Granted Patent
Utility
US 5,116,421 · App. 07/626,572
High temperature fluid loss additive for cement slurry and method of cementing
Inventor:
Kalyan K. Ganguli
Patented Case
View Patent ↗
Granted: May 26, 1992
Filed: Dec 12, 1990
Inventor
Kalyan K. Ganguli
Assignee (at issue)
Western Company of North America
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.