Granted Patent
Utility
US 4,440,228 · App. 06/343,638
Gelled compositions and well treating
Inventor:
Billy L. Swanson
Patented Case
View Patent ↗
Granted: Apr 3, 1984
Filed: Jan 28, 1982
Inventor
Billy L. Swanson
Assignee (at issue)
Phillips Petroleum 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.