Inner Barrel Shear Zone for Coring Tool Separation
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Solution Overview
Problem
Conventional coring tools face challenges in efficiently and minimally damagingly separating inner barrels after core sample extraction, which increases time, labor, and expense, and can compromise the quality of the core samples.
Innovation Solution
Incorporating a shear zone in the inner barrel or connector sub, made of a more brittle material or heat-treated to reduce ductility, allowing for easier separation using a fast pipe cutter, thereby reducing the force required for severing and minimizing damage to the core sample.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional coring tools are used to separate inner barrels after core sample extraction, then the core samples can be obtained, but the separation process requires excessive time, labor, and expense while risking damage to the core samples
Solution Approach 1:
A shear zone is pre-formed in the inner barrel or connector sub at the location where separation is needed. This preliminary structural feature allows the inner barrels to be easily separated after core sample extraction by applying force at the predetermined weak point, eliminating the need for time-consuming conventional cutting or separation methods while protecting the core sample from damage during separation
Solution Approach 2:
The inner barrel or connector sub is designed with a localized shear zone that has different mechanical properties (more brittle, lower ductility) compared to the rest of the structure. This local quality change allows the separation to occur at a specific location with minimal force, reducing the risk of damaging the core sample while maintaining the overall strength of the inner barrel during the coring operation
2Ease of manufacture
If conventional separation methods are used for inner barrels, then separation can be achieved, but the process is costly and labor-intensive
Solution Approach 1:
The shear zone is manufactured into the inner barrel or connector sub during the initial fabrication process. This preliminary action creates a built-in separation feature that simplifies the post-operation separation process, reducing both labor requirements and costs while maintaining structural integrity during use
Solution Approach 2:
The material properties or structural parameters are changed locally at the shear zone to create a region with lower strength or different ductility characteristics. This parameter change enables easy separation through simple mechanical force application, transforming a complex separation process into a straightforward operation
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 shear zone enables efficient and cost-effective separation of inner barrels with reduced risk of damaging the core samples, facilitating higher quality measurements and potential reusability of the inner barrels.
Implementation Method 1
the shear zone may be the same material as the inner barrel, but may be heat treated locally, such as with a laser, to create a portion that is easier to shear
Implementation Method 2
The shear zone may be constructed of a relatively weak or brittle material in comparison with the material used to construct adjacent portions of the inner barrel or connector sub
Data Source
AI summary
The inner barrel system includes a coring inner barrel. The system also includes a connector sub coupled to the coring inner barrel. The connector sub includes a tubular wall defining a central axis and a shear zone extending longitudinally along at least a portion of the tubular wall. The shear zone severs with less force than the coring inner barrel.