Segmented Ring Expansion Mechanism for Oilfield Seal Reliability

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Solution Overview

Problem

Existing expanding and collapsing apparatuses in oilfield applications, such as anti-extrusion rings, face issues with extrusion gaps during expansion, leading to potential failure of seal elements and inefficient use of surface area, which limits the maximum force and pressure rating.

Innovation Solution

A ring structure composed of multiple elements that slide tangentially along planar contact surfaces to transition between expanded and collapsed conditions, providing a continuous support surface and minimizing gaps through interlocking profiles and biasing mechanisms, allowing for efficient expansion and contraction without creating extrusion gaps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If segmented metallic rings are used for expansion mechanisms, then the device can be collapsed to a compact size, but extrusion gaps are created during expansion that may result in failure of seal elements

Engineering Contradiction:
Improvecollapsed volumeVSAvoidseal element reliability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The ring is divided into multiple segments that can slide relative to each other during expansion and collapse together to a compact size. The segmentation allows the ring to reduce volume for transport while maintaining structural integrity during operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The segments move in an axial direction (one dimension) to achieve radial expansion (another dimension). By sliding axially relative to each other, the segments create radial expansion without leaving gaps, solving the extrusion gap problem through dimensional transformation of motion.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If circumferentially lapped segments are used to avoid extrusion gaps, then a continuous support surface is provided, but the ring creates uneven or stepped faces that are spatially inefficient and difficult to collapse

Engineering Contradiction:
Improvecontinuous support surfaceVSAvoidcollapsing mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The ring structure transitions from a static lapped configuration to a dynamic segmented structure where segments slide axially during expansion and collapse. This dynamic approach allows the ring to provide continuous support when expanded while collapsing to a compact configuration, avoiding the permanent uneven faces of lapped segments.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Instead of using circumferential laps, the ring is segmented into discrete elements that can move independently in the axial direction. This segmentation allows for smooth collapsed configuration while maintaining continuous radial support when expanded, solving both the support continuity and collapsing efficiency problems.

Inventive Principle:
Principle #1Segmentation

3Productivity

If radially expanding structures are circumferentially distributed at discrete locations, then the device can be collapsed efficiently, but the surface area available to contact auxiliary engagement surface is reduced, limiting maximum force and pressure rating

Engineering Contradiction:
Improveexpansion efficiencyVSAvoidmaximum force rating
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The expansion mechanism uses axial sliding motion (one dimension) to achieve radial distribution (another dimension). This allows segments to cover the entire circumferential surface area when expanded, maximizing contact area for force transmission while maintaining efficient collapsed configuration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The segmented structure allows complete circumferential coverage when expanded, with each segment contributing to the continuous support surface. This provides maximum surface area contact for auxiliary engagement surfaces, increasing the maximum force and pressure rating while maintaining collapse efficiency.

Inventive Principle:
Principle #1Segmentation

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 enables a solid, gap-free expanded condition with increased surface area contact, enhancing the maximum force and pressure rating while maintaining a compact collapsed state, thus improving the reliability and efficiency of oilfield apparatuses like plugs, packers, and connectors.

Implementation Method 1

each element comprises a first planar contact surface and second planar contact surface respectively in abutment with first and second adjacent elements; and wherein the plurality of elements is operable to be moved between the expanded and collapsed conditions by sliding with respect to one another along their respective planar contact surfaces

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3394385B1Expanding and collapsing apparatus and methods of use
Publication Date: 2023.02.15 PEAK WELL SYST PTY LTD
  • EP3394385B1 patent drawingFigure 1A~1D
  • EP3394385B1 patent drawingFigure 2A~2D
  • EP3394385B1 patent drawingFigure 3A~3B

AI summary

The invention provides an expanding and/or collapsing apparatus and a method of use. The apparatus comprises a plurality of elements assembled together to form a ring structure oriented in a plane around a longitudinal axis. The ring structure is operable to be moved between an expanded condition and a collapsed condition by movement of the plurality of elements. The plurality of elements is operable to be moved between the expanded and collapsed conditions by sliding with respect to one another in the plane of the ring structure, in a direction tangential to a circle concentric with the ring structure. Applications of the invention include oilfield devices, including anti-extrusion rings, plugs, packers, locks, patching tools, connection systems, and variable diameter tools run in a wellbore.