Articulable Downhole Coupling for Bending and Pressure Isolation
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Solution Overview
Problem
Perforating tool strings face challenges in bending flexibility and pressure tolerance due to rigid tandem subs, limiting their ability to navigate bends and deviations in wellbores effectively.
Innovation Solution
The development of an articulable coupling with a ball and socket joint design that allows for flexible articulation between bars, incorporating insulated wires for electrical connectivity, and pressure isolation, enabling the tool string to bend and rotate freely while maintaining electrical conductivity and pressure integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If rigid tandem subs are used to connect perforating tools, then pressure tolerance is improved, but bending flexibility deteriorates
Solution Approach 1:
The tandem sub is divided into multiple segments: a first bar, a second bar, and a ball connection joint between them. This segmentation allows each segment to maintain structural strength while the joint provides articulation capability, resolving the contradiction between pressure tolerance and bending flexibility.
Solution Approach 2:
The ball connection joint introduces dynamic articulation capability to the otherwise rigid tandem sub structure. The joint allows the first and second bars to articulate relative to each other, enabling the tool string to navigate bends and deviations while maintaining pressure containment integrity.
2Strength
If rigid tandem subs are used to connect perforating tools, then structural strength is improved, but ability to navigate wellbore bends deteriorates
Solution Approach 1:
Dividing the tandem sub into articulated segments with a ball connection joint enables the structure to maintain strength in each segment while gaining the ability to navigate complex wellbore geometries through controlled articulation between segments.
Solution Approach 2:
The articulation joint transforms the static rigid structure into a dynamic system that can adapt its configuration to navigate wellbore bends and deviations, improving ease of operation during deployment and retrieval while maintaining structural integrity.
3Adaptability or versatility
If articulable coupling with ball connection is used, then bending flexibility is improved, but pressure containment capability may deteriorate
Solution Approach 1:
The pressure containment function is segmented from the articulation function: the ball connection joint provides articulation while separate seal elements and pressure-containing structures ensure pressure containment, allowing both bending flexibility and pressure reliability to coexist.
Solution Approach 2:
The ball connection joint acts as an intermediary element that transmits forces and maintains pressure containment while allowing articulation. The joint design includes sealing mechanisms that mediate between the articulation movement and pressure containment requirements.
Data Source
AI summary
A swivel assembly includes a first member having a first throughbore, a second member having a second throughbore, a flexible joint coupled between the first member and the second member that permits at least one of the first member and the second member to rotate an unlimited number of rotations relative to the other and that also connects the first throughbore and the second throughbore such that an electrical signal pathway for receiving an electrical signal conductor is formed that extends continuously through the flexible joint and between the first throughbore and the second throughbore, and a pressure bulkhead positioned along the electrical signal pathway that divides the electrical signal pathway into a pressure exposed zone that is exposed to external pressure from the surrounding environment and a pressure isolated zone that is isolated from the external pressure.