MXPA99011570A - Fluids containing viscoelastic surfactant and methods for using the same - Google Patents

Abstract

Sistemas de fluidos acuosos a base de tensioactivos viscoelásticosútiles como agentes espesantes en varias aplicaciones, por ejemplo para suspender partículas producidas durante la excavación de formaciones geológicas. Los tensioactivos son tensioactivos zwiteriónicos/anfotéricos tales como glicinato de dihidroxilalquilo, anfoacetato o propionato de alquilo, alquilbetaína, alquilamidopropilbetaína y alquilamino mono o dipropionatos derivados de ciertas ceras, grasas y aceites. Se usa un agente de espesamiento junto con una sal soluble en agua inorgánico o aditivo orgánico tal comoácido ftálico,ácido salicílico o sus sales.

Description

FLUIDS CONTAINING VISCOELASTIC SURFACTANTS AND METHODS FOR USING THEMSELVES DESCRIPTION OF THE INVENTION This invention relates to viscoelastic fluids containing a surfactant and to a method for suspending particles using viscoelastic fluids. It is known to thicken the aqueous phase of a suspension of solid particles or emulsified droplets. The addition of thickener increases the viscosity of the aqueous phase and in this way delays the sedimentation of the particles or droplets. The delay is useful to keep the particles or droplets in suspension during the storage, use and / or transport of the suspension. Polymeric thickeners have been used, for example, starches, which are thickened by entangling the polymer chains, to make the aqueous phase of suspensions viscous. The thickeners can be degraded under the influence of mechanical shear stress or chemical cleavage (for example, through oxidation or hydrolysis) to see the polymer chains that result in a loss of viscosity and, thus, suspension stability. Cationic surfactants have been found which form barlet micelles under certain conditions. The presence of bar-type micelles impart to fluid J viscoelastic properties. However, cationic surfactants tend to exhibit high toxicity and very high biodegradability. The present invention provides a fluid Viscoelastic useful as a thickener for the suspension of particles. The viscoelastic fluids consist of an amphoteric / zwitterionic surfactant and an organic acid / salt and / or inorganic salts. Thus, this invention specifically relates to a viscoelastic fluid comprising: (1) an aqueous medium; (2) an amount of a surfactant selected from the group consisting of amphoteric surfactants, zwitterionic surfactants, and mixtures thereof, effective to be the aqueous viscoelastic medium; and (3) a member selected from the group consisting of organic acids, salts of organic acid, inorganic salts and combinations of one or more organic acids or salts of organic acid with one or more inorganic salts. In still another embodiment of the present invention, the invention relates to a viscoelastic fluid consisting essentially of: (1) an aqueous medium; (2) an amount of a surfactant comprising an amine oxide surfactant; (3) an anionic surfactant containing a hydrophobe having at least 14 carbon atoms. The term "viscoelastic" refers to those viscous fluids that have elastic properties, that is, the liquid at least partially returns to its original form when an applied tension is released. Thickened aqueous viscoelastic fluids are useful as water-based hydraulic fluids in lubricating and hydraulic fracturing fluids to increase permeability in oil production. The present invention also relates to a method for distributing suspended solid particles such as excavation by-products in a fluid comprised of the viscoelastic fluid of this invention, wherein the solid particles remain suspended for a period extended to one side, conveying the fluid to a site while the solid particles remain suspended in the fluid and deposit the fluid at the site. This invention also relates to a method for fracturing an underground formation comprising pumping the viscoelastic fluid of the invention through a hole and into an underground formation at a pressure sufficient to fracture the formation.

This invention also relates to a detergent formulation comprising a detergent surfactant in admixture with a viscoelastic fluid of this invention. This invention also relates to the use of the viscoelastic fluid as a deviating agent for agricultural formulations. In this regard, this invention relates to an aqueous formulation of an agricultural chemical and to a quantity of the viscoelastic fluid of this invention to increase the average droplet size of a spray of the formulation. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows the viscosity versus constant stress velocity for a viscoelastic surfactant solution prepared by adding 5 percent disodium seboimidodipropionate (Mirataine T2C®) and 2. 25 percent of ophthalmic acid to water. Figure 2 shows the dynamic module G '(storage module) and G' '(loss module) at 25 ° C and 50 ° C of the same solution as in Figure 1. Figure 3 shows the viscosity versus speed of shear stress for a viscoelastic surfactant solution prepared by adding 5 percent disodium seboiminodipropionate (Mirataine T2C®), 4 percent NHC1, and 1.75 ~ 2.0 percent ophthalmic acid to water.

