Inflatable Sealing Section for Offshore Cable Pull-In
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Solution Overview
Problem
Existing undersea cable connection systems for offshore structures face challenges such as restricted flexibility during installation, unreliable sealing, high failure rates, and dynamic protection issues, leading to costly and time-consuming installations, and complications in repairs.
Innovation Solution
A flexible outer conduit assembly with an inflatable sealing section, comprising a thin-walled, fiber-reinforced polyurethane structure and an elastomeric inflatable bladder, which engages and seals the entry hole of the offshore structure, allowing for easy installation and dynamic protection of cables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanically tight fit seal is used onto the flexible cable, then sealing effectiveness is improved, but cable flexibility and movement are restricted
Solution Approach 1:
The patent employs a flexible bladder as the sealing element that can be inflated to create a seal against the cable. This flexible membrane approach allows the seal to conform to cable movements and bending without requiring a rigid mechanical tight fit, thus maintaining both sealing effectiveness and cable flexibility.
Solution Approach 2:
The sealing mechanism changes its physical state by inflating the bladder with fluid or gas. When inflated, the bladder expands to make contact with the cable and create a seal. When deflated, it releases the cable, allowing free movement. This parameter change (volume/pressure) enables dynamic sealing without permanent restriction on cable flexibility.
2Reliability
If compression seals are used to seal the cable, then sealing is achieved, but diver or ROV assistance is required for engagement
Solution Approach 1:
The sealing bladder is pre-positioned in a deflated state within the conduit assembly before cable installation. The cable is pulled through the conduit with the bladder already in place but not engaged. After the cable is positioned, the bladder is inflated to create the seal, eliminating the need for complex underwater engagement operations by divers or ROVs.
Solution Approach 2:
The patent uses pneumatic or hydraulic inflation of the bladder to create the sealing force. Instead of mechanical compression requiring manual intervention, the seal is activated by introducing fluid pressure into the bladder, which expands and contacts the cable. This can be controlled remotely or automatically, reducing the need for underwater human intervention.
3Stability of the object's composition
If the cable is fixed and held in position at the interface during installation, then cable position stability is improved, but cable flexibility and natural movement are restricted
Solution Approach 1:
The sealing system transitions from a static mechanical lock to a dynamic inflatable bladder seal. The bladder can be inflated to secure the cable position when needed and deflated to allow cable movement and flexibility. This dynamic capability enables the system to adapt between stability and flexibility requirements during different operational phases.
Solution Approach 2:
The inflatable bladder seal can automatically adjust to cable position and movement through pressure regulation. The system can self-adjust the sealing force based on cable tension and position, maintaining stability when required while allowing natural cable flexibility without external intervention for mechanical adjustments.
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
The system enables fast, reliable, and flexible cable installation with effective sealing and reduced risk of failure, minimizing the need for underwater interventions and extending cable lifespan by distributing mechanical forces and preventing seawater ingress.
Implementation Method 1
The inflatable sealing section (4) comprises a flexible bladder (18) arranged to be inflated into sealing engagement with the entry hole into the structure.
Implementation Method 2
The inflatable sealing section comprises a flexible bladder arranged to be inflated into sealing engagement with the entry hole
Data Source
AI summary
A cable pull-in system and method for offshore structures (1) of the type having a hollow interior extending from the sea bed to above the surface of the water and an entry hole (2) in the external wall of the structure. The system includes an elongated outer conduit assembly (7) within the interior of which is arranged an elongated cable member (10), the elongated outer conduit assembly being equipped with an inflatable sealing section (4) adapted for engaging the interior of entry hole (2) to seal and affix the outer conduit assembly. The elongated outer conduit assembly is pulled through the entry hole and up to a hangoff point above the water surface such that the inflatable sealing section (4) engages entry hole (2).