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 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: A temperature-stable, non eco-toxic oil-base well fluid that is particularly suitable for high pressure/high temperature drilling comprises an emulsification system comprising at least one superamide that may or may not be polyalkoxylated, optionally associated with a non-ionic co-surfactant. The oil-base well fluid comprising such a system can be used at temperatures of up to about 200° C. due to the production of highly temperature-stable reverse emulsions.

Abstract: A method for using an invert emulsion fluid in a well bore, comprising placing an invert emulsion fluid in a well bore, wherein the invert emulsion fluid comprises an oleaginous fluid, a non-oleaginous fluid and an emulsifier comprising one or more amines generally represented by the formula: wherein R is a radical selected from the group consisting of abietyl, hydroabietyl, dihydroabietyl, tetrahydroabietyl, and dehydroabietyl, each R? may be the same or different and is an alkyl having from about 1 to about 3 carbons, each A may be the same or different and is NH or O, and the sum of x and y ranges from about 1 to about 20, and contacting the invert emulsion fluid with an acid solution to reversibly convert the invert emulsion to an oil-in-water emulsion.

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: The present invention relates to subterranean treatment fluids. In particular, the present invention relates to subterranean treatment fluid compositions that comprise polyoxazoline compositions and methods for using such compositions in subterranean applications. In one embodiment, the present invention provides a method of controlling shale swelling in a subterranean formation comprising introducing a treatment fluid into the subterranean formation, wherein the treatment fluid comprises a base fluid and a polyoxazoline composition. In another embodiment, the present invention provides a method of treating a portion of a subterranean formation comprising the steps of: introducing a treatment fluid that comprises a base fluid and a polyoxazoline composition; and treating a portion of the subterranean formation. Other embodiments are provided.

Abstract: Invert emulsion compositions including an oleaginous, a non-oleaginous and an amine surfactant that are useful in the oil and gas well drilling art are disclosed. The amine surfactant is selected so that the invert emulsion can be converted form a water-in-oil type emulsion to a oil-in-water type emulsion upon the protonation of the amine surfactant. Deprotonation of the amine surfactant reverses the conversion. This solution also permits the conversion of oil-wet solids in the fluid into water-wet solids.

Abstract: A method of controlling and delaying the inversion of a drilling fluid and the wettability of a filtercake by using a delayed phase changing agent. The filtercake is preferably formed while drilling a subterranean formation using a drilling fluid includes: an oleaginous fluid; a non-oleaginous fluid; an amine surfactant having the structure: wherein R is a C12–C22 aliphatic hydrocarbon; R? is an independently selectable from hydrogen or C1 to C3 alkyl; A is NH or O, and 1?x+y?3. In the method, the filter cake is exposed to a delayed phase changing agent selected from the group consisting of aliphatic amine acids, salts of aliphatic amine acids and combinations thereof. In one preferred illustrative embodiment, the delayed phase changing agent is delivered in the form of a pill, the pill including a carrier fluid, a viscosifier and the delayed phase changing agent.

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 method of improving the lubricity of an aqueous based drilling fluid composed of an aqueous base fluid, and a weighting agent. The method involves the addition of an effective amount of a phospholipid to substantially reduce the coefficient of friction when compared to the fluid absent the phospholipids. Preferably the phospholipids have the structure: in which R and R? are C6 to C25 hydrocarbon groups; and A is an anion to counter the cationic charge.

Abstract: Invert emulsion drilling system fluids comprising an oleaginous continuous phase and a non-oleaginous dispersed phase, the dispersed phase comprising organofunctional compound(s) effective to provide shale inhibition. The organofunctional compound(s) may be used either as a supplement to or as a substitute for metallic salts.

