Reel-Lay Pipe Spooling Across Diameter Changes Without Liner Wrinkling
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Solution Overview
Problem
Bimetallic pipes with mechanically lined sleeves face issues during spooling and unspooling, such as wrinkling and deformation, which can hinder fluid flow and reduce fatigue life, especially when bending occurs, as the thin-walled inner liner sleeve lacks mechanical strength and is susceptible to buckling under external pressure.
Innovation Solution
A method involving the sequential spooling of pipelines with different diameters onto a reel by using a pressurized liquid to fill and expand the pipes, employing a first variable-diameter pig to transition between the inner diameters of the pipelines, and a second pig to ensure sealing and prevent wrinkling, allowing for the assembly and spooling of pipelines with varying dimensions on the same reel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thin-walled inner liner sleeve is used to protect the outer pipe from corrosion, then corrosion resistance is improved, but the liner sleeve becomes susceptible to buckling and wrinkling under external pressure during bending
Solution Approach 1:
The patent employs a bimetallic composite structure consisting of an outer pipe made of carbon steel providing mechanical strength and buckling resistance, and an inner liner sleeve made of corrosion-resistant alloy providing corrosion protection. The two materials are mechanically bonded through interference fit, creating a composite structure that leverages the advantages of both materials while compensating for their individual weaknesses.
2Ease of manufacture
If the liner sleeve is made thinner to reduce cost and weight, then material cost is reduced, but the liner sleeve suffers significant deformation and wrinkling under bending and external pressure
Solution Approach 1:
By using a thin-walled liner sleeve of corrosion-resistant alloy mechanically bonded to a thick-walled outer pipe, the design achieves corrosion protection at minimal material cost while the outer pipe provides the necessary mechanical support to prevent liner deformation during handling and installation.
3Strength
If the outer pipe is made thicker to prevent buckling, then mechanical strength is improved, but the overall pipe cost increases and the pipe becomes more difficult to handle during spooling
Solution Approach 1:
The bimetallic construction allows the outer pipe to be optimized for buckling resistance with appropriate thickness while the inner liner provides corrosion protection, achieving the required mechanical performance without the excessive cost and handling difficulty that would result from making a single-wall pipe uniformly thick throughout.
4Ease of manufacture
If a mechanically lined pipe structure is used to reduce cost compared to clad pipe, then manufacturing cost is reduced, but the liner sleeve becomes susceptible to wrinkling during spooling operations
Solution Approach 1:
The patent applies preliminary protective measures by ensuring the liner sleeve is properly supported and positioned before spooling operations begin, and by controlling the spooling process to minimize bending stresses that would cause wrinkling, thereby preventing the problem before it occurs.
5Adaptability or versatility
If successful spooling of lined pipes is achieved, then reel-lay application capability is improved, but the process becomes highly sensitive to bending conditions and requires careful control
Solution Approach 1:
The patent implements preliminary protective measures including proper pipe support arrangements, controlled bending radii, and monitored spooling procedures to prevent liner wrinkling before it occurs, thereby enabling reel-lay applications while managing the inherent sensitivity to bending conditions.
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 method effectively minimizes wrinkling and deformation of the liner sleeve during spooling and unspooling, ensuring smooth fluid flow and extended pipeline life by maintaining internal pressure and using adaptable pigs to manage diameter transitions between different pipelines.
Implementation Method 1
A pipeline is filled with a pressurizing liquid and the liquid pressure is elevated cyclically as pipe stalks are assembled and spooled onto the reel
Implementation Method 2
A first, variable diameter pig is advanced to a trailing end of a first pipeline. The diameter of the first pig changes to match the inner diameter of a second pipeline
Data Source
AI summary
Lined pipelines with different inner diameters are spooled successively onto a reel while their constituent pipe stalks are cyclically pressurised internally to combat wrinkling of the liner. A first, variable diameter pig is advanced to a trailing end of a first pipeline. A transition joint is attached to the trailing end of the first pipeline to effect a transition from the inner diameter of the first pipeline to the different inner diameter of a second pipeline. A leading end of the second pipeline, containing a second pig, is attached to the transition joint. The first pig is driven through the transition joint into the second pipeline. The diameter of the first pig changes to match the inner diameter of the second pipeline. The first and second pigs are then driven along the second pipeline when assembling the second pipeline from a succession of pipe stalks.