Shape Memory Polymer Downhole Packer Seals
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Solution Overview
Problem
Conventional downhole packers and bridge plugs face challenges such as limited size due to deformable elements passing through restrictions, slow swelling of swellable elements, damage to inflatable elements, buckling of compression sleeves, and extrusion issues with thermoplastics, which affect sealing efficacy and retrievability.
Innovation Solution
The use of shape memory polymers (SMPs) in downhole tools, which can change shape in response to stimuli like heat, light, or magnetic fields, allowing for improved sealing, reduced extrusion, and enhanced retrievability by transitioning between compact and expanded states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a deformable element is used to pass through restrictions smaller than the borehole diameter, then the element can be deployed through narrow passages, but the element's size is limited by the smallest restriction diameter
Solution Approach 1:
The packing element uses shape memory polymer material that can dynamically change its shape between a compressed configuration (for passing through restrictions) and an expanded configuration (for sealing the borehole). This dynamic shape transformation allows the element to overcome the size limitation imposed by restriction diameters.
2Area of stationary object
If a compression set element with a long sleeve is used to seal against larger annulus, then the sealing capacity is improved, but the sleeve may buckle or twist during compression
Solution Approach 1:
The packing element employs shape memory polymer material that combines the properties of both rigid and flexible materials. This composite material structure provides the necessary structural stability to prevent buckling and twisting during compression, while still allowing the element to expand and seal against larger annulus areas.
3Object-generated harmful factors
If thermoplastics are used as back-up rings to prevent extrusion, then extrusion resistance is improved, but the rigidity makes them less useful for packing elements that need to expand outward
Solution Approach 1:
The shape memory polymer material undergoes parameter changes in response to thermal or other stimuli, transitioning between a rigid state (providing extrusion resistance) and a flexible state (enabling expansion outward to create seals). This allows the same material to perform both functions that previously required different materials.
4Area of stationary object
If swellable elements are used to form a seal, then the element can expand to seal the borehole, but the elements take several days to swell
Solution Approach 1:
The invention replaces the chemical swelling mechanism with a shape memory effect triggered by thermal or other physical stimuli. This substitution reduces the activation time from several days (chemical swelling) to a much shorter period (thermal response), while achieving the same sealing function.
5Ease of operation
If inflatable elements are used to seal the borehole, then the element can be deployed in a collapsed state, but the elements can become damaged and are affected by temperature changes
Solution Approach 1:
The shape memory polymer material undergoes controlled parameter changes in response to specific thermal stimuli, allowing the element to transition between collapsed and expanded states without the vulnerability of inflatable membranes. The material's inherent structural integrity is maintained throughout the transformation process, reducing damage risks.
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
SMPs enable effective sealing, reduce extrusion, and facilitate easier retrieval of downhole tools by maintaining a seal without absorbing fluids, while providing anti-extrusion benefits and reducing the need for excessive force in setting and retrieval processes.
Implementation Method 1
at least a portion of the inflatable element is composed of a shape memory polymer and activates from a first state to a second state in response to a predetermined stimulus
Implementation Method 2
the sealing element's material tends to flow into any gap between the seal bore and a gage ring... SMPs enable effective sealing, reduce extrusion
Data Source
AI summary
Anti-extrusion devices, packer elements, and inflatable packers include shape memory polymer (SMP) materials to enhance the operation of a packer, a bridge plug, or other downhole isolation tool. Seal system use seals of various material including SMP materials as booster for the seal produced. Tool for flow shut-off and sliding sleeve applications use SMP materials to open or close off flow through a tool.