Downhole Shifting Tool Radial Arm Control
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Solution Overview
Problem
Existing downhole sleeve actuation systems are costly and complex, with a need for robust and reliable methods to simplify the interaction between sleeve valves and shifting tools, particularly in reducing the length and expense of sleeve valves and enabling uphole sleeve actuation.
Innovation Solution
A shifting tool using a radially actuable constrictor spider and J-Slot mechanism to manipulate arms and dogs, allowing for selective engagement and disengagement of sleeve profiles, with a cam profile varying in height to control radial positioning and minimize annular obstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sleeve actuation systems are used, then reliable sleeve operation is achieved, but device complexity and cost increase
Solution Approach 1:
The system divides the sleeve actuation function into separate components: the shifting tool with multiple dogs for engaging different sleeves, and the sleeve valve with dog-receiving profiles. Each component performs a specific function, allowing independent optimization and simplification of the overall system while maintaining reliable operation.
Solution Approach 2:
The shifting tool is designed with multiple dogs and a constrictor spider that can interact with multiple sleeve valves along the tubing string. This multi-functional design allows a single tool to actuate multiple sleeves sequentially, reducing the need for multiple specialized tools and simplifying the overall system architecture.
2Reliability
If conventional sleeve valves are used, then sleeve sealing function is achieved, but length and expense increase
Solution Approach 1:
The dog-receiving profile is integrated directly into the sleeve structure, and the dogs are nested within the shifting tool body. This nesting arrangement eliminates the need for separate external actuation mechanisms, significantly reducing the overall length of the sleeve valve while maintaining the sealing function.
Solution Approach 2:
The actuation function is extracted from the sleeve valve itself and placed in the shifting tool. By removing the complex actuation mechanism from the sleeve and placing it in the conveyed tool, the sleeve valve can be simplified to primarily sealing and flow control functions, reducing its length and cost.
3Adaptability or versatility
If additional components are added for uphole actuation, then versatility is improved, but device complexity increases
Solution Approach 1:
The constrictor spider is designed to be radially movable between expanded and contracted states. When expanded, it engages and radially positions the dogs for sleeve actuation; when contracted, it allows the tool to be conveyed through the tubing. This dynamic transformation allows the same component to serve multiple functions without adding permanent complexity.
Solution Approach 2:
The radial position parameter of the constrictor spider and dogs is changed during operation. By transitioning from a radially contracted state during conveyance to a radially expanded state during actuation, the system achieves versatility without requiring additional components for different operational modes.
4Manufacturing precision
If radially controllable arms are used, then sleeve engagement precision is improved, but annular obstruction increases
Solution Approach 1:
The arms are designed to be radially movable rather than fixed. They extend radially outward only when needed to engage the sleeve dog-receiving profiles with precise positioning. During conveyance and when not in use, the arms are retracted radially inward, minimizing annular obstruction and allowing fluid flow and tool movement.
Solution Approach 2:
The radial position parameter of the arms is dynamically changed based on operational requirements. By transitioning between retracted and extended positions, the system achieves precise sleeve engagement when needed while minimizing interference with fluid flow and tool conveyance at other times.
Data Source
AI summary
A shifting tool is provided for locating and actuating downhole tools in a downhole tubular string, such as sleeve valves spaced along a completion string. The shifting tool includes dogs at ends of two or more radially controllable, and circumferentially spaced support arms. The arms are manipulated with an axially movable arm-constrictor spider for engaging radially variable cams on the sides of the arms. The spider includes cam follower tabs to cam the arms radially inward for in and out of hole movement, and for releasing the arms for sleeve locating and sleeve profile engagement. The tabs are radially inset from the arms to minimize obstruction of a tool annulus and interference damage when travelling along the downhole string.