Abstract: Elemental iodine is used to improve the performance of conventional corrosional inhibitors in oil field acidizing operations. The iodine, because of its solubility, may be used in a formulation which includes a corrosion inhibitor and surfactants dissolved in a suitable organic solvent.

Abstract: Granules containing a gel breaker are used in a well treatment involving the use of a gelled fluid. The granules exhibit delayed release of the breaker to permit placement of the gelled fluid into the subterranean formation. The method of the present invention is used in gravel packing operation to degrade polymeric gelling agents used in the gravel packing liquid.

Abstract: Granules containing a gel breaker are used in a well treatment involving the use of a gelled fluid. The granules exhibit delayed release of the breaker to permit placement of the gelled fluid into the subterranean formation.

Abstract: An acid system for acidizing wells contains corrosion inhibitor additives which consist essentially of a metal selected from antimony and antimony mixtures, a quaternary compound, and a surfactant. The corrosion inhibitor is free of toxic acetylenic compounds.

Abstract: An encapsulated breaker chemical composition used in a fracturing process in an oil or gas stimulation operation which comprises: (a) a breaker chemical; (b) a water soluble sealing layer, such as urea, having a thickness within the range of about 1 to about 30 microns deposited on the surface of said breaker chemical and encapsulating said breaker chemical; and (c) a pinhole free coating of a neutralized sulfonated elastomeric polymer of about 2 to about 80 microns thick deposited onto the surface of the coated breaker chemical, wherein said neutralized sulfonated polymer encapsulates the breaker chemical and is permeable to the breaker chemical.

Abstract: Corrosion inhibitor additives are added directly to an aqueous acid solution used in acidizing subterranean formations. The additives comprise a bismuth compound, a quaternary compound, and a surfactant. The corrosion inhibitor is free of toxic Sb and acetylenic compounds.

Abstract: An encapsulated breaker chemical composition used in a fracturing process in the protection of an oil or gas stimulation operation which comprises: a breaker chemical; and a pinhole free coating of a neutralized sulfonated elastomeric polymer of about 2 to about 80 microns thick deposited onto the surface of the breaker chemical, wherein said neutralized sulfonated polymer encapsulates the breaker chemical, wherein the neutralized sulfonated polymer is permeable to the breaker chemical and the neutralized sulfonated polymer is non-reactive to the breaker chemical.

Abstract: An encapsulated breaker chemical composition used in an oil or gas stimulation operation which comprises: a breaker chemical; and a pinhole free coating of an ionically and covalently crosslinked neutralized sulfonated elastomeric polymer of about 2 to about 80 microns thick deposited onto the surface of the breaker chemical, wherein said polymer encapsulates the breaker chemical, wherein the polymer is permeable to the breaker chemical and the polymer is non-reactive to the breaker chemical.

Abstract: A corrosion inhibitor for an acid well treating composition includes first metal ions including Sb, Cu, and Bi complexed with a quaternary ammonium compound and second metal ions complexed with a quaternary ammonium compound. The complexed compounds may be prepared and introduced into the acid or the first metal ions may be introduced directly into the acid system.

Abstract: An encapsulated breaker chemical composition used in an oil or gas stimulation operation which comprises: a breaker chemical; and a pinhole free coating of an ionically and covalently crosslinked neutralized sulfonated elastomeric polyer of about 2 to about 80 microns thick deposited onto the surface of the breaker chemical, wherein said polymer encapsulates the breaker chemical, wherein the polymer is permeable to the breaker chemical and the polymer is non-reactive to the breaker chemical.

Abstract: An encapsulated breaker chemical composition used in a fracturing process in the protection of an oil or gas stimulation operation which comprises: a breaker chemical; and a pinhole free coating of a neutralized sulfonated elastomeric polymer of about 2 to about 80 microns thick deposited onto the surface of the breaker chemical, wherein said neutralized sulfonated polymer encapsulates the breaker chemical, wherein the neutralized sulfonated polymer is permeable to the breaker chemical and the neutralized sulfonated polymer is non-reactive to the breaker chemical.

Abstract: An encapsulated breaker chemical composition used in a fracturing process in an oil or gas stimulation operation which comprises: (a) a breaker chemical; (b) a water soluble sealing layer, such as urea, having a thickness within the range of about 1 to about 30 microns deposited on the surface of said breaker chemical and encapsulating said breaker chemical; and (c) a pinhole free coating of a neutralized sulfonated elastomeric polymer of about 2 to about 80 microns thick deposited onto the surface of the coated breaker chemical, wherein said neutralized sulfonated polymer encapsulates the breaker chemical and is permeable to the breaker chemical.

Abstract: Corrosion inhibitor additives are added directly to an aqueous acid solution used in acidizing subterranean formations. The additives consist essentially of a metal selected from antimony and antimony mixtures, a quaternary compound, and a surfactant. The corrosion inhibitor is free of toxic acetylenic compounds.

Abstract: A solid polymeric body comprising a polymer matrix containing a substantially water-insoluble reagent leachable into a substantially hydrocarbon liquid environment, the matrix being reagent permeative and the body preferably having a softening point substantially above that of the temperature of the liquid fluid environment in which it is to be employed. The body is useful for the introduction of an additive reagent into a substantially liquid hydrocarbon such as crude and refined oils.

Abstract: Permeability of a subterranean formation is increased by injecting into the formation sufficient amount of chlorine dioxide solution to react with formation clays and silicates. The pH of the ClO.sub.2 solution is controlled between 0.01 and 3.2 using preferably a mineral acid and liquid CO.sub.2 blended with the aqueous ClO.sub.2 solution.

Abstract: A corrosion inhibitor formulation for use in well treatig acids includes a highly polar aprotic solvent having dissolved therein (a) a complex of a metal compound and a quaternary ammonium compound and (b) a dispersant capable of dispersing the complex in the well treating acid solution.

Abstract: A solid polymeric body comprising a polymer matrix containing a water-soluble reagent leachable into a fluid containing condensed water, said matrix being reagent permeative and insoluble in said fluid containing condensed water and the said body preferably having a softening point substantially above that of the temperature of the fluid environment in which it is to be employed is useful for the introduction of an additive reagent into said fluid particularly when said fluid is located in a subterranean formation.

Abstract: A solid polymeric body comprising a polymer matrix containing a water-soluble reagent leachable into a fluid containing condensed water, said matrix being reagent permeative and insoluble in said fluid containing condensed water and the said body preferably having a softening point substantially above that of the temperature of the fluid environment in which it is to be employed is useful for the introduction of an additive reagent into said fluid particularly when said fluid is located in a subterranean formation.

Abstract: A method is provided for the controlled introduction of a reagent into a liquid, preferably a reagent peremeable substantially hydrocarbon liquid, which method comprises the steps of:(a) placing as in a geological crude oil reservoir solid polymeric bodies, each body comprising a reagent permeable polymeric matrix containing a substantially water insoluble reagent such as at least one of a wax crystal modifier, demulsifier, scale inhibitor, corrosion inhibitor, biocide, ashless dispersant, antioxidant and mixtures thereof in said liquid (includes both crude and refined hydrocarbon liquids); and,(b) leaching out said reagent from said bodies at a controlled and predetermined rate into said liquid.

Abstract: An anti-sludge agent useful for acid stimulated hydrocarbon containing formations is an ester of sulfonic acid, e.g. monoethoxylated dodecyl benzene sulfonic acid, preferably used in combination with from 0.1 to 2 parts by weight of a surfactant.