Abstract: Methods of treating a wellbore comprise displacing a drilling fluid comprising an organophilic clay treated with a quaternary ammonium surfactant having an amide linkage into the wellbore. Methods of drilling a wellbore comprise: applying torque to a bit within the wellbore and concurrently applying force to urge the bit to extend through the wellbore; and circulating a drilling fluid past the bit to remove cuttings therefrom, the drilling fluid comprising an organophilic clay treated with a quaternary ammonium surfactant having an amide linkage. Methods of preparing a drilling fluid comprise: forming an organophilic clay treated with a quaternary ammonium surfactant having an amide linkage; and combining the organophilic clay with an oil-based fluid.

Abstract: A method comprising contacting a zwitterionic surfactant, co-surfactant, and water to form a microemulsifier, and contacting the microemulsifier with an oleaginous fluid under low shear conditions to form a microemulsion. A method comprising introducing a first wellbore servicing fluid comprising at least one oleaginous fluid into a wellbore, wherein the first wellbore servicing fluid forms oil-wet solids and/or oil-wet surfaces in the wellbore, and contacting the oil-wet solids and/or oil-wet surfaces in the wellbore with a second wellbore servicing fluid comprising a zwitterionic surfactant, a co-surfactant, and a brine to form a microemulsion.

Abstract: Piezoelectric crystal particles (which include pyroelectric crystal particles) enhance the viscosity of aqueous fluids that have increased viscosity due to the presence of viscoelastic surfactants (VESs). In one non-limiting theory, when the fluid containing the viscosity enhancers is heated and/or placed under pressure, the particles develop surface charges that associate, link, connect, or relate the VES micelles thereby increasing the viscosity of the fluid. The higher fluid viscosity is beneficial to crack the formation rock during a fracturing operation, reduce fluid leakoff, and carry high loading proppants to maintain the high conductivity of fractures.

Abstract: A method of treating a subterranean formation penetrated by a wellbore is accomplished by introducing a fluid into the wellbore containing a combined fluid loss additive and breaker. The combined fluid loss additive and breaker is formed from particles of an organic peroxide provided on a substrate. The particles are sized to facilitate fluid loss control. A treatment operation is carried out wherein a treatment fluid viscosified with a polymer is introduced into the formation through the wellbore.

Abstract: An aqueous fluid system that contains an aqueous dicarboxylic acid solution, a viscoelastic surfactant as a gelling agent to increase the viscosity of the fluid, and an internal breaker such as mineral oil and/or fish oil to controllably break the viscosity of the fluid provides a self-diverting acid treatment of subterranean formations. The internal breaker may be at least one mineral oil, a polyalphaolefin oil, a saturated fatty acid, and/or is an unsaturated fatty acid. The VES gelling agent does not yield viscosity until the organic acid starts to spend. Full viscosity yield of the VES gelling agent typically occurs at about 6.0 pH. The internal breaker allows the VES gelling agent to fully viscosify the spent organic acid at 6.0 pH and higher, but as the spent-acid VES gelled fluid reaching reservoir temperature, controllable break of the VES fluid viscosity over time can be achieved.

Abstract: Disclosed are methods of treating subterranean formations with rapidly hydratable treatment fluids based upon heteropolysaccharides. In particular, the invention relates to treatment methods with fluids containing a heteropolysaccharide, aqueous medium, and an electrolyte, wherein the fluids may further include a gas component, a surfactant and/or an organoamino compound. The fluids exhibit good rheological properties at elevated temperatures, and unusually rapid hydration rates which allows utilizing such fluids without the need of hydration tanks.

Abstract: A method of treating a medium for water fracturing is disclosed, the method comprises: introducing at least one biocide and at least one metabolic inhibitor in the medium, using the medium for water fracturing. In another aspect a method of controlling the post-fracture reservoir souring by the metabolic activities of sulfate reducing bacteria of a well is described: at least one biocide and at least one metabolic inhibitor are introduced in a medium made of water, the medium is used for fracturing the well, and the medium remains in the reservoir to kill and/or inhibit growth of sulfate reducing bacteria.

