Gelled acidic well treating composition and process

Claim 1

A gelled acidic composition comprising: water, a water-thickening amount of a water-dispersible polymer selected from the group consisting of water-dispersible cellulose ethers, polyacrylamides, polymethacrylamides, guar gum, polyvinylpyrrolidone, and biopolysaccharides or heteropolysaccharides produced by the action of bacteria of the genus Xanthomonas upon carbohydrates, an amount of a non-oxidizing acid which is capable of, and sufficient for, reacting with a significant amount of the acid-soluble components of a subterranean formation, and a small, but effective amount, about 0.003 to about 1.2 weight percent, of one or more water-dispersible aldehyde(s) selected from the group consisting of aliphatic monoaldehydes having from one to about 10 carbon atoms per molecule, glyoxal, glutaraldehyde, and terephthaldehyde and from about 0.001 to about 2 weight percent of one or more water-dispersible phenolic compounds selected from the group consisting of phenol, catechol, resorcinol, hydroquinone, phloroglucinol, pyrogallol, 4,4'-diphenol, and 1,3-dihydroxynaphthalene sufficient to cause gelation of an aqueous dispersion of said polymer, said acid, said aldehydes, and said phenolic compounds.