Abstract: The present invention provides an improved metal corrosion inhibitor for use in aqueous acid solutions which is relatively non-toxic and inexpensive. The corrosion inhibitor is a mixture comprised of oligomerized aromatic amines prepared by contacting the still bottoms residue produced in the distillation of quinoline from coal tar with oxygen in the presence of a catalyst.

Abstract: The present invention provides corrosion inhibited organic acid compositions and methods of using the compositions. The compositions basically comprise water, an organic acid, a corrosion inhibitor comprising at least one quaternary ammonium compound and a corrosion inhibitor activator selected from the group consisting of thioglycolic acid, an alkali metal thiosulfate and mixtures thereof.

Abstract: By the present invention, improved metal corrosion inhibited aqueous organic acid compositions and methods are provided. The compositions are basically comprised of water, an organic acid, a corrosion inhibitor comprising at least one rosin amine derivative and a low toxicity corrosion inhibitor intensifier selected from the group consisting of thioglycolic acid and derivatives thereof.

Abstract: The present invention provides an improved metal corrosion inhibitor for use in aqueous acid solutions which is relatively non-toxic and inexpensive. The corrosion inhibitor is a mixture comprised of oligomerized aromatic amines prepared by contacting the still bottoms residue produced in the distillation of quinoline from coal tar with oxygen in the presence of a catalyst.

Abstract: The present invention provides corrosion inhibited well acidizing compositions and methods of using the compositions to acidize wells. The compositions basically comprise an aqueous acid solution, a corrosion inhibitor comprising at least one quaternary ammonium compound and a corrosion inhibitor intensifier comprised of aliphatic carboxylic acids, crude tall oil, tall oil fatty acids, rosin acids and mixtures thereof.

Abstract: The present invention provides improved quaternary ammonium compounds useful as metal corrosion inhibitors in aqueous acid solutions, methods of preparing the compounds, metal corrosion inhibited aqueous acid solutions containing the compounds and methods of protecting metal surfaces from acid corrosion using the compounds. The compounds are prepared by contacting the still bottoms residue produced in the distillation of quinoline from coal tar with oxygen to oligomerize aromatic amines contained therein and then reacting the oligomerized amines with a benzylhalide.

Abstract: The present invention provides a corrosion inhibitor intensifier for acidizing solutions for use in subterranean formation treatments wherein the corrosion inhibitor comprises a quaternary ammonium compound. The intensifier comprises an effective amount of a source of iodide ions and a source of formic acid.

Abstract: Methods and compositions for controlling iron in aqueous well fracturing fluids are disclosed. In accordance with the methods, ferric iron contained in a fracturing fluid is prevented from precipitating or otherwise disadvantageously reacting by adding a thioalkyl acid or derivative thereof to the fracturing fluid. The thioalkyl acid or derivative reduces ferric ion to ferrous ion which remains in solution at pH levels below about 7.5.

Abstract: A composition and method for acidizing a formation in the presence of ferric ion, free sulfur and/or sulfides is disclosed. The composition employs a ferric ion reducing agent and a sulfide reactant separately or in combination. The ferric ion reducing agent is a thioalkyl acid. The sulfide reactant compounds include .alpha.-diketones and saturated and .alpha.-unsaturated cyclic ketones. In another aspect, the reducing activity of the thioalkyl acid is accelerated by the presence of a catalytic quantity of a compound or mixture of compounds which yield in acid solution cuprous ion, cupric ion or combinations thereof with iodide ion.

Abstract: Methods and compositions for reducing the precipitation of metal sulfides from acid solutions are provided. The methods basically comprise reducing the precipitation of metal sulfide compounds from an aqueous acid solution when the solution dissolves sulfide and metal ions by combining at least one oxime with the acid solution in an amount whereby the oxime preferentially reacts with sulfide ions in the solution and thereby prevents the sulfide ions from reacting with metal ions therein.