Abstract: A method of increasing shale formation stability with a water based drilling fluid, the method including: delivering to the shale formation a drilling fluid formulated to include an aqueous fluid; a first reactant which is a soluble monomer, oligomer, or polymer with exposed ketone, aldehyde, or aldol groups or with groups which can be shifted to ketone or aldehyde functionality; and, a second reactant which is a primary amine, diamine, or polyamine which by condensation reaction forms a semi-soluble or precipitated filming product with the first reactant.

Abstract: A method and product is disclosed which provides emulsion stability and filtration control to invert emulsion drilling fluids. The product comprises a blend of a carboxylic acid terminated polyamide and/or a wetting agent with a reaction product or mixture produced by the Diels-Alder reaction of dienophiles, preferably carboxylic acids, polycarboxylic acids, acid anhydrides, or combinations or mixes thereof, with a mixture of fatty acids and resin acids. The product of the invention is extremely effective, decreasing by about two-thirds the amount of emulsifier generally required to formulate an effective drilling fluid. The product of the invention also greatly reduces and in many cases eliminates the need for conventional fluid loss additives, and additionally provides electrical stability.

Abstract: A method for drilling a borehole employing a drilling fluid including an additive comprising a glucose derivative with pH lowering acid, buffers and surface active agents. The drilling fluid additive preferably exhibits the following properties: activity of approximately 30%–45% in water solution; pH of about 4.5 to 5.5; a light amber to clear liquid appearance and a density of approximately 1.200 grams per cubic centimeter.

Abstract: An invert emulsion fluid, method for making same, and method for using same as a servicing fluid in a well bore. The invert emulsion fluid contains an oleaginous fluid, a non-oleaginous fluid, and an emulsifier comprising one or more amines generally represented by the formula: wherein R is a cycloaliphatic hydrocarbon, each R? may be the same or different and is H or an alkyl having from about 1 to about 3 carbon atoms, each A may be the same or different and is NH or O, and the sum of x and y ranges from about 1 to about 20. In a preferred embodiment, R is a radical selected from the group consisting of abietyl, dihydroabietyl, tetrahydroabietyl, and dehydroabietyl, R? is H, and A is O.

Abstract: A method of making a rheology modified aqueous composition, particularly useful for drilling, milling and mining applications, is disclosed. The method includes admixing, with a clay and water, a material or materials whose constituents substantially conform to the proportions of the empirical formula M?mM?n(OH)(2m+3n+qa+br)(Aq)a(Br)b.xH2O, where M? is a divalent metal cation, M? is a trivalent metal cation, A and B are anions, and a, b, m, n, q, r, and x are defined herein. Calcined hydrotalcite and hydrotalcite-like materials are particularly preferred as starting materials. Optionally, an aluminum oxide, a nitrogen-containing compound, or both may be added. The resulting composition is preferably an elastic solid exhibiting stress-dependent fluidity, desirable temperature resistance, lubricity, inhibition of reactivity, relatively low cost, and pressure resistance. A dry composition and method of making are also disclosed.

Abstract: A method and composition is provided for a suspending agent for supporting components in drilling fluids, particularly oil-based drilling fluids, the suspending agent comprising the condensation product of a dimer or trimer fatty acid and diethanolamine.

Abstract: A method for drilling a borehole employing a drilling fluid including an additive comprising a glucose derivative with pH lowering acid, buffers and surface active agents. The drilling fluid additive preferably exhibits the following properties: activity of approximately 30%-45% in water solution; pH of about 4.5 to 5.5; a light amber to clear liquid appearance and a density of approximately 1.200 grams per cubic centimeter.

Abstract: Invert emulsion compositions including an oleaginous, a non-oleaginous and an amine surfactant that are useful in the oil and gas well drilling art are disclosed. The amine surfactant is selected so that the invert emulsion can be converted form a water-in-oil type emulsion to a oil-in-water type emulsion upon the protonation of the amine surfactant. Deprotonation of the amine surfactant reverses the conversion. This solution also permits the conversion of oil-wet solids in the fluid into water-wet solids.

