Coiled Tubing Tempering Without Bending to Prevent Cracking
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Solution Overview
Problem
Existing methods for heat treating coiled tubing often result in significant deformation and cracking due to the need for bending during the process, which can lead to defects and safety hazards.
Innovation Solution
A method of heat treating coiled tubing by tempering unspooled pipes without bending, followed by optional further tempering after coiling, to achieve desired mechanical properties while minimizing deformation and defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If coiled tubing is bent inside a furnace for tempering to achieve required residence time, then the heat treatment process can be completed, but significant defects and cracking occur in the coiled tube
Solution Approach 1:
The patent applies preliminary tempering action before bending by tempering the coiled tube in a straight condition first to achieve minimum required tempering, then bending the tube for coiling. This preliminary tempering reduces brittleness before the bending operation, preventing cracking and defects that would occur if bending were performed on as-quenched material.
Solution Approach 2:
The heat treatment process is segmented into distinct stages: (1) straightening the coiled tube, (2) tempering in straight condition to achieve minimum residence time and reduce brittleness, (3) bending and coiling the tempered tube, and (4) optional additional tempering after coiling. This segmentation allows the tube to be tempered before bending, avoiding defects.
2Ease of manufacture
If coiled tubing is tempered in as-quenched condition without prior straightening, then the heat treatment can be applied, but significant deformation and cracking occur due to bending
Solution Approach 1:
The patent applies preliminary straightening action before tempering by straightening the coiled tube to a substantially straight condition prior to the tempering operation. This preliminary straightening eliminates curved sections that would cause uneven heating and deformation during tempering, enabling the tube to be tempered without significant deformation or cracking.
Solution Approach 2:
The patent applies preliminary anti-action by straightening the tube to counteract the curved coiled configuration before tempering. This preliminary anti-action prevents the curved sections from causing uneven thermal stress and deformation during the subsequent tempering process, maintaining manufacturing precision.
3Stability of the object's composition
If minimum tempering is applied before bending, then ductility is improved to avoid defect generation, but additional tempering operations are required after coiling
Solution Approach 1:
The patent applies preliminary tempering action before coiling by tempering the straightened tube for a minimum required residence time at tempering temperature. This preliminary tempering achieves sufficient ductility to prevent defect generation during the coiling operation. The patent specifies that this minimum tempering may be sufficient in some cases, or additional tempering may be applied after coiling to achieve final desired properties.
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 produces defect-free coiled tubing with improved ductility and toughness, reducing the risk of cracking and enabling safer handling and use in applications like underwater oil transportation.
Implementation Method 1
heating the unspooled pipe to a temperature above Ac3, quenching the unspooled pipe
Implementation Method 2
tempering the unspooled pipe prior to any subsequent bending of the pipe
Data Source
AI summary
Embodiments of a method of heat treating a coiled tube, in particular coiled tubes for use in the oil and gas industry, and pipes produced from the methods. In particular, embodiments of the heat treating method can utilized tempering without bending in order to avoid the generation of subsequent defects.