Under-Balanced Seal Ring for Deepwater Flange Thermal Movement

Solution Overview

Problem

Existing seal rings designed for oil and gas production in deep water cannot withstand the high pressures and temperatures required by new design guidelines, and fail due to non-uniform movement and thermal growth of joint components, leading to potential failure.

Innovation Solution

A seal ring design with asymmetrical inner and outer sealing portions and a web or rib that accommodates non-uniform movement, featuring a thicker portion adjacent to the inner sealing portion to provide flexibility and reduce hoop stress, allowing the seal ring to withstand pressures up to 20,000 psi and temperatures up to 350°F.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a symmetrical seal ring design is used, then the structure is simple and easy to manufacture, but it cannot accommodate non-uniform movement and thermal growth under high pressure and temperature conditions

Engineering Contradiction:

Improveseal ring manufacturing simplicityVSAvoidseal ring performance under high pressure and temperature

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The seal ring employs an asymmetrical cross-sectional design where the inner sealing portion has a different longitudinal length than the outer sealing portion. Specifically, the inner sealing portion has a greater longitudinal length than the outer sealing portion, creating an under-balanced configuration that accommodates non-uniform movement and thermal growth between flange components under high pressure and temperature conditions.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The web connecting the inner and outer sealing portions has non-uniform thickness, being thicker in the portion adjacent to the inner sealing portion and thinner in the portion adjacent to the outer sealing portion. This local variation in thickness provides flexibility to accommodate differential thermal expansion and movement while maintaining structural integrity under extreme operating conditions.

Inventive Principle:

Principle #3Local quality

2Device complexity

If the inner and outer sealing portions have equal longitudinal length, then the seal ring structure is balanced and simple, but it fails to accommodate non-uniform movement of joint components

Engineering Contradiction:

Improveseal ring structural complexityVSAvoidaccommodation of non-uniform movement

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The seal ring employs an asymmetrical cross-sectional design where the inner sealing portion has a different longitudinal length than the outer sealing portion. Specifically, the inner sealing portion has a greater longitudinal length than the outer sealing portion, creating an under-balanced configuration that accommodates non-uniform movement and thermal growth between flange components under high pressure and temperature conditions.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The non-uniform thickness of the web provides dynamic flexibility, allowing the seal ring to adapt its shape during operation. The varying thickness enables different portions of the seal ring to move independently, accommodating the non-uniform thermal expansion and movement of flange components while maintaining sealing effectiveness.

Inventive Principle:

Principle #15Dynamics

3Strength

If a thicker web is used throughout, then the seal ring has greater strength, but it reduces flexibility to accommodate thermal growth and movement

Engineering Contradiction:

Improveseal ring structural strengthVSAvoidflexibility for thermal expansion

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The web connecting the inner and outer sealing portions has non-uniform thickness, being thicker in the portion adjacent to the inner sealing portion and thinner in the portion adjacent to the outer sealing portion. This local variation in thickness provides flexibility to accommodate differential thermal expansion and movement while maintaining structural integrity under extreme operating conditions.

Inventive Principle:

Principle #3Local quality

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 seal ring effectively seals under high pressure and temperature conditions, accommodating non-uniform movement and thermal growth, ensuring reliable operation and easy release from flanges, while maintaining a reusable and self-energized seal.

Implementation Method 1

the web or rib provides some flexibility, allowing the thinner portion of the web or rib to move and/or rotate to some extent with respect to the thicker portion of the web or rib

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the web or rib provides some flexibility, allowing the thinner portion of the web or rib to move and/or rotate to some extent with respect to the thicker portion of the web or rib

Methodology Applied

Scientific EffectHoop stress:

Data Source

PatentUS12584554B2Under-balanced seal ring

Publication Date: 2026.03.24 LTS ENERGY INC

AI summary

A piping system for oil and gas in very deep water includes two opposing flanges and a seal ring between the flanges. Each flange has an annular ridge between concentric grooves. The seal ring has a radial web that connects longitudinal inner and outer sealing portions, which are received in the concentric grooves with the annular ridge received sealingly between the inner and outer sealing portions. The inner sealing portion of the seal ring is longer than the outer sealing portion. The web is as thick as or thicker than the inner and outer sealing portions. The seal ring comprises inner and outer concentric hollow cylinders having a non-uniform wall thickness and an annular rib that connects the hollow cylinders together, where one cylinder is longer than the other and where the rib has a longitudinal thickness that is as great as the radial thickness of the walls of the hollow cylinders.