Annular Seal Pusher Assembly for Irregular Wellbore Sealing
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Solution Overview
Problem
Existing annular sealing systems fail to effectively seal irregularly shaped annular spaces around expanded well tubulars, particularly during the expansion process, and are limited in sealing wide annular spaces.
Innovation Solution
A method and system utilizing a seal pusher assembly with a support ring and concave pusher segments, combined with an annular elastomeric sealing ring and staggered strips, which expand and compress to seal the annular space by shortening the axial distance between secured locations, ensuring a liquid-tight seal even in irregularly shaped spaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional annular sealing system is used, then the sealing structure is simple, but it cannot effectively seal irregularly shaped annular spaces or wide annular spaces
Solution Approach 1:
The sealing ring is divided into multiple axially spaced segments that can independently expand and conform to irregular wellbore surfaces. Each segment can be actuated separately by the expansion tool, allowing the seal to adapt to wide or irregular annular spaces while maintaining sealing effectiveness.
Solution Approach 2:
The sealing system transitions from a static rigid structure to a dynamic expandable structure. The sealing segments are initially compact during installation but expand radially outward when actuated by the expansion tool, enabling them to seal irregular or wide annular spaces that would be inaccessible to conventional fixed seals.
2Reliability
If the well tubular is expanded to seal the annulus, then the seal effectiveness improves, but the axial distance between secured locations increases requiring longer sealing components
Solution Approach 1:
The sealing segments are nested within each other in an axially compressed configuration during tool assembly and installation. When the expansion tool is actuated, the segments expand radially and unfold axially in sequence, converting radial expansion force into axial sealing contact without requiring the entire sealing assembly to be initially as long as the final expanded configuration.
Solution Approach 2:
The sealing system uses dynamic transformation where the axial distance between secured locations is initially short during installation but increases as the segments expand and conform to the wellbore. This dynamic length adjustment allows the seal to accommodate irregular surfaces without requiring excessively long sealing components from the start.
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 system provides a reliable, self-energizing seal that maintains effectiveness across varying annular space sizes and shapes, preventing cement U-tubing during liner expansion, even in irregular wellbores.
Implementation Method 1
an annular elastomeric sealing ring arranged with an inwardly tapered first end thereof against an outwardly tapered second end of the seal pusher assembly
Implementation Method 2
expanding the tubular, thereby shortening an axial distance between the selected first and second locations
Data Source
AI summary
An annular space surrounding an expandable well tubular (1) is sealed by: —a concave seal pusher assembly (5) with concave pusher elements comprising buckling joints (7) of which assembly (5) a first end is secured at a selected first location (2) of the outer surface of the unexpanded well tubular (1); —an annular elastomeric sealing ring (9) arranged with an inwardly tapered first end thereof against an outwardly tapered second end (8) of the concave seal pusher assembly (5); —a set of staggered and overlapping steel support strips (11) arranged around a second end of the sealing ring (9) and connected at one end thereof to a selected second location (3) of the outer surface of the unexpanded tubular (1); —expanding and thereby shortening the tubular (1) to push the inwardly tapered end of the sealing ring over the outwardly tapered end (8) of the seal pusher assembly (5) and buckling the staggered strips (11) against the outer surface (12) of the annular space surrounding the expanded tubular (1) to compress the sealing ring (9) and seal off the annular space.