Segmented Flotation Vessel Control for Deepwater Pipeline Elevation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for controlling the elevation and attitude of objects in deep water environments, such as subsea pipelines, are limited by hydrostatic crush and require expensive and time-consuming processes, especially when dealing with heavy or complex structures like pipelines containing cables or other pipelines, which are prone to damage and have depth limitations.
Innovation Solution
A flotation control system that divides pressure-containing vessels into reciprocal serial hydraulically discrete compartments for a selected flotation medium and an incompressible ballast medium, allowing for precise control of buoyancy and depth by varying the quantity of the ballast medium, enabling the vessel and attached objects to maintain stable elevation and attitude across varying depths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If glass microspheres containing gas are dispersed in liquid to form buoyant fluid for deep water operations, then buoyancy is provided, but the microsphere wall thickness must increase to withstand hydrostatic pressure, reducing the volume of buoyant gas
Solution Approach 1:
The pressure-containing vessel is divided into multiple discrete compartments, each independently containing buoyant fluid. This segmentation allows each compartment to be optimized for pressure resistance while maintaining overall buoyancy, as the pressure load is distributed across multiple smaller structures rather than requiring a single thick-walled container
Solution Approach 2:
The system uses hydraulics by filling compartments with incompressible ballast medium that can be precisely controlled. The buoyant fluid compartments are designed to withstand hydrostatic pressure while maintaining their volume, and the hydraulic system allows for precise depth control by adjusting the ballast medium quantity
2Speed
If the bladder is expanded or contracted to control buoyancy, then elevation control is achieved, but the shape and position of the bladder become unpredictable, compromising system stability
Solution Approach 1:
The system divides the pressure-containing vessel into multiple discrete compartments rather than using a single expandable bladder. Each compartment maintains a fixed, predictable shape and position, eliminating the instability caused by bladder deformation while still allowing elevation control through ballast adjustment
Solution Approach 2:
Each compartment is designed with specific local properties - rigid walls with predictable geometry - that ensure stable positioning. The compartments are strategically positioned within the vessel to provide both elevation control and attitude stability, with each compartment contributing known buoyant forces
3Adaptability or versatility
If the void between bladder and housing is not fully evacuated, then the system can operate at various depths, but the ratio of buoyant fluid to water is not precisely known, reducing control precision
Solution Approach 1:
The vessel is divided into discrete compartments with defined volumes, allowing precise tracking of fluid quantities. Each compartment can be independently filled or evacuated, enabling precise control of the buoyant fluid to water ratio while maintaining adaptability for various depth operations
Solution Approach 2:
The system incorporates flow meters and sensors that provide feedback on the quantity of ballast medium and buoyant fluid in each compartment. This feedback mechanism allows for precise measurement and control of fluid ratios, enabling both accurate elevation control and adaptability to different operational depths
4Force
If a single large bladder is used for buoyancy, then the system can provide sufficient lift, but the housing must be substantially expanded, making elongated structures like pipelines impractical
Solution Approach 1:
The system divides the buoyancy function into multiple smaller compartments distributed along the length of the vessel. This allows elongated structures like pipelines to incorporate buoyancy segments at intervals, providing sufficient total buoyant force while maintaining a practical, manageable housing structure that can be easily integrated with pipelines and other elongated objects
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 system allows for efficient and cost-effective control of the elevation and attitude of pressure-containing vessels and objects in deep water, reducing the risk of hydrostatic crush and enabling the laying of offshore pipelines at great depths with reduced operational costs and time.
Implementation Method 1
The selected flotation medium in the flotation medium compartment is counterbalanced against the selected incompressible ballast medium in the ballast medium compartment
Data Source
Figure 1~9
Figure 2A~2B
Figure 3A~3D
AI summary
A flotation control system comprising a pressure containing vessel; a first source of a flotation medium MF capable of increasing a buoyancy of said vessel in a liquid and a second source of an incompressible ballast medium MB capable of decreasing said buoyancy of said vessel in the liquid; a pig P held in confinement by the inner walls of said vessel and dividing said vessel into reciprocal serial hydraulically discrete compartments, a first said compartment CF in discrete communication with said first source for transmitting said flotation medium therebetween and a second said compartment CB in discrete communication with said second source for transmitting said incompressible ballast medium therebetween; a first valve F connected between said first source and said first compartment for controlling flow of said flotation medium into and out of said first compartment and a second valve B connected between said second source and said second compartment for controlling flow of said incompressible ballast medium into and out of said second compartment, said first valve being operable to fix a quantity of said flotation medium in said first compartment and said second valve being operable to vary a quantity of said incompressible ballast medium in said second compartment to control an elevation of said pressure-containing vessel in the body of liquid; and a flow meter measuring said quantity of incompressible ballast medium injected into and exhausted from said second compartment.