Abstract: Drilling fluids are provided that comprise an organophilic clay treated with a quaternary ammonium surfactant having an amide linkage. The quaternary ammonium surfactant may comprise a compound generally represented by the following formula: where M? is an anion such as a chloride, methyl sulfate, bromide, acetate, or iodide ion; R1 is an alkyl group such as a saturated hydrocarbon with 10 or more carbons; R2, R3, and R4 are the same or different alkyl groups such as a methyl, ethyl, or benzyl group, and x is greater than or equal to 1. The organophilic clay treated in this manner is substantially biodegradable. In embodiments, the drilling fluids comprise the foregoing organophilic clay, an oil-based fluid and a weighting agent. In still more embodiments, the drilling fluids comprise the foregoing organophilic clay, an invert emulsion, an emulsifier, and a weighting agent.

Abstract: Fluids viscosified with viscoelastic surfactants (VESs) may have their viscosities affected (increased or reduced, e.g. gels broken) by the indirect or direct action of a composition that contains at least one fatty acid that has been affected, modified or reacted with an alkali metal base, an alkali earth metal base, ammonium base, and/or organic base compound, optionally with an alkali metal halide salt, an alkali earth metal halide salt, and/or an ammonium halide salt. The composition containing the resulting saponification product is believed to either act as a co-surfactant with the VES itself to increase viscosity and/or possibly by disaggregating or otherwise affecting the micellar structure of the VES-gelled fluid. In a specific, non-limiting instance, a brine fluid gelled with an amine oxide surfactant may have its viscosity broken with a composition containing naturally-occurring fatty acids in canola oil or corn oil affected with CaOH, MgOH, NaOH and the like.

Abstract: Viscoelastic surfactant (VES) gelled aqueous fluids containing water, a VES, an internal breaker, a VES stabilizer, a fluid loss control agent and a viscosity enhancer are useful as treating fluids and particularly as fracturing fluids for subterranean formations. These VES-based fluids have faster and more complete clean-up than polymer-based fracturing fluids. The use of an internal breaker permits ready removal of the unique VES micelle based pseudo-filter cake with several advantages including reducing the typical VES loading and total fluid volume since more VES fluid stays within the fracture, generating a more optimum fracture geometry for enhanced reservoir productivity, and treating reservoirs with permeability above the present VES limit of approximately 400 md to at least 2000 md.

Abstract: The present invention provides aqueous viscoelastic compositions comprising a cleavable surfactant and possibly also an electrolyte. The cleavable surfactants useful in the present invention comprise at least one weak chemical bond, which is capable of being broken under appropriate conditions, to produce oil soluble and water soluble products typically having no interfacial properties and surface activity compared with the original surfactant molecule. Further, the rheological properties of the aqueous viscolelastic composition are usually altered upon cleavage of the cleavable surfactant generally resulting in the elimination of the viscofying, viscoelastic and surfactant properties of the composition. Aqueous viscoelastic compositions in accordance with the present invention are suitable for use in oil-field applications, particularly for hydraulic fracturing of subterranean formations. Thus, the present invention also relates to a wellbore service fluid and a method of fracturing a subterranean formation.

Abstract: A method comprising contacting a zwitterionic surfactant, co-surfactant, and water to form a microemulsifier, and contacting the microemulsifier with an oleaginous fluid under low shear conditions to form a microemulsion. A method comprising introducing a first wellbore servicing fluid comprising at least one oleaginous fluid into a wellbore, wherein the first wellbore servicing fluid forms oil-wet solids and/or oil-wet surfaces in the wellbore, and contacting the oil-wet solids and/or oil-wet surfaces in the wellbore with a second wellbore servicing fluid comprising a zwitterionic surfactant, a co-surfactant, and a brine to form a microemulsion.

