Abstract: A method of recovering crude oil from a subterranean hydrocarbon containing formation which comprises (a) injecting into said formation an aqueous solution containing an effective amount alkali metal, alkaline-earth or ammonium salts of alcohol ether sulfonates derived from unsaturated alcohol ethers, and (b) displacing said solution into one or more injection wells and recovering the oil from one or more production wells. The unsaturated alkoxylated alcohol contain various amounts of ethylene oxide, propylene oxide and butylene oxides elected to optimize their interfacial properties with different types of crude oil with different brines.

Abstract: A well service fluid comprising one or more anionic viscoelastic surfactants and one or more polymers is described. The fluids can contain an aqueous or non-aqueous fluid and/or a buffer for adjusting the pH of the fracturing fluid. The well service fluid can be used as a fracturing fluid in order to control water production from a well, while simultaneously increasing the oil production from the well.

Abstract: Composition and method for shortening the shear recovery time of cationic, zwitterionic, and amphoteric viscoelastic surfactant fluid systems by adding an effective amount of a co-gelling agent selected from triblock oligomeric compounds having hydrophilic (for example polyether) and hydrophobic (for example alkyl) portions. The co-gelling agent also increases fluid viscosity and very low co-gelling agent concentration is needed. Preferred surfactants are betaines and quaternary amines. The fluids are useful in oilfield treatments, for example fracturing and gravel packing.

Abstract: A thermoviscoelastic system (TVE) fluid useful in a well treatment method can include a hydrophobically-modified polymer and a viscoelastic surfactant (VES) in an aqueous medium, wherein the polymer has a lower critical solution temperature (LCST). The polymer can have water solubility for preparation below the LCST, and the TVE has a low viscosity for pumping down a well bore in communication with a subterranean formation. When the TVE is heated above the LCST, interaction between the hydrophobic groups of the polymer and the VES form a cross-linked network to increase the viscosity to transport proppant into a fracture. The thickened TVE can have a low leak-off rate, optionally including colloidal particles or other fluid loss control agent, and can be broken by contact with hydrocarbons as during flowback from the reservoir.

Abstract: The invention provides a fluid for use in a subterranean formation penetrated by a wellbore, the fluid comprising: (a) water; (b) delayed release acid; (c) a surfactant comprising a tertiary alkyl amine etboxylate generally represented by the following formula: wherein R is an alkyl group or groups, X is about 2 to about 15, and Y is about 2 to about 15; and (e) a gelling agent. The invention also provides a method of fracturing a subterranean formation, comprising the step of forming a foamed fracturing fluid comprising water; a surfactant comprising a tertiary alkyl amine ethoxylate generally represented by the formula above; a gelling agent; and a gas. The method also provides the step of introducing the foamed fracturing fluid into a subterranean formation at a pressure sufficient to create a fracture in the subterranean formation. The method also provides the step of introducing an acid into the subterranean formation.

Abstract: Barium sulfate and/or calcium carbonate scale inhibitor composition composed of a water-soluble polymer having incorporated phosphate functionality, the polymer being formed from at least one ethylenically unsaturated carboxylic acid monomer, at least one ethylenically unsaturated vinyl sulfonate monomer, or a mixture thereof. The scale inhibitor composition can be used as a means of detecting inhibitor composition in downhole and topside oilfield treatments by means that are faster and more accurate than turbidometric measurement.

Abstract: Acid based micro-emulsions are disclosed comprising water, an acid blend, an anionic surfactant, a nonionic surfactant, a co-solvent, a solvent and an oxidizer. The micro-emulsions have particular utility in cleaning oil sludges and drilling mud residues from well cuttings, well formations and down hole and surface oil well drilling and production equipment.

Abstract: The invention is a method for improving conformance during a carbon dioxide foam flood, which comprises injecting into the formation an aqueous solution of about 0.05% to about 5% by weight of a carbon dioxide foaming surfactant, and about 0.05% to about 5% by weight of a lignosulfonate-acrylic acid graft copolymer having about 2% to about 70% by weight of acrylic acid, and injecting into the formation carbon dioxide to sweep the hydrocarbons towards a production well for recovery.

Abstract: Disclosed is a hydrophilic, water soluble polymer concentrate for addition to aqueous liquids to enhance the properties thereof, particularly to increase the viscosity or decrease the fluid loss of well drilling and servicing fluids, the concentrate comprising a hydrophobic, water insoluble liquid, an organophilic clay suspension agent, the water soluble polymer, and a stabilizing agent comprising one or more acids in an amount from about 0.001% to about 1.5%, one or more anionic surfactants in an amount from about 0.001% to about 1.0%, one or more nonionic surfactants in an amount from 0.001% to about 0.625% and, from about 0% to about 0.75% of one or more water soluble organic liquids, wherein the total concentration of the stabilizing agent is from about 0.1% to about 2.5%, these percentages being based on the weight of the concentrate.

