Abstract: Drag reduction of fluids containing a water phase, e.g. hydrocarbon-in-water mixture, flowing through a conduit, is reduced by incorporating within the water phase a polymer obtained by radiation-induced polymerization of acrylamide, methacrylamide, acrylic acid, methacrylic acid, alkali metal salts thereof, or mixtures thereof. The polymerization is preferably carried out in 10-60% aqueous monomer solution with gamma radiation. The mixture of monomers, before radiation, preferably contains 25-99% acrylamide and 75-1% sodium acrylate. The polymer preferably shows viscoelastic effects at high concentrations in a solvent. Concentrations of about 1-10,000 ppm of the polymer in the water phase is desired. Examples of fluids useful with this invention include hydrocarbon-in-water and water-in-hydrocarbon slurries, the hydrocarbon is preferably comminuted oil shale or coal, congealed particles of crude oil and/or wax, viscous crude oil, etc.

Abstract: Oil and water emulsions containing a high molecular weight polymer (e.g. a partially hydrolyzed polyacrylamide) and a surfactant (e.g. monovalent cation-containing petroleum sulfonate) are broken with a de-emulsifying agent made up of a divalent cation-containing salt, e.g. CaCl.sub.2, and a strong oxidizing or reducing agent, e.g. sodium hypochlorite or hydrazine.

Abstract: The injectivity profile of a heterogeneous formation and/or vertical conformance is improved by injecting an aqueous solution into the formation, the solution containing a polymer obtained as a product of radiation-induced polymerizatin of acrylamide and/or methacrylamide and acrylic acid, methacrylic acid, and/or alkali metal salts thereof. The polymerization is preferably carried out in a 10-60% aqueous solution with gamma radiation; the aqueous monomer solution preferably contains 25-99% acrylamide and 1-75% sodium acrylate. Immiscible, miscible, or miscible-like displacing processes can be used in conjunction with this invention.

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.

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.