Abstract: A powder composition comprising viscoelastic surfactant forms, in aqueous solution, a viscoelastic wellbore treatment fluid.

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 hydraulic fracturing fluid includes a hydrocarbon fluid and viscosifying agent, wherein the viscosified fluid is a Newtonian fluid; a hydrocarbon fluid and gelling agent, wherein the viscosified fluid is a power law fluid; a hydrocarbon fluid, a gelling agent, and a rheological additive, wherein the viscosified fluid is a yield power law fluid; or a hydrocarbon fluid, a gelling agent, a rheological additive, and solvent for the rheological additive, wherein the viscosified fluid is a yield power law fluid. The hydrocarbon fluid is preferably weighted with nano-scale or self suspending weighting agents. The hydraulic fracturing fluids are prepared for use in fracturing a subterranean petroliferous formation. A weighted (preferably with nano-scale weighting agent), oil-based hydraulic fracture fluid breaker is also disclosed.

Abstract: An aqueous viscoelastic surfactant (VES) fluid foamed or energized with carbon dioxide, in which the VES is more compatible with the carbon dioxide, is made by the addition of one or more than one synergistic co-surfactant. The synergist co-surfactant includes quaternary amines and ethoxylated carboxylates having a hydrophobic chain shorter than the hydrophobic chain of the VES. Improved compatibility is evidenced for a given surfactant concentration either by formation and maintenance of a foam under conditions at which the foam could not otherwise have been formed or maintained, or by either higher viscosity of the foamed fluid at a given temperature or longer foam life at a given temperature or a higher temperature at which useful fluid viscosity can be generated or maintained for a useful time. The aqueous carbon dioxide foamed fluids may be used in acidizing, acid fracturing, gravel packing, diversion, and well cleanout.

Abstract: The current disclosure describes a multifunctional fluid that addresses a new concept in the removal of filter cake. A composition is disclosed comprising: a carrier fluid, a surfactant, a fluorine source and an organic stabilizer able to minimize precipitation of fluorine The associated method to remove the filter cake is also described.

Abstract: The present invention relates to well bore stabilization and, more particularly, to treatment fluids that may reduce the tendency of shales to swell and associated methods. In some embodiments, the present invention provides a method of stabilizing a subterranean formation that comprises a shale, the method comprising contacting the subterranean formation that comprises the shale with a treatment fluid, the treatment fluid comprising a base fluid, and a hydrophobically modified polymer. In other embodiments, the treatment fluids comprise a base fluid and a hydrophilically modified polymer. In yet other embodiments, the present invention provides shale-inhibiting components, treatment fluids, and methods of reducing the tendency of shale to swell when exposed to a treatment fluid.

Abstract: An oilfield treatment method is given that uses fluids that contain surfactants used as foamers and/or viscosifiers such that the fluids pass the Alberta Energy and Utilities Board Directive 27 requirements for low toxicity to certain bioluminescent bacteria. Such fluids may be used in oilfield treatments, for example drilling and stimulation, near fresh water aquifers. The surfactants are certain non-ionic surfactants that are not aromatic, or certain amphoteric surfactants (that can be neutral), or certain zwitterionic surfactants, (in which both positive and negative charges are present in a single molecule so that the whole molecule is neutral).

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: Single phase microemulsions improve the removal of filter cakes formed during drilling with oil-based muds (OBMs). The single phase microemulsion removes oil and solids from the deposited filter cake. Optionally, an acid capable of solubilizing the filter cake bridging particles may also be used with the microemulsion. In one non-limiting embodiment the acid may be a polyamino carboxylic acid. Skin damage removal from internal and external filter cake deposition can be reduced. In another optional embodiment, the single phase microemulsion may contain a filtration control additive for delaying the filter cake removal, destruction or conversion.

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: Single phase microemulsions improve the removal of filter cakes formed during drilling with invert emulsions. The single phase microemulsion removes oil and solids from the deposited filter cake. Optionally, an acid capable of solubilizing the filter cake bridging particles may also be used with the microemulsion. In one non-limiting embodiment the acid may be a polyamino carboxylic acid. Skin damage removal from internal and external filter cake deposition can be reduced.

