Abstract: An aqueous formulation for slick water fracturing includes (i) a polymer (AA) which includes acrylamido repeat units and may be a polyacrylamide; (ii) water; and (iii) a quaternary ammonium compound.

Abstract: A crosslinked polymer comprising reactants of a first repeating unit, a second repeating unit, and a crosslinker that react to form the crosslinked polymer, wherein the first repeating unit is a sulfonic acid-containing monomer present from 50% to 99% by weight of the reactants, wherein the second repeating unit is selected from the group consisting of an N-vinyl amide-containing monomer, a terminal double bond-containing monomer, and any combination thereof, and is present from 1% to 50% by weight of the reactants, and wherein the crosslinker comprises at least two olefinic bonds, and is present in the range of about 9% to about 25% by weight of the reactants.

Abstract: The present invention relates to a method to prepare a rheological agent comprising the polymerization of the following monomers: (a) at least one styrene-based monomer, (b) at least one (meth)acrylate-based monomer or butadiene, and (c) optionally a copolymerisable surfactant containing an optionally substituted vinyl function and moieties derived from propylene oxide and/or ethylene oxide, optionally in the presence of a non polymerisable surfactant containing moieties derived from propylene oxide and/or ethylene oxide, and optionally in the presence of another surfactant, wherein at least the copolymerisable surfactant or the non polymerisable surfactant is present during the said polymerization, as well as a rheological agent obtainable by said method, an oil-based drilling fluid containing such a rheological agent, the use of such a rheological agent as a thixotropic agent in an oil-based drilling fluid and a method of drilling using an oil-based drilling fluid containing such a rheological agent.

Abstract: The present invention relates to a method to reduce the water loss in slurries and solutions used in oil field or gas field operations, for example for drilling, cementing and completion operations by adding a copolymer having a high molecular weight characterized by a K value of at least 300, said copolymer comprising structural units derived from monomers having sulfonic acid or derivative thereof, phosphonic acid or derivative thereof and acrylamide functionality.

Abstract: A method comprising introducing a treatment fluid into a subterranean formation, wherein the treatment fluid comprises a base fluid and a crosslinked polymer, the crosslinked polymer comprising reactants of a first repeating unit, a second repeating unit, and a crosslinker that react to form the crosslinked polymer, wherein the first repeating unit is a sulfonic acid-containing monomer present from 50% to 99% by weight of the reactants, wherein the second repeating unit selected from the group consisting of an N-vinyl amide-containing monomer, a terminal double bond-containing monomer, and any combination thereof, and is present from 1% to 50% by weight of the reactants, and wherein the crosslinker comprises at least two olefinic bonds.

Abstract: The present invention relates to the field of shale inhibitors for drilling fluids, and discloses a shale inhibitor, a method for producing the shale inhibitor, a water-based drilling fluid, and a shale gas drilling and extraction method, wherein, the shale inhibitor contains structural units A represented by formula (I), optional structural units B represented by formula (II) and structural units C represented by formula (VIII), where, n is an integer within a range of 0-3; the shale inhibitor is an amino-terminated hyperbranched polymer; the quantity ratio of the structural units A to the structural units B to the structural units C is m:(m?1):(2m+2), wherein m is an integer within a range of 1-10.

Abstract: The present invention relates to the technical field of petroleum drilling, specifically provides an encapsulating agent and preparing method thereof, and a drilling fluid, wherein the encapsulating agent comprises an acrylamide monomer structure unit represented by formula (I), an anti-temperature monomer structure unit represented by formula (II) and an cation monomer structure unit represented by formula (III); wherein R1 and R2 are each independently H, and linear or branched alkyl of C1-C15, and R3 is H or the linear or branched alkyl of C1-C5. The drilling fluid provided in the present invention has strong inhibition property and stable rheological property.

Abstract: A method of transmitting a fluid into an oil well bore including the steps of providing a frame supporting a vessel, the vessel having an interior, upper and lower end portions, a conically shaped side wall, and an outlet for discharging the fluid from the vessel. Further including the steps of adding a viscous polymeric material to the vessel interior, placing a discharge pipe having a vertical section below the vessel wherein the discharge pipe is in communication with the outlet, placing a positive displacement pump within the discharge pipe wherein the pump transmits fluid from the outlet into the discharge pipe downstream of the vertical pipe section, and selectively transmitting fluid to either the vessel interior (for recirculating) or into the well. Air is added to the discharge flow line downstream of the pump. Preferably, the vessel contains a flexible bladder/bag that holds the material to be pumped.

