Self-Arming Perforating Gun With Movable Detonator Holder
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Solution Overview
Problem
Existing perforating gun systems for subterranean wells face challenges in reducing tool length, minimizing human error in assembly, and achieving accurate orientation in horizontal wells, particularly due to the use of wired-in switches and large initiating cartridges, as well as inaccuracies in traditional orienting methods using eccentric weight bars.
Innovation Solution
A perforating gun system with a movable detonator holder that transitions from a ballistically unarmed to a ballistically armed position upon connection with another gun, eliminating the need for direct alignment with the detonating cord, and utilizing a self-arming mechanism to connect the detonator to the ballistic train.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wired-in switches and large initiating cartridges are used in perforating gun systems, then reliable detonation can be achieved, but tool length increases and assembly complexity increases
Solution Approach 1:
The patent extracts the detonator from fixed positioning within the gun body and places it on a movable holder that can be positioned independently. This allows the use of a compact initiator while maintaining reliable detonation, eliminating the need for large initiating cartridges and reducing overall tool length.
Solution Approach 2:
The detonator is mounted on a movable holder that can transition between different positions during assembly and operation. This dynamic positioning capability allows the system to achieve reliable ballistic alignment without requiring the detonator to be pre-positioned at a fixed location, thereby reducing tool length while maintaining detonation reliability.
2Ease of operation
If wired-in switches are used in perforating gun systems, then detonation control can be achieved, but device complexity and assembly errors increase
Solution Approach 1:
The patent replaces wired-in electrical switches with a mechanical self-arming mechanism. The movable detonator holder automatically establishes or breaks ballistic contact based on its position, eliminating the need for complex electrical wiring and switches, thereby reducing assembly complexity and potential assembly errors while maintaining detonation control.
Solution Approach 2:
The system uses the physical position of the movable detonator holder itself to control detonation through automatic ballistic contact establishment or breaking. This self-service mechanism eliminates the need for separate control systems, reducing device complexity and minimizing assembly errors associated with wiring and switch installation.
3Adaptability or versatility
If traditional orienting methods using eccentric weight bars are used in horizontal wells, then orientation can be achieved, but orientation accuracy decreases
Solution Approach 1:
The movable detonator holder provides dynamic positioning capability that enables more precise orientation control compared to static eccentric weight bars. The ability to actively adjust and lock the detonator at specific angular positions allows for improved orientation accuracy while maintaining adaptability to different well configurations.
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
Reduces tool length, minimizes assembly errors, and enhances orientation accuracy in horizontal wells by simplifying the assembly process and eliminating the need for direct detonator-cord alignment, thereby improving operational efficiency and safety.
Implementation Method 1
a detonator housed in a hinged detonator holder configured to move the detonator between a ballistically unarmed position to a ballistically armed position
Data Source
AI summary
A method and apparatus for a perforating gun having a movable detonator holder in a first perforating gun that is positioned inside the carrier such that the detonator is not directly positioned end to end nor side by side with the detonating cord in the loading tube. When a second perforating gun is screwed onto the first perforating gun, the entire charge tube assembly moves, closing the detonator holder further into the carrier such that the detonating holder closes in on the detonating cord until the detonator is adjacent to the detonating cord to connect the detonator to detonating cord ballistic train.