Abstract: Method for treating earthen formations which contain water-sensitive, finely divided particulate matter wherein there is injected into the formation steam or a mixture of steam and hot water containing an effective fines-stabilizing amount of a compound containing ammoniacal nitrogen selected from the group consisting of ammonium hydroxide, an ammonium salt of an inorganic acid, an ammonium salt of a carboxylic acid, ammonium cyanate, derivatives of ammonium cyanate, ammonium thiocyanate, and a water-soluble ammonia or ammonium ion precursor selected from the group consisting of amides of carbamic acid and thiocarbamic acid, derivatives of such amides, tertiary carboxylic acid amides and their substituted and akylated derivatives. Preferred additives include ammonium carbonate and urea. If the formation is a subsurface oil-containing formation, the treatment can be part of a method for enhanced oil recovery.

Abstract: A composition and method for providing improved mobility control in secondary and tertiary recovery processes obtained by injecting into a subterranean hydrocarbon-bearing formation, as part of the secondary or tertiary recovery fluid, an aqueous solution of a mixture of a heteropolysaccharide produced by bacteria of the genus Xanthomonas together with a polyacrylamide or a chemically altered derivative of a polyacrylamide.

Abstract: A composition and method for providing improved mobility control in secondary and tertiary recovery processes obtained by injecting into a subterranean hydrocarbon-bearing formation, as part of the secondary or tertiary recovery fluid, an aqueous solution of a mixture of a heteropolysaccharide produced by bacteria of the genus Xanthomonas together with a polyacrylamide or a chemically altered derivative of a polyacrylamide.

Abstract: A method of selectively plugging permeable water-producing zones in a subterranean formation of nonuniform permeability comprising sequentially injecting into the formation (1) an aqueous solution of a first reactant material rendered more viscous than the subsequently injected liquids by the addition of a viscosity increasing agent, (2) a low viscosity inert aqueous spacer liquid, (3) a low viscosity aqueous solution containing a second reactant material which, on contact, will react with the first reactant material to produce an insoluble precipitate, (4) a low viscosity inert aqueous spacer liquid and (5) an additional amount of the aqueous solution of a first reactant material, which aqueous solution is optionally rendered more viscous than the previously injected aqueous solution containing the second reactant material by the addition thereto of a viscosity increasing agent.