Granted Patent
Utility
US 4,743,384 · App. 06/862,746
Carboxymethyl guar based drilling fluids
Inventors:
Cheng Lu, Carl A. Lukach, Robert R. Pas
Patented Case
View Patent ↗
Granted: May 10, 1988
Filed: May 13, 1986
Inventors
Cheng Lu
Carl A. Lukach
Robert R. Pas
Assignee (at issue)
Aqualon Company
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.