1. Field of the Invention
The present invention relates to the injection into formations of fluids comprising water classified in Class 166, subclasses -275 and -305 of the United States Patent Office Classification System.
2. Description of the Prior Art
The prior art reviewed in the aforementioned copending applications is of general pertinence to the present application.
J. Polymer Science I, page 180, sets forth the various synthesis routes from acrylonitrile to acrylamide. "Acrylonitrile" M. Sittig Chemical Process Monograph No. 14 (1965) pp. 61-64 discusses uses of acrylamides, general methods for its hydrolysis reaction and suitable conditions therefor. U.S. Pat. No. 3,023,242 teaches yield versus reaction time relationship in the preparation of monomeric acrylic acid amide from acrylonitrile. "Acrylamide, Its Preparation and Properties," by E. L. Carpenter and H. S. Davis, J. Appl. Chem. 7, p 672 (1957) describes conversion of acrylonitrile into acrylamide with concentrated hydrochloric acid to form betachloropropionamide followed by elimination of hydrogen chloride by treatment with potassium carbonate, or aqueous caustic and also describes preparation of acrylamide by hydrolysis of acrylonitrile with sulfuric acid monohydrate in the presence of a polymerization inhibitor.
None of the above prior art teaches polymerization of hydrolyzed and neutralized acrylonitrile in solution and without isolation to conveniently produce high molecular weight polyacrylamide useful in the control of viscosity of aqueous solutions used in supplemented recovery of petroleum, with or without hydrolysis and/or methylolation and/or sulfomethylation of such polyacrylamide.