Patents by Inventor Yuh H. Tsao

Yuh H. Tsao has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method for reducing friction in drilling operations
    Patent number: 4665996
    Abstract: Hardfacing the principal bearing surface of a drill pipe with an alloy having the composition of: 50-65% Cobalt, 25-35% Molybdenum, 1-18% Chromium, 2-10% Silicon and less than 0.1% Carbon reduces the friction between the drill string and the casing or rock. As a result, the torque needed for the rotary drilling operation, especially directional drilling, is decreased. The alloy also provides excellent wear resistance on the drill string while reducing the wear on the well casing.
    Type: Grant
    Filed: March 31, 1986
    Date of Patent: May 19, 1987
    Assignee: Exxon Production Research Company
    Inventors: Z. Andrew Foroulis, Yuh H. Tsao