Patents by Inventor Margaret H., all of Graham

Margaret H., all of Graham 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).

  • Fluid loss-reducing additives for oil-based well working fluids
    Patent number: 4941983
    Abstract: A fluid loss additive for oil-based well-working fluids, the fluid loss additive comprisingthe product of mixing in an oil or oil based liquid,(i) lignite or humic acid(ii) (a) an oil soluble or oil dispersible amine or amine salt;(b) an aliphatic amide or hydroxyamide, or a cyclic derivative thereof, containing no primary or secondary amine or amine salt groups; and/or(c) an oil soluble or oil dispersible amine salt containing at least one C.sub.1-22 alkyl, C.sub.2-22 alkenyl or C.sub.1-22 acyl group partially or fully salted with phosphoric acid; and(iii) a dimer and/or trimer fatty acid.
    Type: Grant
    Filed: August 29, 1988
    Date of Patent: July 17, 1990
    Assignee: Sandoz Ltd.
    Inventors: Jacqueline A. Coates, John M. Farrar, Margaret H., all of Graham