Abstract: The present invention provides methods and compositions for treating subterranean zones penetrated by well bores utilizing environmentally safe viscous fluids. A method of the invention comprises the following steps. A viscous treating fluid composition is provided comprised of water, a viscosity increasing polymer and a water soluble delayed polymer breaker that comprises a mixture of sodium perborate tetrahydrate and a solubility increasing boron complex or ester forming compound. The viscous treating fluid composition is introduced into the subterranean zone wherein the viscous treating fluid is allowed to break into a thin fluid of reduced viscosity.

Abstract: A low residue well treatment fluid comprises: an aqueous solvent; a gelling agent comprising one or modified polysaccharides, the modified polysaccharides having hydrophilic groups; and a crosslinking composition. The fluid may optionally further comprise a gel breaker, a buffer and/or a proppant. The fluids generate no or minimal residue upon being broken, and are particularly useful in well fracturing operations.

Abstract: This invention provides methods of fracturing subterranean zones, fracturing fluids and breaker activators for use in the fracturing fluids. The fracturing fluids are basically comprised of water, a gelling agent, a particulate proppant material, a delayed viscosity breaker and a breaker activator.

Abstract: The present invention provides improved methods of fracturing subterranean zones penetrated by well bores and improved fracturing fluids. The fracturing fluids are basically comprised of water, a terpolymer of 2-acrylamido-2-methylpropane sulfonic acid, acrylamide and acrylic acid, or its salts, a cross-linking agent for the terpolymer and a delayed viscosity breaker for effecting a controlled reduction in the viscosity of the fracturing fluid.

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

Abstract: Methods of fracturing subterranean zones to produce maximum hydrocarbon productivity are provided. The methods are basically comprised of providing a fracturing fluid comprised of water, a gelling agent present in an amount in the range of from about 0.06% to about 0.3% by weight of the water and an inorganic salt for preventing clay swelling present in an amount in the range of from about 0.01% to about 1% by weight of the water. The fracturing fluid is introduced into the subterranean zone at a rate and pressure sufficient to form fractures and the fracturing fluid is recovered from the zone.

Abstract: A method of reducing friction resulting from turbulent flow in an aqueous fracturing fluid in an oil field fracturing process comprising adding to the aqueous fracturing fluid an effective friction-reducing amount of one or more dispersion polymers, wherein the dispersion polymer is composed of from about 5 to about 95 mole percent of one or more nonionic monomers and from about 95 to about 5 mole percent of one or more cationic or anionic monomers and has a molecular weight of at least 100,000.

Abstract: The present invention relates to methods, aqueous treating fluids and friction pressure reducers for the treating fluids. A treating fluid of the invention comprises water and a non-toxic environmentally acceptable friction pressure reducer comprising a mixture of a copolymer of acrylamide and dimethylaminoethyl acrylate quaternized with benzyl chloride and a stabilizing and dispersing homopolymer of ethanaminium,N,N,N-trimethyl-2-[(1,oxo-2-prbpenyl)oxy]-chloride.

Abstract: A well fracturing 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 buffer for adjusting the pH of the fracturing fluid. The well service fluid can used as a fracturing fluid in order to control water production from a well, while simultaneously increasing the oil production from the well.

Abstract: A method of fracturing a zone of a subterranean formation penetrated by a well bore is shown in which a gelable fracturing fluid is formed by combining an aqueous base fluid and a hydratable polymer. A transition metal crosslinker is added to the aqueous base fluid for crosslinking the hydratable polymer to form a gelled fluid of sufficient viscosity to facilitate fracturing of the formation. A proppant can also be added to the gelable fracturing fluid. The gelled fluid and proppant are then injected into the well bore and into contact with the formation under sufficient pressure to fracture the formation. The gelable fracturing fluid has incorporated therein a delayed release breaker comprising a complex multivalent chelating agent that is released slowly over a period of time to compete with the polymer for the transition metal crosslinker, thereby reducing the viscosity of the fluid.

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: A well service fluid composition comprises a fracturing fluid and a gas hydrate inhibitor. Preferably, the gas hydrate inhibitor does not affect the function of the fracturing fluid and is present in an amount sufficient to control and/or minimize the formation of gas hydrates. The well service fluid composition is useful in hydraulic fracturing in which the composition is injected into a subterranean formation under sufficient pressure to initiate and propagate a fracture in the formation. The fracturing fluid may be subsequently recovered when the fracturing operation is completed.

