Patents by Inventor Millard L. Hallman

Millard L. Hallman 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).

  • Drill string diverter apparatus and method
    Patent number: 6182766
    Abstract: The present invention relates to a drill string diverter apparatus for reducing surge pressure when lowering a liner into a partially cased wellbore. The diverter apparatus is connected in a pipe string above a liner being lowered into a wellbore. The diverter apparatus comprises a tubular housing with ports defined therethrough to communicate and redirect fluids received in the liner to the annulus between the diverter apparatus and casing previously set in the wellbore. The diverter apparatus has an open position whereby the ports are open and communication is established and a closed position whereby flow through the ports is prevented. A sliding sleeve is disposed about an outer surface of the tubular housing and engages the casing. The sleeve moves vertically relative to the tubular housing once the diverter apparatus has been lowered into the casing to selectively open and close the flow ports. A J-slot means is provided for locking the diverter apparatus in its closed position.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: February 6, 2001
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Henry E. Rogers, Wesley G. Duke, Millard L. Hallman, Tommy T. Stewart