Patent ID: 7540325
Filing Date: 2009-06-02
Classification: E21B

Abstract:
1. An apparatus for cementing a zone in a wellbore formation with cement, comprising: (a) a first concentric drill string comprising an inner string having an inner conduit and situated within an outer string to form an annular conduit therebetween; (b) an isolation cementing tool having an expandable and contractible packer means therearound, and adapted to be operably connected to said first concentric drill string such that the isolation cementing tool is in fluid communication with both said conduits; and (c) a cementing flow control device comprising a center tube and an outer casing for stopping or regulating flow through the annular conduit, or the inner conduit and adapted to be operably connected to said first concentric drill string such that the cementing flow control device is in fluid communication with both of said conduits, wherein the inner diameter of said center tube or the inner diameter of said outer casing is reduced at some point, for landing a plug.