Downhole Trigger Device Using Extrudable Time Delay Material
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Solution Overview
Problem
Existing downhole tool trigger mechanisms face challenges in customizing activation time, requiring large battery packs for heat generation, which are costly, space-intensive, and pose safety concerns, while also needing to shield heat-sensitive components and manage high temperatures.
Innovation Solution
A trigger device with a housing, actuating member, and a retaining member featuring an extrudable material that moves at a known rate to set the downhole tool, eliminating the need for external heat sources by using wellbore temperature and allowing customization for various depths and tool sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a battery operated heat source is used to burn Kevlar fibers and release the trigger, then the trigger can be released, but the battery pack must be large enough to provide sufficient energy, increasing device size and complexity
Solution Approach 1:
The patent extracts the heat generation function from the battery pack by using the natural wellbore temperature as the heat source. This eliminates the need for a large battery pack while still achieving reliable trigger release through the thermal degradation of the retaining member at the predetermined temperature.
Solution Approach 2:
The system uses the wellbore environment itself (its temperature) to provide the heating function that was previously requiring an external battery-powered heat source. The wellbore temperature serves the dual purpose of both maintaining the tool in the unset position and eventually triggering the release when the temperature reaches the degradation point of the retaining member.
2Reliability
If high temperature is generated to burn fibers, then the trigger releases, but heat sensitive components must be shielded, increasing device complexity
Solution Approach 1:
The patent applies local quality by designing the retaining member with specific thermal properties (using materials like PTFE or polypropylene that degrade at predetermined temperatures) and positioning it such that it experiences the wellbore temperature directly. This localized thermal response allows trigger release without requiring widespread heat shielding throughout the tool.
3Reliability
If a large battery pack is used to provide sufficient electrical capacity for heat generation, then the trigger can be released, but the cost and reliability of the battery pack become problems
Solution Approach 1:
The patent removes the battery pack entirely from the system by extracting the heating function and replacing it with the natural wellbore temperature. This eliminates all costs and reliability issues associated with battery packs while maintaining the ability to release the trigger through thermal degradation of the retaining member.
4Reliability
If heat is applied to melt a plug to start the setting sequence, then the trigger is released, but the battery size becomes a space concern
Solution Approach 1:
The patent extracts the battery-powered heating function and replaces it with the wellbore temperature as the heat source. This eliminates the need for a large battery pack, thereby resolving the space constraint issue while still achieving reliable trigger release through the thermal melting of the plug at the appropriate depth.
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 enables predictable activation of downhole tools without heat sources, reducing tool size and cost, and improving safety by using extrudable materials that can be calibrated for specific operations, ensuring efficient and reliable tool actuation.
Implementation Method 1
when the extrudable material is moved, e.g., compressed or extruded, by an actuating member in the trigger device
Implementation Method 2
the extrudable material of the retaining member is moved, e.g., extruded or forced out of the path of movement of the actuating member
Data Source
AI summary
A trigger device for setting a downhole tool includes a retaining member that restricts the downhole tool from setting until it is properly positioned within the well and a force acts upon an actuating member. The retaining member includes an extrudable material that extrudes through an orifice when the force acts upon the actuating member. The extrudable material is preferably one that moves at a known rate so that the amount of time necessary for the downhole tool to set is pre-determined.