Patents by Inventor Steven W. Stringfellow

Steven W. Stringfellow 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).

  • Patent number: 5803173
    Abstract: An apparatus and method are disclosed for pumping segregated fluids through a tubular member, such as is required when cementing a liner into a well bore. A liner wiper plug has an internal bore formed therethrough, with a flapper valve mounted in the liner wiper plug. The flapper valve can pivot to an open position to allow fluid flow through the wiper plug, and the flapper valve can pivot to a closed position to prevent fluid flow through the wiper plug. A work string, or a stinger attached to a work string, can be positioned within the internal bore of the wiper plug, holding the flapper valve in the open position. The wiper plug can be run into the well on the work string, with the flapper valve held open, and with flow of a first fluid in progress. The wiper plug can be releasably supported from the liner. The work string is withdrawn from the wiper plug to allow the flapper valve to close.
    Type: Grant
    Filed: July 29, 1996
    Date of Patent: September 8, 1998
    Assignee: Baker Hughes Incorporated
    Inventors: James M. Fraser, III, Steven W. Stringfellow