Abstract: Compositions and methods are given for delayed breaking of viscoelastic surfactant gels inside formation pores, particularly for use in hydraulic fracturing. Breaking inside formation pores is accomplished without mechanical intervention or use of a second fluid. Acidic internal breakers such as sulfuric acid and nitric acid are used. The break may be accelerated, for example with a free radical propagating species, or retarded, for example with an oxygen scavenger.

Abstract: Embodiments of the Present Invention relate to a reversibly thickenable non-polymeric fluid that has low viscosity in strong acid, gels when the acid concentration is reduced by only a small amount, and is subsequently decomposed by the acid. In particular it relates to an aqueous mixture of zwitterionic surfactants, inorganic acids, and organic acids Most particularly it relates to the use of this fluid as a diverting agent for easily-damaged sandstones, for example prior to matrix acidizing.

Abstract: Compositions and methods are given for delayed breaking of viscoelastic surfactant gels inside formation pores, particularly for use in hydraulic fracturing. Breaking inside formation pores is accomplished without mechanical intervention or use of a second fluid. Acidic internal breakers such as sulfuric acid and nitric acid are used. The break may be accelerated, for example with a free radical propagating species, or retarded, for example with an oxygen scavenger.

Abstract: Among many things, in some embodiments, dual-function additives that enhance fluid loss control and the stability of viscoelastic surfactant fluids, and their associated methods of use in subterranean formations, are provided. In one embodiment, the methods comprise: providing a viscoelastic surfactant fluid that comprises an aqueous base fluid, a viscoelastic surfactant, and a dual-function additive that comprises a soap component; and introducing the viscoelastic surfactant fluid into at least a portion of a subterranean formation.

Abstract: Methods and compositions including a method comprising: providing a treatment fluid comprising an aqueous fluid, a relative permeability modifier, and a chelating agent; introducing the treatment fluid into a well bore that penetrates a subterranean formation; and allowing at least a first portion of the treatment fluid to penetrate into a portion of the subterranean formation so as to substantially divert a second portion of the treatment fluid to another portion of the subterranean formation.

Abstract: Fluids viscosified with viscoelastic surfactants (VESs) may have their fluid loss properties improved with at least one mineral oil which has a viscosity greater than 20 cps at ambient temperature. The mineral oil may initially be dispersed oil droplets in an internal, discontinuous phase of the fluid. In one non-limiting embodiment, the mineral oil is added to the fluid after it has been substantially gelled in an amount between about 0.2 to about 10% by volume.

Abstract: The present invention relates to novel aqueous wellbore treatment fluids containing a gas component, a heteropolysaccharide, an electrolyte, and a surfactant, wherein the fluids may further include an organoamino compound. The fluids exhibit good rheological properties at elevated temperatures. Methods of use of fluids comprising at least an aqueous medium, a gas component, a heteropolysaccharide and a surfactant for hydraulically fracturing, well cleanup and gravel packing operations, are also disclosed.

Abstract: Alkaline earth metal compounds may be fluid loss control agents for viscoelastic surfactant (VES) fluids used for well completion or stimulation in hydrocarbon recovery operations. The VES fluid may further include proppant or gravel, if it is intended for use as a fracturing fluid or a gravel packing fluid, although such uses do not require that the fluid contain proppant or gravel. The fluid loss control agents may include, but not be limited to, oxides and hydroxides of alkaline earth metal, and in one case magnesium oxide where the particle size of the magnesium oxide is between 1 nanometer to 0.4 millimeter. The fluid loss agent appears to associate with the VES micelles and together form a novel pseudo-filter cake crosslinked-like viscous fluid layer that limits further VES fluid flow into the porous media. The fluid loss control agent solid particles may be added along with VES fluids.