Abstract: A high temperture aqueous based zirconium (IV) crosslinked guar fracturing fluid having a pH from about 9 to about 12 includes a polymer solution and a zirconium (IV) crosslinking agent in an amount from about 0.1 PPTG to about 5 PPTG of the polymer solution. The polymer solution includes an aqueous fluid, natural guar gum in an amount from about 10 PPTG to about 100 PPTG of the aqueous fluid, a stabilizer in an amount from about 1 PPTG to about 50 PPTG of the aqueous fluid, a non-delayed alkaline buffer in an amount from about 1 PPTG to about 40 PPTG of the aqueous fluid, and a gelation delaying agent in an amount from about 0.25 PPTG to about 3.75 PPTG of the aqueous fluid, where those agents are combined to produce a fracturing fluid suitable to the purposes of hydraulically fracturing subterranean formations with static bottom-hole temperatures greater than 250° F.

Abstract: The present invention provides environmentally safe foamed fracturing fluids, additives for foaming and stabilizing foamed fracturing fluids and methods of fracturing subterranean zones. The foamed fracturing fluids of this invention are basically comprised of water, a gelling agent for forming the water into gelled water and increasing the viscosity thereof, sufficient gas to form a foam, and an effective amount of an additive for foaming and stabilizing the gelled water comprised of hydrolyzed keratin.

Abstract: The present invention relates to a wellbore fluid comprising a particulate material composed of the reaction product of A) one or more water soluble organic compound having possessing a molecular weight of less than 30,000 and possessing at least two hydroxyl groups and B) any other organic compound(s) capable of forming acetal or hemiacetal cross-links with the hydroxyl groups of compound A. The invention relates also to the specific particulate material itself and to applications of the wellbore fluid of the invention for well processes such as drilling, under-reaming, completing, working over, sealing loss zones, sealing fractures, sealing cavities or other very high permeability conduits in a rock formation, or hydraulic fracturing to stimulate a hydrocarbon-producing zone.

Abstract: Improved methods of forming fractures containing resilient proppant particle packs which prevent the production of sand and fines with produced fluids and prevent proppant flow-back in a subterranean zone penetrated by a well bore are provided. As the fractures are formed, a liquid hardenable resin component is mixed with a liquid hardening agent component and a liquid rubber component to form a hardenable resin composition. The hardenable resin composition is coated onto dry proppant particles which are suspended in the fracturing fluid and placed in the fractures. The hardenable resin composition on the resin composition coated proppant particles is allowed to harden and consolidate the proppant particles into high strength resilient permeable packs.

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 formation treating fluid comprises one or more borate esters, a liquid carrier and, one or more cross linkable polymer wherein the formation treating fluid has an alkaline pH when the formation treating fluid is positioned in a formation. The formation treating fluid is useful in high temperature operations such as hydraulic fracturing.

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

Abstract: 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: It has been discovered that borate crosslinked fracturing fluid breaker mechanisms are improved by the inclusion of a cation-releasing material. When cations are released or liberated within the fracturing fluid, they complex with the hydroxide or carbonate pH buffers used within the borate crosslinked fracturing fluid, which in turn reduces the pH of the fracturing fluid. Once the pH is lowered, viscosity reduction (breaking) occurs by uncrosslinking of the polymer within the fracturing fluid, and by initiating or increasing activity of an enzyme breaker, if present. In one embodiment, the cations are divalent cations. The divalent cations are preferably slowly released over a period of time. Two specific, preferred materials for releasing divalent cations are calcium lignosulfonate and calcium chloride, the latter preferably in encapsulated form.

Abstract: The present invention related to a method for fracturing subterranean formations including the steps of (a) providing a water source; (b) adding a crosslinking agent to said water source; (c) adding a polymeric component to said water to create a fracturing fluid; (d) pumping said fracturing fluid into said formation. The fluid may contain an acrylamide-acrylate copolymer and any suitable number of additives. The additives are preferably combined with the water source to form an additive stream, to which the polymer is later added.

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

Abstract: The present invention provides seawater-based cross-linked fracturing fluids and methods of preparing and using the fluids in fracturing subterranean formations penetrated by well bores and having temperatures above about 200° F. The improved cross-linked fracturing fluids are basically comprised of a gelling agent, seawater present in an amount sufficient to hydrate the gelling agent and to form a gelled aqueous fluid, and a delayed cross-linking agent, capable of causing delayed cross-linking of the gelling agent in the gelled aqueous fluid at a pH below the threshold for precipitate formation in seawater.

