Abstract: This Invention relates to methods of treating a subterranean hydrocarbons reservoir comprising contacting the formation with a treating fluid comprising an aqueous solution, an acid, a surfactant acting as gelling agent essentially consisting of erucylamidopropyl betaine (or a protonated/deprotonated homolog or salt thereof). The treating fluid may further comprise a lower n-alcohol for improved temperature stability.

Abstract: A process for stimulating a formation is disclosed wherein a diverting fluid is used to divert an acid treatment package from a high permeability or damaged portion of a formation to a low permeability or undamaged portion of a formation. The fluid, which preferably forms vesicles, comprises at least one surfactant, at least one quaternary amine polyelectrolyte, water, and a non-aqueous solvent.

Abstract: It was found that the addition of polymers to viscoelastic surfactant base system allows to adjust the rheological properties of the base fluid. Depending in particular on one side of the ratio of the concentration of added polymer and the concentration of viscoelastic surfactant and on the other side of the molecular weight of the added polymer, the same polymer—or the same type of polymer—may perform different functions such as viscosity enhancer, viscosity breaker or viscosity-recovery enhancer.

Abstract: The present invention relates to acidic treatment fluids that comprise an acid fluid and an ester-containing quaternary ammonium compound (“esterquat”) and methods of their use. One embodiment of the present invention provides a method of inhibiting metal corrosion during a subterranean treatment operation comprising using an acidic treatment fluid comprising an acidic fluid and an esterquat. Another embodiment of the present invention provides a method of reducing sludge formation during a subterranean treatment operation formation comprising the step of using an acidic treatment fluid comprising an acidic fluid and an esterquat. Another embodiment of the present invention provides a method of inhibiting the formation of emulsions during a subterranean treatment operation comprising using an acidic treatment fluid comprising an acidic fluid and an esterquat. Another embodiment of the present invention provides an acidic subterranean treatment fluid comprising an acidic fluid and an esterquat.

Abstract: Methods of treating subterranean zones and treating fluids are provided. The methods are basically comprised of preparing or providing a subterranean zone treating fluid comprising an aqueous fluid and an additive for preventing the swelling and migration of formation clays in the subterranean zone selected from the group consisting of 1-carboxy-N,N,N-trimethyl methanaminium chloride, 2-hydroxy-N,N,N-trimethyl ethanaminium acetate, and 2-hydroxy-N,N,N-trimethyl 1-propanaminium acetate.

Abstract: It has been discovered that fluids viscosified with viscoelastic surfactants (VESs) may have their viscosities reduced (gels broken) by the direct or indirect action of a biochemical agent, such as bacteria, fungi, and/or enzymes. The biochemical agent may directly attack the VES itself, or some other component in the fluid that produces a by-product that then causes viscosity reduction. The biochemical agent may disaggregate or otherwise attack the micellar structure of the VES-gelled fluid. The biochemical agent may produce an enzyme that reduces viscosity by one of these mechanisms. A single biochemical agent may operate simultaneously by two different mechanisms, such as by degrading the VES directly, as well as another component, such as a glycol, the latter mechanism in turn producing a by-product (e.g. an alcohol) that causes viscosity reduction. Alternatively, two or more different biochemical agents may be used simultaneously.

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: 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: The present invention generally relates to a method and a composition useful in restoring the permeability of a porous underground petroleum containing formation. Restoring permeability to the formation enhances the injectivity thereby accelerating petroleum recovery. The method of the invention comprises treating said formation with a composition which comprises a combination of at least one nonionic compound, preferably an alkoxylated alcohol, with at least one cationic compound, preferably a quaternary ammonium compound, in an amount effective to improve the permeability of the formation. The composition may also optionally contain an alkyl glycoside.

Abstract: A method for treating a wellbore (or well casing) and the contiguous wellbore area to remove scale (mineral deposits comprised of, e.g., BaSO4, CaCO3, etc.) in the context of hydrocarbon recovery and other applications is disclosed, said method including contacting the scale with a fluid comprised of an ionic liquid or liquids.

