Wellhead Seal Assembly Single-Load Dual Sealing
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Solution Overview
Problem
Traditional dual seal assemblies in high-pressure wellhead applications require distinct pressures to set each seal, increasing the risk of improper sealing and component stress, while also being less space-efficient.
Innovation Solution
A tubing or casing hanger seal assembly with a dual seal packoff configuration, where both seals are set using a single load, utilizing a first carrier ring, energizing ring, and lock ring with angled engagement profiles to apply radial force, and a second energizing ring to secure the second seal, reducing the overall load and risk of missetting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If distinct pressures are applied to set each seal sequentially, then each seal can be set independently, but the device complexity increases and the risk of improper sealing increases
Solution Approach 1:
The patent combines the functions of setting multiple seals into a single pressure application event. The bellows structure expands simultaneously to engage multiple seals at once, eliminating the need for sequential pressure control and reducing operational complexity while maintaining sealing reliability
Solution Approach 2:
The single pressure application serves multiple functions: it simultaneously sets the first seal between the hanger and wellhead, sets the second seal between the bellows and wellhead, and provides axial support for the hanger. This multi-functionality reduces the number of operational steps required
2Reliability
If traditional dual seal assemblies are used with sequential pressure setting, then each seal can be independently controlled, but the space efficiency decreases and component stress increases
Solution Approach 1:
The patent employs a nested configuration where the bellows structure contains the sealing elements within its expansion chambers. The first and second seals are positioned within the bellows structure, allowing compact arrangement that reduces overall assembly volume while maintaining independent seal functionality
Solution Approach 2:
The bellows structure utilizes radial expansion to achieve seal engagement, transitioning from axial positioning to radial force application. This dimensional change allows the seals to be set simultaneously through radial expansion of the bellows, reducing the axial space required compared to traditional sequential setting mechanisms
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 allows for efficient and reliable sealing of high-pressure wellheads with reduced component stress and increased space efficiency, minimizing the risk of undersetting or oversetting the seals.
Implementation Method 1
the first carrier ring and the first lock ring comprise corresponding angled engagement profiles for providing a radial force against the first lock ring relative a central axis of the seal assembly in response to the application of the first load to the seal assembly
Implementation Method 2
a first energizing ring coupled to the first carrier ring and configured to set a first seal of the seal assembly in response to the application of a first load to the seal assembly
Data Source
AI summary
An embodiment of a tubing or casing hanger seal assembly includes a first carrier ring, a first energizing ring coupled to the first carrier ring and configured to set a first seal of the seal assembly in response to the application of a first load to the seal assembly, and a first lock ring configured to secure the first seal to the tubing or casing hanger in response to the application of the first load to the seal assembly, wherein the first carrier ring and the first lock ring include corresponding angled engagement profiles for providing a radial force against the first lock ring relative a central axis of the seal assembly in response to the application of the first load to the seal assembly.