Annular Barrier With Segmented Sleeve For Collapse Resistance
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Solution Overview
Problem
Annular barriers in wellbores face challenges in withstanding collapse pressure due to insufficient collapse rating, which can lead to sealing failures, especially in high drawdown pressure environments, and increasing material strength or wall thickness to address this issue increases expansion pressure, which is undesirable.
Innovation Solution
The annular barrier design incorporates an expandable sleeve with a unique element structure that includes a first part fastened to the inner face and a second part projecting radially or at an angle, providing additional strength and resistance to collapse without increasing material strength or wall thickness, allowing for lower expansion pressure and enhanced sealing capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the wall thickness of the expandable sleeve is increased to increase the collapse rating, then the collapse rating is improved, but the expansion pressure increases
Solution Approach 1:
The expandable sleeve is divided into multiple sections along its longitudinal extension, with at least one section having increased thickness. This segmentation allows the sleeve to have higher collapse resistance in specific areas without requiring the entire sleeve to be thick-walled, thereby reducing the overall expansion pressure needed while maintaining adequate collapse rating.
2Strength
If the strength of the material is increased to increase the collapse rating, then the collapse rating is improved, but the expansion pressure increases
Solution Approach 1:
Instead of using high-strength material throughout the entire sleeve, the invention applies increased thickness locally to specific sections where collapse resistance is most needed. This local quality approach provides enhanced collapse rating in critical areas while using standard material properties elsewhere, thereby minimizing the required expansion pressure.
3Strength
If the wall thickness is increased to withstand high collapse pressure, then the collapse rating is improved, but the device complexity and cost increase
Solution Approach 1:
The sleeve structure is segmented into different thickness zones along its length, with only specific sections having increased thickness. This segmentation avoids the need for a uniformly complex thick-walled structure, reducing overall device complexity while providing enhanced collapse resistance where required by the application.
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
This design significantly increases the collapse rating of the annular barrier, enabling it to withstand higher pressures while maintaining or reducing expansion pressure and enhancing sealing effectiveness, thus addressing the limitations of existing annular barriers.
Implementation Method 1
The expandable sleeve may be expanded by increasing the pressure within the well
Implementation Method 2
The expandable sleeve is typically made of an elastomeric material
Data Source
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AI summary
The present invention relates to an annular barrier to be expanded in an annulus between a well tubular structure and an inside wall of a borehole downhole. The annular barrier comprises a tubular part for mounting as part of the well tubular structure, an expandable sleeve surrounding the tubular part and having an inner face facing the tubular part, each end of the expandable sleeve being connected with a connection part which is connected with the tubular part, a space between the inner face of the sleeve and the tubular part, and an element arranged in connection with the sleeve, the element having a first part and a second part both of which extend around the inner face, the first part of the element being fastened to the inner face.