In-Tubing Probe Retainer Assembly With External Stress Isolation
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Solution Overview
Problem
Existing methods for securing cylindrical members, such as electronics packages, within tubular members in downhole drilling applications face challenges with significant stresses during assembly, leading to potential collapse and increased manufacturing costs due to the use of high-cost securing methods like keying and splining.
Innovation Solution
The use of a retention member with a slip-fit engagement and a press-fit ring, along with axially-extending inserts, to secure the cylindrical member within the tubular member, reducing stresses on the retention member and allowing for simpler and less expensive maintenance by separating the tubular member engagement from the probe engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If keying and splining methods are used to secure the retention member, then rotational security is improved, but manufacturing cost increases and the retention member becomes more complex
Solution Approach 1:
The patent extracts the rotational securing function from the retention member itself and places it in a separate component (the drill string or housing). This allows the retention member to maintain a simple, cost-effective design while rotational security is provided by the extracted securing mechanism in the surrounding structure.
Solution Approach 2:
The patent introduces an intermediary component (such as a keyway, spline, or separate locking mechanism in the drill string) that mediates between the retention member and the drill string. This intermediary provides rotational security without requiring complex features on the retention member itself, thus reducing manufacturing cost while maintaining reliability.
2Device complexity
If the retention member is directly press-fitted into the tubular member, then assembly stress is reduced, but the retention member may still collapse under downhole conditions
Solution Approach 1:
The patent segments the retention member into functional zones: a simplified press-fit outer portion for easy assembly and an internally reinforced structure with ribs or strengthening features that provide collapse resistance. This segmentation allows the outer interface to remain simple while the internal structure provides the necessary strength.
Solution Approach 2:
The patent employs composite construction within the retention member, combining materials or structural features that provide both ease of assembly and collapse resistance. The composite structure allows the retention member to withstand downhole pressures while maintaining a simple press-fit assembly process.
3Strength
If the retention member is made more robust to prevent collapse, then strength is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent applies local quality by providing strengthening features (such as ribs, thickening, or material reinforcement) only in the specific regions of the retention member where collapse resistance is needed, rather than making the entire retention member robust. This localized reinforcement maintains manufacturing efficiency while providing necessary strength.
4Reliability
If complex securing methods like keying are used, then rotational security is improved, but ease of repair worsens due to higher maintenance costs
Solution Approach 1:
The patent extracts the complex rotational securing features from the retention member and places them in the drill string or housing. This allows the retention member to remain simple and inexpensive, making replacement and repair more cost-effective while rotational security is maintained by the extracted securing mechanism.
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 solution effectively reduces the risk of retention member collapse and lowers maintenance costs by distributing stresses externally, providing a secure and cost-effective means of retaining cylindrical members within tubular members.
Implementation Method 1
a press-fit ring configured for receipt within the interior space and press-fit engagement against the inner wall to secure the retention member against the internal upset
Implementation Method 2
a slip-fit ring configured for receipt within the interior space and slip-fit engagement against the inner wall
Data Source
AI summary
An assembly for securing a probe retention member at a desired location within a tubular interior such as in a drill string collar. The assembly may use one or more securing members external to the retention member. In some embodiments most of the stresses from the probe retention structures of the retention member are isolated.