Expandable Packer Sealing Element With Alternating Bands
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Solution Overview
Problem
Conventional expandable tubing sealing methods often result in unreliable seals due to low seal pressure and localized sealing, which fails to effectively block fluid flow through the annulus surrounding the tubing in wellbores.
Innovation Solution
An expandable packer assembly with a sealing element featuring alternating thick and thin bands on its outer surface, where the thin bands allow for greater expansion, creating undulations that enhance sealing performance by increasing collapse resistance and maintaining high pressure sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a uniform sealing element is used on expandable tubing, then the structure is simple and easy to manufacture, but the sealing pressure is insufficient and the seal is unreliable
Solution Approach 1:
The sealing element employs alternating thick and thin bands along its length, creating localized variations in sealing pressure. The thin bands concentrate sealing force at specific points to achieve reliable sealing, while the thick bands provide structural support and material reservoir. This non-uniform distribution resolves the contradiction by making different portions of the sealing element serve different functions.
Solution Approach 2:
The sealing element is divided into discrete thick and thin bands rather than being uniform. This segmentation allows the element to create undulations in the tubing wall during expansion, with thin bands forming contact points that concentrate sealing pressure. The segmented structure enables reliable sealing without requiring excessive overall complexity.
2Reliability
If the tubing is expanded uniformly, then the structure remains simple, but elastic recovery reduces sealing pressure and compromises seal integrity
Solution Approach 1:
The expansion is made non-uniform through the alternating thick and thin bands. The thin bands expand more than the thick bands, creating localized undulations in the tubing wall. This localized expansion pattern maintains higher sealing pressure by preventing uniform elastic recovery, as the undulated structure creates mechanical interlocking with the surrounding formation.
Solution Approach 2:
The sealing element transitions from a uniform pre-expansion state to a dynamic undulated state during expansion. The alternating bands create a progressive expansion pattern where thin bands form contact points that dynamically adjust to the formation geometry, maintaining sealing pressure despite elastic recovery of the tubing material.
3Reliability
If a single-band sealing element is used, then the design is simple, but the sealing is localized and often fails to achieve sufficient seal pressure
Solution Approach 1:
The sealing element is segmented into multiple thick and thin bands along its length, creating multiple contact points with the formation. The thin bands specifically are designed to protrude less and form the primary sealing contact points. This segmentation distributes sealing force across multiple locations, achieving reliable sealing pressure that overcomes the limitations of a single-band design.
Solution Approach 2:
Different bands serve different sealing functions: thin bands create concentrated sealing pressure at contact points, while thick bands provide structural support and material compliance. This local differentiation of band properties enables the sealing element to achieve high seal pressure through the thin bands without compromising overall structural integrity.
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 achieves improved sealing performance by increasing sealing pressure and reducing elastic recovery, maintaining high pressure sealing up to 6500 psi without failure, significantly surpassing the capabilities of prior sealing elements.
Implementation Method 1
The tubing is expanded such that relatively greater expansion occurs at where the thin bands are located compared to where the thick bands are located
Implementation Method 2
maintaining high pressure sealing up to 6500 psi without failure
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Methods and apparatus include tubing expanded to create a seal in an annulus surrounding the tubing. The tubing includes a sealing material selected to cause forming of undulations in a diameter of the tubing upon expansion of the tubing. Various factors of the sealing material such as deviations in its thickness influence sealing performance of the tubing with the sealing material.