Ball-Activated Flapper Valve Retainer for Solids Pass-Through
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Solution Overview
Problem
The accumulation of solids in the annulus of a ball-activated flapper valve in a float collar leads to clogging and potential damage, slowing down the run-in process and increasing upward fluid pressure, which can break the retainer.
Innovation Solution
A downhole tool with a mandrel, tube, and retainer design that allows a first impediment to move axially and offset from the central longitudinal axis, featuring larger openings between fingers to accommodate larger solids and prevent clogging, along with valves that switch between inactive and active states based on the tube's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the annulus around the ball is kept small to control fluid flow, then fluid flow control is improved, but solids accumulation and clogging worsen
Solution Approach 1:
The retainer is divided into multiple fingers with openings between them, creating segmented flow paths. This allows solids to pass through the openings while the fingers maintain control over fluid flow, resolving the contradiction between fluid control and solids accumulation.
Solution Approach 2:
The fingers are positioned asymmetrically with non-uniform spacing, creating openings of varying sizes. This asymmetric configuration allows larger solids to pass through certain openings while maintaining effective fluid flow control, addressing both requirements simultaneously.
2Stress or pressure
If the ball is centered in the annulus to maintain flow path, then fluid flow is improved, but retainer breakage from increased upward force worsens
Solution Approach 1:
The fingers are pre-positioned to contact the ball before excessive upward force builds up. This preliminary contact redirects the force through the fingers to the retainer body, preventing the force buildup that would lead to retainer breakage while maintaining fluid flow.
Solution Approach 2:
The fingers act as intermediaries between the ball and the retainer body. They transfer and distribute the upward force from the ball to the retainer structure, preventing direct transmission of excessive force that would cause breakage while allowing the ball to remain centered for proper fluid flow.
3Productivity
If the run-in process is slowed to allow solids to pass through, then solids transport is improved, but run-in time increases
Solution Approach 1:
The finger structure adds a radial dimension to the flow path with openings positioned at different radial locations. This allows solids to pass through the openings in a different spatial configuration, enabling efficient solids transport without requiring slowing of the run-in process.
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
Prevents clogging and potential damage by allowing larger solids to pass through, reducing the risk of retainer failure and enhancing the run-in process efficiency.
Implementation Method 1
When the wellbore fluids exert an upward force on the ball (e.g., during run-in), the ball contacts the retainer
Implementation Method 2
The retainer is shaped such that a center of the first impediment is offset from a central longitudinal axis of the retainer when the first impediment is in the maximum upper position. Each adjacent pair of the fingers defines an opening therebetween. A first of the openings is larger than a remainder of the openings.
Data Source
AI summary
A downhole tool includes a mandrel and a tube positioned within the mandrel. The tube defines an inner shoulder proximate to a lower end thereof. The downhole tool also includes a retainer positioned within the mandrel and proximate to an upper end of the tube. A first impediment is configured to move axially between a maximum lower position and a maximum upper position. The first impediment is in the maximum lower position when the first impediment is in contact with the inner shoulder. The first impediment is in the maximum upper position when the first impediment is in contact with the retainer. The retainer is shaped such that a center of the first impediment is offset from a central longitudinal axis of the retainer when the first impediment is in the maximum upper position.