Abstract: Methods of drilling well bores using an invertible oil external-water internal emulsion drilling fluid and then inverting the drilling fluid to a water external-oil internal emulsion are provided. The methods basically comprise the steps of contacting the oil external-water internal emulsion with an aqueous acid solution containing an anionic sulfonate surfactant for preventing aqueous acid solution-crude oil emulsions and crude oil sludging and a chemical for preventing the anionic sulfonate surfactant from reacting with the emulsifier in the oil external-water internal emulsion.

Abstract: Methods of drilling well bores using an invertible oil external-water internal emulsion drilling fluid and then inverting the drilling fluid to a water external-oil internal emulsion are provided. The methods basically comprise the steps of contacting the oil external-water internal emulsion with an aqueous acid solution containing an anionic sulfonate surfactant for preventing aqueous acid solution-crude oil emulsions and crude oil sludging and a chemical for preventing the anionic sulfonate surfactant from reacting with the emulsifier in the oil external-water internal emulsion.

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 &agr;-diketones and saturated and &agr;-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: Improved metal corrosion inhibitors, acid compositions containing the inhibitors and methods of using the acid compositions are provided by the present invention. The metal corrosion inhibitors are basically comprised of one or more acetylenic alcohols and hexamethylenetetramine.

Abstract: The present invention provides microemulsion surfactant additives for use in aqueous well treating fluids to prevent the formation of stable emulsions and sludge when the aqueous treating fluids contact hydrocarbons. The additives are basically comprised of a solvent, a co-solvent, water, an aqueous liquid-hydrocarbon liquid de-emulsifying surfactant and a liquid hydrocarbon antisludging surfactant. Aqueous compositions including the additives and methods of treating subterranean formations or zones containing hydrocarbons using the compositions are also provided.

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: The present invention relates to improved environmentally friendly solvent compositions for materials such as pipe dope, thread lubricants and the like and methods of utilizing such compositions. The nonaqueous solvent compositions are basically comprised of an emulsion of a surface active agent for breaking up and dispersing the materials, and D-limonene and a mixture of other terpenes including dipentene for dissolving the materials and glacial acetic acid.

Abstract: An additive for addition to conventional well treatment fluids to enhance the ability of the fluids to be recovered from subterranean formations, to generate a foam in association with the fluids and/or to enhance the ability of the fluids to remove water and other connate fluids interlocked with gas in the formations. The additive includes about 25% to about 50% by volume of a microemulsion generating component which forms an acid and/or water external microemulsion when added to the treatment fluid, and about 50% to about 75% by volume of a foaming agent component. The foaming agent component includes at least one nonionic surface active agent having an HLB of from 12 to 22. The additive is particularly suitable for addition to foam fracturing fluids useful for stimulating tight or otherwise unconventional gas formations. Also provided are a gas well treatment composition employing the inventive additive and a method of treating a subterranean formation in which the inventive composition is employed.

Abstract: A concentrate which forms an acid internal microemulsion well treatment composition when added to an acid treatment fluid. The concentrate comprises in the range of from about 20% to about 98% by weight of a hydrocarbon carrier fluid, in the range of from about 1% to about 50% by weight of an alkyl alcohol having from 4 to 18 carbon atoms and in the range of from about 1% to about 50% by weight of an emulsifying agent comprising at least one compound selected from the group consisting of sulfate esters, phosphate esters, alkyl aromatic sulfonic acids, amine salts having ester or amide linkages, quaternary ammonium compounds having ester of amide linkages, propoxylated fatty acids, and propoxylated alcohols. Also disclosed are an acid internal microemulsion well treatment composition and a method of treating a subterranean formation to increase the production of hydrocarbons therefrom.

Abstract: A concentrate which forms an acid and/or water external microemulsion when added to a treatment fluid. The concentrate comprises an alkyl alcohol having in the range of from 4 to 18 carbon atoms, an emulsifying agent, a mutual solvent selected from the group consisting of glycol ethers and alkyoxylates of glycol ethers, and a co-solvent selected from the group consisting of polyethylene glycol, primary alcohols and alkyoxylates of alkyl alcohols. Also disclosed are an acid and/or water external microemulsion well treatment composition and a method of treating a subterranean formation to increase the production of hydrocarbons therefrom.

Abstract: The present invention relates to a method of treating a carbonate-containing subterranean formation to increase the production of hydrocarbons therefrom. The subterranean formation is contacted with an aqueous solution of a composition represented by the formula: ##STR1## wherein a is a whole number or fraction thereof in the range of from about 4 to about 18;wherein b is a whole number or fraction thereof in the range of from about 0 to about 30;wherein c is a whole number or fraction thereof in the range of from about 0 to about 3;wherein d is independently a whole number or fraction thereof in the range of from about 0 to about 3;wherein e is a whole number or fraction thereof in the range of from about 1 to about 3;R is independently selected from the group consisting of hydrogen and a methyl group whereby mixtures containing both groups may result; andX.sup.

Abstract: Foamed high viscosity aqueous inorganic acid solutions and methods of treating subterreanean well formations using such solutions are provided. The foamed acid solutions are comprised of water, at least one water soluble inorganic acid, a gelling-foaming agent comprised of a solution of a water soluble organic solvent and an ethoxylated fatty amine or a mixture of such amines and an inert gas.

Abstract: Asphaltenic and paraffinic containing deposits are removed by contacting the deposits with an aqueous dispersion of a hydrocarbon solvent, an amine and a nonionic alkylated aryl polyether alcohol.

Abstract: A composition for inhibiting scale and methods of using said composition consisting of a relatively water-insoluble organic precipitate formed by the reaction of a water-soluble polyelectrolytic organic polymer having an average molecular weight in the range of from about 1,000 to about 100,000 and a water-soluble organic cationic surface active compound.