Kobe Sub Shielding Cap Capture Mechanism
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Solution Overview
Problem
In wellbore operations, kobe plugs can be inadvertently removed or become loose, leading to interference with tools and string structures, and existing solutions do not effectively prevent accidental opening or capture the cap portion after removal.
Innovation Solution
A kobe sub with a shielding structure to protect the cap portion from inadvertent removal and a capturing mechanism to secure the cap portion after opening, ensuring it does not become loose in the inner bore.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the cap portion is made accessible in the inner bore for easy removal, then the ease of operation is improved, but the risk of inadvertent removal by tools or treatment strings increases
Solution Approach 1:
A shielding structure is introduced as an intermediary element between the cap portion and external tools. This shielding structure blocks treatment strings and tools from directly contacting and inadvertently removing the cap portion, while still allowing controlled access when needed for intentional opening of the port
2Productivity
If the cap portion is made removable to open the port, then the productivity is improved, but the cap portion may become loose and interfere with string operations
Solution Approach 1:
The cap portion is extracted from its normal position and redirected into a dedicated receiving cavity within the shielding structure. This extraction removes the cap from the general inner bore space where it would cause interference, and places it in a controlled location where it cannot obstruct tools or string operations
Solution Approach 2:
The potentially harmful loose cap portion is converted into a beneficial captured element. By designing the shielding structure with a receiving cavity, the cap that is removed during port opening is instead captured and contained, transforming what would be debris causing interference into a controlled component that cannot obstruct operations
3Reliability
If a shielding structure is added to protect the cap portion, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The shielding structure is merged with the kobe sub assembly itself rather than being a separate external component. The shielding structure forms an integrated part of the tubular body and kobe plug assembly, combining multiple functions (protection, cap positioning, and structural support) into a single unified component, thereby limiting the increase in overall device complexity
Data Source
AI summary
To address concerns of kobe plug cap portions being inadvertently removed, for example, by abutment with strings or tools passing thereby, a shielding structure may be employed to protect the cap against inadvertent removal. The port opening tool useful with the kobe plug is selected to overcome the shielding structure to open the kobe plug. To address concerns of a portion of the kobe plug becoming loose in the tubing string inner bore, a capturing mechanism may be provided that captures the cap portion after it is removed to open the kobe plug and prevented the cap portion from becoming loose in the inner bore of the tubing string.