Abstract: It has been discovered that borate crosslinked fracturing fluid breaker mechanisms are improved by the inclusion of a polyol together with an enzyme. In fact, synergistic results may be achieved when both are used together as contrasted to the cases where each are used separately. Removing the borate ion from the crosslinked polymer reduces the pH of the fluid and in turn increases the activity of the enzyme. That is, once the pH is lowered, viscosity reduction (breaking) occurs by uncrosslinking of the polymer within the fracturing fluid, and by initiating or increasing activity of an enzyme breaker, if present. In one embodiment, the polyol has at least two cis-hydroxyl groups. In another embodiment, the polyols are monosaccharides such as glycerols and sugar alcohols, and may include mannitol, sorbitol, glucose, fructose, galactose, mannose, allose, etc. and mixtures thereof. Oligosaccharides and derivatives of monosaccharides and oligosaccharides are also useful.

Abstract: The effect of various chemical or biological agents in well treatment fluids can be delayed by sequestering the agents in the discontinuous phase of an emulsion for a period of time, before the emulsion is destabilized by exposure to at least one of: (1) a change in temperature, (2) a change in pH, (3) a change in salinity, (4) a change in alcohol concentration, (5) a change in stabilizing surfactant concentration, (6) a change in organic ion concentration, (7) a change in destabilizing surfactant concentration, (8) a change in surfactant adsorbent material concentration, (9) an ultrasonic pulse, and (10) an electrical field. Upon exposure to the emulsion destabilizing condition, the agent sequestered in the discontinuous phase of the emulsion is released into the continuous phase of the fluid composition, where it can have its intended effect.

Abstract: Herein is disclosed a well completion or stimulation fluid, comprising (i) a carrier fluid; (ii) a viscoelastic surfactant; and (iii) a fluid loss control additive (FLA) comprising at least one polymer and at least one crosslinker. The fluid may further comprise 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 comprise proppant or gravel. Also disclosed herein are methods of fracturing a subterranean formation, comprising (i) providing a fracturing fluid discussed above and (ii) injecting the fracturing fluid into the formation at a pressure sufficiently high to fracture the formation. In addition, disclosed herein are methods of gravel packing a wellbore, comprising (i) providing a gravel packing fluid discussed above and (ii) injecting the gravel packing fluid into the wellbore.

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: A dry powder product comprised of an inorganic silicate-based compound and an organic compound are mixed with fresh water as a catalyst, such that the mixture enters into hydration reaction, and when injected into existing fractures in low permeability formations surrounding earth boreholes, the resulting increase in volume of the mixture from the hydration reaction causes the existing fractures to have increased dimensions.

Abstract: The invention provides a method of fracturing, including the provision and use of a fracturing fluid suspension containing an effective amount of a solid particulate breaker material having delayed breaking or degradation characteristics, additionally including an amount of durable fibers and/or platelets sufficient to enhance wellbore solids, such as proppant, transport. In a preferred aspect, solid particulate matter, which comprises or is composed of a specified organic polymeric compound or composition having an average molecular weight of at least 10,000, or a mixture of such compounds or compositions, and which solid organic polymeric matter reacts or decomposes, as described, is combined in a fracturing fluid with or containing a specified gellant and proppant, to form a fracturing fluid suspension, and the suspension formed is pumped downwell and deposited as a gelled suspension in the subterranean formation, generally under fracturing conditions.

Abstract: Improved methods and compositions for treating subterranean formations penetrated by well bores are provided. A method for breaking a gelled hydrocarbon fluid comprised of a hydrocarbon liquid, a ferric iron or aluminum polyvalent metal salt of a phosphonic or phosphoric acid ester is provided.

Abstract: Sulfonated uintaite is prepared by sulfonating a naturally occurring uintaite charge with a sulfonating agent such as sulfur trioxide, fuming sulfuric acid, chlorosulfonic acid, oleum, or concentrated sulfuric acid to produce sulfonic acids of uintaite. The resulting sulfonic acids are neutralized with a caustic neutralizing agent and sulfonated uintaite is the product. The sulfonated uintaite product is dried and packaged. The produced sulfonated uintaite is useful in oil and gas well working fluids (drilling muds). Neutralization of the resulting sulfonic acids with sodium hydroxide or ammonium hydroxide as the caustic neutralizing agent yields water and oil-soluble or dispersible salts of the sulfonated uintaite. Neutralization with Ca(OH)2 (calcium hydroxide) as the caustic neutralizing agent yields a product which is preferable in oil-based muds.

