Abstract: A method for inhibiting inorganic sulfate scale growth in an aqueous fluid present within or produced from a subterranean formation is performed by contacting the aqueous fluid in situ with a scale inhibitor composition containing two homopolymers in solution within an aqueous liquid medium. The first homopolymer is a polyvinyl sulfonate and the second homopolymer is a polyacrylic acid. The weight ratio of the first homopolymer to second homopolymer is preferably at least about 1:1 and the aqueous fluid being contacted by the composition typically contains a relatively high concentration of precursor ions of inorganic sulfate scale, including scale-forming inorganic cations and scale-forming sulfate anions.

Abstract: A relatively high molecular weight polyvinyl sulfonate and a process for inhibiting scale deposition, particularly inorganic sulfate such as barium sulfate, wherein an aqueous fluid present in or produced from a subterranean formation is contacted with an aqueous solution having a relatively high molecular weight polyvinyl sulfonate dissolved therein. The aqueous fluid has a pH equal to or less than 6.0 and the polyvinyl sulfonate has a molecular weight of from about 9,000 to about 30,000.

Abstract: A process for the sulfonation of a hydrocarbon feedstock, particularly one containing naphthenes, is improved by ozonating the hydrocarbon feedstock prior to sulfonation. The ozonation results in a greater conversion of the sulfur trioxide to sulfonate, a reduction in the salts, for example, sulfites, which are formed, a decrease in the amount of colored bodies and a more efficient extraction and separation of unreacted hydrocarbons from the sulfonated product. The process is especially applicable to petroleum feedstocks such as crude oil, topped crude oil, gas oil and mixtures thereof.