Patents by Inventor Derek James Stuart

Derek James Stuart 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).

  • Downhole tractor
    Patent number: 9004194
    Abstract: A method of translating a member through a bore involving moving fluid through a tubular member such as a drill string, and generating impulses on the member by varying the passage of fluid through the member using a valve which opens at a first rate and closes at a different second rate to urge the member to advance in a selected direction. The valve may close quickly and open slowly, or may close slowly and open quickly.
    Type: Grant
    Filed: November 10, 2010
    Date of Patent: April 14, 2015
    Assignee: National Oilwell Varco, L.P.
    Inventors: Alan Martyn Eddison, David Anderson Coull, Derek James Stuart
  • DOWNHOLE TRACTOR
    Publication number: 20120279724
    Abstract: A method of translating a member through a bore comprises moving fluid through a tubular member such as a drill string (2A), and generating impulses on the member by varying the passage of fluid through the member using a valve (60) which opens at a first rate and closes at a different second rate to urge the member to advance in a selected direction. The valve may close quickly and open slowly, or may close slowly and open quickly.
    Type: Application
    Filed: November 10, 2010
    Publication date: November 8, 2012
    Applicant: NATIONAL OILWELL VARCO L.P.
    Inventors: Alan Martyn Eddison, David Anderson Coull, Derek James Stuart