Patents by Inventor Penny L. Sperl

Penny L. Sperl 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).

  • Enhanced oil recovery using denitrifying microorganisms
    Patent number: 5044435
    Abstract: A method of microbial enhanced oil recovery includes introducing, into an underground carbonate-containing rock formation that defines an anaerobic environment, denitrifying microorganisms, water, and a source of nitrate ion. The microorganisms reduce the nitrate and produce sulfuric acid which dissolves the rock formation, releasing oil. The microorganisms can be denitrifying Thiobacilli, such as T. denitrificans.
    Type: Grant
    Filed: July 16, 1990
    Date of Patent: September 3, 1991
    Assignee: Injectech, Inc.
    Inventors: George T. Sperl, Penny L. Sperl