Abstract: Piezoelectric crystal particles (which include pyroelectric crystal particles) enhance the viscosity of aqueous fluids that have increased viscosity due to the presence of viscoelastic surfactants (VESs). In one non-limiting theory, when the fluid containing the viscosity enhancers is heated and/or placed under pressure, the particles develop surface charges that associate, link, connect, or relate the VES micelles thereby increasing the viscosity of the fluid. The higher fluid viscosity is beneficial to crack the formation rock during a fracturing operation, reduce fluid leakoff, and carry high loading proppants to maintain the high conductivity of fractures.

Abstract: Drilling fluids are provided that comprise an organophilic clay treated with a quaternary ammonium surfactant having an amide linkage. The quaternary ammonium surfactant may comprise a compound generally represented by the following formula: where M? is an anion such as a chloride, methyl sulfate, bromide, acetate, or iodide ion; R1 is an alkyl group such as a saturated hydrocarbon with 10 or more carbons; R2, R3, and R4 are the same or different alkyl groups such as a methyl, ethyl, or benzyl group, and x is greater than or equal to 1. The organophilic clay treated in this manner is substantially biodegradable. In embodiments, the drilling fluids comprise the foregoing organophilic clay, an oil-based fluid and a weighting agent. In still embodiments, the drilling fluids comprise the foregoing organophilic clay, an invert emulsion, an emulsifier, and a weighting agent.

Abstract: A method for treating solid materials is disclosed, where the treating compositions coats surfaces or portions of surfaces of the solid materials changing an aggregation or agglomeration propensity of the materials. Treated solid materials are also disclosed. The methods and treated materials are ideally suited for oil field applications.

Abstract: Foamed treatment fluids comprising water, a gas, and a foaming and foam stabilizing surfactant mixture comprising an alkali salt of an alkyl ether sulfate, wherein the alkali salt of the alkyl ether sulfate comprises an alkali salt of a C6-10 alkyl ether sulfate, and an alkali salt of a C4 alkyl ether sulfate, an alkyl amidopropyl amphoteric surfactant selected from the group consisting of an alkyl amidopropyl hydroxysultaine, an alkyl amidopropyl betaine, and combinations thereof, and an alkyl amidopropyl dimethylamine oxide. Methods comprising providing the foamed treatment fluid and introducing the foamed treatment fluid into a subterranean formation.

Abstract: A method for shortening the shear recovery time of cationic, zwitterionic, and amphoteric viscoelastic surfactant fluid systems by adding an effective amount of a rheology enhancer selected from partially hydrolyzed polyvinyl ester and partially hydrolyzed polyacrylates. The rheology enhancer also increases fluid viscosity and very low rheology enhancer concentration is needed. Preferred surfactants are betaines and quaternary amines. The fluids are useful in oilfield treatments, for example fracturing and gravel packing.

Abstract: Well treatment is disclosed that includes injecting a well treatment fluid with insoluble polyol polymer such as polyvinyl alcohol (PVOH) dispersed therein, depositing the insoluble polymer in the wellbore or an adjacent formation, and thereafter dissolving the polymer by reducing salinity and/or increasing temperature conditions in the environment of the polymer deposit. The method is disclosed for filter cake formation, fluid loss control, drilling, hydraulic fracturing and fiber assisted transport, where removal of the polyol at the end of treatment or after treatment is desired. The method is also disclosed for providing dissolved polyol as a delayed breaker in crosslinked polymer viscosified systems and viscoelastic surfactant systems. Also disclosed are well treatment fluids containing insoluble amorphous or at least partially crystalline polyol, and a PVOH fiber composition wherein the fibers are stabilized from dissolution by salinity.

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 method for shortening the shear recovery time of cationic, zwitterionic, and amphoteric viscoelastic surfactant fluid systems by adding an effective amount of an amphiphilic polymeric rheology enhancer containing at least one portion that is a partially hydrolyzed polyvinyl ester or partially hydrolyzed polyacrylate. The rheology enhancer also increases fluid viscosity and very low rheology enhancer concentration is needed. Preferred surfactants are betaines and quaternary amines. The fluids are useful in oilfield treatments, for example fracturing and gravel packing.

