Abstract: A fracturing fluid is provided for use in fracturing subterranean formations. It comprises a hydrocarbon base. In the base, acidified alkyl phosphate esters are complexed with metallic cations, to form a gel.

Abstract: The present invention provides improved cross-linked well treating fluids and methods for preparing and using the fluids in treating wells such as fracturing subterranean zones therein. The improved cross-linked treating fluids comprise water, a galactomannan gelling agent, a cross-linking agent for cross-linking the galactomannan gelling agent, and a viscosity stabilizing agent selected from the group consisting of formaldehyde, formic acid, or mixtures thereof. The viscosity stabilizing agent alters the properties of the well treating fluids and enables them to retain their viscosity over prolonged periods of time when compared to prior well treating fluids.

Abstract: The improved recovery of hydrocarbons from subterranean formations by fracturing and matrix acidizing a subterranean formation is accomplished. Well treatment fluids having a viscoelastic surfactant fluid containing worm like micelles are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The viscolastic surfactant-based fracturing fluids of the present Invention are stable across a wide pH spectrum, allowing them to be used for fracturing treatments at low pH, as well as matrix acidizing treatments. In addition, the stability of these fluids is enhanced in the presence of organic anions. Two-stage fracturing treatments comprised of a viscoelastic surfactant-based fracturing fluid and a polymer-based system, wherein the two fluids are either blended or pumped into the formation sequentially (the polymer last) are also presented.

Abstract: The invention relates to compositions and methods for gelling liquid hydrocarbons by the introduction of certain phosphate esters, a crosslinking agent, and an enhancer. The enhancer of the present invention is preferably an oxyalkylated amine or a blend of an oxyalkylated amine with another amine or a non-nitrogen-containing component. Mixed phosphate esters containing an oxyalkylene group are useful in the practice of the invention. Gel-forming compositions for addition to liquid hydrocarbons, as well as methods for forming fracturing fluids, are encompassed. The present compositions and methods are an improvement in the field of hydrocarbon gelling, e.g., in fracturing formations, by providing more rapid gellation and greater viscosities.

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

Abstract: A fracturing fluid is provided for use in fracturing subterranean formations. It comprises a hydrocarbon base. In the base, acidified alkyl phosphate esters are complexed with metallic cations, to form a gel.

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

Abstract: A composition for delaying the cross-linking of water soluble polymer solutions includes a boron source suspended by an organophilic clay in a solution of a non-aqueous solvent. One process of manufacturing the composition includes the steps of first suspending the organophilic clay in the non-aqueous solvent and then suspending the boron source in the organophilic clay-non-aqueous solvent suspension. Another process of manufacturing composition includes the steps of first mixing the boron source and the organophilic clay to form a dry mixture and then suspending the dry mixture of the boron source and the organophilic clay in a non-aqueous solvent. In a method of hydraulically fracturing a formation, a water soluble polymer solution with a pH between about 8.5 and 12.5 and the boron source suspended by the organophilic clay in the solution of the non-aqueous solvent are pumped into the formation under sufficient pressure to cause a fracture in the formation rock.

Abstract: The present invention relates to a gelled hydrocarbon fluid useful as a fracturing fluid in subterranean formations comprising at least one gelling agent which is a salt of a carboxylic acid having from about 6 to about 30 carbon atoms. An activator which is a difunctional and/or trifunctional carboxylic acid is preferably added to control gel time.

Abstract: According to the present invention, a composition and method for hydraulically fracturing a subterranean formation is provided. The composition comprises an aqueous mixture of a hydrated polysaccharide, preferably a galactomannan gum, the hydrated polysaccharide having a plurality of bonding sites; a crosslinking agent for crosslinking the hydrated polysaccharide at the bonding sites at the conditions of the subterranean formation with a polyvalent metal ion to form a polyvalent metal crosslink, thereby increasing the viscosity of the hydrated polysaccharide; and a controlled solubility compound for releasing a chelating agent for controllably breaking the polyvalent metal crosslink and bonding with the polyvalent metal ion released by breaking the crosslink, thereby decreasing the viscosity of the hydrated polysaccharide.

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

Abstract: A wellbore service fluid comprising viscoelastic surfactants in combination with means for controlling the concentration of at least partially charged sites within the fluid is described.

