Abstract: A method for controlling phosphonates which tend to precipitate with metal ions in water treatment operations comprising, adding to the water a water-soluble copolymer containing one or more of the following monomeric units:[a] ##STR1## in which: R is hydrogen or an alkyl group, R.sub.1 is an alkyl group and X is hydrogen, NH.sub.4.sup.+, a water soluble metal ion or organic base; and[b] a monocarboxylic acid monomer; and adding the copolymer to the water to be treated in an amount sufficient to prevent precipitation of said phosphonates.

Abstract: A gelable composition and process are disclosed that delay the gelation and increase the gel strength of gelled water soluble acrylamide-containing polymers contains: (1) a water dispersible first crosslinking compound selected from the group consisting of p-aminosalicylic acid, furfuryl alcohol, RArOC(O)R' and HOArC(O)OR" wherein Ar represents a phenyl group which can be substituted or non-substituted; R is a hydrogen or a carboxylic group; R' is a C.sub.1 -C.sub.6 alkyl; R" is a hydrogen, a phenyl group, or a C.sub.1 -C.sub.6 alkyl; and when R is a carboxylic group, R and C(O)OR" can be at ortho, meta, or para position with respect to the OC(O)R' group and the OH group, respectively; (2) a water dispersible second crosslinking compound selected from the group consisting of aldehydes and aldehyde-generating compounds; (3) a water soluble acrylamide-containing polymer; and (4) water.

Abstract: Oil and gas wells and injection wells are cleaned of oil-based drilling muds, pipe thread compounds, other oil contaminants, cement and contaminants in injection water by a composition comprising fresh water or seawater, one-half to ten percent concentration of an alkyl polyglycoside surfactant and one to ten percent of a caustic agent such as sodium hydroxide, potassium hydroxide or ammonium hydroxide.