Deformable Ball-and-Seat Sealing for Reverse-Pressure Downholes
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Solution Overview
Problem
Existing downhole sealing technologies rely on pressure differentials to maintain seals, which can be unreliable in reverse pressure conditions, and alternative solutions like latches are complex.
Innovation Solution
A deformable ball and seat arrangement that engages bidirectionally, forming a seal through axial translation and deformation, utilizing a seat with restrictions and tapers to lock the ball in place, ensuring sealing engagement in both normal and reverse pressure conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a ball and seat arrangement is used to create a seal, then fluid isolation is achieved, but the seal fails under reverse pressure differential causing the ball to lift off
Solution Approach 1:
The ball is made deformable rather than rigid, allowing it to dynamically adapt its shape based on pressure direction. Under normal pressure, the ball deforms to seal against the seat; under reverse pressure, it deforms to engage with the tapered surface for mechanical retention, transforming from a static sealing component to a dynamic, pressure-responsive element
Solution Approach 2:
The system changes the physical state and geometric parameters of the ball based on pressure conditions. The ball transitions between different deformation states and engagement configurations depending on whether normal or reverse pressure is applied, allowing it to maintain functionality across varying pressure regimes
2Reliability
If a latch arrangement is used to provide bidirectional sealing, then sealing under reverse pressure is improved, but device complexity increases
Solution Approach 1:
The complex latch mechanism is removed entirely from the system. Instead of adding mechanical retention features, the invention extracts the retention function and integrates it into the ball itself through deformability, allowing the ball to provide both sealing and mechanical retention through its material properties rather than through separate structural components
Solution Approach 2:
The sealing function and mechanical retention function are merged into a single component - the deformable ball. Rather than having separate sealing elements and latch mechanisms, the ball simultaneously performs both functions through its ability to deform and engage with different surfaces of the seat based on pressure direction
3Reliability
If the ball is made deformable to improve sealing, then sealing engagement is enhanced, but the ball may become stuck in the seat
Solution Approach 1:
The ball's deformability is dynamic and reversible rather than permanent. After deforming to seal or engage during operation, the ball can recover its original shape when pressure is released, enabling it to be retrieved by reverse circulation without becoming permanently stuck in the seat
Solution Approach 2:
The deformable ball acts as a cushioning element that can be compressed or deformed to absorb pressure differentials and prevent permanent damage or sticking. This elastic deformation capability provides a safety mechanism that prevents the ball from becoming permanently lodged under high pressure conditions
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 solution provides a reliable, bidirectional seal that maintains sealing engagement under both normal and reverse pressure differentials, enhancing operational stability and reliability in downhole operations.
Implementation Method 1
at least one of the ball and the seat being deformable
Implementation Method 2
The ball may comprise a material which deforms on engagement with the seat but is capable of recovering to an original form or is self-healing
Implementation Method 3
The ball may move in the first axial direction in response to at least one of gravitational forces, entrainment in a moving fluid stream, or a differential pressure acting across the ball
Implementation Method 4
The ball may move in the first axial direction in response to at least one of gravitational forces, entrainment in a moving fluid stream
Implementation Method 5
the ball and the seat having an open first configuration and a sealing second configuration, in the open first configuration the ball and seat being spaced apart such that fluid may flow through the seat, and in the sealing second configuration the ball and the seat being in sealing engagement and configured to maintain the sealing engagement in response to a differential pressure acting in a first axial direction and in response to a differential pressure acting in an opposite second axial direction
Data Source
AI summary
A downhole sealing apparatus for location in a downhole tubular includes a ball and a downhole seat. The ball may comprise a rigid core and a deformable covering. The ball is translatable downhole towards the seat, the ball and the seat having an open first configuration and a sealing second configuration. In the open first configuration the ball and seat are spaced apart such that fluid may flow through the seat. In the sealing second configuration the ball and the seat are in sealing engagement and the ball is deformed to maintain the sealing engagement with the seat in response to a differential pressure acting in a first axial direction and in response to a differential pressure acting in an opposite second axial direction.