Abstract: A fluid that is useful in stimulation operations, and in particular, in hydraulic fracturing treatments, comprises a carrier fluid; a solvatable, crosslinkable polymer; a cross-linking agent that does not cause substantial cross-linking of the polymer at temperatures less than about 105° F. and a pH of about 10 or greater; and an organic amine stabilizing agent that has a first pKa or a pH in water of at least about 9.5. One group of such amines has the formula H2N—(R1NH)n—H where R1 is C1-C4 alkyl and n is from 1-6. In one embodiment, the cross-linking agent is an organic zirconate, such as bis(hydroxyethyl)glycine zirconate. The organic zirconate is effective to cross-link the polymer when the composition is at a temperature of at least about 105° F., and a pH of about 10 or higher, preferably a pH in the range of about 10.5-12.

Abstract: A composition for delaying the cross-linking of water soluble polymer solutions includes a boron source suspended by an organophilic clay in a solution of a non-aqueous solvent. One process of manufacturing the composition includes the steps of first suspending the organophilic clay in the non-aqueous solvent and then suspending the boron source in the organophilic clay- non-aqueous solvent suspension. Another process of manufacturing composition includes the steps of first mixing the boron source and the organophilic clay to form a dry mixture and then suspending the dry mixture of the boron source and the organophilic clay in a non-aqueous solvent. In a method of hydraulically fracturing a formation, a water soluble polymer solution with a pH between about 8.5 and 12.5 and the boron source suspended by the organophilic clay in the solution of the non-aqueous solvent are pumped into the formation under sufficient pressure to cause a fracture in the formation rock.

Abstract: Improved high temperature, low residue viscous well treating fluids and methods of using the fluids are provided by the present invention. The improved viscous well treating fluids are basically comprised of water; a hydrated galactomannan gelling agent; a retarded cross-linking composition for buffering the treating fluid and cross-linking the hydrated galactomannan gelling agent comprised of a liquid solvent, an organotitanate chelate and a borate ion producing compound; and a delayed gel breaker.

Abstract: Granules composed of a particulate breaker chemical dispersed in a wax matrix are used in fracturing operations to break hydrocarbon liquids gelled with salts of alkyl phosphate esters. The wax granules are solid at surface temperature and melt or disperse in the hydrocarbon liquid at formation temperature releasing the breaker chemical to react with gelling agent.

Abstract: A fracturing fluid and method is disclosed comprising an aqueous metal hydrated galactomannan gum, buffered to a pH of from about 9 to about 11, and using reduced amounts galactomannan gum. Further, the invention provides a metal ion source, such as borate, to crosslink the galactomannan gum polymer in subterranean fractures. In one embodiment a slowly dissolving slurried borate is used in pumping an alkaline fracturing fluid into a subterranean formation to increase production of hydrocarbons. In another embodiment, an encapsulated borate source is used. A chemical stabilizer optionally may be used.

Abstract: A subterranean formation is treated by introducing a fracturing treatment composition comprising a polymer treatment fluid containing a dispersion of hydrophilic water swellable particles into the formation. The water swellable particles comprise synthetic polymers that are crosslinked so that they are water insoluble, but capable of swelling in the presence of relatively small amounts of water. When used with treatment fluids containing at least a small amount of water, the particles swell and reduce fluid loss to the formation during the treatment. When used during a hydraulic fracturing treatment of a hydrocarbon bearing formation, the particles may also reduce or eliminate water production following the fracturing treatment by restricting the extension of a fracture into water-bearing formations, and/or by restricting the flow of fluids from water-bearing areas.

Abstract: An encapsulated breaker is enclosed within a hydrolytically degradable polymer coating. Compositions containing this encapsulated breaker, methods of making and methods of use are also described.

Abstract: Liquid hydrocarbons are gelled by the introduction of a phosphate ester and a crosslinking agent. Gelling times and viscosities are improved through the use of an enhancer which is, preferably, an oxyalkylated amine or a blend of an oxyalkylated amine with another amine or a non-nitrogen-containing component. Preferred phosphate esters are ether phosphate esters.

