Patents Assigned to Tri-State Oil Tool (UK)
  • Side-tracking mills
    Patent number: 5199513
    Abstract: The invention, which can be applied to both starting mills and window mills for use in sidetracking a cased borehole, makes use of carbide discs as cutting elements and the geometrical disposition of blades on which the discs are mounted to enhance cutting efficiency. The blades are angularly offset with respect to the tool centerline in a variety of configurations.
    Type: Grant
    Filed: February 11, 1991
    Date of Patent: April 6, 1993
    Assignee: Tri-State Oil Tool (UK)
    Inventors: David Stewart, Paul Hilliard, Thomas Doig