Deformable Formation Tester Seal Pad with Raised Edges
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Solution Overview
Problem
Existing formation testing tools face premature seal pad failure due to stress and pressure from downhole conditions, leading to unreliable sealing and reduced durability, which affects the accuracy and repeatability of hydrocarbon well testing.
Innovation Solution
A seal pad assembly featuring a metal skirt with an elastomeric pad element, where the pad is laterally supported by raised edges and ridges, reducing deformation stress and enhancing durability by distributing pressure across the seal surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple rubber pad is used for sealing, then the device complexity is reduced, but the seal pad durability and resistance to stress deteriorate
Solution Approach 1:
The seal pad assembly combines a rubber sealing element with a metal support member featuring raised edges and ridges. This composite structure integrates the sealing capability of rubber with the mechanical strength and stress distribution properties of the metal reinforced structure, thereby extending seal pad life while maintaining reasonable device complexity.
Solution Approach 2:
The metal support member incorporates raised edges and ridges that create a curved, three-dimensional sealing surface. This curvature distributes stress more evenly across the sealing interface compared to a flat surface, reducing stress concentration and extending the durability of the seal pad assembly.
2Duration of action of stationary object
If the seal pad is made more durable with reinforced structure, then the seal pad life is extended, but the device complexity increases
Solution Approach 1:
The combination of rubber and metal in a single integrated assembly provides durability enhancement without requiring multiple separate components. The metal support member with raised edges works synergistically with the rubber element, creating a durable seal pad assembly that maintains operational simplicity.
Solution Approach 2:
The raised edges and ridges on the metal support member are designed to deform dynamically under pressure, allowing the seal pad to adapt to variations in borehole wall conditions while maintaining sealing integrity. This dynamic response enhances durability without requiring an overly complex rigid structure.
3Reliability
If the isolation pad seals tightly against high pressure, then the sealing reliability is improved, but the stress on the pad increases leading to premature failure
Solution Approach 1:
The raised edges and ridges create a curved sealing surface that distributes the high sealing pressure across a larger area rather than concentrating it at a single point. This stress distribution maintains sealing reliability while preventing premature pad failure due to excessive stress concentration.
Solution Approach 2:
The metal support member bears the majority of the high sealing pressure, while the rubber element provides the necessary flexibility and sealing contact. This composite load-bearing approach protects the rubber pad from excessive stress while maintaining tight sealing against high pressure conditions.
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 enhanced seal pad assembly provides extended durability and reliability, allowing for increased testing cycles without replacement, ensuring accurate and repeatable hydrocarbon well data acquisition.
Implementation Method 1
The isolation pad seals against the formation and around a hollow sample probe, creating a sealing arrangement that creates a seal between the sample probe and the formation
Implementation Method 2
The pad is laterally supported by raised edges and ridges, reducing deformation stress and enhancing durability by distributing pressure across the seal surface
Data Source
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AI summary
A formation tester seal pad (400, 500, 600, 724, 824) includes a support member (402, 502, 602) and a deformable seal pad element (404, 504, 604) coupled to the support member, the seal pad element including an outer sealing surface having a plurality of raised portions (410, 510, 610) and adjacent spaces (420, 520, 620). In some embodiments, the raised portions are deformable into the adjacent spaces in response to a compressive load on the outer sealing surface. In some embodiments, the support member includes an inner raised edge (440, 540, 640) and an outer raised edge (450, 550, 650) to capture the deformable seal pad element. In some embodiments, a deformable seal pad element includes a volume (622) of seal pad material above a support member outer profile (442, 642) and a volume (624) of space below the outer profile. In some embodiments, the space volume receives a portion of the seal pad volume in response to a compressive load. Some embodiments further include a work string (5, 50, 101) and a formation tester (10, 60, 120, 200, 700, 800) including an extendable sample probe (64, 220, 706, 806).