Abstract: A fluid for use in a subterranean formation penetrated by a wellbore, the fluid comprising: (a) water; (b) an orthoester; and (c) a surfactant comprising a tertiary alkyl amine ethoxylate generally represented by the following formula: (CH2—CH2—O)XH R—N< (CH2—CH2—O)YH wherein R is an alkyl group or aryl group, and wherein X and Y are each independently at least one. A method of fracturing a subterranean formation, comprising the step of forming a foamed fracturing fluid comprising water; an orthoester; a surfactant comprising a tertiary alkyl amine ethoxylate generally represented by the formula above; 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.

Abstract: A process of preparing a well servicing fluid comprising viscosifying a heavy brine by contacting with a cationic polysaccharide and a composition thereof.

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: A completion and workover fluid composition comprising, water and at least one rheology modifier and/or fluid loss control agent, and at least one other ingredient selected from the group consisting of inorganic salts, shale inhibitors, corrosion inhibitor, biocide, defoamers and finely divided solids particles (e.g., bentonite, attapulgite, sepiolite, calcium carbonate, etc.), depending upon the desired attributes, wherein the rheology modifier and/or the fluid loss control agent is an ethoxylated raw cotton linters or a modified ethoxylated raw cotton linters. The ethoxylated raw cotton linters provides comparable or better rheology and viscosity properties compared to high molecular weight commercial HECs made from purified cotton linters. These ethoxylated raw cotton linters derivatives are suitable for applications in oil-well servicing fluids, particularly to enhance functional properties of completion and workover fluids used during oil-well drilling operations.

Abstract: A synergistic blend for foaming concentrated brines comprises at least one foaming agent (in an amount between from about 10 to about 90 weight percent of the blend) and a compound of the formula: CnH2n+1—N—[(CH2)mCOOM]2??(I) wherein n is 4 to 11, M is an alkali metal and m is 1 to 3. Especially suitable as foaming agent are quaternary ammonium salts, alkyl betaines, alkylamidopropyl betaines, sulfabetaines, hydroxysultaines, amphoteric perfluorohydrocarbons, as well as alkylether sulfates. Such synergistic blends are especially useful in the foaming of saturated or near saturated brines.

Abstract: An aqueous oilfield treatment fluid containing a chelating agent and an HF source is described. This fluid is effective at dissolving siliceous materials such as clays and keeping the dissolved materials in solution. In particular it is effective at preventing re-precipitation of initially-dissolved silicon as silica and therefore reduces damage to sandstones with which it is contacted. Methods are given for using this fluid for sandstone matrix stimulation, removal of clay-containing drilling fluid components and filter cakes from wellbores, sandstone acid fracturing, and gravel pack and proppant pack cleaning.

Abstract: A method for inhibiting the formation of gas hydrates in a petroleum fluid having hydrate-forming constituents is claimed. More specifically, the method can be used to treat a petroleum fluid, such as natural gas conveyed in a pipe, to inhibit the formation of a hydrate flow restriction in the pipe. The preferred hydrate inhibitors used for practicing the method comprise substantially water soluble homopolymers and copolymers of isopropylmethacrylamide derivatives which have a bimodal molecular weight distribution.

Abstract: A method is described for treating a subterranean formation with a low viscosity fluid system that contains a viscoelastic surfactant at a concentration too low to viscosify the fluid, but that is concentrated in the formation so that the fluid system gels. The fluid also contains a formation-dissolving agent. The fluid is used in acidizing, acid fracturing, and diversion.

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: Improved desulfurization compositions are provided for removing substantial fractions of sulfur, sulfur complexes, and sulfur compounds from liquid hydrocarbons such as crude oil and fuels. The preferred compositions comprise respective quantities of an alkylphenol ethoxylate, an amine, and an alkali metal nitrite. The compositions may be contacted with liquid hydrocarbons to achieve high levels of desulfurization.

