John T Rhudy

US Patent:

39385949, Feb 17, 1976

Filed:

Apr 8, 1974

Appl. No.:

5/458740

Inventors:

John S. Rhudy - Littleton CO
Bruce L. Knight - Littleton CO

Assignee:

Marathon Oil Company - Findlay OH

International Classification:

E21B 4326

US Classification:

166308

Abstract:

Improved fracturing of subterranean formations with water-based fracturing fluids is obtained by incorporating into an aqueous fracturing fluid (1) a water-soluble, high molecular weight polymer that will crosslink in the presence of chromic ion and (2) controlled amounts of chromic ion to crosslink the polymer to form a gel of desired viscosity. Useful polymers include partially hydrolyzed polyacrylamide and copolymers of acrylamide and sodium acrylate.

US Patent:

42344336, Nov 18, 1980

Filed:

Oct 4, 1978

Appl. No.:

5/948610

Inventors:

John S. Rhudy - Littleton CO
Connie L. Gibb - Evergreen CO

Assignee:

Marathon Oil Company - Findlay OH

International Classification:

E21B 4322

US Classification:

252 855D

Abstract:

Plugging of reservoirs with high molecular weight polymers, e. g. partially hydrolyzed polyacrylamide, is overcome by chemically treating a polymer having an excessively high average molecular weight prior to injection into a reservoir with an oxidizing chemical, e. g. sodium hypochlorite, and thereafter incorporating a reducing chemical, e. g. , sodium sulfite, to stop degradation of the polymer when a desired lower average molecular weight and flooding characteristics are attained.

US Patent:

39376338, Feb 10, 1976

Filed:

Nov 21, 1973

Appl. No.:

5/418158

Inventors:

Bruce L. Knight - Littleton CO
John S. Rhudy - Littleton CO
William B. Gogarty - Littleton CO

Assignee:

Hercules, Incorporated - Wilmington DE

International Classification:

C04B 702

US Classification:

106 90

Abstract:

Water loss from cement slurries is reduced by incorporating within a cement slurry a polymer obtained as a product of radiation-induced polymerization of acrylamide and/or methacrylamide and acrylic acid, methacrylic acid, and/or alkali metal salts thereof. The polymerization is preferably carried out in 10-60% aqueous monomer solution with gamma radiation. The aqueous monomer solution preferably contains 25-99% acrylamide and 75-1% sodium acrylate. The polymer can be present in concentration of about 0. 001 to about 3. 0 weight percent, based on the aqueous phase of the slurry.