Abstract: Methods and compositions are disclosed for controlled addition of components that decrease the viscosity of the viscoelastic surfactant fluids or for controlled changes in the electrolyte concentration or composition of the viscoelastic surfactant fluids. One aspect of the invention relates to the use of internal breakers with a delayed activation. Another aspect of the invention relates to the use of precursors that release a breaking system such as alcohol by a process such as melting, slow dissolution, reaction with a compound present in the fluid or added to the fluid during or after the step of injecting, rupture of an encapsulating coating and de-adsorption of a breaking agent absorbed into solid particles. In another aspect of the invention, alcohols are included in a pad to reduce the low-shear viscosity and reduce the resistance to flow of the treatment fluids during a desired phase of the treatment.

Abstract: A method is disclosed for using aqueous VES-based gravel carrier fluids in gravel packing operations using screens and shunt tubes that have been run into a well completed with an oil-based mud. With this method, the previously necessary but undesirable steps of first running in a perforated liner and then displacing the oil-based mud with an aqueous-based fluid in the region to be gravel packed are both avoided while the advantages of gravel packing with an aqueous-based fluid are retained.

Abstract: Methods and compositions are disclosed for controlled addition of components that decrease the viscosity of the viscoelastic surfactant fluids or for controlled changes in the electrolyte concentration or composition of the viscoelastic surfactant fluids. One aspect of the invention relates to the use of internal breakers with a delayed activation. Another aspect of the invention relates to the use of precursors that release a breaking system such as alcohol by a process such as melting, slow dissolution, reaction with a compound present in the fluid or added to the fluid during or after the step of injecting, rupture of an encapsulating coating and de-adsorption of a breaking agent absorbed into solid particles. In another aspect of the invention, alcohols are included in a pad to reduce the low-shear viscosity and reduce the resistance to flow of the treatment fluids during a desired phase of the treatment.

Abstract: A method of fracturing a formation with a fracturing fluid wherein the formation has particulate material that swells or migrates upon exposure to the fracturing fluid comprises preparing a fracturing fluid comprising (1) a thickening compound comprising a first surfactant selected from the group consisting of a cationic surfactant having only a single cationic group, an amphoteric surfactant and a mixture thereof; and, an anionic surfactant; and, (2) water, wherein no or essentially no inorganic salt is added to the fracturing fluid; and using the fracturing fluid to fracture the formation. A method for recycling a fracturing fluid is also provided.

Abstract: A class of quaternary ammonium compounds are found to be effective as corrosion inhibitors. These quaternary ammonium compounds may be used alone or in combination with additional components. For example, phosphate esters can be used with the quaternary ammonium compounds. Moreover, thiocarbonyl compounds can also be added to the corrosion inhibitor compositions. These corrosion inhibitors are effective against ferrous metal corrosion, especially under downhole conditions.

Abstract: An improved method and fracturing fluid for hydraulic fracturing of a subterranean formation, the fracturing fluid comprising a surfactant, a water soluble or dispersible anionic organic salt, an acid and a low molecular weight organic solvent.

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: An environmentally friendly corrosion inhibiting formulation for the oil-water interface of pipe lines and oil well drilling systems which is prepared pursuant to a process including the steps of reacting an acid selected from the group consisting of a fatty acid anhydride and a 21 carbon dibasic acid with an amine or imidazoline to form a corrosion inhibitor consisting essentially of a fatty acid derivative; dissolving the inhibitor in a fatty acid oil or ester selected from the group consisting of soybean oil or methyl soya ester; adding water dispersing agents consisting of sulfonates and a long chain ethoxylated alcohol; and adjusting the viscosity with an alcohol comprising isopropanol.

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: Compositions and methods for treating systems, especially oil and/or gas wells, characterized by metal sulfide deposits are provided. Compositions according to the invention generally comprise a thioacid, an amine salt, and a diphosphonic acid. Methods according to the invention may comprise introducing such composition into a system characterized by metal sulfide deposits, or alternatively, introducing into the system individual quantities of the composition components.

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 method of treating a hydrocarbon-containing formation is disclosed.

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: 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 Invention relates to fluids and techniques to optimize/enhance the production of hydrocarbon from subterranean formations (e.g., “completion fluids”), in particular, fluids and techniques are. disclosed and claimed which remove wellbore damage and near-wellbore damage in the form of coating formed from drilling and production-related operations (“filtercake”); the techniques can be applied either by themselves or in conjunction with other completion operations, such as gravel packing; preferred embodiments are chelating agent and enzyme systems in a viscoelastic surfactant (VES) matrix.