Abstract: An under-balanced drilling fluid additive is disclosed which reduces reactive shale and/or clay swelling during under-balanced drilling operations, where the additive includes an effective amount of a choline salt. A method for under-balanced drilling is also disclosed including the step of circulating a drilling fluid including an effective amount of a choline salt to reduce reactive shale and/or clay swelling during under-balanced drilling operations.

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: Novel wellbore service fluids are disclosed. The fluid may include an aqueous solvent and a synthetic degradable polymer that is soluble in the solvent. In a controlled way the molecular weight of the polymer may be reduced in response to internal or external triggers at the required time and temperature. The polymers are formed by essentially non degradable polymer chains “polymer type A” copolymerized with essentially degradable polymer chains “polymer type B”. This feature of “selective degradation” is not present in any of the polymeric fluids known as friction reducers.

Abstract: A composition and method for removing a filter cake from a horizontal wellbore in a subterranean formation using a composition containing a inorganic or organic acidic material, a cationic fluorocarbon surfactant, an alkyl alcohol, water optionally containing ammonium chloride and at least one of an alkyl polyglycoside and a betaine surfactant to produce a stable foam used to remove filter cake from a horizontal wellbore.

Abstract: A composition and method for removing a filter cake from a horizontal wellbore in a subterranean formation using a composition containing a inorganic or organic acidic material, a cationic fluorocarbon surfactant, an alkyl alcohol, water optionally containing ammonium chloride and at least one of an alkyl polyglycoside and a betaine surfactant to produce a stable foam used to remove filter cake from a horizontal wellbore.

Abstract: Corrosion and gas hydrate inhibitors having improved water solubility and increased biodegradability The invention thus provides the use of compounds of the formula (1) where R1, R2 are each independently C1- to C22-alkyl, C2- to C22-alkenyl, C6- to C30-aryl or C7- to C30-alkylaryl, R3 is C1- to C22-alkyl, C2- to C22-alkenyl, C6- to C30-aryl or C7- to C30-alkylaryl, —CHR5—COO? or —O?, R4 is M, hydrogen or an organic radical which optionally contains heteroatoms and has from 1 to 100 carbon atoms, B is an optionally substituted C1- to C10-alkylene group, D is an ethylene group substituted by an organic radical having from 1 to 600 carbon atoms, X, Y are each independently O or NR6, R5, R6 are each independently hydrogen, C1- to C22-alkyl, C2- to C22-alkenyl, C6- to C30-aryl or C7- to C30-alkylaryl, and M is a cation as corrosion and gas hydrate inhibitors, and also the compounds of formula 1.

Abstract: Treating compositions containing mutual solvents suitable for forming and maintaining single-phase aqueous fluid treating compositions containing very high concentrations of acids and/or chelating agents are described. Methods of use of these treating compositions for dissolving and removing scale and formation matrix material in oil-field treatments such as stimulation and remediation are given.

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: 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: Many methods are provided herein including a method of providing fluid loss control comprising: providing a treatment fluid; adding to the treatment fluid an acid-generating fluid loss control additive comprising an acid-generating component wherein the acid-generating fluid loss control additive forms droplets in the treatment fluid; and placing the treatment fluid into a subterranean formation. Other methods are provided as well.

Abstract: A method for removing preexisting filtercake from a portion of a subterranean formation penetarted by a wellbore is carried out by providing water-degradable particles formed from a solid polymeric acid precursor material that is capable of a degrading to acid for reacting with materials of the filtercake. A slurry is formed from the particles with a carrier fluid. The slurry of particles is introduced into the formation through the wellbore and allowed to degrade to form acid, whereby the formed acid facilitates decomposition of preexisting filtercake material. In certain applications, the water-degradable particles may also be used in combination with non-water-degradable particles, which may be used for forming a gravel pack. The water-degradable particles may also be used to reduce fluid loss temporarily to areas of the formation immediately surrounding the wellbore.

