Patents Examined by Chris H. Kang
  • Patent number: 6062309
    Abstract: A mandrel-operated torque roller anchor for insertion into the casing of a well, which when set resists axial movement and prevents rotation of itself and the string above it in one direction, but permits such motion when rotated in the other direction. The anchor comprises a central mandrel and a slip cage. The slip cage has a number of elongated slots. A number of drag slips rest on the mandrel within the slip cage and provide limited outward movement, through the slots, to bear against the casing. Each drag slip has a surface with wickers to grip the casing and set the anchor, and an adjacent unwickered drag portion to bear against the casing to allow the mandrel to rotate relative to the slips and cage, but permit axial movement of the string. Slots running through the drag portion of the slip provide flow around the anchor. Biasing elements extend between the mandrel and an interior surface of each slip to force the drag portion of the corresponding slip against the casing when in an unset position.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: May 16, 2000
    Assignee: Variperm Limited
    Inventor: Darryl Gosse