Patents by Inventor W. J. Barnhill

W. J. Barnhill 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).

  • Carbide coated blast tube construction for use in oil and gas well completion across perforations
    Patent number: 5133576
    Abstract: An oil well tubing joint coated with a carbide blast coating provides an elongated, hollow tubing section having an open ended continuous cylindrical internal bore and a continuous carbide coating over substantially all of the tubing section outer surface. An internally threaded connection portion of the bore at a first end of the tubing section is provided with an externally threaded connection member being positioned at the second end of the tool bore. The tubing section has a larger constant external diameter that extends over a majority of its length and three reduced external diameter portions that extend a distance from each end of the tubing, including one reduced diameter portion adjacent one end of the tubing joint and two of the reduced diameter portions being adjacent the second end of the tubing joint.
    Type: Grant
    Filed: February 28, 1991
    Date of Patent: July 28, 1992
    Inventor: W. J. Barnhill