Patents by Inventor Robert E. Slingerland

Robert E. Slingerland 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).

  • Water-based drilling fluids having enhanced fluid loss control
    Patent number: 4652606
    Abstract: A water based drilling fluid and process for using the same comprising a mixture of water and a polymer complex, wherein the polymer complex is the reaction product of a dispersant selected from the group consisting of lignite, sulfonated lignite, lignosulfonate, and sulfoalkylated lignite, and salts thereof and a water-soluble sulfonated polystyrene having a molecular weight of at least 70,000 and containing 0.7 to 2.0 sulfonic acid groups per styrene unit.
    Type: Grant
    Filed: August 30, 1985
    Date of Patent: March 24, 1987
    Assignee: NL Industries, Inc.
    Inventor: Robert E. Slingerland
  • Water-based drilling fluids having enhanced fluid loss control
    Patent number: 4650593
    Abstract: A water based drilling fluid and process for using the same comprising a mixture of water and a polymer complex, wherein the polymer complex is the reaction product of a dispersant selected from the group consisting of lignite, sulfonated lignite, lignosulfonate, and sulfoalkylated lignite, and salts thereof and a water-soluble sulfonated polystyrene having a molecular weight of at least 70,000 and containing 0.7 to 2.0 sulfonic acid groups per styrene unit.
    Type: Grant
    Filed: September 19, 1977
    Date of Patent: March 17, 1987
    Assignee: NL Industries, Inc.
    Inventor: Robert E. Slingerland