Radially Expandable Cup Seal Assembly for Downhole Wellbore Sealing
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Solution Overview
Problem
Existing downhole seal assemblies face challenges in achieving high expansion ratios without compromising sealing performance, often resulting in poor performance under high pressures and susceptibility to axial leakage and extrusion.
Innovation Solution
A seal assembly featuring a radially expandable seal element and a setting arrangement that displaces the seal element from a retracted to an extended configuration, forming a cup seal, which provides enhanced sealing and resistance to operational forces through a combination of mechanical and fluid-actuated mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the seal element is radially expanded to achieve high expansion ratios, then the seal can pass through wellbore restrictions and be deployed in constrained spaces, but the sealing performance deteriorates with poor performance against high pressures and susceptibility to axial leakage and extrusion
Solution Approach 1:
The seal element transitions from a compressed transport configuration to an expanded operational configuration. The element is radially expandable, allowing it to be run into the wellbore in a compact state and then expanded to engage the bore wall for sealing. This dynamic transformation enables both high expansion ratio and maintained sealing performance.
Solution Approach 2:
The seal element's radial dimension is changed from a retracted state to an expanded state. By controlling the expansion parameters and the degree of radial expansion, the element achieves sufficient interference with the bore wall to provide effective sealing while maintaining structural integrity against high pressures and extrusion forces.
2Reliability
If the seal element is expanded to provide adequate sealing interference with the bore wall, then sealing performance improves, but the outer diameter increases making deployment through constricted spaces difficult
Solution Approach 1:
The seal element utilizes dynamic radial expansion to achieve large outer diameter only when needed for sealing. During deployment and transport, the element maintains a small compressed outer diameter. The expansion is activated at the sealing location to provide the necessary interference fit with the bore wall.
Solution Approach 2:
The seal element is structured as a radially expandable component that can be divided into different functional zones. The expansion mechanism allows selective radial displacement of portions of the element, enabling adequate sealing interference at the sealing surface while keeping other portions compact for easy deployment through constricted spaces.
3Length of stationary object
If the seal element is highly expanded to reach the bore wall, then the sealing contact is achieved, but the element becomes susceptible to extrusion and axial leakage
Solution Approach 1:
The seal element's radial position is changed from retracted to extended configuration through controlled expansion. This parameter change achieves sufficient seal contact with the bore wall while maintaining the element's structural parameters (such as wall thickness and material properties) to resist extrusion and axial leakage under operational conditions.
Solution Approach 2:
The seal element transitions dynamically between compressed and expanded states. In the expanded state, the element achieves full seal contact with the bore wall. The dynamic nature of the expansion allows the element to maintain optimal structural integrity for resisting extrusion forces while providing adequate sealing contact.
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 enables effective sealing with high expansion ratios while maintaining performance under pressure, reducing axial leakage and extrusion risks, and providing stability to the seal element.
Implementation Method 1
When in the extended configuration, the seal element responds to a pressure differential across the seal to establish and/or enhance a seal with a bore wall
Implementation Method 2
a setting arrangement mounted on the mandrel and being arranged to displace the seal element radially outwardly from a retracted configuration to an extended configuration
Data Source
AI summary
A seal assembly for establishing a seal in an annulus between a mandrel and a bore wall includes a mandrel, a radially expandable seal element mounted on the mandrel, and a setting arrangement mounted on the mandrel and being arranged to displace the seal element radially outwardly from a retracted configuration to an extended configuration. The expandable seal element defines a cup seal when in the extended configuration.