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

Abstract: Invert emulsion compositions including an oleaginous, a non-oleaginous and an amine surfactant that are useful in the oil and gas well drilling art are disclosed. The amine surfactant is selected so that the invert emulsion can be converted form a water-in-oil type emulsion to a oil-in-water type emulsion upon the protonation of the amine surfactant. Deprotonation of the amine surfactant reverses the conversion.

Abstract: A wellbore fluid having a non-aqueous continuous liquid phase that exhibits an electrical conductivity increased by a factor in order of 104 to 107 compared to conventional invert emulsion comprises from about 0.2% to about 10% by volume of carbon black particles and one or more emulsifying surfactant(s) selected from the class including nonionic emulsifiers of Hydrophilic-Lipophilic Balance (HLB) less than about 12, and anionic surfactants wherein the counter-ion (cation) is any of alkali metal, ammonium, or hydrogen ions. This wellbore fluid can be used for drilling or completing a well and can be used for providing enhanced information from electrical logging tools, measurement while drilling, logging while drilling, geosteering and the like.

Abstract: Present invention relates to high brine carrier fluid, said carrier fluid selected from the group consisting of organic acids, organic acid salts, inorganic salts and combination of one or more organic acids or organic acid salts, a co-surfactant and an amount of a zwitterionic surfactant. The invention also relates to methods of treating a subterranean wellbore, including drilling, hydraulic fracturing, gravel placement, scale removing, mud cake removing, using said high brine carrier fluid.

Abstract: The present invention relates to a borehole fluid comprising a lubricating compound containing at least one amphiphilic non-ionic compound obtained by reacting at least one vegetable oil or fatty acid as such or in a polymerized state on at least one amino alcohol. In one variant, the compound can be mixed with a solvent. The invention also relates to a method for verifying the lubrication power of a water-based fluid. The invention further relates to the application of said method to borehole fluids with a high pH.

Abstract: Methods are provided for increasing the production of hydrocarbons from shaly formations that contain adsorbed condensed hydrocarbon gases by treating such formations with dewatering compositions comprising surfactants that cause the surfaces of the formation to be or to remain oil-wet. The methods may be used in stimulation (acidizing or acid fracturing or hydraulic fracturing), remediation or workover, and in enhancing flow from natural fractures or from unstimulated formations.

Abstract: A brine for use during drilling operations, preferably a completion brine, comprising an amount of a low molecular weight water-soluble organic compound effective to reduce the crystallization point of the brine. The low molecular weight water soluble organic compound can be a variety of compounds, with preferred compounds being ethylene glycol, tripropylene glycol bottoms, and combinations thereof. A method of lowering the crystallization point of the brine using a low molecular weight water soluble organic compound also is provided.

Abstract: A method and product is disclosed which provides emulsion stability and filtration control to invert emulsion drilling fluids. The product comprises a blend of a carboxylic acid terminated polyamide and a mixture produced by the Diels-Alder reaction of dienophiles, preferably carboxylic acids, polycarboxylic acids, acid anhydrides, or combinations or mixes thereof, with a mixture of fatty acids and resin acids. The product is extremely effective, decreasing by about two-thirds the amount of emulsifier generally required to formulate an effective drilling fluid. The product also greatly reduces and in many cases eliminates the need for conventional fluid loss additives, and additionally provides electrical stability. Moreover, the product has a pour point as low as about 20 degrees Fahrenheit with minimal solvents, thereby eliminating the need to ship large amounts of inert material for use, and may be transported in a highly active state.

Abstract: Methods of drilling well bores using an invertible oil external-water internal emulsion drilling fluid and then inverting the drilling fluid to a water external-oil internal emulsion are provided. The methods basically comprise the steps of contacting the oil external-water internal emulsion with an aqueous acid solution containing an anionic sulfonate surfactant for preventing aqueous acid solution-crude oil emulsions and crude oil sludging and a chemical for preventing the anionic sulfonate surfactant from reacting with the emulsifier in the oil external-water internal emulsion.

