Resettable Downhole Tool Actuator with Deformable Collet
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Solution Overview
Problem
Existing downhole tool actuators are unsuitable for repeated operation and inconvenient to use, as they either require permanent shearing of components or need special tools for resetting, limiting their application in applications requiring frequent actuation and high actuation loads.
Innovation Solution
A resettable downhole tool actuator with a housing, axially movable support, and a collet that allows a ball to engage and restrict fluid flow, generating a pressure differential to drive the support and piston for movement, with a design that enables the ball to pass through and reset the actuator for repeated cycling, minimizing load transmission through the collet and reducing the risk of damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dropped ball actuator uses permanent shearing of a shear pin to allow ball passage, then the ball can pass through the seating, but the actuator cannot be reset for repeated operation
Solution Approach 1:
The collet is designed to be dynamically deformable rather than permanently deformed. The increased diameter region allows the collet to elastically expand outward when the ball engages the seating, enabling the ball to pass through without permanent shearing of any pins or components. This dynamic deformation allows the actuator to be reset and cycled repeatedly.
Solution Approach 2:
The internal diameter of the housing is changed at a specific location to create an increased diameter region. This parameter change allows the collet to expand beyond its normal constraints when needed, enabling ball passage without permanent damage. The parameter change is localized and reversible, allowing repeated operation.
2Reliability
If high pressure fluids are applied to urge the seating to expand, then the ball can pass through, but a braking load is applied that prevents reliable operation
Solution Approach 1:
The housing is segmented into regions with different diameters, creating a constrained section and an expanded section. This segmentation allows the collet to expand in a controlled manner at the increased diameter region while maintaining constraints elsewhere, reducing unwanted braking loads on the seating and enabling reliable repeated operation.
3Ease of operation
If a special resetting tool is used to reset the valve, then the valve can be reset for repeated use, but the device becomes inconvenient and complex to operate
Solution Approach 1:
The actuator is designed to reset automatically when the ball passes through the seating and the collet returns to its original position. The increased diameter region allows the collet to expand and contract reversibly without requiring external resetting tools. The system serves itself by using the ball's passage and fluid pressure to accomplish the reset function.
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
Enables repeated and convenient actuation with the ability to apply large loads, reducing the risk of damage to the collet and allowing reliable operation in applications requiring frequent cycling, such as under reamers, by resetting the actuator after each use.
Implementation Method 1
fluid flow through an axially extending passage provided in the support is restricted, increasing the fluid pressure to which the piston is exposed thereby applying an increased load to the support urging the support for movement relative to the housing
Implementation Method 2
the movement of the ball is temporarily arrested when it reaches the actuator by engagement of the ball with part of the actuator... the pressure upstream of the ball and seating rises, physically displacing the seating
Data Source
AI summary
A resettable downhole tool actuator comprises a housing, a collet slidable within the housing and defining a seating with which a ball is engageable, in use, the collet being mounted upon a moveable support including a piston and arranged such that, when the bail engages the seating, fluid flow through an axially extending passage provided in the support is restricted, the housing including an increased diameter region arranged such that, when the seating is aligned with the increased diameter region, outward deflection of the collet permits the ball to pass through the seating and through the axially extending passage.