Figure 4 shows the viscosity versus shear rate for solutions of viscoelastic surfactants prepared by adding 4 or 5 percent disodium oleamidopropyl betaine (Mirataine BET-O®), 3 percent KCl and 0.5 percent phthalic acid to water . Figure 5 shows the dynamic module G '(storage module) G "(loss module) at 25 ° C and 50 ° C of the same solution as in Figure 4. The property of the viscoelasticity in general is well known and reference is made to S. Gravsholt, Journal of Coll. And Interface Sci, 57 (3), 575 (1976); Hoffmann et al., "Influence of Ionic Surfactants on the Viscoelastic Properties of Zosteric Surfactant Solutions", Langmuir, 8, 2140-2146 (1992); and Hoffmann et al., The Rheological Behavior of Different Viscoelastic Surfactant Solutions, Tenside Surf. Det., 31, 389-400, 1994. Of the test methods specified by these references to determine whether a liquid possesses viscoelastic properties, a test that has been found useful in determining the viscoelasticity of an aqueous solution consists of swirling the solution and Visually observe if the bubbles created by the whirlpool recede after the swirl has stopped. Any recoil of the bubbles indicates the viscoelasticity. Another useful test is to measure the storage module (G ') and the loss modulus (G ") at a given temperature. If G "> G" at some point or on the same scale of points below 10 rad / sec, typically from about 0.001 to about 10 rad / sec, very typically from about 0.1 to about 10 network / sec., at a given temperature and if G '> 10 ~ 2 Pascals, preferably 10"1 Pascals, the fluid is typically considered viscoelastic at that temperature. Rheological measurements such as G 'and G "are discussed more fully in" Rheological Measurements, "Encyclopedia of Chemical Technology, vol. 21, pp. 347-372, (John Wiles &Sons, Ins., N. Y., N. Y., 1997, 4th ed.). To the extent necessary for termination, the above descriptions are expressly incorporated herein by reference. Viscoelasticity is used by a different type of micelle formation than the usual spherical micelles formed by most surfactants. The viscoelastic surfactant fluids form micelles of the worm type, rod type or cylindrical in solution. The formation of long, cylindrical micelles creates useful rheological properties. The viscoelastic surfactant solution exhibits a shear thickening behavior and remains stable despite repeated high shear applications. In -comparation, the typical polymeric thickener will irreversibly degrade when subjected to high shear stress.

In the brief description of the invention and detailed description, each numerical value must be read once as modified by the term "approximately" (unless it is already expressed without modification), and then read again as unmodified, unless that is indicated otherwise in the context. The viscoelastic surfactants can be either ionic or non-ionic. The present invention comprises an aqueous viscoelastic surfactant based on amphoteric or zwitterionic surfactants. The amphoteric surfactant is a class of surfactant having both a positively charged portion and a negatively charged portion on a certain pH scale (eg, typically slightly acidic)., only a negatively charged portion on a certain pH scale (eg, typically, slightly alkaline) and only a positively charged portion at a different pH scale (eg, typically, moderately acidic), while a zwitterionic surfactant has a portion positively charged permanently in the molecule without considering the pH value and a negatively charged portion at an alkaline pH. The viscoelastic fluid comprises water, surfactant and a water-soluble compound selected from the group consisting of organic acids, salts of organic acid, inorganic salts and mixtures thereof. Alternatively, the viscoelastic fluid may comprise water, an oxide of amine oxide surfactant and an anionic surfactant containing a hydrophobe having at least about 14 carbon atoms. The viscoelastic surfactant solution is useful as a fracturing fluid or a water-based hydraulic fluid. The viscoelastic fluid used as a fracturing fluid may optionally contain a gas such as air, nitrogen or carbon dioxide to provide an energized fluid or foam. The component of the fluid, which will be present in the largest concentration, is water, that is, water will typically be a greater amount by weight of the viscoelastic fluid. Water is typically present in a quantity by weight, greater than or equal to about 50% by weight of the fluid. Water can be from any source as long as the source does not contain any contaminants that are incompatible with the other components of the viscoelastic fluid (for example, causing unwanted precipitation) in this way, the water does not need to be potable and can be slightly brackish or contain other materials typical of water sources found in or near oil fields.