Abstract: Compounds of the formula H(CH2)zCOO—[C2H4O]xCyH2y+1 where z is 0-2, x is an integer from 1 to 5 and y is an integer from 4-9 are used as emulsion breakers and defoamers in formation treatment fluids in the recovery of hydrocarbons from subterranean formations. A preferred material has the formula HCOO—[C2H40]3C6H7.

Abstract: A method for stimulating thick or multilayered heterogeneous or homogeneous formations in a single trip without packers involves perforating with tubing conveyed perforation, then injecting a self-diverting acid, then moving the tubing string and perforating at a new location, and then injecting additional self-diverting acid. The sequence may be repeated. The acid is preferably a viscoelastic diverting acid. The self-diverting acid may be alternated with conventional treatment fluid. The job is designed to treat the least permeable zone(s) first and maximizes acid efficiency.

Abstract: Viscoelastic surfactant based aqueous fluid systems useful as thickening agents in various applications, e.g. to suspend particles produced during the excavation of geologic formations. The surfactants are zwitterionic/amphoteric surfactants such as dihydroxyl alkyl glycinate, alkyl ampho acetate or propionate, alkyl betaine, alkyl amidopropyl betaine and alkylimino mono- or di-propionates derived from certain waxes, fats and oils. The thickening agent is used in conjunction with an inorganic water-soluble salt or organic additive such as phthalic acid, salicylic acid or their salts.

Abstract: The present invention generally relates to a method for treating a subterranean formation with an aqueous viscoelastic treating fluid that an aqueous base fluid and one or more non-ionic amido amine oxide surfactant gelling agents. The treatment method comprises injecting the aqueous viscoelastic surfactant treating fluid through a wellbore and into the subterranean formation under conditions effective to control fluid loss, and breaking the gel of the aqueous viscoelastic treating fluid subsequent to treating said formation.

Abstract: A process for enhancing the productivity of a formation consists of introducing into the formation a viscoelastic fluid which contains at least one surfactant, at least one quaternary amine polyelectrolyte, water, and a non-aqueous solvent. The surfactant forms aggregation structures or vesicles. The fluid, which significantly enhances fluid viscosity and thermal stability, is particularly effective as a diverting fluid to divert an acid treatment package from a high permeability or undamaged portion of a formation to a low permeability or damaged portion of a formation as well as a fracturing fluid. In addition, the fluid is useful for sand control completion.

Abstract: The present invention generally relates to aqueous, acidic compositions thickened with an amidoamine oxide gelling agent and/or viscoelastic surfactant of the general formula I: wherein R1 is a saturated or unsaturated, straight or branched chain aliphatic group of from about 7 to about 30 carbon atoms, R2 is a divalent alkylene group of 2–6 carbon atoms which may be linear or branched, substituted or unsubstituted, and R3 and R4 are independently C1–C4 alkyl or hydroxyalkyl groups or together they form a heterocyclic ring of up to six members, and R5 is hydrogen or a C1–C4 alkyl or hydroxyalkyl group. The aforementioned gelling agents advantageously provide gels that do not undergo phase separation over extended periods of time and exhibit high heat stability. The thickened acid gels of the invention have applications in household and industrial cleaners and degreasers, oilfield stimulation applications and the like.

Abstract: It has been discovered that fluids viscosified with viscoelastic surfactants (VESs) may have their viscosities reduced (gels broken) by the direct or indirect action of a biochemical agent, such as bacteria, fungi, and/or enzymes. The biochemical agent may directly attack the VES itself, or some other component in the fluid that produces a by-product that then causes viscosity reduction. The biochemical agent may disaggregate or otherwise attack the micellar structure of the VES-gelled fluid. The biochemical agent may produce an enzyme that reduces viscosity by one of these mechanisms. A single biochemical agent may operate simultaneously by two different mechanisms, such as by degrading the VES directly, as well as another component, such as a glycol, the latter mechanism in turn producing a by-product (e.g. an alcohol) that causes viscosity reduction. Alternatively, two or more different biochemical agents may be used simultaneously.

