Patents by Inventor D. C. Freeman

D. C. Freeman 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 preventing bitumen backflow in injection wells when steam injection is interrupted
    Patent number: 4919206
    Abstract: A steam flood operation in which each injector is fitted with a pressure transducer and control valve which are tied into a water supply. Upon a loss of steam injection, and injection pressure, the pressure transducer signals the control valve and a pump actuator so as to cause water injection to take place and thus prevent heavy oil containing bitumen or bitumen backflow.
    Type: Grant
    Filed: July 19, 1989
    Date of Patent: April 24, 1990
    Assignee: Mobil Oil Corporation
    Inventors: D. C. Freeman, N. F. Djabbarah