Abstract: A method of electrically logging subterranean wells using a conductive double emulsion fluid includes a miscible combination of an oleaginous fluid, an emulsifier capable of forming a microemulsion, an emulsifier capable of forming an invert emulsion, and an electrolytic salt. A microemulsion is the continuous phase of an invert emulsion. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The fluid may additionally contain a polar organic solvent and a carbon dioxide buffer. The polar organic solvent may be an oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like.

Abstract: Novel corrosion inhibiting compositions comprising a combination of amino thiol or amino disulfide compounds with acidic amino acid polymers inhibit carbon dioxide induced corrosion of ferrous metals in aqueous systems. Particularly effective inhibitor compositions are the natural amino acids cysteine and cystine and their decarboxylated analogues cysteamine and cystamine in combination with polyaspartic acid. The inhibitor compositions are particularly useful for preventing corrosion and scale formation in oil production applications.

Abstract: Improved methods of drilling well bores utilizing foamed aqueous drilling fluids are provided. The methods basically comprise circulating an aqueous drilling fluid containing a single foaming and defoaming surfactant and a gas downwardly through a rotary drill pipe and drill bit connected thereto. Well bore cuttings generated by the drill bit are lifted to the surface by foam produced from the aqueous drilling fluid and gas. Upon reaching the surface, the foamed aqueous drilling fluid is defoamed whereby the cuttings and gas are removed therefrom and the aqueous drilling fluid is combined with additional foaming surfactant when needed and additional gas. The foaming and defoaming of the aqueous drilling fluid are accomplished by changing the pH of the aqueous drilling fluid from basic to acidic which causes the single foaming and defoaming surfactant to foam and defoam the aqueous drilling fluid.

Abstract: An acidic fluid that is useful in stimulation and workover operations, and in particular, for the control of iron in acidizing operations, the removal of alkaline earth carbonate scale in scale removal operations, and matrix or fracture acidizing operations, comprises an acid, such as hydrochloric acid; water; and a hydroxyethylaminocarboxylic acid. Preferred hydroxyethylaminocarboxylic acids are hydroxyethylethylenediaminetriacetic acid (HEDTA) and hydroxyethyliminodiacetic acid (HEIDA). Also disclosed herein are methods of controlling iron, removing alkaline earth carbonate scale, or matrix or fracture acidizing, involving the use of the acidic fluid.

Abstract: A biodegradable drilling mud, comprising a water/organic phase reverse emulsion in a volume ratio ranging from 50/50 to 10/90, which contains: a) from 1 to 5% by volume of at least one nitrogen compound selected from the group consisting of amino acids, carbamic mono- and polyamides and mono- and polycarbamic amides, of formulae (I) and (II) respectively, taken alone or as a mixture: R—[NH—CH2]n—CO—NH2  (I) R—NH—[CO—NH]m—H  (II)  wherein R is hydrogen or an alkyl group comprising from 1 to 10 carbon atoms and n and m are integers ranging from 1 to 5, b) from 2 to 10% by volume of at least one phosphorus derivative selected from the group consisting of surfactant phosphorus compounds, and c) from 2 to 10% by volume of at least one oxygenated compound selected from the group consisting of fatty acids, fatty acid esters of fatty alcohols comprising carbon-based chains comprising from 12 to 24 carbon atoms, alone or

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscoelastic surfactant fluid containing wormlike micelles are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The invention further relates to novel fracturing methods useful for increasing hydrocarbon production, limiting connate water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of micelles of surfactant in aqueous zones of the subterranean formation facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

Abstract: A method of electrically logging subterranean wells using a conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, an electrolytic salt, and a carbon dioxide buffer. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The polar organic solvent may be an oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like. The electrolytic salt or brine preferably includes a quaternary amine salt having the formula: wherein R is an alkyl having 8 to 18 carbon atoms, R′ is 2 to 6 carbon atoms alkyl group, B is hydrogen, oxyalkyl having 1 to 4 carbon atoms or alkyl having 1 to 4 carbon atoms, A is hydrogen or alkyl with 1 to 4 carbon atoms, x+y=1 to 15, z is 0 to 3, and M is a counter anion; or combinations thereof. The carbon dioxide buffer is preferably a trialkylanol amine.