Abstract: Acid based micro-emulsions are disclosed comprising water, an acid blend, an anionic surfactant, a nonionic surfactant, a co-solvent, a solvent and an oxidizer. The micro-emulsions have particular utility in cleaning oil sludges and drilling mud residues from well cuttings, well formations and down hole and surface oil well drilling and production equipment.

Abstract: Subterranean formation treating fluid concentrates, treating fluids and methods are provided by the present invention. The treating fluid concentrates are basically comprised of water and a substantially fully hydrated depolymerized polymer. The treating fluids which are formed by adding water to the treating fluid concentrates are basically comprised of water, a substantially fully hydrated depolymerized polymer and a crosslinking agent for crosslinking the hydrated depolymerized polymer.

Abstract: A well treatment fluid such as a fracturing fluid or drilling fluid which comprises a water-in-oil emulsion containing an amine or amine oxide surfactant of the following formula: or a protonated form thereof wherein R3 is a hydrocarbyl or substituted hydrocarbyl having from about 8 to about 30 carbon atoms, and R1 and R2 are independently hydrogen, a hydrocarbyl or substituted hydrocarbyl having up to 30 carbon atoms.

Abstract: An acid corrosion inhibitor composition is provided for petroleum wells and water wells subjected to stimulation with acid solutions. The inhibitor combines cinnamaldehyde and an organo-sulfur compound. The inhibitor provides a reduced rate of corrosion and fewer instances of pitting than inhibitors which include cinnamaldehyde alone. The inhibitor does not suffer from the well-known oil field aldehyde/polyacrylamide crosslinking incompatibility. The enhanced performance by the inhibitor of the present invention is provided by a synergistic action between the cinnamaldehyde and an organo-sulfur compound.

Abstract: An improved concentrated surfactant formulation and process for the recovery of residual oil from subterranean petroleum reservoirs, and more particularly an improved alkali surfactant flooding process which results in ultra-low interfacial tensions between the injected material and the residual oil, wherein the concentrated surfactant formulation is supplied at a concentration above, at, or, below its CMC, also providing in situ formation of surface active material formed from the reaction of naturally occurring organic acidic components with the injected alkali material which serves to increase the efficiency of oil recovery.

Abstract: Polymeric well completion and remedial compositions which form highly pliable impermeable masses of desired rigidity and methods of using the compositions are provided. The compositions are basically comprised of water, a water soluble polymerizable monomer, a polymerization initiator and an oxygen scavenging agent. The composition is usually foamed and contains a gelling agent and a solid filler material to increase the density and/or rigidity of the impermeable mass formed.

Abstract: A composition for and an improved process of, enhancing petroleum recovery from a petroleum reservoir by injecting said composition into the reservoir through a wellbore are provided. The aqueous composition is derived from a concentrate which includes a defoaming agent, a demulsifying agent, and optionally a stabilizing agent suitable for stabilizing the concentrate as an aqueous emulsion. In one embodiment, the defoaming agent is dispersed in carrier solvent and the concentrate further includes an emulsifying agent suitable for emulsifying the carrier solvent in water. The composition is preferably injected at a high pumping rate directly into the formation through the tubing-casing annulus and allowed to permeate into the reservoir surrounding the wellbore before oil production commences. The composition and method are particularly suited for used in conjunction with steam injection oil recovery techniques.

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 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: An improved method for acidizing an oil bearing formation in the presence of water bearing zones having high permeability is described. An aqueous fluid is pumped into the formation preceding the injection of stimulation material. This fluid contains hydroxyethylcellulose, a fluorescent dye and an organic acid anhydride, which during hydrolysis reduces the pH and the viscosity of the solution making it retrievable without damage to the formation.

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 for recovering surfactants from produced fluids by mixing with produced fluids about 0.1% to about 5% of a nonionic surfactant having a phase inversion temperature above the temperature of the produced fluids, heating the mixture above the phase inversion temperature, mixing the phase containing oil and the surfactants with water, and cooling the mixture below the phase inversion temperature to extract the surfactants into an aqueous phase, provided that if a sufficient concentration of the nonionic surfactant is already in the produced fluids, it need not be added.

Abstract: Improved cement compositions and methods of using such compositions in carrying out construction and remedial operations in oil and gas wells at high temperatures are provided. The compositions are basically comprised of hydraulic cement, sufficient water to form a pumpable slurry, and a dispersing and stabilizing additive comprised of an ethoxylated alkali metal salt of an alkyl polyether sulfonate.