Examples of zwitterionic surfactants useful in the present invention are represented by the formula: Wherein Ri represents a hydrophobic portion of alkyl, alkylarylalkyl, alkoxyalkyl, alkylamloalkyl, and alkylamidoalkyl, wherein alkyl represents a group containing from about 12 to about 24 carbon atoms, which may be straight or branched chain and which can be saturated or unsaturated. Representative long chain alkyl groups include tetradecyl (myristyl), hexadecyl (cetyl), octadecentyl (oleyl), octadeyl (stearyl), docosenoic (erucyl) and the derivatives of tallow, coconut, soybean and rapeseed oils. Preferred alkyl and alkenyl groups are alkyl and alkenyl groups having from about 16 to about 22 carbon atoms. Representative of alkylamidoalkyl is alkylamidopropyl with the alkyl being as described above. R2 and R3 are independently an aliphatic chain (ie, as opposed to aromatic at the atom attached to the quaternary nitrogen, for example, alkyl, alkenyl, arylalkyl, hydroxyalkyl, carboxyalkyl, and hydroxyalkyl, polyaxyalkylene, eg, hydroxyethyl-polyoxyethylene , or hydroxypropyl-polyoxypropylene) having from one to 30 atoms, preferably from about 1 to 30 atoms, preferably from about 1 to 20 atoms, preferably from about 1 to 10 atoms and more preferably from 1 to about 6 atoms wherein the Aliphatic group can be straight or branched chain, saturated or unsaturated. Preferred alkyl chains are methyl, ethyl, arylalkyl, benzyl is preferred, and preferred hydroxyalkyls are hydroxyethyl or hydroxypropyl, while preferred carboxyalkyl are acetate and propionate. R 4 is a hydrocarbyl radical (eg, alkylene) with a chain length of from 1 to 4. Preferred are the methylene or ethylene groups. Specific examples of zwitterionic surfactants include the following structures: CH2CH2OH c:, H2CH2OH : H3 IV. RiCONHCHaCHíCKj .CHACOO " v. R1CONHCH2CH, CH ^ CH; COOH CH, CH2COO " where Ri has been previously defined here. Examples of amphoteric surfactants include those represented by formula VI: c Where Ri, R2, R / are the same as defined above. Other specific examples of amphoteric surfactants include the following structures: CH2CH2COO " 2COO "X" CH2CH2OH VIII R? CONHCH? CH? CH.- * H CH, CH2COO " Where Ri has been as previously defined-here, and X + is an inorganic cation such as Na + K +, NH4 + associated with a carboxylate group or hydrogen atom in an acid medium. A typical chemical process for synthesizing dihydroxyethylate-glycinate starting from ethoxylated alkylamine as follows: (CH2CH2O) xH (CH2CH2O) xH I ClCH2COONa RJ ~ * "Rl ~ N-CH2COONa (CH2CH2O) yH (CH2CH2O) yH The final products may also include some of the unreacted starting dihydroxyethylalkylamide, and small amounts of sodium glycolate, diglycolate and sodium chloride as by-products. A similar process can be used to prepare propoxylated analogues. A typical chemical process for synthesizing alkylminiodipropionate from alkylamide is as follows: CH2CH2COOMe I RjNH2 + 2 CH2 = CHCOOMe • »R \ - N CH2CH2COOMe H2O / NaOH CH2CH2COONa H2CH2COONa The final products will also include a small amount of methanol, unreacted acrylic acid, alkylamide and some oligomeric acrylate or acid as byproducts. A typical chemical process for synthesizing alkylamidopropyl betaine from alkylamide is as follows: CH2 - OOCRi CH - OOCRi + HNCH2CH2CH2N (CH3) 2 I * R i CONHCH2CH2CH2N (CH3) 2 CH2 ~ OOCR] ClCH2COONa CH3 + RlC-NHCH2CH2CHr ~ CH2COO CH3 The final products will also include a small amount of sodium glycolate, diglycolate, sodium chloride and glycerin as by-products. In yet another embodiment of the invention, the zwitterionics surfactant is selected from an amine oxide. This material has the following structure: R, Where Ri, R2, and R3 are as defined above. The surfactants are used in an amount which in combination with the other ingredients is sufficient to form a viscoelastic fluid, the amount of which will typically be a minor amount by weight of the fluid (eg, less than about 50% by weight). The surfactant concentration may vary from about 0.5% to about 10% by weight of the fluid, typically from about 0.5% to about 8% and still very typically from about 0.5% to about 6%. The optimal concentrations for any particular group of parameters can be determined experimentally. The fluid also comprises one or more members of the group of organic acids, salts of organic acid and inorganic salts. Mixtures of the forelimbs are specifically contemplated within the scope of the invention. This member will typically be present only in a minor amount (eg, less than about 20% by weight of the fluid). The organic acid is typically a sulfonic acid or a carboxylic acid and the anionic counterion of the organic acid salts are typically sulfonates or carboxylates. Representative of the organic molecules include various aromatic sulfonates and carboxylates such as p-toluene sulfonate, naphthalenesulfonate, chlorobenzoic acid, salicylic acid, phthalic acid and the like, wherein the counterions are soluble in water. More preferred are salicylate, oftallate, p-toluenesulfonate, hydroxynaptalene carbolytes, for example, 5-hydroxy-1-naptoic acid, 6-hydroxy-1-naphthoic acid, 7-hydroxy-1-naphthoic acid, 1-hydroxy-2-acid. -naphthoic, l-hydroxy-2 naphthoic acids preferably 3-hydroxy-2-naphthoic acid, 5-hydroxy-2-naphthoic acid, 7-hydroxy-2-naphthoic acid, and 1,3-hydroxy-naphthoic acid and 3, 4- diclobenzoate. The organic acid or salt thereof typically helps the development of increased viscosity, which is characteristic of preferred fluids. Without wishing to be bound by any theory unless otherwise expressly noted in the context, it is believed that the association of the organic acid or the salt thereof with the micelle reduces the aggregation curvature of the micelle reduces the aggregation curvature of the micelle and in this way accelerates the formation of a worm-type micelle of the rod type. The organic acid or salt thereof will typically be present in the viscoelastic fluid at a concentration in weight of from about 0.1% to about 10% more typically from about 0.1% to about 7%, and even more typically from about 0/1% to approximately 6%. Inorganic salts that are particularly suitable for use in the viscoelastic fluid include water-soluble potassium, sodium and ammonium salts, such as potassium chloride and ammonium chloride. In addition, calcium chloride channels calcium bromide and zinc halide salts can also be used. The inorganic salts can help the development of increased viscosity, which is characteristic of preferred fluids. In addition, the inorganic salt can help maintain the stability of a geologic f-ormation to which the fluid is exposed. The stability of formation and in particular the stability of clay (inhibiting the hydration of the clay) is achieved at a concentration level of little percentage by weight and as such the density of fluid is not significantly altered by the presence of the inorganic salt Unless the density of the fluid becomes an important consideration, at the point, heavier inorganic salts can be used. The inorganic salt will typically be present in the viscoelastic fluid at a concentration by weight of from about 0.1% to about 30%, more typically from about 0.1% to about 10%, and even more typically from about 0.1% to about 8%. Organic salts, for example, trimethylammonium chlorohydrate and tetramethylammonium chloride, in addition to, or as a replacement for the inorganic salts may also be useful. As an alternative to organic salts and inorganic salts, or as a partial substitute thereof, a medium for long chain alcohol can be used. (preferably an alcohol), preferably having from five to ten carbon atoms, or an alcohol ethoxylate (preferably an alkanol ethoxylate preferably an alkanol ethoxylate) preferably an alcohol of 12 to 16 carbon atoms and having from 1 to 6 , preferably 1-4 oxyethylene units. In the embodiment wherein the selected surfactant is an amine oxide, it is preferably used in combination with an anionic surfactant containing a hydrophobe having at least about 14 carbon atoms. Examples of suitable anionic surfactants include alkylsulfate or sulfonates having alkali metal or alkylcarboxylate counterions, wherein the alkyl represents a group containing from about 14 to about 24 carbon atoms, which may be straight or branched chain and which may be saturated or unsaturated, and more preferably contain between about 16 and about 22 carbon atoms. For this embodiment (amine oxide-anionic surfactant) the weight ratio of amine oxide to anionic surfactant is about 100: 1 about 50:50. In addition to the water-soluble salts and thickeners described above, the viscoelastic fluid used as a hydraulic fracturing fluid may contain other conventional constituents that perform specific desired functions, for example, correction inhibitors, fluid loss additives and the like. , a support material can be suspended in the fracturing fluid. The pH of the fluid will typically vary strongly from acid (e.g., pH less than about 3) slightly alkaline (e.g. at a pH greater than 7.0 to about 8.5, more typically about 8.0) or moderately alkaline (e.g., a pH from about 8.5 to about 9.5). Highly alkaline pH values (for example, pH above about 10) should be avoided. It is also conceivable to combine the above amphoteric / zwitterionic surfactants with conventional anionic, nonionic and cationic surfactants to obtain the desired viscoelastic fluid for one skilled in the art. In typical embodiments, the amphoteric / zwitterionic surfactant is typically present in a higher amount by weight of all surfactants, and more typically essentially the only surfactant present. Typically, the viscoelastic fluid will be essentially free of anionic surfactants, for example, it will contain less than about 0.5%, more typically less than about 0.2%, even more typically less than 0.1% by weight of anionic surfactant.

