Hanger Floating Ring Isolates Pressure Stress on Seals

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Solution Overview

Problem

In mineral extraction systems, hanger movement due to pressure causes stress and deformation of seals and other components, compromising sealing integrity and leading to potential leaks during drilling and production operations.

Innovation Solution

The implementation of a floating ring between the hanger and the landing ring isolates hanger movement, and a radially retractable seal assembly with metal seals configured to distribute and manage sealing and energizing loads, preventing damage during installation and maintaining seal integrity under pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hanger is used to suspend strings in the wellhead assembly, then the hanger provides sealing capabilities and suspends strings, but hanger movement under pressure puts pressure on other components and compromises sealing integrity

Engineering Contradiction:

Improvesealing integrityVSAvoidpressure on landing shoulders and seals

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

A floating ring is introduced as an intermediary component between the hanger and the landing ring. This floating ring can move axially with hanger displacement while maintaining radial sealing contact with the landing ring, thereby mediating between the hanger's pressure-driven movement and the sealing requirements of the landing ring and seals.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The landing ring is designed with dynamic characteristics, allowing it to deform elastically under pressure loads. This dynamic response enables the landing ring to accommodate hanger movement while maintaining sealing contact, transforming the static sealing interface into a dynamic system that adapts to pressure changes.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the hanger is made adjustable to accommodate different positions, then the hanger can be positioned flexibly, but adjustability compromises the ability to provide sealing during operation

Engineering Contradiction:

Improvehanger position adjustabilityVSAvoidsealing capability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The sealing function is segmented from the hanger body by introducing a separate floating ring and landing ring assembly. This segmentation allows the hanger to be adjustable while the floating ring and landing ring maintain dedicated sealing contact, isolating the sealing mechanism from the adjustability mechanism.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The floating ring serves as an intermediary that decouples the hanger's adjustable positioning from the sealing interface. It can move axially with the hanger while maintaining constant radial contact with the landing ring, thereby preserving sealing integrity despite hanger adjustability.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If pressure from above or below the hanger causes hanger movement, then the hanger can respond to pressure changes, but this movement puts pressure on landing shoulders and seals

Engineering Contradiction:

Improvehanger response to pressureVSAvoidstress on seals and landing shoulders

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The floating ring acts as a mediator that absorbs and distributes the pressure forces generated by hanger movement. It provides a compliant interface between the hanger and landing ring, reducing stress concentrations on the seals and landing shoulders while allowing the hanger to respond to pressure changes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The floating ring and landing ring assembly is designed beforehand to provide cushioning against pressure-induced stress. The elastic deformation capability of the landing ring and the axial freedom of the floating ring create a pre-configured cushioning mechanism that mitigates harmful stresses on seals and landing shoulders before they can cause damage.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS8944156B2Hanger floating ring and seal assembly system and method

Publication Date: 2015.02.03 CAMERSON INT CORP

AI summary

Systems and methods are provided for isolating a landing ring of a hanger from pressure inside a wellhead and sealing a portion of the hanger via a seal assembly. The hanger includes a floating ring axially interposed between the landing ring and the seal assembly, and between the landing ring and a shoulder of the hanger. The seal assembly includes one or more radially retractable elastomeric seals that are radially retracted during run in of the seal assembly. The radially retractable seals may be radially expanded via shearing of one or more shear pins by torque applied to the seal assembly. The seal assembly may also include one or more metal seals having a plurality of rings having a nib configuration that includes three smaller nibs for sealing and a larger flat nib for withstanding the energizing load on the seal assembly.