Granted Patent
Utility
US 4,502,964 · App. 06/530,569
Terpolymers for use as high temperature fluid loss additive and rheology stabilizer for high pressure, high temperature oil well drilling fluids
Inventors:
David M. Giddings, Donald G. Ries, Allen R. Syrinek
Patented Case
View Patent ↗
Granted: Mar 5, 1985
Filed: Sep 9, 1983
Inventors
David M. Giddings
Donald G. Ries
Allen R. Syrinek
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.