Patents by Inventor Michael S. Stephens

Michael S. Stephens 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 additives for well cementing compositions containing a tetrapolymer
    Patent number: 5153240
    Abstract: An additive for reducing water loss from cement comprising a tetrapolymer, a base, an electrolyte, at least one surfactant, and water is disclosed. A process for producing cement slurries with improved water loss properties, as well as an improved method for cementing gas and oil well is also disclosed.
    Type: Grant
    Filed: November 30, 1990
    Date of Patent: October 6, 1992
    Assignee: Phillips Petroleum Company
    Inventor: Michael S. Stephens