Abstract: A method and an amide composition used therein for inhibiting, retarding, mitigating, reducing, controlling and/or delaying formation of hydrocarbon hydrates or agglomerates of hydrates. The method may be applied to prevent or reduce or mitigate plugging of conduits, pipes, transfer lines, valves, and other places or equipment where hydrocarbon hydrate solids may form under the conditions. At least one amide compound is added into the process stream, where the compound may be mixed with another compound selected from amino alcohols, esters, quaternary ammonium, phosphonium or sulphonium salts, betaines, amine oxides, other amides, simple amine salts, and combinations thereof.

Abstract: A method for increasing the rate of shear rehealing of fluids made with cationic, zwitterionic, and amphoteric viscoelastic surfactant fluid systems by adding an effective amount of a rheology enhancer package containing, for example a polyethylene glycol-polypropylene glycol block copolymer and a polynaphthalene sulfonate. The rheology enhancer package allows viscoelastic surfactant fluids to be used at lower viscoelastic surfactant concentrations in certain applications, for example certain oilfield treatments, for example fracturing and gravel packing. Preferred surfactants are betaines and quaternary amines.

Abstract: Coatings for well screens that protect the screens from damage as they are inserted into the wellbore and once in the well, release reactive materials to react with and degrade potentially plugging materials such as drill solids, fluid filtercakes, fluid loss additives, and drilling fluids. The coatings can be specifically designed for individual well conditions and are comprised of a binder that either melts or dissolves within the wellbore and one or more reactive materials such as acids, enzymes, surfactants, chelants, oxidizers or free radical generators and the like which are released into the screen and the near wellbore area and which are effective in degrading or dissolving materials which could potentially plug the screen.

Abstract: A scale dissolver fluid for dissolving scale in a subterranean hydrocarbon-bearing formation comprises an effective amount of a scale dissolver formulation and an effective amount of a surfactant for controlling the viscosity of the fluid. In use, formation hydrocarbons act on the surfactant to reduce the viscosity of the fluid so that the fluid selectively invades a hydrocarbon-bearing zone of the formation.

Abstract: A method for increasing the foam stability of foams made with cationic, zwitterionic, and amphoteric viscoelastic surfactant fluid systems by adding an effective amount of an amphiphilic polymeric foam stabilizer containing at least one portion that is a partially hydrolyzed polyvinyl ester or partially hydrolyzed polyacrylate. The foam stabilizer allows foams to be used at temperatures at which the unfoamed fluids would not have stable viscosity, and allows use of lower viscoelastic surfactant concentrations in the liquid phase. Preferred surfactants are betaines and quaternary amines. The fluids are useful in oilfield treatments, for example fracturing and gravel packing.

Abstract: Among many things, compositions and methods relating to the prevention and remediation of surfactant gel damage are provided. In one embodiment, the method includes providing a treatment fluid comprising a carrier fluid; at least one component selected from the group consisting of a chelating agent and a scale control agent; at least one component selected from the group consisting of an alcohol, a glycol, a pH modifier, a hydrocarbon, a mutual solvent, an oxidizer, a reducer, an enzyme, a transition metal, a combination thereof, and a derivative thereof; and at least one component selected from the group consisting of a nonemulsifier, a demulsifier, a combination thereof, and a derivative thereof, and introducing the treatment fluid into a subterranean formation.

Abstract: Among many things, compositions and methods relating to the prevention and remediation of surfactant gel damage are provided. In one embodiment, the method includes providing a treatment fluid comprising a carrier fluid and at least one component selected from the group consisting of a chelating agent and a scale control agent, and introducing the treatment fluid into a subterranean formation that has been treated with a viscoelastic surfactant fluid.

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: Fluids, such as completion fluids, containing at least one alkali metal tungstate and optionally at least one chelating agent are described. Methods of removing a filter cake from a well bore surface, which may include one or more alkaline earth metal sulfates, is also described, wherein the method includes contacting the filter cake with the completion fluid of the present invention. A drilling fluid or mud is also described wherein the drilling fluid contains at least one alkali metal tungstate. The drilling fluid preferably further contains at least one emulsifier or surfactant and at least one hydrocarbon-based fluid. The various fluids of the present invention can contain other conventional ingredients and optionally at least one alkali metal formate. The present invention permits the fluids to be essentially solids free due to the use of the alkali metal tungstate.