Abstract: Fracturing fluids and methods of fracturing a subterranean formation using such fluids are provided. A fracturing fluid having a first pH is foamed by introducing a gas to the fluid. The fracturing fluid comprises a surfactant that facilitates formation of the foam at the first pH. The foamed fracturing fluid is subsequently pumped to the subterranean formation to fracture it. The pH of the fracturing fluid is then changed to a second pH at which the surfactant facilitates reduction of the foam. The fracturing fluid releases proppant contained in the fluid to the subterranean formation. The fracturing fluid is then allowed to flow back to the surface. It can be recycled by changing the pH of the fracturing fluid back to the first pH and adding a gas to the fluid, causing it to foam again.

Abstract: The present invention relates to foamed cement slurries, additives and methods. A foamed cement slurry of the invention comprises a hydraulic cement, sufficient water to form a slurry, sufficient gas to form a foam and an environmentally benign foaming and stabilizing additive comprising a mixture of an ammonium salt of an alkyl ether sulfate surfactant, a cocoamidopropyl hydroxysultaine surfactant, a cocoamidopropyl dimethylamine oxide surfactant, sodium chloride and water.

Abstract: Well completion foamed spacer fluids and methods of using the foamed spacer fluids are provided. A method of the invention for displacing a first fluid from a well bore with an incompatible second fluid comprises the following steps. A foamed spacer fluid is placed between the first and second fluids to separate the first and second fluids and to remove the first fluid from the walls of the well bore. Thereafter, the first fluid and the foamed spacer fluid are displaced from the well bore with the second fluid.

Abstract: Compounds of the formula H(CH2)zCOO—[C2H4O]xCyH2y+1 where z is 0-2, x is an integer from 1 to 5 and y is an integer from 4-9 are used as emulsion breakers and defoamers in formation treatment fluids in the recovery of hydrocarbons from subterranean formations. A preferred material has the formula HCOO—[C2H4O]3C6H7.

Abstract: Fracturing fluids and methods of fracturing a subterranean formation using such fluids are provided. A fracturing fluid having a first pH is foamed by introducing a gas to the fluid. The fracturing fluid comprises a surfactant that facilitates formation of the foam at the first pH. The foamed fracturing fluid is subsequently pumped to the subterranean formation to fracture it. The pH of the fracturing fluid is then changed to a second pH at which the surfactant facilitates reduction of the foam. The fracturing fluid releases proppant contained in the fluid to the subterranean formation. The fracturing fluid is then allowed to flow back to the surface. It can be recycled by changing the pH of the fracturing fluid back to the first pH and adding a gas to the fluid, causing it to foam again.

Abstract: Improved methods of generating gas in and foaming well treating fluids introduced into a subterranean zone are provided. A method of the invention includes the steps of combining one or more gas generating chemicals with the well treating fluid and combining one or more delayed encapsulated activators having selected release times with the well treating fluid containing the gas generating chemicals so that the gas generating chemicals react with the delayed encapsulated oxidizing agent activators and gas and foam are formed in the treating fluid while the treating fluid is being pumped and after being placed in the subterranean zone.

Abstract: Improved methods of generating gas in and foaming aqueous well fluids introduced into a subterranean zone are provided. A method of the invention includes the steps of combining with an alkaline aqueous well fluid one or more gas generating chemicals and a mixture of foaming and foaming stabilizing surfactants so that the gas generating chemical or chemicals react with the alkaline aqueous well fluid and gas and foam are formed in the well fluid while it is being pumped, and then pumping the well fluid into the subterranean zone.

