Granted Patent
Utility
US 5,009,267 · App. 07/578,883
Method for temporarily reducing permeability of subterranean formations
Inventors:
Charles D. Williamson, Stephan J. Allenson, Robert K. Gabel
Patented Case
View Patent ↗
Granted: Apr 23, 1991
Filed: Sep 7, 1990
Inventors
Charles D. Williamson
Stephan J. Allenson
Robert K. Gabel
Assignee (at issue)
Nalco Chemical 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.