REMOVABLE BRIDGE PLUG OR PACKER

摘要

A composite packer or bridge plug is disclosed. The design features substantially all nonmetallic components. The design allows the setting tool metallic components to be retrieved after the bridge plug is set. The slips contain flats with mating flats on the cones which extend to one end of the cones and guides for the slips to facilitate proper slip movement into engagement with the wellbore. A lock ring rides on the nonmetallic mandrel and secures the set, using a buttress-type thread to engage into the mandrel body. Alternative designs are revealed for backup to the sealing elements to prevent extrusion. In one design, split rings are axially compressed so that they grow in radial dimension to act as extrusion barriers. In another design, tapered scored rings are rotationally locked against each other and are axially compressed so that they bend into contact with the wellbore to act as extrusion barriers. Axial travel to obtain an extrusion barrier is minimized. The slips are made of a cohesive component and separate from each other upon advancement with respect to the cone. Mandrels of different plugs can lock together to facilitate mill-out in multi-plug installations.