Granted Patent
Utility
US 4,436,636 · App. 06/332,652
Invert emulsion well servicing fluids
Inventor:
William M. Carnicom
Patented Case
View Patent ↗
Granted: Mar 13, 1984
Filed: Dec 21, 1981
Inventor
William M. Carnicom
Assignee (at issue)
NL Industries, Inc.
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.