Abstract: Non-aqueous base wellbore fluids characterized by enhanced electrical conductivity due to formulation with specified ionic liquids are disclosed. Drilling, completion, and workover methods utilizing the wellbore fluids are also disclosed.

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: The corrosion of metal equipment which is cleaned with an inorganic acid is inhibited by treating the equipment with a corrosion inhibitor composition containing at least one quaternary ammonium compound, a sulfur-containing compound and a nonionic surfactant in a solvent.

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: A method of fracturing a formation with a fracturing fluid wherein the formation has particulate material that swells or migrates upon exposure to the fracturing fluid comprises preparing a fracturing fluid comprising (1) a thickening compound comprising a first surfactant selected from the group consisting of a cationic surfactant having only a single cationic group, an amphoteric surfactant and a mixture thereof; and, an anionic surfactant; and, (2) water, wherein no or essentially no inorganic salt is added to the fracturing fluid; and using the fracturing fluid to fracture the formation. A method for recycling a fracturing fluid is also provided.

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

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: Methods of treating wells for cementing operations and for improving placement of cement in wells containing water swelling clays include treatment of the well with a fluid containing clay precipitating agents capable of coagulating clays in the well. The coagulating fluid can contain quaternary ammonium salts, aqueous salts of potassium or cesium, or silicates as the clay coagulating agent. The coagulating fluids can be applied to convert soft mud cake into hard mud cake prior to placement of cement.

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 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: Liquids comprised solely of anions and cations (“ionic liquids”) are disclosed as novel components of fluids (and techniques relying upon those fluids) for stimulation of hydrocarbon wells. In particular, the fluids disclosed are useful in matrix acidizing. Formation of the ionic liquids of the present Invention is highly exothermic, hence the heat generated can be used, for instance, to melt de-watered drilling fluid in the near-wellbore region of the formation. Further, reaction of the ionic liquids with water results in acid generation; this acid can be used to, for instance, to stimulate a formation, either by conventional matrix acidizing or fracture acidizing. In addition, certain preferred species of the ionic liquids of the present Invention are highly stable solvents, hence they can be used as carrier fluids for highly reactive super acids (e.g., SbF5+HF) in connection with matrix acidizing.

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: 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: The Invention relates to novel fluids and techniques to optimize/enhance the production of hydrocarbon from subterranean formations (e.g., "completion fluids"), in particular, fluids and techniques are disclosed and claimed which remove wellbore damage and near-wellbore damage in the form of coating formed from drilling and production-related operations ("filtercake"); the techniques can be applied either by themselves or in conjunction with other completion operations, such as gravel packing; preferred embodiments are chelating agent and enzyme systems in a viscoelastic surfactant (VES) matrix.

Abstract: The present invention provides an improved metal corrosion inhibitor for use in aqueous acid solutions which is relatively non-toxic and inexpensive. The corrosion inhibitor is a mixture comprised of oligomerized aromatic amines prepared by contacting the still bottoms residue produced in the distillation of quinoline from coal tar with oxygen in the presence of a catalyst.

Abstract: The present invention provides improved methods of treating subterranean formations using borate cross-linking compositions and borate cross-linked well treating fluids. The borate cross-linking compositions are basically comprised of a low viscosity hydrocarbon liquid, an organophillic clay, a slightly water soluble borate, a buffer and a dispersing agent.

Abstract: A method is provided for limiting the inflow of formation water during a well turn around to maximize polymer recovery after a hydraulic fracturing treatment of a formation. The method includes a step for selectively blocking the pore structure in a water-bearing zone and not blocking the pore structure of a hydrocarbon zone at the formation face; performing a hydraulic fracturing treatment using a fluid having a polymer; and turning the well around to recover the polymer. There is also provided a method of acidizing, preferably matrix acidizing, a formation having a hydrocarbon zone and a water-bearing zone. The method includes a step for selectively blocking the pore structure in the water-bearing zone at the formation face to selectively retard migration of acid into the water-bearing zone; and injecting acid into the formation, wherein the acid is diverted from the water-bearing zone to the hydrocarbon zone as a result of the selective blocking step.

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: 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.