Abstract: Improved methods and compositions for treating subterranean formations penetrated by well bores are provided. A method of the invention for fracturing a subterranean formation comprises the steps of preparing a gelled hydrocarbon fracturing fluid comprised of a hydrocarbon liquid, a ferric iron or aluminum polyvalent metal salt of a phosphonic acid ester, a proppant material, water and a delayed gel breaker, and then contacting the subterranean formation with the gelled liquid hydrocarbon fracturing fluid under conditions effective to create at least one fracture in the subterranean formation.

Abstract: This invention relates to a well treatment fluid and a method to treat an/or fracture a subterranean formation comprising: injecting a well treatment fluid into the formation at sufficient pressure to fracture the formation wherein the fluid comprises: (a) one or more amphoteric surfactants; (b) water; (c) one or more nonaqueous solvents; (d) optionally, an acid forming compound; and (e) provided that if the acid forming compound is present a hydrophilic alcohol may also be optionally present; wherein the all or part of the fluid forms vesicles.

Abstract: A fracturing fluid is disclosed consisting of an emulsion having a continuous phase of a liquified gas, a discontinuous phase of a hydrocarbon, and a surfactant soluble in the two phases. The surfactant is preferably a hydrofluoroether.

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

Abstract: A well fracturing 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: A viscous fluid is shown which is useful in treating subterranean formations. The fluid is formulated from an aqueous base, an alkyl sarcosinate surfactant and a buffer suitable for adjusting the pH of the blended fluid to a range in which the fluid is suitably viscosified. The fluid can also include an additional source of anions, such as chloride or fluoride ions, in order to increase the temperature stability of the fluid. The fluids have application for conventional well fracturing, coiled tubing fracturing, gravel packing and frac packing, as well as for use as selective water control additives and other applications.

Abstract: Subterranean formation treating fluid concentrates, treating fluids and methods are provided by the present invention. The treating fluid concentrates are basically comprised of water and a substantially fully hydrated depolymerized polymer. The treating fluids which are formed by adding water to the treating fluid concentrates are basically comprised of water, a substantially fully hydrated depolymerized polymer and a crosslinking agent for crosslinking the hydrated depolymerized polymer.

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 fracturing fluid for use in fracturing subterranean formations surrounding oil and gas wells comprises water, an anionic surfactant, and a cationic surfactant.

Abstract: The present invention provides environmentally safe foamed fracturing fluids, additives for foaming and stabilizing foamed fracturing fluids and methods of fracturing subterranean zones. The foamed fracturing fluids of this invention are basically comprised of water, a gelling agent for forming the water into gelled water and increasing the viscosity thereof, sufficient gas to form a foam, and an effective amount of an additive for foaming and stabilizing the gelled water comprised of hydrolyzed keratin.

Abstract: This invention relates to a well treatment fluid and a method to treat an/or fracture a subterranean formation comprising: injecting a well treatment fluid into the formation at sufficient pressure to fracture the formation wherein the fluid comprises: (a) one or more amphoteric surfactants; (b) water; and (c) one or more nonaqueous solvents; (d) optionally, an acid forming compound, and (e) provided that if the acid forming compound is present a hydrophilic alcohol may also be optionally present.

Abstract: The present invention provides environmentally safe foamed fracturing fluids, additives for foaming and stabilizing foamed fracturing fluids and methods of fracturing subterranean zones. The foamed fracturing fluids of this invention are basically comprised of water, a gelling agent for forming the water into gelled water and increasing the viscosity thereof, sufficient gas to form a foam, and an effective amount of an additive for foaming and stabilizing the gelled water comprised of hydrolyzed keratin.

Abstract: A fracturing fluid for use in fracturing subterranean formations surrounding oil and gas wells comprises water, an anionic surfactant, and a cationic surfactant.

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: Polymers are derivatized and then may be introduced into a wellbore, such as in a hydraulic fracturing treatment. A polymer may be a guar powder that is mixed with a organic solvent and derivatized using a derivatizing agent, such as sodium chloroacetate. The polymer is typically derivatized in bulk prior to introduction into the wellbore. The derivatized polymer may be hydrated and/or crosslinked prior to introduction into the wellbore.

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: The present invention relates to a method of breaking an aqueous fracturing fluid comprising introducing said aqueous fracturing fluid into contact with an encapsulated viscosity reducing agent said encapsulated viscosity reducing agent comprising an aqueous fluid soluble breaker for said fracturing fluid encapsulated within a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide, said membrane having an embrittlement effective amount of a micron sized particulate present therein and said membrane having been cured at a temperature of at least about 115° F., such that an aqueous fluid in said fracturing fluid can contact said breaker after fracture failure of said membrane to dissolve at least a portion of said breaker and break the fracturing fluid in contact therewith.

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.