To prepare the aqueous fluids according to the present invention, the surfactant is added to an aqueous solution in which a water soluble inorganic salt has been dissolved, for example, potassium chloride or ammonium chloride and / or at least one acid organic or a water soluble organic acid salt to provide selective control of the loss of particle suspension properties. In the embodiment wherein the fluid is a mixture of water, and an amine oxide surfactant and an anionic surfactant, a simple mixture of the three components is used. Standard mixing procedures known in the art can be employed, since heating of the solution and special stirring conditions are usually not necessary. Of course, if they are used under extreme cold conditions such as those found in Alaska, normal heating procedures should be employed. It has been found in some cases to preferably dissolve the thickener in a lower molecular weight alcohol before mixing it with an aqueous solution. The lower molecular weight alcohol, eg, isopropanol, functions as an auxiliary to solubilize the thickener. Other similar agents can also be employed. further, a defoaming agent such as a polyglycol can be employed to prevent undesirable foaming during the preparation of viscoelastic fluid if a foam is not desired under the conditions of the treatment. If a foam or fluid energized with gas is desired, any gas such as air, nitrogen, carbon dioxide, and the like can be added. The fluid of this invention is particularly useful in the handling of particles generated during the excavation of a geological formation, for example, excavation, drilling, blasting, dusting, tunneling, and the like, for example, in the course of road construction, bridges , buildings, mines, tunnels and similar. The particles are mixed with the viscoelastic fluid through which they are effective to disperse the particles in the fluid. The particles generally have a particle size that varies from a fine powder to a coarse gravel, for example, dust, sand and gravel. The particle size affects the suspension capacity of the excavation to process waste. For example, small particles are better suspended than large particles, and very fine particles are also suspended that the mixture can become too thick to transport through a pump or similar means. The distribution of waste processing excavation sizes is also important, since waste containing particles that extend over a wide range of sizes is more easily suspended than waste where the particles are about the same size. Therefore, it may be preferred to sift the waste particles before applying the method herein to scrape the particles that are too large for the suspension to obtain a better particle size distribution. The viscoelastic fluids of the present invention can be used to carry soil or excavated materials during the formation of holes, during the operations of hole formation, excavation and trench formation in the deep base construction industry, the underground construction industry and in the tunneling, in the drilling of wells and in other applications of ground support fluids. The ability of digging system tools to maintain and remove an increased load of soil is improved by the suspending properties and lubricating properties of viscoelastic surfactant fluids. In a preferred embodiment of this invention, the surfactant can be combined with some fluid loss control additives known in the industry as water-soluble or water-dispersible polymers (guar and guar derivatives, xanthan, polyacrylamide, starch and derivatives thereof). starch, cellulose derivatives, polyacrylates, polyDADMAC [poly (diallyl dimethyl ammonium chloride] and combinations thereof), clay (Bentonite and attapulgite) in order to give control properties of fluid loss to the excavation fluid and contribute to the stabilization of the excavation wall. ^ More comprehensive information can be found in The University of Houston, Department of Chemical 5 Engineering, Publication No UHCE 93-1, entitled, Effect of Mineral and Polymer slurries on Perimeter Load Trasfer in Drilled shafts, published in January 1993 and in the PCT Application WO 96/23849, the descriptions of which are incorporated by reference. previous to suspend solids have U many applications, particularly in mining and in the management of mining waste. The disclosure of U.S. Patent No. 5,439,317 (Bishop et al.) Is incorporated herein by reference in this respect. An application is transport and place ore processing waste in underground caverns or below grade cavities. Another application is to fill excavations or open quarries without the use of very expensive equipment and intensive work for deployment. In addition, the method can be used to place clay or other linings to hold or store ponds that are used to hold liquids and to prevent the entry of these liquids into the groundwater regime and / or place liners on land for a similar purpose. Another application of The method is for the extinction and / or containment of carbon mining fires by deploying amounts of solids below the ground to seal the fire from sources of oxygen. Still another application of the method is to place solids in previously mined cavities to avoid surface subsidence. The hydraulic fracturing method of this invention uses otherwise conventional techniques. The disclosure of U.S. Patent No. 5,551,516 (Norman et al.) Is incorporated herein by reference in this regard. Field oil applications of various materials are described in "Oil-field Applications," Enclyclopedia of Polymer Science and Enginnering, vol. 10, pp. 328-366 (John Wiley &Sons, Inc., New York, New York, 1987) references cited therein, the descriptions of which are incorporated herein by reference. Hydraulic fracturing is a term that has been applied to a variety of methods used to stimulate the production of fluids such as oil, natural gas, etc., from underground formations. In hydraulic fracturing, a fracturing fluid is injected through a hole and against the face of the formation at a pressure and flow rate at least sufficient to overcome the pressure of coating material and to initiate and / or extend a fracture towards the formation. The furation fluid usually carries a support material such as sand of 20-40 mesh, bauxite, glass beads, etc., suspended in the fracturing fluid and transported to a fracture. The support material then keeps the formation from closing on itself when the pressure is released. The support material that fills the fractures provides permeable channels through which the formation fluids can flow into the hole and thus be removed. Viscoelastic fluids have also been widely used in the treatment of gravel packs. In addition to the applications discussed above, viscoelastic fluids can also be used as an industrial derivative control agent, or as a rheology modifier for personal care formulations (eg cleaners, conditioners, etc.) and household cleaners ( for example, detergent formulations). A detergent formulation of the viscoelastic fluids of this invention will also comprise a detersive surfactant. Examples of detersive surfactants and other conventional ingredients of detergent and / or personal care formulations are described in US Patent No. 08 / 726,437, filed October 4, 1996, the disclosure of which is incorporated herein by reference.

