Patents Assigned to Grant Prideco, Inc.
  • Patent number: 5535837
    Abstract: An apparatus and method are provided for enhancing fatigue and stress resistance properties of a subterranean well drill pipe string section by providing a helical groove near the pipe to tool joint weld. Stresses in and around the top portion of the pipe are redistributed to and absorbed by the helical groove region of the drill pipe string section, which has a relatively greater resistance to fatigue caused by bending and other stresses, thereby making the drill pipe string section less prone to fail due to rotational, tensile, and bending stresses.
    Type: Grant
    Filed: July 5, 1994
    Date of Patent: July 16, 1996
    Assignee: Grant Prideco, Inc.
    Inventor: Frank J. Carlin