Abstract: Blends of alkyl polyglycoside surfactants having an alkyl chain length of C11 to C16 and blends of alkyl polyglycoside surfactants, in the presence of an ethoxylated alcohol cosurfactant, will form Winsor type III microemulsions in a water-oil mixture in a hydrophile-lipophile balance range of at least about 9.8 to 10.8 at 130.degree. F. wherein the water may be a chloride brine. The compositions are particularly useful in oil and gas well cleanout operations, formation acidizing, and well cementing operations and provide superior cleaning ability for removal of oil based drilling fluids, hydrocarbons and oil based pipe sealant and lubricant compositions, for example.

Abstract: Subterranean oil-bearing formations are treated with aqueous acid solutions which include an effective amount of an ester or salts of sulfonated fatty acids, which exhibits both antisludge and demulsification properties.

Abstract: The invention provides: (1) a process to enhance the removal of solids such as clays, clay-like solids, and shale solids-drill solids-from the surface of a borehole, the solids being deposited from well drilling, completion, or workover fluids during well servicing operations; and (2) a process to enhance the removal of such solids from screens or other sand control devices present in a borehole. The process comprises contacting the solids with an acidic soak solution containing a polyglycol or mono ether derivative thereof and thereafter contacting the surface of the borehole with a wash solution to remove the solids from the borehole.

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: 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: This invention relates to anionic compositions, containing an alkyl aryl sulfonic acid or salt thereof, a nonethoxylated glycol and an acetylenic alcohol in an alkyl alcohol solvent, that have proved effective for controlling sludge and emulsion formation during acid stimulation and treatment of hydrocarbon wells.

Abstract: The present invention relates to a method, comprising the steps of:introducing into a well borehole a composition, comprising water, an acid, and (A) at least one reaction product of (A-1) at least one hydrocarbyl-substituted carboxylic acylating agent selected from the group consisting of a dicarboxylic acylating agent, a succinic acylating agent, a Dieis-Alder diacid, a dimer acid acylating agent, a tricarboxylic acylating agent, a polycarboxylic acylating agent, or mixtures thereof, and (A-2) at least one amine-terminated polyoxyalkylene or (A-3) at least one hydroxy-terminated polyoxyalkylene having a number average molecular weight from about 600 to about 30,000, or a mixture of said (A-2) amine-terminated polyoxyalkylenes and (A-3) hydroxy-terminated polyoxyalkylenes. The reaction product (A) may be used alone, or in combination with one or more surfactants.

Abstract: The invention relates to iron control in an acid medium for forestalling the formation of precipitates known as "sludges" (asphaltic products) in contact with certain crude oils.Use is made of compounds comprising a mercaptan function non miscible in water and, in combination, a selection of catalysts.Application to acid treatments for oil, gas, water, geothermal and analogous wells, as well as to industrial cleaning.

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: Subterranean oil-bearing formations are treated with aqueous acid solutions which include an effective amount of an alkoxylated alkyl substituted phenol sulfonate which exhibits both antisludge and demulsification properties.

Abstract: A method of stimulating production in sandstone formations of oil and gas wells is achieved by using an acid system which slowly dissolves the silicate and clay formations of the sandstone to increase its permeability. The acid system uses phosphonate compounds, including phosphonate acids and the salts and esters thereof, in combination with hydrofluoric acid. The hydrofluoric acid may be provided by hydrolyzing ammonium bifluoride or hydrofluoric acid itself. The phosphonate compounds of the acid systems retard the rate at which the hydrofluoric acid reacts with the clays while enhancing the reaction rate with silica, which comprises the bulk of sandstone formations. This allows more penetration of the formation immediately adjacent to the wellbore. The phosphonate materials also improve the dispersion and suspension properties of the treating solution with silts and fines and improves the complexing capacity of the acids with silicate and alumni complexes.

Abstract: Methods are provided for acidizing treatment of a permeable matrix by infusing a pre-acidizing composition and an activating composition. Components of the pre-acidizing composition include hydrochloric acid, phosphoric acid, a hydroxy carboxylic acid and a dicarboxy acid.