Multi-layer Backup Ring with Interlock Segments
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Solution Overview
Problem
In the drilling and completion industry, packers used to isolate production zones tend to extrude past gage rings during radial expansion, necessitating multiple packers and fixed ends for setting, which can be inefficient and prone to extrusion issues.
Innovation Solution
A backup ring assembly with radially offset ring members and interlock members that restrain radial expansion, featuring axially extending segments with alternating l-shaped slots or dovetail designs that shear to create end walls to block extrusion, allowing for effective sealing without extrusion past the gage rings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the elastomeric seal is compressed axially to expand radially and form a seal, then the sealing capability is improved, but the seal tends to extrude past the gage rings
Solution Approach 1:
The backup ring is divided into multiple axially extending segments with gaps between them, allowing controlled radial expansion while the interlock members prevent excessive extrusion by restraining the segments' movement
Solution Approach 2:
Interlock members are introduced as intermediary elements between the axially extending segments, acting as restrainers that limit radial outward expansion and control the extrusion behavior of the elastomeric seal
2Reliability
If multiple packers are used to provide isolation above and below production zones, then the sealing coverage is improved, but the device complexity and risk of extrusion issues increase
Solution Approach 1:
The backup ring assembly with multiple axially extending segments and interlock members provides both sealing support and extrusion prevention functions in a single integrated structure, eliminating the need for multiple separate packers
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 effectively prevents extrusion of sealing elements during radial expansion, maintaining a strong and flexible seal while adapting to irregular borehole shapes, reducing the need for multiple packers and enhancing the sealing process.
Implementation Method 1
An interlock member includes a first end supported at the first interlock member support and a second end supported at the second interlock member support. The interlock member restrains radially outward expansion of the ring
Implementation Method 2
featuring axially extending segments with alternating l-shaped slots or dovetail designs that shear to create end walls to block extrusion
Implementation Method 3
A packer typically includes of a cylindrical elastomeric element that is compressed axially, or set, from one end or both by gage rings within a backup system that cause the elastomer to expand radially and form a seal
Data Source
AI summary
A backup ring assembly has a plurality of radially offset ring members including an outermost ring member formed from plurality of axially extending segments. Each of the plurality of axially extending segments includes an outer surface. A first interlock member support is coupled to the outer surface of one of the plurality of axially extending segments of the outer most ring member. A second interlock member support is coupled to the outer surface of an another one of the plurality of axially extending segments of the outermost ring member. An interlock member includes a first end supported at the first interlock member support and a second end supported at the second interlock member support. The interlock member restrains radially outward expansion of the ring and circumferential expansion of a gap extending between the one of the axially extending segments and the another one of the axially extending segments.