Patents by Inventor Masahide Yanagiya

Masahide Yanagiya 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 plugging lost circulation areas and lost circulation material to be used therefor
    Patent number: 4958685
    Abstract: A method for plugging the areas of lost circulation occurred during the drilling of a well with the use of a drilling mud, and a lost circulation material to be used therefor. The lost circulation material comprising 1 to 90 parts by weight of a water-soluble solvent containing no active hydrogen atoms and hardly miscible with mineral oils and 10 to 99 parts by weight of a hydrophlic urethane prepolymer, and the method comprises injecting through the drilling pipe the lost circulation material sandwiched by a spacer of mineral oils, so as to allow the lost circulation material to penetrate into the lost circulation areas, to react with water which is present at the areas, and to plug the areas through its polymerization.
    Type: Grant
    Filed: May 24, 1989
    Date of Patent: September 25, 1990
    Assignee: Toho Kagaku Kogyo Co., Ltd.
    Inventors: Takeshi Hihara, Masahide Yanagiya, Kazuhito Ono