Movable Mandrel Packer for Thermal Expansion Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional packers for sealing against a formation surface in oil wells face challenges such as mechanical wear and damage due to pressure differentials and thermal expansion, which can lead to suboptimal sealing and potential fracturing of the formation surface.
Innovation Solution
A packer design featuring a mandrel that is free to move axially with respect to the packing and anchoring elements, allowing for thermal expansion without affecting the seal, combined with an interlock mechanism for controlled setting and a separate anchoring element that can withstand differential pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional packers use rubber inflatable elements or swelling elements to seal against formation surface, then sealing capability is achieved, but mechanical wear and damage occur due to pressure differentials causing element movement
Solution Approach 1:
The packer is divided into separate functional elements: a packing element for sealing and an anchoring element for securing the packer. This segmentation allows each element to perform its specific function optimally without the packing element bearing the full mechanical stress of anchoring, thereby reducing wear and damage while maintaining sealing capability.
Solution Approach 2:
The mandrel is designed to be free to move axially within the packer body after setting. This dynamic capability allows the mandrel to accommodate thermal expansion and contraction of the packer components without transmitting excessive forces to the packing element or formation surface, preventing mechanical damage while maintaining seal integrity.
2Reliability
If substantial pressure differential is applied across the packing element to maintain seal, then sealing effectiveness is improved, but element movement is caused resulting in mechanical wear
Solution Approach 1:
By separating the packing element from the anchoring element, the pressure differential across the packing element can be optimized for sealing effectiveness without being compromised by anchoring requirements. The anchoring element independently handles the securing function, allowing the packing element to remain stable under pressure differentials.
Solution Approach 2:
The packer body acts as an intermediary between the packing element and the external environment. It transmits the pressure differential to the packing element for sealing while the separate anchoring element provides stability, preventing element movement even under substantial pressure differentials.
3Stability of the object's composition
If packer components are rigidly fixed to prevent movement, then anchoring stability is improved, but thermal expansion and contraction cause damage to formation surface
Solution Approach 1:
The mandrel is designed to move axially within the packer body, creating a dynamic system that can accommodate thermal expansion and contraction. This movement capability allows the packer to maintain anchoring stability through the separate anchoring element while the mandrel absorbs thermal dimensional changes, preventing damage to the formation surface.
Solution Approach 2:
The packer design explicitly accounts for thermal expansion and contraction of components. The movable mandrel and separate anchoring element configuration allow the packer to expand and contract thermally without generating excessive forces that would damage the formation surface, while maintaining stable anchoring through the dedicated anchoring element.
4Device complexity
If anchoring element is integrated with packing element, then device complexity is reduced, but differential pressure causes element movement and seal failure
Solution Approach 1:
The packer employs separate packing and anchoring elements that can function independently. This segmentation allows the anchoring element to provide stable mechanical securing while the packing element maintains the seal, with both elements optimized for their specific functions rather than compromising performance through integration.
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 design ensures a stable seal that is not compromised by thermal changes or pressure differentials, reducing the risk of formation damage and maintaining packer integrity over time.
Implementation Method 1
the mandrel is free to move with respect to the packing and anchoring elements... allows the mandrel, in use and once the packer is set, to move in response to thermal changes occurring within the well
Implementation Method 2
the element engages the rock surface and relies on seal friction between the element and the formation surface to provide the anchor
Data Source
AI summary
A packer for a well is described. The packer comprises at least one packing element, at least one anchoring element, and a mandrel coupled to the at least one anchoring element. The packer is arranged such that, once set, the mandrel is free to move with respect to the packing and anchoring elements. In one embodiment the at least one anchoring element is integral with the at least one packing element. In an alternative embodiment the at least one anchoring element is separate from the at least one packing element.