Downhole Stop Collar With Compressible Slip Ring Grip
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stop collars for downhole tubulars lack efficient mechanisms for secure and reliable mounting, particularly in unstable or depleted formations, leading to issues with grip and stability during drilling operations.
Innovation Solution
A slimline stop collar design featuring a cylindrical housing with a threaded inner surface, a compressible slip ring with teeth, and a compressible cam ring, which are driven together by a threaded bolt to radially compress the slip ring and engage its teeth with the tubular, providing a secure grip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional stop collar design is used for mounting to downhole tubulars, then the structure is simpler, but the grip and stability are insufficient in unstable formations
Solution Approach 1:
The stop collar is divided into distinct functional segments: a compressible slip ring with teeth for engagement, a cam ring for compression control, and a threaded bolt for actuation. This segmentation allows each component to perform its specific function optimally, with the slip ring providing grip through its teeth and the cam ring controlling the compression force, thereby improving reliability without excessive complexity.
Solution Approach 2:
The stop collar employs dynamic compression through the cam ring mechanism that converts rotational motion of the threaded bolt into radial compression of the slip ring. This dynamic action allows the teeth of the slip ring to actively engage with the tubular surface, enhancing grip and stability in unstable formations rather than relying on static contact.
2Reliability
If the slip ring is compressed to engage teeth with the tubular, then the grip is enhanced, but the mounting mechanism becomes more complex
Solution Approach 1:
The cam ring acts as an intermediary mechanism between the threaded bolt and the slip ring. It translates the axial force from the threaded bolt into radial compression force on the slip ring, enabling controlled engagement of the teeth with the tubular. This intermediary mechanism provides a reliable grip while maintaining a manageable level of complexity through clear functional separation.
3Stability of the object's composition
If a compressible cam ring and slip ring mechanism is used, then the stability is improved, but the device complexity increases
Solution Approach 1:
The mechanism utilizes parameter changes in the form of controlled compression force applied to the slip ring through the cam ring. By adjusting the compression parameter through the threaded bolt, the engagement force of the teeth with the tubular is optimized, providing stable mounting. The compressible nature of both rings allows for gradual parameter adjustment, enhancing stability while keeping the mechanism relatively simple through the use of elastic deformation.
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 slimline stop collar effectively secures the tubular by compressing the slip ring to engage its teeth with the tubular periphery, enhancing stability and preventing slippage during drilling, even in challenging formations.
Implementation Method 1
Screwing the threaded surfaces of the housing and the bolt is operable to drive the tapered surfaces together, thereby compressing the slip ring
Implementation Method 2
a compressible slip ring having teeth formed in an inner surface thereof and a pair of tapered outer surfaces; a compressible cam ring having a tapered inner surface
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A stop collar for mounting to a downhole tubular includes: a cylindrical housing having a threaded inner surface and a tapered inner surface; a compressible slip ring having teeth formed in an inner surface thereof and a pair of tapered outer surfaces; a compressible cam ring having a tapered inner surface; and a cylindrical bolt having a threaded outer surface. A natural outer diameter of each ring is greater than a minor diameter of the threaded surfaces. Screwing the threaded surfaces of the housing and the bolt is operable to drive the tapered surfaces together, thereby compressing the slip ring such that the teeth engage a periphery of the tubular.