Locking Collar for Tubular Centralizer Axial Rotation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lock collars for securing centralizers in oilfield tubulars require special torque tools or small fasteners, posing safety hazards and being difficult to install, while also failing to reliably prevent axial and rotational movement of centralizers during downhole operations.
Innovation Solution
A lock collar design featuring internal springs and retaining pins that induce hoop stress and axial compression to securely attach to the tubular, resisting rotation and axial movement without the need for special tools or fasteners, utilizing a cylindrical body with channels and apertures to hold the springs in an expanded position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional stop rings are anchored by applying torque to energize C-ring components or by installing set screws and hammering in wires, then the centralizer can be secured to the tubular, but the installation process becomes complex requiring special torqueing tools and small fasteners, and safety hazards increase
Solution Approach 1:
The patent replaces complex mechanical fastening systems (torque tools, set screws, wires, nails) with a simple friction-based compression system. The lock collar is compressed axially to create friction engagement with the tubular OD, eliminating the need for specialized tools and small fasteners while maintaining securing reliability.
Solution Approach 2:
The lock collar design allows the friction force generated by axial compression to automatically secure the centralizer without requiring additional fastening operations. The system self-secures through the friction between the compressed collar and tubular surface, eliminating the need for separate anchoring steps.
2Ease of operation
If the centralizer is not rotationally locked to the tubing OD, then the installation process is simpler, but the equipment cannot be rotated to break out of tight spots and the load required to push equipment into horizontal section increases
Solution Approach 1:
The lock collar provides rotational locking while maintaining the simplicity of installation. The friction-based compression system creates sufficient rotational resistance to prevent unwanted rotation during installation, yet allows controlled rotation when needed to break out of tight spots, optimizing both installation ease and operational capability.
3Device complexity
If the centralizer is not rotationally locked to the tubular, then no additional locking mechanism is needed, but axial movement of the centralizer cannot be prevented
Solution Approach 1:
The lock collar design achieves both axial movement prevention and rotational locking with a single friction-based compression mechanism. The same compressive force that prevents axial slippage also provides rotational resistance, eliminating the need for separate locking mechanisms for different movement types.
4Reliability
If conventional anchoring methods are used with multiple components, then the centralizer can be secured, but the device complexity increases and installation time increases
Solution Approach 1:
The lock collar is designed as a single integrated component that combines the functions of multiple separate parts (C-ring components, set screws, wires, nails) into one unit. This segmentation into a single compressible collar reduces the number of installation steps and components while maintaining securing reliability.
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 solution provides a safe, easy-to-install mechanism that effectively prevents axial and rotational movement of centralizers, reducing drag and installation load, and can be used in horizontal sections without rotating the pipe, enhancing operational safety and efficiency.
Implementation Method 1
A first expandable spring member is provided having a pair of opposing ends and is located in the first channel. A second expandable spring member is provided having a pair of opposing ends and is located in the second channel.
Implementation Method 2
A first retaining pin is removably located in the first aperture, between the ends of the first spring so as to hold the first spring in an expanded position. A second retaining pin is removably located in the second aperture, between the ends of the second spring so as to hold the second spring in an expanded position.
Data Source
AI summary
A lock collar for locking a centralizer in place on a tubular of the type used in production strings in the oilfield. The lock collar relates to mechanisms such as stop rings or lock collars commonly used in downhole applications to prevent axial and/or rotational movement of centralizers mounted on the tubing or casing outer surface.