Patents Assigned to Petro-Design, Inc.
  • Remote control selector valve
    Patent number: 4655289
    Abstract: A control system for use on fluid conducting pipe strings in earth boreholes to permit cycling of fluid flow between preselected flow rates to change conditions downhole as a result of surface exercise of fluid flow controls. A resulting change of state downhole is indicated by a change in fluid flow related pressure detectable at the surface.
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: April 7, 1987
    Assignee: Petro-Design, Inc.
    Inventor: William N. Schoeffler
  • Angle deviation tool
    Patent number: 4655299
    Abstract: A normally straight drill string component for use just above a downhole drilling motor, or directional jet, that can be caused to be alternately straight or bent by cycling the drilling fluid flow rate between selected flow rate limits by use of controls at the earth surface.
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: April 7, 1987
    Assignee: Petro-Design, Inc.
    Inventor: William N. Schoeffler