Typically, the detersive surfactant will be an anionic or non-ionic. Preferred water soluble anionic organic surfactants herein include linear alkylbenzene sulphonate containing from about 10 to about 18 carbon atoms in the alkyl group; branched alkylbenzenesulfonates containing from about 10 to about 18 carbon atoms of the alkyl group; tallow alkyl sulphates; coconut scale alkyl glyceryl sulfonates; alkyl ether sulfonates (ethoxylates), wherein the alkyl portion contains from about 12 to 18 carbon atoms and wherein the average degree of ethoxylation varies from 1 to 12, especially from 3 to 9; the sulfated condensation products of tallow alcohol with about 3 to 12, especially 6 to 9 moles of ethylene oxide; and olefin sulphonates containing from about 14 to 16 carbon atoms. Preferred specific anionics for use herein include: linear C 1 or C alkyl alkyl benzene sulphonates (THE); the branched C10-C14 alkylbenzenesulfonates. (ABS); tallow alkyl sulfates, cocoalkyl glyceryl ether sulfonates; the sulfated condensation products of tallow alcohols of series C or-C? s mixed with about 1 to about 14 moles of ethylene oxide; and mixtures of higher fatty acids containing from 10 to 18 carbon atoms. Particularly preferred anionic surfactants for use in liquid, powder and gel applications include the condensation product of C? Alcohol or 3 moles of ethylene oxide; the condensation product of tallow alcohol with 9 moles of ethylene oxide; the condensation product of coconut alcohol with 5 moles of ethylene oxide; the condensation product of coconut alcohol with 6 moles of ethylene oxide; the condensation product of Cio alcohol with 5 moles of ethylene oxide; the condensation product of C? 2-? 3 alcohol with 6.5 moles of ethylene oxide, and the same condensation product which is separated in order to remove substantially all the lower ethoxylated and non-ethoxylated fractions; the condensation product of C12-13 alcohol with 2.3 moles of ethylene oxide, and the same condensation product, which is separated in order to remove substantially all the lower ethoxylated and non-ethoxylated fractions; the condensation product of C12-13 alcohol with 9 moles of ethylene oxide; the condensation product of C14-C15 alcohol with 2.25 moles of ethylene oxide; the condensation product of C14-C15 alcohol with 4 moles of ethylene oxide; the condensation product of C14-C15 alcohol with 7 moles of ethylene oxide; the condensation product of C 4 -? s alcohol with 9 moles of ethylene oxide. Particular detergent applications for which the viscoelastic fluid will be useful include as a thickener for acid bath cleaners, such as those described in U.S. Patent No. 5,639,722 (Kong et al.) And bath gels such as those described in the Patent. North American No. 5,607,678 (Moore et al.), The descriptions of which are incorporated herein by reference. Viscoelastic fluids will also be useful in the manufacture of gypsum, chalk / lime, lime / cement based building products or cements such as those described in U.S. Patent No. 5,470,383 (Schermann et al.) And foam fluids such as such as those described in U.S. Patent No. 5,258,137 (Bonekamp et al.) the descriptions of which are incorporated herein by reference. In particular, the fluid will be useful to improve water retention of sludge and cement slurries that allow better pumping and working capacity with a minimum of "free water." Fluids will also be useful as thickeners for sludge, acidic water - (for example, at a pH of less than about 5) of carbonates and mineral oxides, for example, iron oxide, cerium oxide, silica suspensions, titanium oxide, calcium carbonate, and zirconium oxide. , the disclosure of US Patent No. 4,741,781 (De Witte) is incorporated herein by reference.The viscoelastic fluid of this invention will also be useful in formulations for the agricultural supply of solid fertilizers and pesticides such as micronutrients, biologics, insecticides., herbicides, fungicides, and plant growth regulators. The formulations are typically suspensions or aqueous solutions composed of a major amount of water and an agriculturally effective amount of an agriculturally useful chemical. The viscoelastic fluid is typically combined with the other ingredients of the formulation in an amount that effectively reduces the number of drops below about 150 microns, ie, the drops most responsible for the problems of derivation. The following examples are presented to illustrate the preparation and properties of hydraulic fluids based on aqueous viscoelastic surfactants and should not be constructed to limit the scope of the invention, unless otherwise expressly indicated in the appended claims. All the percentages, concentrations, relationships, parts, etc., are in weight unless you observe something else or are evident from the context of its use.

