Multi-Piece Packing Element Containment System

Abstract

Methods and devices for retaining a packer element in a set condition within a wellbore and for preventing or minimizing extrusion of the packer element after setting. A packer device includes a plurality of deformable packer elements which radially surround a packer mandrel. One or more of the packer elements is contained against axial extrusion using a packer containment system. The packer containment system includes a flexible metal backup ring, which partially encases the packer element by substantially covering at least one axial side and a portion of the exterior radial surface of the packer element. The packer containment system also includes a plurality of annular support rings, or “petal rings” which have petal-shaped radial protuberances with slots between them.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The invention relates generally to packer devices used within a wellbore.[0003]2. Description of the Related Art[0004]Packers are used to create a fluid seal within a wellbore between a central work string, such as a production tubing string, and a surrounding tubular, such as a wellbore wall. A common packer design has a central mandrel with an elastomeric packer element surrounding the mandrel. The packer element is set by axially compressing it on the mandrel. As the packer element is compressed axially, the packer element is expanded radially outwardly and into contact with the surrounding surface.[0005]One problem with packer devices of this type is that of extrusion of the packer element axially along the space between the packer mandrel and the surrounding wellbore. This can occur as a result of high wellbore temperatures, pressures and / or caustic chemicals which act upon the packer element. Severe extrusion of t...

AI Technical Summary

Benefits of technology

[0006]The invention provides methods and devices for containing a packer element in a set condition within a wellbore and for preventing or minimizing extrusion of the packer element after setting. An exemplary packer device is described which includes a plurality of deformable packer elements which radially surround a packer mandrel. One or more of the packer elements is contained against axial extrusion using a packer containment system. In a preferred embodiment, the packer containment system includes a flexible metal backup ring, which partially encases the packer element by substantially covering at least one axial side and a portion of the exterior radial surface of the packer element. The packer co

Problems solved by technology

One problem with packer devices of this type is that of extrusion of the packer element axially along the space between the packer mandrel and the surrounding wellbore.

Severe extrusion of the packer element can cause the seal to fail.

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