Abstract: This Invention relates to a novel reversible thickener, i.e., a fluid whose viscosity can be carefully modulated—from very low viscosity to sufficient viscosity to act as a barrier to further flow; particularly preferred embodiments are directed to fluids and methods for stimulating hydrocarbon low viscosity to sufficient viscosity to act as a barrier to further flow; particularly preferred-bearing formations—i.e., to increase the production of oil/gas from the formation. In particular, the Present Invention is directed to a family of fluids (and methods incorporating those fluids) intended to be pumped through a wellbore and into the hydrocarbon-bearing formation.

Abstract: A method of making a rheology modified aqueous composition, particularly useful for drilling, milling and mining applications, is disclosed. The method includes admixing, with a clay and water, a material or materials whose constituents substantially conform to the proportions of the empirical formula M′mM″n(OH)(2m+3n+qa+br)(Aq)a(Br)b.

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscosifying surfactant fluid containing viscosifying micelles, for example, wormlike micelles, are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The invention further relates to novel fracturing and acidizing methods useful for increasing hydrocarbon production, limiting water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of viscosifying micelles of surfactant in aqueous zones of the subterranean formation diverts fracturing fluid or acid from the aqueous zones to the hydrocarbon-bearing zones and also facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

Abstract: This invention is of a drilling fluid composition containing a liquid thixotrope, which thixotrope is free of solvents or any other diluent, and is in easily usable, liquid form, pourable at ambient temperatures, and which provides effective and efficient rheological properties when used at low levels in such compositions. In a specific aspect, the invention provides an oil or oil invert emulsion drilling fluid composition containing one or more organoclays, and in addition contains a additive which comprises the reaction product of an alkoxylated nitrogen containing compound or a diamine, and one or more polycarboxylic acids in a specified equivalent ratio.

Abstract: A method of electrically logging subterranean wells using a conductive fluid in which the conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, and an electrolytic salt. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The medium may further include gelling agent, weight material, surfactant, or corrosion inhibitors. The polar organic solvent may preferably be a oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like.

Abstract: Pumpable multiple phase compositions for carrying agents and components downhole and controllably releasing them by breaking the suspensions are described. The multiple phase composition may have an external or third phase, which in turn has a first pumpable emulsion internally. The first pumpable emulsion has a second phase containing a first phase which bears the agent to be controllably released. The entire pumpable multiple phase composition may thus be an oil phase-in-aqueous phase-in-oil phase emulsion, or an aqueous phase-in-oil phase-in-aqueous phase emulsion. For example, a water-soluble shale stabilizer could be delivered downhole in an aqueous phase-in-oil phase-in-aqueous phase multiple phase emulsion by injecting the multiple phase composition into a water-based drilling fluid, and then the suspension broken by rotary bit nozzles under high shear stress to release the shale stabilizer at the drilling zone.

Abstract: A method of electrically logging subterranean wells using a conductive fluid includes a miscible combination of an oleaginous fluid, a polar organic solvent, an electrolytic salt, and a carbon dioxide buffer. The electrolytic salt or brine of the salt is present in a concentration sufficient to permit the electrical logging of the subterranean well. The polar organic solvent may be an oil soluble glycol or glycol ether such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, and the like.

Abstract: Invert emulsion compositions including an oleaginous, a non-oleaginous and an amine surfactant that are useful in the oil and gas well drilling art are disclosed. The amine surfactant is selected so that the invert emulsion can be converted form a water-in-oil type emulsion to a oil-in-water type emulsion upon the protonation of the amine surfactant. Deprotonation of the amine surfactant reverses the conversion.