EXAMPLES EXAMPLE 1 Solutions of viscoelastic surfactant were prepared by adding 5 percent ammonium chloride and 3 to 5 percent dihydroxyethyl seboglycine (Mirataine TM ©) to water. The systems were shaken until all of the surfactants dissolved. All samples were observed as viscoelastic through the bubble back test. The rheology of the solution was measured through Rheometric ARES at 25 ° C. The results are presented below in Table 1. Table 1 EXAMPLE 2 In a manner similar to Example 1, 0.3 percent phthalic acid and 2 to 4 percent dihydroxyethyl seboglycinate (Mirataine TM®) were placed in solution. All samples were observed to be viscoelastic through the bubble back test.

The rheological measurements were made in the manner described in Example 1 at 25 ° C. The results are shown below in Table 2: Table 2 EXAMPLE 3 The rheological measurements were also performed at higher temperatures through the FANN rheometer. The results for 4 percent dihydroxyethyl seboglycinate (Mirataine TM®) and 0.3 percent phthalic acid solution are shown below in Table 3. Table 3 Temperature (° F) Viscosity at 100 rpm (cps) 82 170 129 51 1 89 30 239 22 288 15 EXAMPLE 4 The viscoelastic surfactant solutions were prepared by adding 5% disodium seboimidodipropionate (Mirataine T2C®) and 2.25% phthalic acid to water. The systems were stirred and heated to 50 ° C until all the phthalic acid dissolved. All samples were observed as viscoelastic through the bubble back test. The rheology was measured for viscosity and dynamic modulus G '(storage module) and G' '(loss modulus) through Rheometric SR-200 at 25 ° C and 50 ° C. The results are shown in Figures 1 and 2. EXAMPLE 5 In a similar manner to Example 4, 5 percent disodium seboimidodipropionate (Mirataine T2C®), 4 percent NH4C1 and 1.75-2.0 percent phthalic acid in water are They mixed together. All samples were observed as viscoelastic through the bubble back test. Rheological measurements were performed in the manner described in Example 4 at 25 ° C. The results are shown in Figure 3. EXAMPLE 6 Viscoelastic surfactant solutions were prepared through 4 ~ 5% vision of oleamidopropyl betaine (Mirataine BET-O®), 3% KCl and 0.5% phthalic acid to water . The system was stirred until all the phthalic acid dissolved. The rheology was measured for the viscosity of stable and the dynamic modulus G '/ G' 'through Rheometric ARES at 25 ° C. The results are shown in Figures 4 and 5.

EXAMPLE 7 A solution of viscoelastic surfactant was prepared by mixing together in 95.65 parts of water 4 parts of euridoamidopropylenedimethylamine oxide and 0.35 parts of sodium oleumsulfate. The pH was adjusted to 8 by the addition of NaOH. Its stability at temperature was determined by measuring its viscosity in cps (at a shear rate of 100 seconds1). The results are shown in Table 4. EXAMPLE 8 A viscoelastic surfactant solution was prepared by mixing together in 95.50 parts of water 4.0 parts of erucidic amidopropylenedimethylamine oxide and 0.50 parts of sodium oleyl sulfate. Its temperature stability was determined by measuring its viscosity in cps (at a shear rate of 100 seconds-1). The results are shown in Table 4.

Table 4 EXAMPLE 9 A viscoelastic surfactant solution was prepared by mixing together in 96.1 parts of water 3.0 parts of amidopropylamine euric acid oxide and 0.9 parts of sodium behenyl sulphate. The pH was adjusted to 9 through the addition of NaOH. Its temperature stability was determined by measuring its viscosity in cps (at a shear rate of 100 sec. "1) .The results are shown in Table 5. EXAMPLE 10 A solution of viscoelastic surfactant was prepared by mixing together at 94.8. water parts 4.0 parts of eurydic amidopropylamide oxide and 1.2 parts of sodium behenyl sulphate The pH was adjusted to 9 by the addition of NaOH Its temperature stability was determined by measuring its viscosity in cps (at a shear rate of 100). sec.-1) The results are shown in the Table 5. Table 5

Claims (54)

