Beveled Lock Ring Wedging Action for Frac Sleeve
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Solution Overview
Problem
Existing lock devices for frac sleeves are costly and operationally complex due to the use of double-sided lock rings, which reduce the drift dimension of the innermost sleeve and complicate the process of maintaining frac ports open during cementing and pressure penetration.
Innovation Solution
A lock ring with a beveled end that engages an internal taper in the housing, creating a wedging action to maintain the frac sleeve in the open position, using a ratchet pattern that aligns with the lock ring to prevent closure, and is loosely retained in a housing recess for efficient assembly and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a double-sided lock ring is used to protect the interior sleeve during cementing and frac operations, then the sleeve is locked in the shifted position, but the drift dimension of the innermost sleeve is reduced and the device complexity increases
Solution Approach 1:
The patent extracts the protective function from a complex double-sided lock ring system and implements it through a simpler single-sided lock ring combined with a tapered leading end on the sliding sleeve. The tapered end acts as an integrated protection mechanism that eliminates the need for additional lock features on both sides of the ring.
Solution Approach 2:
The patent applies local quality by creating a tapered leading end specifically at the front of the sliding sleeve where protection is needed during cementing and frac operations. This localized taper provides the necessary protection and locking function without requiring complex double-sided locking mechanisms throughout the entire device.
2Reliability
If a double-sided lock ring is used to lock the sleeve in the shifted position, then the sleeve remains locked, but the operational complexity and cost increase
Solution Approach 1:
The patent removes the unnecessary second-sided locking mechanism from the design, keeping only the essential single-sided lock ring. This extraction of redundant features simplifies manufacturing while maintaining the core locking function needed for reliable sleeve positioning.
Solution Approach 2:
Instead of using a complex double-sided lock ring to achieve protection and locking, the patent inverts the approach by using a simple lock ring combined with a tapered leading end on the sliding sleeve. This inverted design achieves the same protective and locking functions with simpler, more manufacturable components.
3Reliability
If the lock ring is tightly fitted in the housing recess, then the locking is more secure, but the assembly and operation become more difficult
Solution Approach 1:
The patent applies dynamics by making the lock ring loosely fitted rather than tightly secured in the housing recess. This allows the lock ring to move dynamically and self-align with the ratchet teeth during operation, facilitating easier assembly and operation while maintaining secure locking when engaged.
Solution Approach 2:
The loosely fitted lock ring serves itself by automatically aligning and engaging with the ratchet teeth through its own movement within the housing recess. This self-aligning mechanism eliminates the need for precise manual positioning during assembly, making the operation easier while ensuring reliable locking engagement.
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 effectively locks the frac sleeve in the open position, reducing operational complications and costs while ensuring unhindered movement during desired operations, and can be adapted for various well operations beyond fracturing.
Implementation Method 1
a tapered leading end that in the event of a force that would otherwise urge the sliding sleeve back to the closed position creates a wedging action off the surrounding housing that forces the lock ring against the sliding sleeve
Implementation Method 2
a ratchet pattern on the sleeve that comes into engagement with a lock ring
Data Source
AI summary
A lock ring fits into a housing recess defined by a sliding member such as a sleeve. The lock ring is loosely fitted in the recess when the sleeve is in an initial position. The lock ring is preferably smooth on an outer dimension and has a beveled end. The beveled end engages an internal taper in the housing if a force is placed on the sliding sleeve to return it toward the original position. Preferably the shifting of the sleeve to a ports open position places the ratchet on the sleeve in alignment with the lock ring to hold the sliding sleeve locked in the open position.