Granted Patent
Utility
US 5,021,170 · App. 07/135,140
Oil-based well bore fluids and gellants therefor
Inventors:
Thomas G. Shumate, Louis Sokol
Patented Case
View Patent ↗
Granted: Jun 4, 1991
Filed: Dec 18, 1987
Inventors
Thomas G. Shumate
Louis Sokol
Assignee (at issue)
Baroid Technology, 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.