation Method 1
via at least one subsea acoustic sensor, detecting at least one characteristic associated with acoustic energy in sea water proximate to the sensor
Implementation Method 2
flow induced vibration can be experienced as fluid flows along a pipeline and this is proportional to a velocity of fluid flow along a fluid pathway
Implementation Method 3
particularly at resonance frequencies, be amplified by the structure
Data Source
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AI summary
A method and apparatus are disclosed for reducing flow induced vibration in at least one subsea structure. The method comprises the steps of, via at least one subsea acoustic sensor (190), detecting at least one characteristic associated with acoustic energy in sea water proximate to the sensor (190), responsive to the detected characteristic, varying at least one operational parameter of a fluid flowing along a fluid flow pathway associated with a pipe member (160).