Abstract: An organic based emulsion-breaking formulation for use in treating well bores drilled in oil-bearing mud that is not eco-toxic and is optimally compatible with formation fluids comprises: as the emulsion-breaking agent, at least one constituent selected from non-ionic amphiphilic compositions obtained by reacting at least one polymerized vegetable oil with at least one aminoalcohol and alkyl esters (for example C1 to C8) of fatty acids derived from natural, vegetable or animal oils; optionally, at least one wetting agent selected from anionic surfactants; and optionally at least one solvent; the assembly being as a mixture in an organic base. Such a formulation can be weighted by mineral fillers.

Abstract: An aqueous-based composition containing cesium formate and at least one chelating agent is described. Methods of removing scaling deposits, which may include alkaline earth metal sulfates, present on surfaces, including porous media, such as alkaline earth metal sulfate buildup in a well bore, is also described, wherein the method includes contacting the alkaline earth metal sulfate with the compositions of the present invention to remove the scaling deposits. A completion fluid containing at least one alkali metal formate, at least one acid and/or at least one chelating agent, and optionally at least one surfactant or mutual solvent is also described. Methods of removing a filter cake from a well bore surface, which may include weighting agents such as calcium carbonate, is also described, wherein the method includes contacting the filter cake with the completion fluid of the present invention.

Abstract: It has been discovered that aminocarboxylic acids are effective breakers for polymer-gelled aqueous fracturing fluids, particularly in the temperature range between about 120° F. (49° C.) and about 280° F. (138° C.). The aminocarboxylic acids are believed to act directly on the polymer and not to any great extent or not to as an effective extent on a crosslinking agent, if present. The polymer may be a polysaccharide, and the aminocarboxylic acid may be selected from the group including, but not necessarily limited to, tetrasodium ethylenediaminetetraacetic acid (Na4EDTA), tetrasodium propylenediaminetetraacetic acid (Na4PDTA), trisodium hydroxyethylenediaminetetraacetic acid (Na4HEDTA), trisodium nitrilotriacetic acid (Na3NTA), salts of these acids, and mixtures thereof.

Abstract: An aqueous oilfield treatment fluid containing a chelating agent and an HF source is described. This fluid is effective at dissolving siliceous materials such as clays and keeping the dissolved materials in solution. In particular it is effective at preventing re-precipitation of initially-dissolved silicon as silica and therefore reduces damage to sandstones with which it is contacted. Methods are given for using this fluid for sandstone matrix stimulation, removal of clay-containing drilling fluid components and filter cakes from wellbores, sandstone acid fracturing, and gravel pack and proppant pack cleaning.

Abstract: The present invention relates to an additive, and its use for inhibiting nucleation, growth and agglomeration of gas hydrates by adding an effective amount of an inhibitor to a multiphasic mixture which tends to hydrate formation and consists of water, gas and optionally condensate, or to a drilling fluid which tends to form gas hydrates. Said inhibitor comprising dialkoxylated quaternary ammonium compounds of the formula 1 where R1, R2 are each independently radicals of the formulae—(B)—(O—A)n—O—CO—R5 or —(A—O)n—(C)—CO—O—R5, R3 is C1- to C30-alkyl or C2- to C30-alkenyl, R4 is an organic radical which optionally contains heteroatoms and has from 1 to 100 carbon atoms, R5 is an alkyl or an alkenyl, n is a number from 1 to 20, A is an alkylene group, B is an alkylene group, C is a C1- to C6-alkylene group and X is an anion, are used as gas hydrate inhibitors.

Abstract: The present invention is directed to ophthalmic compositions containing a gelling amount of a combination of galactomannan polysaccharides and borates. The compositions gel or partially gel upon administration to the eye. The present invention also discloses methods of topical ophthalmic administration of the compositions to the eye.