Granted Patent
Utility
US 4,548,720 · App. 06/487,196
Removal of hydrogen sulfide from drilling fluids
Inventor:
Thomas J. Gilligan
Patented Case
View Patent ↗
Granted: Oct 22, 1985
Filed: Apr 21, 1983
Inventor
Thomas J. Gilligan
Assignee (at issue)
Diamond Shamrock Chemicals 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.