Abstract: This invention is directed to a gelling agent composition comprising the reaction product of a high molecular weight gelling agent additive, a low molecular weight phosphate diester acid, and a Group II or Group III metal salt, to methods of preparing the gelling agent composition, to a gelled hydrocarbon liquid comprising the gelling agent composition and to a method of fracturing subterranean formations using the gelled hydrocarbon liquid.

Abstract: The present Invention relates to hydrocarbon well stimulation, and more particularly to methods and compositions to remove (or more generally to transfer) fluid introduced into a subsurface fracture, in which the methods involve creating then exploiting chemical potential gradients at the fracture face to induce fluid flow from the fracture into the formation; the methods and compositions involve creating, or relying upon an intrisic or previously created, a selectively permeable membrane that is permeable to water but that does not allow solutes to pass through.

Abstract: The crosslinking of galactomannan gum fracturing fluids by borate ion is delayed for high temperature applications by completing boron in a basic solution with an organic polyol. Low pumping friction pressures are achieved by the delay in the crosslinking with the boron being available at high temperatures to add high temperature stability to the fracturing fluid at temperatures ranging upto about 300.degree. F.

Abstract: Method and composition for gel formation in hydrocarbon recovery, in which an organic phosphate ester is gelled by a novel activator composition comprising iron sulfate, dibutylaminoethanol, and a phosphate surfactant.

Abstract: Viscoelastic surfactant fluids for fracturing subterranean formations penetrated by a wellbore. The surfactant fluids are comprised of an aqueous medium; an effective amount of an inorganic water soluble salt; and an effective amount of at least one surfactant selected from the group consisting of: i) anionic surfactants; ii) nonionic surfactants; and iii) hydrotropic surfactants. The surfactant compositions can be further stabilized and the viscosity increased by the addition of one or more hydrophobic organic alcohols. This invention also relates to a method for fracturing subterranean formations using said viscoelastic surfactant fluids.

Abstract: A process is provided for reducing the permeability of or fluid mobility within a high-temperature treatment region in or proximate to a hydrocarbon-bearing formation below an earthen surface penetrated by a well bore. The process is initiated by preparing a gelation solution at the earthen surface which includes a base loading of a high molecular weight acrylamide polymer, an additive loading of a low molecular weight acrylamide polymer, a crosslinking agent, and an aqueous solvent. The crosslinking agent is preferably a chromium(III) complex having one or more chromium(III) cations and one or more carboxylate anions. The resulting gelation solution is injected into the well bore and displaced into the treatment region where it is gelled in situ to form a gel which substantially reduces the permeability of or fluid mobility within the treatment region.

Abstract: Methods are provided for fracturing subterranean formations using fluids having substantially reduced polymer loadings that have performance equivalent to conventional fluids. Reduced polymer loadings provide significant advantages such as reduced treatment costs and less damage to the fracture sand pack and surrounding subterranean formations.

Abstract: For hydraulic fracturing treatment to increase productivity of subterranean hydrocarbon bearing formation, a hydraulic fracturing additive including a dry mixture of water soluble crosslinkable polymer, a crosslinking agent, and a reinforcing material of fibers and/or comminuted plant materials. The method of forming a hydraulic fracturing fluid includes contacting the additive with water or an aqueous solution, with a method of hydraulically fracturing the formation further including the step of injecting the fluid into the wellbore.

Abstract: Method and composition for gel formation in hydrocarbon recovery, in which an organic phosphate ester is gelled by a novel activator composition comprising iron sulfate, dibutylaminoethanol, and a phosphate surfactant.

Abstract: Methods and apparatus are disclosed for fracturing subterranean formations using fracturing fluids that are hydrated from dry mix blends. One aspect of the invention comprises a dry blended particulate composition for hydraulic fracturing comprising a particulate hydratable polysaccharide, a particulate crosslinking agent, and a slowly releasing particulate base. The compositions employ controlled release methods of particle dissolution. The invention reveals a dry blended particulate composition capable of significantly improved high temperature stability. Further, methods of fracturing and apparatus for rapidly hydrating and pumping the fracturing fluid into subterranean formations are disclosed.

Abstract: Viscoelastic surfactant based aqueous fluid systems are described that are useful in fracturing subterranean formations penetrated by a wellbore. The preferred surfactant compositions contain quaternary ammonium salts wherein the long chain alkyl substituent contains about 3% or less of groups containing 18 or less carbon atoms. The amount of intermediate compounds in the surfactant composition is less than about 1%. The surfactant composition can be used in conjunction with an inorganic water soluble salt such as ammonium chloride or potassium chloride, and an organic stabilizing additive.

