Patents by Inventor Stephan van Tapavizca

Stephan van Tapavizca 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 and well-servicing fluids with swellable, synthetic layer silicates
    Patent number: 4888120
    Abstract: Synthetic swellable layer silicates corresponding to the following formulaMgO.aMA.bAl.sub.2 O.sub.3.cSiO.sub.2.nH.sub.2 O (I)in whichM is Na.sup.+ and Li.sup.+ having an Na:Li ratio of at least 1;A is F.sup.-, OH.sup.- or 1/2O.sup.2- or a mixture thereof;a is 0.1 to 0.6;b is 0 to 0.3;c is 1.2 to 1.7; andn is 0 to 3.0.are used in water-based well-servicing fluids as a high-temperature-stable thixotrope substantially unaffected by alkaline earth metal ions.
    Type: Grant
    Filed: September 9, 1987
    Date of Patent: December 19, 1989
    Assignee: Henkel Kommanditgesellschaft auf Aktien
    Inventors: Heinz Mueller, Claus-Peter Herold, Stephan van Tapavizca, Hans Dolhaine, Wolfgang von Rybinski, Winfried Wichelhaus