Abstract: The invention relates to multiphase lubricant concentrates with improved properties for use in aqueous fluids for geological exploration by drilling which contain organic lubricating components which are solid and/or liquid at room temperature (O phase) together with emulsifiers finely dispersed in a continuous aqueous phase (W phase). These concentrates are characterized in that the system of O phase/W phase and emulsifiers has a phase inversion temperature (PIT) above room temperature and has been produced by heating the multiphase system to temperatures equal to or above the PIT and subsequent cooling to temperatures below the PIT. The present invention also relates to the use of the multiphase lubricant concentrates as an additive in water-based fluids for use in geological exploration by drilling and for the subsequent treatment of the resulting boreholes.

Abstract: A pourable concentrate suitable for forming structured surfactant drilling muds on dilution with aqueous electrolyte comprises: a) from 30 to 80% by weight, based on the weight of the composition, of surfactant consisting of at least 25%, based on the weight of the surfactant, of an anionic surfactant, from 0 to 70% by weight, based on the total weight of surfactant, of an alkanolamide, and from 0 to 20% based on the total weight of surfactant, of other non-ionic surfactant and/or amphoteric surfactants; b) from 3 to 60% by weight of the composition of a compound of the formula RHX where R is hydrogen or a C1-6 alkyl group and X is a random or block copolymeric chain comprising a total of from 3 to 20 ethoxy and propoxy units in a relative numerical proportion of 0 to 10:1; and c) up to 65% by weight of water.

Abstract: Increased foam quality and resistance to hydrocarbon defoaming for foams used in well boring and stimulation processes as well as secondary and tertiary oil recovery is obtained using imidazoline-based amphoacetates of higher purity, containing essentially negligible amounts of unalkylated amido amines, lower amounts of glycolic acid salts and monochloroacetate salts.The higher purity amphoacetates can be obtained via processes utilizing precise pH control during the reaction of imidazoline, or its open-chain derivatives, with alkylating agents, e.g. sodium monochloroacetate. These higher-purity amphoacetates contain essentially fully alkylated products and lower amounts of glycolic acid derivatives, even though a ratio of monohaloalkylate to substituted imidazoline, or its open-ring derivative, of less than 1.5:1.0 and close to 1.0:1.0 is used.

Abstract: The present invention provides a method for suppressing the formation of hydrates during drilling operations under conditions that are conducive to hydrate formation comprising using a water based fluid selected from the group consisting of a drilling, a drill-in, and a completion fluid, wherein said water based fluid comprises as an integral component a hydrate suppressing amount of a water-soluble organic compound having a molecular weight below about 800 and said fluid has effective rheology and fluid loss control properties.

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscoelastic surfactant fluid containing wormlike micelles are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The invention further relates to novel fracturing methods useful for increasing hydrocarbon production, limiting connate water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of micelles of surfactant in aqueous zones of the subterranean formation facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

Abstract: Gelatin capsules containing oil field chemicals, preferably weighted with a heavy metal compound, are made more stable under certain conditions by the incorporation of a strong chelating agent. The microcapsules can provide an extended treatment period since many materials that would damage the microcapsules are controlled by the chelating agent.

Abstract: This invention relates to drilling fluid additives that suppress clay swelling within a subterranean well and to methods for controlling clay swelling during the drilling of a subterranean well. In one embodiment trihydroxy alkyl amine is reacted with an alkyl halide or a water soluble quaternary amine to form a quaternized trihydroxy alkyl amine. The reaction products can also include condensed reaction products of quaternized trihydroxy alkyl amines. In another embodiment a choline derivative is used. The quaternized reaction products and choline derivatives are characterized by low toxicity and compatibility with anionic drilling fluid components. The products are added to water base drilling fluids which are circulated throughout a well. The drilling fluid additives and the method of controlling clay swelling provide for improved control of the rheological properties of drilling fluids along with increased environmental and drilling fluid compatibility.