Outwardly Biased Grappling Means Patents (Class 294/86.28)
  • Patent number: 6357528
    Abstract: A one-trip system for removing casing from a wellhead is described. The string includes a cutting device spaced at the required depth and a grappling device above it at the appropriate location. A swivel tool, such as a marine swivel, is used in conjunction with a seal-pulling assembly so that after cutting the casing, the seal assembly can be pulled without an additional trip into the well. The grappling device or spear can be hydraulically actuated to grab the casing for removal from the wellbore. The spear features a drop-in restrictor which allows sufficient flow during cutting operations with a mechanical cutter without actuating the spear, while at the same time allowing actuation of the spear by circulation after dropping in the restrictor after the casing section has been cut.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: March 19, 2002
    Assignee: Baker Hughes Incorporated
    Inventors: John Phillip Davis, David Blair Haughton