Abstract: Improved aqueous fracturing fluids are disclosed that are particularly useful as well stimulation fluids to fracture tight (i.e., low permeability) subterranean formations. Gas wells treated with these fracturing fluids have rapid cleanup and enhanced well production. The fluids contain small but sufficient amounts of certain amine oxides to aid in the removal of the fracturing fluid from the formation. By facilitating the removal of fluid from the invaded zones, the amount of damage to the fracture faces in the formation is thereby minimized. The amine oxides correspond to the formula I, wherein R1 is an aliphatic group of from 6 to about 20 carbon atoms, and wherein R2 and R3 are each independently alkyl of from 1 to about 4 carbon atoms. The amine oxides in which R1 is an alkyl group are preferred, and those in which R1 is an alkyl group of from 8 to 10 carbon atoms and R2 and R3 are each methyl or ethyl groups are most preferred.

Abstract: The present invention relates to a method for inhibiting corrosion of corrosion-prone metal surfaces by organic acid-containing petroleum streams by providing an effective corrosion-inhibiting amount of certain sulfur and phosphorus-free aromatic compounds substituted with nitrogen, containing functional groups at the 5- or 3, 5-position, typically up to 1000 wppm, to the metal surface.

Abstract: A method for controlling the rheology of aqueous systems, particularly for those intended for underground use, includes injecting an aqueous viscoelastic fluid containing a surfactant gelling agent into the system. The viscoelastic surfactant composition of the invention comprises, as a gelling agent, at least one fatty aliphatic amidoamine oxide in a glycol solvent. The composition also maintains the levels of free fatty acid and free amine within critical parameters in order to achieve superior performance. The additives may be incorporated in the viscoelastic fluid to tailor its use in stimulation fluids, drilling muds, fracture fluids, and in applications such as permeability modification, gravel packing, cementing, and the like.

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: A method for controlling the rheology of aqueous systems, particularly for those intended for underground use, includes injecting an aqueous fluid containing a surfactant gelling agent into the system. The surfactant gelling agents are, for example, fatty aliphatic amidoamine oxides, salts of an alkoxylated monoamine with an aromatic dicarboxylic acid, and salts of an alkyldiamine with an aromatic dicarboxylic acid. The surfactant gelling agents can be adsorbed onto particulate supports to facilitate delivery of the gelling agent. The additives may be incorporated in the viscoelastic fluid to tailor its use in hydraulic fluids, drilling muds, fracture fluids, and in applications such as permeability modification, gravel packing, cementing, and the like.

Abstract: The invention relates to a process for facilitating the disposal of flowable and pumpable working fluids based on emulsifiers containing W/O invert emulsions--more particularly corresponding auxiliaries of the type used in geological exploration, such as oil-based w/o invert drilling muds--and for the simplified cleaning of solid surfaces soiled therewith, if desired using flowable spraying aids, the process being characterized in that, by selecting and adapting the emulsifiers/emulsifier systems to the oil phase of the invert emulsion, temperature-controlled phase inversion is achieved at temperatures below the in-use temperatures of the w/o invert emulsions, but above the freezing point of the aqueous phase and in that disposal and cleaning are carried out at temperatures in and/or below the phase inversion temperature range.

Abstract: The present invention provides improved foamed well cement slurries, additives and methods. The additives, which foam and stabilize a cement slurry containing fresh water or salt water, are basically comprised of a mixture of an ethoxylated alcohol ether sulfate surfactant, an alkyl or alkene amidopropyl betaine surfactant and an alkyl or alkene amidopropyl dimethyl amine oxide surfactant.

Abstract: A method for controlling the rheology of aqueous systems, particularly for those intended for underground use, includes injecting an aqueous fluid containing a surfactant gelling agent into the system. The surfactant gelling agents are, for example, fatty aliphatic amidoamine oxides, salts of an alkoxylated monoamine with an aromatic dicarboxylic acid, and salts of an alkyldiamine with an aromatic dicarboxylic acid. The surfactant gelling agents can be absorbed onto particulate supports to facilitate delivery of the gelling agent. The additives may be incorporated in the viscoelastic fluid to tailor its use in hydraulic fluids, drilling muds, fracture fluids, and in applications such as permeability modification, gravel packing, cementing, and the like.