Expandable Packer Sealing Element Multi-Point Engagement
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Solution Overview
Problem
Existing expandable casing systems for oil and gas wells struggle to effectively seal open-hole wells, as the sealing elements often fail to provide a reliable isolation between different well regions due to inadequate contact with the wellbore walls.
Innovation Solution
The expandable casing packing element system includes a sealing element disposed between retainer rings, which are designed to expand radially outward, allowing the sealing element to extrude and engage the wellbore wall at multiple points, ensuring a secure seal by utilizing either flat cross-section retainer rings or flared retainer rings that compress and extrude the sealing element through a gap to contact the wellbore.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sealing element is designed to contact the wellbore wall with a simple single-point contact mechanism, then the device complexity is reduced, but the sealing reliability deteriorates due to inadequate contact with the wellbore walls
Solution Approach 1:
The sealing element is divided into multiple contact points or segments that can independently engage with the wellbore wall. This segmentation allows each point to make reliable contact while distributing the sealing load, thereby improving overall sealing reliability without requiring an overly complex mechanism. The segmented design enables the sealing element to adapt to wellbore irregularities at multiple locations simultaneously.
Solution Approach 2:
The sealing mechanism transitions from simple radial contact to multi-dimensional engagement by incorporating axial and angular components. The sealing element is designed to engage the wellbore wall not only radially but also with axial compression and angular orientation, creating a three-point or multi-point contact system. This dimensional enhancement improves sealing reliability by distributing contact forces across multiple spatial dimensions.
2Reliability
If the sealing element is made highly compliant to ensure contact with irregular wellbore surfaces, then the sealing reliability improves, but the ability to maintain structural integrity under high pressure deteriorates
Solution Approach 1:
The sealing element is constructed from composite materials that combine the compliance needed for surface contact with the strength required for pressure resistance. This may involve combining elastomeric materials for compliance with reinforcement fibers or layered composite structures. The composite construction allows the sealing element to deform and conform to irregular wellbore surfaces while maintaining sufficient structural integrity to withstand high wellbore pressures without failing.
Solution Approach 2:
Different regions of the sealing element are designed with different material properties or structural characteristics. The outer surface contacting the wellbore is made highly compliant for conformal contact, while the inner structure maintains higher strength and rigidity to resist pressure. This local differentiation of material quality allows the sealing element to simultaneously achieve both compliance for sealing and strength for pressure resistance in different zones of the same component.
3Device complexity
If the expandable casing is designed to expand uniformly in all directions, then the structural simplicity is maintained, but the ability to achieve effective sealing engagement with the wellbore wall deteriorates
Solution Approach 1:
The expansion mechanism is designed to provide non-uniform, localized expansion in specific directions rather than uniform expansion in all directions. The casing structure incorporates features that enable differential expansion, allowing certain segments to expand radially outward with greater force or precision to achieve optimal sealing engagement. This localized expansion capability improves sealing precision by directing expansion forces where they are most needed at the sealing interface.
Solution Approach 2:
The expansion mechanism transitions from a static, uniform expansion design to a dynamic, controlled expansion system. The casing is designed to expand in a controlled sequence or with varying rates in different directions, allowing precise adjustment of the sealing engagement. This dynamic expansion capability enables the system to adapt to wellbore conditions and achieve precise sealing contact, improving manufacturing precision of the sealing engagement.
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 solution provides a robust and reliable sealing mechanism that effectively isolates well regions by ensuring the sealing element engages the wellbore wall at multiple points, enhancing the sealing efficiency and durability of the expandable casing system in both open-hole and cased wellbores.
Implementation Method 1
the sealing element is forced radially outward by the expansion of the expandable casing against the two retainer rings
Implementation Method 2
the flares are forced inward to compress the sealing element which is then extruded radially outward
Implementation Method 3
applying a radial load to expand the expandable casing
Implementation Method 4
the expandable casing is expanded by the cone. The expansion of the expandable casing causes the sealing device to contact the formation
Data Source
AI summary
The expandable casing packing element systems for cased and open-hole wellbores include an expandable casing member having a sealing device comprising a sealing element disposed between at least two retainer rings. The retainer rings have flat cross-sections and the sealing element is forced radially outward by the expansion of the expandable casing against the two retainer rings such that the sealing element protrudes outwardly beyond the retainer rings and engages the wall of a wellbore in three locations. The retainer rings can also include flares that extend outwardly from the body of the expandable casing to which they are attached. As the expandable casing is expanded, the flares are forced inward to compress the sealing element which is then extruded radially outward through a gap between the two retainer rings to engage and seal off the wellbore.