Frangible Electrical Connector for Perforating Gun Retrieval
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Solution Overview
Problem
Existing perforating gun systems often experience issues with tool strings becoming stuck in wellbores due to damaged electrical connectors, leading to costly and time-consuming retrieval processes.
Innovation Solution
The implementation of a frangible electrical connector with a conductor rod having a shear strength of 1,500 pound-force (lbf) or less, featuring frangible grooves that weaken the rod and allow it to yield under shear loads, thereby facilitating dislodgment of stuck tool strings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional electrical connector is used in the perforating gun system, then electrical connectivity is maintained, but the connector may become dislodged and project into the annulus causing the tool string to become stuck
Solution Approach 1:
The electrical connector is segmented into a frangible portion and a non-frangible portion. The frangible portion is designed to break away under certain conditions, while the non-frangible portion maintains structural integrity and electrical connectivity. This segmentation allows the connector to fulfill its electrical function while preventing it from becoming a hazard that could cause the tool string to stick.
Solution Approach 2:
The harmful potential of the electrical connector is extracted by making the frangible portion detachable. When the connector becomes dislodged, the frangible portion breaks away and is removed from the system, preventing it from projecting into the annulus and causing the tool string to become stuck, while the non-frangible portion remains to maintain electrical connectivity.
2Reliability
If the electrical connector is made stronger to prevent dislodgment, then connectivity is improved, but the risk of the connector projecting into the annulus and jamming the tool string increases
Solution Approach 1:
Different portions of the electrical connector have different strength properties. The frangible portion is designed with lower shear strength to break away under excessive force, while the non-frangible portion is designed with higher strength to maintain structural integrity and electrical connectivity. This local differentiation of quality allows the connector to both maintain connectivity and prevent jamming.
3Ease of operation
If a frangible conductor rod with low shear strength is used, then the connector can yield under shear loads to prevent sticking, but the electrical connectivity may be compromised
Solution Approach 1:
The electrical connector is divided into frangible and non-frangible portions, where the frangible portion yields under shear loads to enable tool string retrieval, while the non-frangible portion maintains electrical connectivity. This segmentation ensures that the weakening necessary for easy retrieval does not compromise the electrical connection.
Solution Approach 2:
The frangible portion is extracted as a separate functional element that can yield or break away under shear loads. This extracted portion provides the ease of operation for tool string retrieval, while the remaining non-frangible portion continues to provide reliable electrical connectivity.
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 frangible electrical connector effectively reduces the risk of tool strings becoming stuck by allowing the connector to shear or yield under tension, enabling successful retrieval of the tool string without the need for expensive specialized equipment.
Implementation Method 1
the frangible conductor rod having a shear strength of 1,500 pound-force (lbf) or less
Data Source
AI summary
A perforating gun deployable in a wellbore includes an outer housing included of a generally tubular wall structure having a pair of opposed longitudinal ends and a central passage extending between the pair of longitudinal ends, a charge carrier assembly received in the central passage of the outer housing and including a tubular charge carrier having a pair of opposed longitudinal ends and at least one radially oriented receptacle configured to receive a combustive shaped charge, an initiator assembly, the initiator assembly including a detonator and an electrical switch configured to detonate the detonator in response to receiving a firing signal, and an electrical connector positioned in the central passage of the outer housing and electrically connected to the initiator assembly, the electrical connector including an electrical contact including a frangible conductor rod, the frangible conductor rod having a shear strength of 1,500 pound-force (Ibf) or less.