Backup Bullet Seal with Actuation Delay
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Solution Overview
Problem
Existing high pressure and high temperature seal designs face reliability issues due to significant temperature fluctuations, particularly above 200 degrees F, as they lack a backup seal mechanism that is effectively activated only when the primary seal fails, and are prone to premature activation during assembly, which can lead to distortion or failure.
Innovation Solution
A sealing system featuring primary and secondary bullet seals where the secondary seal is bidirectional and activated by differential pressure after a temperature-sensitive stop material softens, allowing a t-shaped ring to advance and spread the fins for enhanced sealing, with the backup seal being delayed in deployment until primary seal failure or specific thermal conditions are met.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a backup seal is installed in an activated configuration to provide immediate sealing, then sealing reliability is improved, but the seal is prone to premature activation during assembly causing distortion or failure
Solution Approach 1:
The backup seal is pre-positioned in a dormant state during assembly, with the t-shaped ring and stop material arranged to prevent premature activation. The seal is prepared in advance but remains inactive until thermal conditions trigger the stop material to soften, allowing the ring to advance and activate the seal only when needed.
Solution Approach 2:
The activation state of the backup seal is controlled by changing the temperature parameter. The stop material is selected to soften at a specific temperature threshold, transforming the seal from a dormant to an activated state. This temperature-dependent parameter change ensures the seal activates only under the intended thermal conditions, not during assembly.
2Reliability
If a backup seal is designed to activate immediately under pressure, then sealing reliability is improved, but temperature fluctuations cause premature activation
Solution Approach 1:
The stop material serves as an intermediary element between the pressure differential and the t-shaped ring. It mediates the activation process by blocking the ring's advancement until the temperature causes the material to soften. This intermediary prevents direct pressure-induced activation while allowing controlled activation through thermal softening of the stop material.
Solution Approach 2:
The activation mechanism relies on temperature-induced parameter changes in the stop material. The material's physical properties (softening point) change at a specific temperature threshold, triggering the seal activation. This parameter-based control distinguishes between normal temperature fluctuations and the specific thermal condition that should activate the backup seal.
3Reliability
If the stop material is made more resistant to prevent premature activation, then activation control is improved, but the delay in backup seal deployment increases
Solution Approach 1:
The stop material is selected with specific thermal properties that define a clear activation threshold. By carefully choosing materials with appropriate softening temperatures, the system achieves reliable discrimination between normal operating temperatures and the specific thermal condition requiring backup seal activation. This parameter optimization balances activation control with timely response.
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 solution ensures reliable sealing performance by delaying the activation of the backup seal until primary seal failure or specific thermal conditions, preventing leakage and maintaining structural integrity under extreme temperature and pressure conditions, while facilitating easier assembly by reducing premature activation risks.
Implementation Method 1
there is the effect of temperature of well fluids to allow the t-shaped ring to advance as the material on the leading branch of the t-shaped ring softens
Data Source
AI summary
A sealing system features a primary and secondary bullet seals where the secondary seal is preferably bidirectional and is activated to spread fins with a t-shaped ring that is driven with differential pressure to advance after temperature exposure softens a stop material on the extending portion of the t-shaped ring. Opposed t-shaped rings are disposed at ends of the backup ring that have fins at both ends. Advancement of the t-shaped ring spreads the fins and retains them in the spread condition for enhanced sealing. Optionally the primary seal can also be actuated with a similar t-shaped ring with a temperature sensitive delay feature.