1. CLAIMS 1. A viscoelastic fluid characterized in that it consists essentially of: (i) an aqueous medium; (ii) a surfactant selected from the group consisting of amphoteric surfactant, zwitterionic surfactant, and mixtures thereof; and (iii) a member selected from the group consisting of organic acids, salts of organic acid, inorganic salts, and combinations of one or more organic acids or salts of organic acid with one or more inorganic salts; where the fluid exhibits the property of viscoelasticity
2. 2. The fluid according to claim 1, characterized in that the amount of the surfactant is from about 0.5% to about 6% by weight of the fluid.
3. 3. The fluid according to claim 1, characterized in that the member is selected from the group consisting of organic acids and salts of organic acid.
4. 4. The fluid in accordance with the claim 1, characterized in that the member is selected from the group of inorganic water soluble salts.
5. 5. The fluid according to claim 1, characterized in that the surfactant is a zwitterionic surfactant comprising a hydrophilic portion of quaternary ammonium.
6. 6. The fluid according to claim 5, characterized in that the quaternary ammonium portion of the zwitterionic surfactant is covalently linked with an alkyl or hydroxyalkyl group.
7. 7. The fluid according to claim 1, characterized in that the surfactant comprises a hydrophilic portion of carboxylate.
8. 8. The fluid in accordance with the claim 1, characterized in that the member comprises an aromatic portion selected from the group consisting of sulfonic portions, sulfonate portions, carboxylic portions and carboxylate portions.
9. 9. The fluid in accordance with the claim 8, characterized in that the aromatic portion is selected from the group consisting of salicylate ions and phthalate ions, hydroxynaphthalene carboxylate ions and mixtures thereof.
10. 10. The fluid in accordance with the claim 1, characterized in that it also comprises a particulate support material suspended therein.
11. 11. The fluid according to claim 1, characterized in that it further comprises an additive selected from the group consisting of corrosion inhibitors and fluid loss additives and mixtures of the same.
12. 12. The fluid according to claim 1, characterized in that the member is an inorganic salt.
13. 13. The fluid in accordance with the claim 1, characterized in that the member is an inorganic salt and is present in an amount of from about 0.1% to about 30% by weight.
14. 14. The fluid according to claim 1, characterized in that the member is an inorganic salt and is present in an amount of from about 0.1% to about 8% by weight.
15. 15. The fluid according to claim 1, characterized in that the member is an organic acid or salt thereof and is present in an amount of about 0.1% to about 10% by weight.
16. 16. The fluid according to claim 1, characterized in that the member is an organic acid or salt thereof and is present in an amount of from about 0.1% to about 8% by weight.
17. 17. The fluid according to claim 1, characterized in that the surfactant is represented by the formula I: R2 (I) RA COO " wherein Ri represents alkyl, alkenyl, alkylarylalkylene, alkenylarylalkylene, alkylaminoalkylene, alkenylaminoalkylene, alkylamidoalkylene or alkenylamidoalkylene, wherein each of the alkyl groups contains from about 14 to about 24 carbon atoms and can be branched or straight and saturated or unsaturated, and wherein the alkylene groups have from about 1 to 6 carbon atoms, R2 and R3 are independently aliphatic chains having about 1 to 30 carbon atoms, and R is a hydrocarbyl radical with a chain length of from about 1 to about 4.
18. 18. The fluid according to claim 17, characterized in that Ri is selected from the group consisting of tetradecyl, hexadecyl, octadecentyl and octadecyl.
19. 19. The fluid according to claim 17, characterized in that Ri is an alkyl group derived from tallow, coconut, soybean or rapeseed oil.
20. 20. The fluid in accordance with the claim 17, characterized in that the alkyl and alkenyl groups of Ri are selected from alkyl groups and alkenyl groups respectively having from about 16 to about 22 carbon atoms.
21. 21. The fluid according to claim 17, characterized in that R2 and R3 are independently alkyl, alkenyl, arylalkyl, hydroxyalkyl, carboxyalkyl, or hydroxyalkyl-polyoxyalkylene, each having about 1 to about. 10 carbon atoms.
22. 22. The fluid in accordance with the claim 17, characterized in that R2 and R3 are independently methyl, ethyl, benzyl, hydroxyethyl, hydroxypropyl, carboxy ethyl or carboxyethyl.
23. 23. The fluid according to claim 17, characterized in that R4 is methylene or ethyl.
24. 24. The fluid according to claim 17, characterized in that R2 and R3 are each beta-hydroxyethyl.
25. 25. The fluid according to claim 24, characterized in that Ri is RCONHCH2CH2CH2- wherein R is an alkyl group containing about 14 to 24 carbon atoms, which may be straight or branched chain and may be saturated or unsaturated.
26. 26. The fluid according to claim 17, characterized in that R2 and R3 are each methyl.
27. 27. The fluid according to claim 2-6, characterized in that Ri is RCONHCH2CH2CH2- wherein R is an alkyl group containing about. from 14 to about 24 carbon atoms, which may be straight or branched chain and may be saturated or unsaturated.
28. 28. The fluid in accordance with the claim 1, characterized in that the surfactant is represented by the formula (VI): R- ^ R < COO " wherein Ri represents alkyl, alkenyl, alkylarylalkylene, alkenylarylalkylene, alkylaminoalkylene, alkenylaminoalkylene, alkylamidoalkylene, or alkenylamidoalkylene, wherein each of the alkyl groups contains about 14 to about 24 carbon atoms and can be straight or branched chain and saturated or unsaturated, wherein the alkylene groups have from about 1 to about 6 carbon atoms, R 2 is selected from the group of alkyl, alkenyl, arylalkyl, hydroxyalkyl, carboxyalkyl, and hydroxyalkyl-polyoxyalkylene, each having about 1 to about 10. carbon atoms, and R 4 is a hydrocarbyl radical with a chain length of about 1 to about 4.
29. 29. The fluid according to claim 28, characterized in that R 2 is beta-carboxyethyl and R 4 is ethylene.
30. 30. The fluid according to claim 28, characterized in that Ri is RCONHCH2CH2CH2- wherein R is an alkyl group containing about 14 to about 24 carbon atoms, which may be straight or branched chain and saturated or unsaturated.
31. 31. The fluid according to claim 1, characterized in that the surfactant is dihydroxyethyl seboglycinate.
32. 32. The fluid according to claim 1, characterized in that the surfactant is disodium seboiminodipropionate.
33. 33. The fluid according to claim 1, characterized in that the surfactant is oleamidopropyl betaine.