Abstract: Wellbore fluids are disclosed which comprise liquid dispersions of particulate mixed divalent metal carbonates having a generally platy crystal form. Mixed alkaline earth metal carbonates are preferred. The invention further relates to a method of well construction, well remediation, or stimulation utilizing such wellbore fluids.

Abstract: The present invention relates to methods of treating subterranean formations and viscosified aqueous well treating compositions which break into thin fluids at temperatures in the range of from about 100.degree. F., to about 300.degree. F. A breaker system is included in the compositions comprised of an alkali metal chlorite or hypochlorite breaker and a breaker activator comprised of copper II ion or an amine, or both.

Abstract: Oil degradable encapsulated breaker particles are used in fracturing operations to break hydro-carbon liquid gelled with salts of alkyl phosphate esters. The preferred breaker chemical is particulate urea coated with sulfonated EPDM.

Abstract: The invention, in one embodiment, relates to a fluid loss control additive or composition comprising a granular starch composition and fine particulate mica, in specified proportions. The invention further comprises a fracturing fluid containing a starch composition and mica, in a specified ratio. In yet a third embodiment, the invention comprises a method of fracturing a subterranean formation penetrated by a borehole, comprising injecting into the borehole and into contact with the formation, at a rate and pressure sufficient to fracture the formation, a fracturing fluid containing starch and mica, in specified ratios, and in an amount sufficient to provide fluid loss control.

Abstract: The present invention provides a method for reducing the amount of water produced from a subterranean formation as a result of stimulation of the subterranean formation. The method comprises the introduction of a gelled fluid to initiate a fracture in a formation, introduction of a first and second reactive polymer which leak-off into the formation along the fracture and which are capable of subsequently reacting together to form a reaction product which selectively reduces the permeability of the formation to water flow through the formation into the fracture and introduction of a crosslinked gelled fluid to extend the fracture into the formation and facilitate the introduction of a propping agent into the created fracture. The reactive polymers react in situ to form a reaction product that binds to the formation in such a manner that the flow of water is selectively retarded through the matrix while the flow of oil is substantially unaffected.

Abstract: The invention, in one embodiment, relates to a fluid loss control additive or composition comprising a granular starch composition and fine particulate mica, in specified proportions. The invention further comprises a fracturing fluid containing a starch composition and mica, in a specified ratio. In yet a third embodiment, the invention comprises a method of fracturing a subterranean formation penetrated by a borehole, comprising injecting into the borehole and into contact with the formation, at a rate and pressure sufficient to fracture the formation, a fracturing fluid containing starch and mica, in specified ratios, and in an amount sufficient to provide fluid loss control.

Abstract: There is provided an additive for and a method of using the additive to treat a clay-containing earthen formation, such as a subterranean formation, to substantially reduce formation damage caused by contact of the formation with an aqueous liquid foreign to the formation. The additive, which is employed in a water solution, is comprised of a chloride-free, quaternary ammonium compound which can be used without adverse affect upon animal, soil and water resources due to the chloride-free and substantial organic nature thereof. It thus biodegrades to environmentally acceptable end products.

Abstract: There is provided an improved fluid for fracturing an underground formation penetrated by a well bore comprising a mixture of a liquified gas and a gas.

Abstract: A method is provided for controlling the delay time of aqueous borate-crosslinked polysaccharide-based fluids for hydraulic fracturing and related applications which allows on-the-fly control of the delay time without comprising overall fluid integrity. Without having to modify the total boron content nor pH of the fracturing fluid, the delay time is controlled by adding a polyol to the fracturing fluid at a first rate, determining the resulting delay time and then adjusting the rate of the polyol addition to the fracturing fluid until the desired delay time is achieved.

