Abstract: A method of acidizing a subterranean formation with an acqueous acid solution wherein the acid solution contains corrosion inhibiting amounts of an amine derivative prepared by reacting an unsaturated carboxylic acid with (a) fatty amine or polyamine, or (b) a fatty amido amine or polyamine, or (c) a fatty imidazoline amine or polyamine. The derivative is characterized by the absence of primary amino groups, and preferably contains only tertiary amino groups.

Abstract: Corrosion inhibition is obtained by treating a system containing corrosion susceptible metal with a corrosion inhibiting amount, preferably 1 to 10,000 ppm of a thio substituted quaternary ammonium salt, preferably of the general structure: ##STR1## wherein R.sub.1 is preferably H or an alkyl group of 8 to 18 carbon atoms, n is 2 or 3, R.sub.2, R.sub.3 and R.sub.4 are preferably alkyl groups of 1 to 18 carbon atoms and two of R.sub.2, R.sub.3 and R.sub.4 are methyl.

Abstract: Corrosion inhibition of metals is obtained treating a system with a corrosion-inhibiting amount, preferably 1 to 10000 ppm, of an optionally-substituted .beta.-pyridyl-ethylamine or a salt thereof, which may be prepared by reacting an amine with a vinylpyridine, preferably in the presence of an acidic catalyst such as acetic acid. The .beta.-pyridyl-ethylamine is a compound of the general formula: ##STR1## wherein R is an alkyl, aryl, aralkyl, alkaryl, halo or amino group of a group --COX where X is hydrogen, alkyl, aryl, hydroxy, alkoxy, aryloxy, amino or halo group, n is zero or an integer from 1 to 4, and R.sup.1 and R.sup.2, which may be the same or different, each represent a hydrogen atom, an optionally substituted hydrocarbyl radical, an alkylamino radical, a heterocyclic radical or a group ##STR2## or R.sup.1 and R.sup.2 with the intervening nitrogen atom together represent a saturated or unsaturated heterocyclic ring optionally containing one or more additional heteroatoms.

Abstract: A method for inhibiting acid corrosion of metal well equipment which comprises introducing into an aqueous acid solution an inhibiting amount of a quaternary compound prepared by reacting a tertiary aromatic heterocyclic amine with a (halo-substituted-aryl) alkyl halide, and contacting the well equipment with the inhibited aqueous acid solution.

Abstract: A method for treating a hydrocarbon stream containing free sulfur wherein a formulation comprising a diaryldisulfide and a film forming corrosion inhibitor are introduced into the hydrocarbon stream.