Granted Patent
Utility
US 5,194,422 · App. 07/773,631
Use of selected oleophilic alcohols in water-based drilling fluids of the O/W-emulsion type and corresponding drilling fluids with improved ecological acceptability
Inventors:
Heinz Mueller, Klaus Herold, Stephan von Tapavicza, Johann F. Fues
Patented Case
View Patent ↗
Granted: Mar 16, 1993
Filed: Nov 15, 1991
Inventors
Heinz Mueller
Klaus Herold
Stephan von Tapavicza
Johann F. Fues
Assignee (at issue)
Henkel Kommanditgesellschaft auf Aktien
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.