Patents by Inventor Sibrand A. Ubels

Sibrand A. Ubels 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).

  • Method for reducing pressure drop in the transportation of drag reducer
    Patent number: 4881566
    Abstract: Method for reducing pressure drop in a conduit carrying a viscous drag reducing material by injecting a lower viscosity liquid which is immiscible with the drag reducing material at the periphery of the conduit to form a flowing annular layer of such lower viscosity liquid thereby reducing the pressure drop in the conduit.
    Type: Grant
    Filed: October 11, 1988
    Date of Patent: November 21, 1989
    Assignee: Conoco Inc.
    Inventors: Sibrand A. Ubels, Steven L. Baxter