34. 34. The viscoelastic fluid characterized in that it consists essentially of: (i) an aqueous medium; (ii) a surfactant selected from the group consisting of the formula (I): and those of the formula VI R ^ (VI) Ri N H 'COO " wherein Ri represents alkyl having from about 16 to about 22 carbon atoms or RCONHCH2CH2CH2- wherein R is an alkyl group containing from about 16 to about 22 carbon atoms, R2 and 3 are independently methyl, ethyl, benzyl, hydroxyethyl , hydroxypropyl, carboxymethyl, or carboxyethyl, and R4 is methylene or ethyl; and (iii) a member selected from the group consisting of a) organic acids and their salts, wherein the organic acid or its salts comprise an aromatic portion selected from the group consisting of portions of sulfonate and carboxylate portion, b) inorganic salts selected from the group of ammonium salts soluble in water and c) combinations of one or more of the organic acids, or their salts, and one or more inorganic salts; wherein the fluid exhibits the property of viscoelasticity.
35. 35. The fluid in accordance with the claim 34, characterized in that the surfactant is present in an amount of about 0.5% to about 10%, the member is present in an amount of about 0.1% to about 30%.
36. 36. The fluid in accordance with the claim 35, characterized in that the member is composed of inorganic salts.
37. 37. The fluid according to claim 35, characterized in that the member comprises the combination of one or more of the organic acid or its salts, with one or more of the inorganic salts.
38. 38. The fluid in accordance with the claim 35, characterized in that the member is composed of organic acids and their salts.
39. 39. The fluid in accordance with the claim 38, characterized in that the surfactant is selected from the group consisting of dihydroxyethylglycinate, alkylamidopropylbetaine and dipropionates derived from amphoteric imidazoline.
40. 40. The fluid in accordance with the claim 39, characterized in that the surfactant is dihydroxyethyl seboglycinate.
41. 41. The fluid according to claim 39, characterized in that the surfactant is disodium seboimidopropionate.
42. 42. The fluid according to claim 39, characterized in that the surfactant is oleamidopropylbetaine.
43. 43. A viscoelastic fluid characterized in that it comprises: (i) an aqueous medium; (ii) from about 0.5% to about 6% of a surfactant selected from the group consisting of hydroxyethyl seboglycinate, seboiminodipropionate and oleamidopropylbetaine; and (iii) from about 0.1% to about 6% of a combination of a member selected from the group consisting of p-toluenesulfonate, naphthalenesulfonate, chlorobenzoic acid, salicylic acid and phthalic acid with a member comprising one or more ammonium salts soluble in Water; wherein the fluid exhibits the property of viscoelasticity.
44. 44. A method for suspending solid particles of excavation by-products in a viscoelastic fluid, characterized in that the solid particles remain suspended for an extended period at a site, comprising the steps of transporting the fluid to a site while the solid particles remain suspended in the fluid and depositing the fluid at the site, wherein the viscoelastic fluid comprises: (i) an aqueous medium; (ii) a surfactant selected from the group consisting of anteroteric surfactants, zwitterionic surfactants or mixtures thereof; and (iii) a member selected from the group consisting of organic acids and their salts, inorganic salts and combinations of one or more organic acids or their salts, with one or more inorganic salts; wherein the fluid exhibits the property of viscoelasticity.
45. 45. A method for fracturing an underground formation characterized in that it comprises the step of pumping a viscoelastic fluid through a hole and into an underground formation at a pressure sufficient to fracture the formation, wherein the viscoelastic fluid comprises: (i) a medium aqueous; (ii) a surfactant selected from the group consisting of anteroteric surfactants, • zwitterionic surfactants and mixtures thereof; and (iii) a member selected from the group consisting of organic acids, organic acid salts, inorganic salts, and combinations of one or more organic acids or salts of organic acid with one or more inorganic salts; wherein the fluid exhibits the property of viscoelasticity.
46. 46. The method for fracturing according to claim 44, characterized in that the viscoelastic fluid further comprises a particulate support material suspended therein.
47. 47. An aqueous formulation of an agricultural chemical and a quantity of a viscoelastic fluid sufficient to increase the average droplet size of a spray of the formulation, characterized in that the viscoelastic fluid comprises: (i) an aqueous medium; (ü) a surfactant selected from the group consisting of zwitterionic surfactants, amphoteric surfactants and mixtures thereof; and (iii) a member selected from the group consisting of organic acids, organic acid salts, inorganic salts, and combinations of one or more organic acids or salts of organic acid with one or more inorganic salts; wherein the fluid exhibits the property of viscoelasticity.
48. 48. A viscoelastic fluid characterized in that it consists essentially of: (i) an aqueous medium; (ii) an amount of a surfactant comprising an amine oxide surfactant; and (iii) an anionic surfactant containing a hydrophobe having at least 14 carbon atoms; wherein the fluid exhibits the property of viscoelasticity.
49. 49. The fluid according to claim 48, characterized in that the amine oxide surfactant has the formula R, wherein Ri represents alkyl, alkenyl, alkylarylalkylene, alkenylarylalkylene, alkylaminoalkylene, alkenylaminoalkylene, alkylamidoalkylene, or alkenylamidoalkylene, wherein each of the alkyl groups contains from about 14 to about 24 carbon atoms and can be straight or branched chain and saturated or unsaturated, and wherein the alkylene groups have from 1 to 6 carbon atoms; and R2 and R3 are each independently aliphatic salts having from about 1 to about 30 carbon atoms.
50. 50. The fluid according to claim 48, characterized in that the anionic surfactant is an alkyl sulfate or sulfonate having alkali metal counterions or an alkylcarboxylate, wherein the alkyl represents a group containing from about 14 to about 24 carbon atoms which can be straight chain or branched and saturated or unsaturated.
51. 51. The fluid according to claim 50, characterized in that the alkyl represents a group containing from about 16 to about 22 carbon atoms which can be straight or branched chain and saturated or unsaturated.
52. 52. The fluid according to claim 48, characterized in that the weight ratio of component 2 to component 3 ranges from about 100: 1 to about 50:50.
53. 53. A method for fracturing an underground formation characterized in that it comprises the step of pumping a viscoelastic fluid through a hole and into an underground formation at a pressure sufficient to fracture the formation, wherein the viscoelastic fluid essentially comprises: (i) a aqueous medium; (ii) an amount of surfactant comprising an amine oxide surfactant; and (iii) an amount of an anionic surfactant containing a hydrophobe having at least 14 carbon atoms; wherein the fluid exhibits the property of viscoelasticity.
54. 54. The process according to claim 52, characterized in that the fracturing step occurs at temperatures greater than about 37.7 ° C (100 ° F).