Patents Assigned to Drilltech Services (ASIA) Pte Limited
  • Friction-reducing drill pipe component
    Patent number: 6655477
    Abstract: The friction reducing drill pipe component in the form of a sub (10) is adapted to form part of a drill string. The sub (10) comprises a tubular mandrel (12) having first and second ends for connection to adjacent components of the drill string. A sleeve (18) is mounted on the mandrel (12), and first and second stops on the mandrel (16, 20) restrain the sleeve 18 against axial movement relative to the mandrel (12). One of the stops (20) is removable or retractable to permit the sleeve (18) to be removed over the first end of the mandrel.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: December 2, 2003
    Assignee: Drilltech Services (ASIA) Pte Limited
    Inventors: Robert Patrick Appleton, Gholam Hossein Rastegar