Abstract: A method of fracturing a subterranean formation which surrounds a well bore comprises the steps of providing a fracturing fluid, and injecting the fracturing fluid into the well bore at a pressure sufficient to form fractures in the subterranean formation which surrounds the well bore. The pressure is then released from the fracturing fluid, after which the fluid may be removed from the well and the well placed into production. The fracturing fluid comprises an aqueous liquid, a polysaccharide soluble or dispersible in the aqueous liquid in an amount sufficient to increase the viscosity of the aqueous liquid, an enzyme breaker which degrades said polysaccharide at a temperature above 180.degree. F. Fracturing fluid compositions and enzyme breaker systems useful for carrying out the invention are also disclosed.

Abstract: Hydrocarbon fracturing fluids are made by combining organic phosphate esters with polyvalent metal salts in hydrocarbon carriers to form gels; breaking of the gel is retarded or otherwise controlled over a wide range of water concentrations through the use of slowly soluble alkaline earth metal compounds, preferably hard burned magnesium oxide, which may be added along with the gel component.

Abstract: The present invention provides borate cross-linked well treating fluids and methods of preparing and using the fluids in treating wells such as fracturing subterranean zones therein. The improved cross-linked treating fluids are basically comprised of water, a hydrated galactomannan gelling agent and a borate composition for buffering the treating fluid and cross-linking the hydrated galactomannan gelling agent comprised of water, a soluble boron source and an alkanolamine or alkylamine.

Abstract: Hydrocarbon fracturing fluids are made by combining organic phosphate esters with polyvalent metal salts in hydrocarbon carriers to form gels; breaking of the gel is retarded or otherwise controlled over a wide range of water concentrations, through the use of slowly soluble alkaline earth metal compounds, preferably hard burned magnesium oxide, which may be added along with the gel component. The slowly soluble alkaline earth metal compound is employed together with an oily acid breaker retarding agent such as tall oil.

Abstract: A method of formulating a zirconium lactate compound is accomplished by combining in solution lactic acid or a lactate salt with zirconium carbonate. The reacting solution forms zirconium lactate and carbon dioxide which is evolved as a gas from the solution. This eliminates the need to filter or wash the zirconium lactate in order to remove undesirable by-products. The zirconium lactate can be used as a crosslinking agent for crosslinking aqueous polymer gels used in such things as fracturing fluids for fracturing subterranean formations of oil and gas wells.

Abstract: The present invention provides improved quaternary ammonium compounds useful as metal corrosion inhibitors in aqueous acid solutions, methods of preparing the compounds, metal corrosion inhibited aqueous acid solutions containing the compounds and methods of protecting metal surfaces from acid corrosion using the compounds. The compounds are prepared by contacting the still bottoms residue produced in the distillation of quinoline from coal tar with oxygen to oligomerize aromatic amines contained therein and then reacting the oligomerized amines with a benzylhalide.

Abstract: This invention relates to improved hydrocarbon gels which find use in the fracturing of petroleum producing formations. In particular it relates to the use of a defined class of gelling agents for hydrocarbons which provide excellent results in such fracturing. The gelling agents comprise combinations of selected orthophosphate esters and ferric ammonium citrate or lower alkyl amine derivative thereof. The lower alkyl amine derivatives are referred to as ferric alkylamine citrates.

Abstract: The invention, in one embodiment, is a novel fracturing fluid composition comprising an aqueous metal hydrated galactomannan gum, buffered to a pH of from about 9 to about 11. In another embodiment, a method of fracturing a formation is disclosed, the method being characterized by the use of the compositions mentioned.

Abstract: The present invention relates to a method of breaking an aqueous based viscosified fluid having potassium ions present therein with a breaker comprising an alkali metal chlorite or hypochlorite through use of a breaker activator comprising a source of ammonium ion in the aqueous fluid. The method is particularly effective in providing a controlled break in a treatment fluid introduced into a subterranean formation having a static temperature in the range of from about 100.degree. F. to about 300.degree. F. In some instances, a second breaker activator comprising a source of thioglycolate ion also may be admixed with the viscosified fluid to further accelerate breaker activation at temperatures below about 200.degree. F.

Abstract: The present invention relates to a method of breaking an aqueous based viscosified fluid containing a breaker comprising an alkali metal chlorite or hypochlorite through use of a breaker activator comprising thioglycolate ion or a compound capable of producing thioglycolate ion in the aqueous fluid. The method is particularly effective in providing a controlled break in a treatment fluid introduced into a subterranean formation having a static temperature in the range of from about 100.degree. F. to about 200.degree. F.