Patents by Inventor Douglas D. Applegath

Douglas D. Applegath 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 of inhibiting lost circulation from a wellbore
    Patent number: 4526240
    Abstract: A fibrous mass or fluff comprising a fibrous absorbent and a water-swellable hydrophilic polymer absorbent is injected into a borehole during well drilling process. The fibrous mass or fluff forms an essentially fluid-tight plug when wetted with water and acts to reduce drilling fluid loss via penetration of porous subterranean structure or formation openings.
    Type: Grant
    Filed: October 17, 1983
    Date of Patent: July 2, 1985
    Assignee: The Dow Chemical Company
    Inventors: Mark J. McKinley, Douglas D. Applegath