Abstract: The present subject matter relates to the drilling fluid field, and discloses a viscosifier for oil-based drilling fluids and a method for preparing the viscosifier for oil-based drilling fluids. The preparation method comprises the following steps: (1) mixing an initiator with an unsaturated amide, an unsaturated organic sulfonic acid, and an unsaturated organic carboxylic acid in an aqueous phase solution and initiating a polymerization reaction with an oil phase solution that contains emulsifier and base oil, to obtain a polymer emulsion; (2) purifying and drying the polymer emulsion to obtain a composition; (3) mix the composition, sepiolite powder, and an acid while stirring, and then drying the obtained mixture. The viscosifier for oil-based drilling fluids disclosed in the present subject matter can make up for the shortage of viscosifiers for oil-based drilling fluids in the art, and has favorable temperature tolerance property, viscosity improvement property and environmental friendliness.

Abstract: Zwitterionic polymers having adhesive groups, methods for making the polymers, surfaces having the polymers grafted thereto and grafted therefrom, and methods for making and using the polymer-modified surfaces.

Abstract: A method is provided for use in various well services, the method including the steps of: (a) forming or providing a well fluid comprising cellulose nanowhiskers; and (b) introducing the well fluid into a well. The method can be used, for example, for increasing the strength of a cement, for increasing the viscosity of a water-based well fluid, such as for a kill pill, a fracturing fluid, a gravel packing fluid.

Abstract: Fluid treatment systems and compositions are provided including (a) at least one material including (1) at least one carboxylic acid functional group and (2) at least one sulfur-containing group selected from the group consisting of sulfonyl functional groups, sulfonate functional groups and mixtures thereof; and (b) at least one scale control agent. The fluid treatment systems and compositions can be used to treat aqueous systems, for example as fracturing fluids for treating aqueous compositions found in subterranean formations. Methods for inhibiting formation and/or precipitation of calcium salts in an aqueous composition using the fluid treatment systems or compositions also are provided.

Abstract: Fluid treatment systems and compositions are provided including (a) at least one material including (1) at least one carboxylic acid functional group and (2) at least one sulfur-containing group selected from the group consisting of sulfonyl functional groups, sulfonate functional groups and mixtures thereof; and (b) at least one friction reducing agent selected from the group consisting of guar gums, polyacrylamides, hydratable cellulosic materials, viscoelastic surfactants, and mixtures thereof. The fluid treatment systems and compositions can be used to treat aqueous systems, for example as fracturing fluids for use in fracturing subterranean formations. Methods for inhibiting formation and/or precipitation of metal oxides in an aqueous composition using the fluid treatment systems or compositions also are provided.

Abstract: A aqueous solution that includes water, from 100,000 to 300,000 ppm of dissolved solids, from 0.5 to 3 gallons per thousand gallons of a water-in-oil emulsion, and an inverting surfactant. The water-in oil emulsion includes an oil phase and an aqueous phase where the oil phase is a continuous phase comprising an inert hydrophobic liquid and the aqueous phase is present as dispersed distinct particles in the oil phase. The aqueous phase contains water, a water soluble polymer, and surfactants. The water soluble polymer includes 30 to 50 weight percent of a non-ionic monomer, 5 to 15 weight percent of a sulfonic acid containing monomer, and 40 to 60 weight percent of a cationic monomer. The water soluble polymer makes up from 10 to 35 weight percent of the water-in-oil emulsion.

Abstract: Methods of stabilizing water-sensitive clays in subterranean formations may include introducing a drill-in treatment fluid into at least a portion of a subterranean formation comprising water-sensitive minerals, where providing the drill-in treatment fluid comprises an aqueous-based fluid and a hydrophobically-modified cationic polymer; and allowing the hydrophobically-modified cationic polymer to at least partially coat the water-sensitive mineral.

Abstract: Aqueous and substantially anhydrous fluids having particularly low thermal conductivities and variable densities are disclosed. The fluids include: one or more organic and/or inorganic salts and at least one aprotic polar organic solvent, a mixture of aprotic and protic polar organic solvents, and/or a polar organic solvent having both protic and aprotic polar functional group linkages. The fluids optionally include one or more viscosifying agents and are free of cross-linking agents. Methods for formulating and using the fluids are also disclosed.

Abstract: Fluid treatment systems and compositions are provided including (a) at least one material including (1) at least one carboxylic acid functional group and (2) at least one sulfur-containing group selected from the group consisting of sulfonyl functional groups, sulfonate functional groups and mixtures thereof; (b) at least one friction reducing agent selected from the group consisting of guar gums, polyacrylamides, hydratable cellulosic materials, viscoelastic surfactants, and mixtures thereof; and (c) at least one scale control agent. The fluid treatment systems and compositions can be used to treat aqueous systems, for example as fracturing fluids for treating aqueous compositions found in subterranean formations. Methods for inhibiting formation and/or precipitation of metal oxides in an aqueous composition using the fluid treatment systems or compositions also are provided.

Abstract: Various embodiments disclosed relate to a composition including a crosslinkable ampholyte polymer or a crosslinked product of the same, methods of making and using the composition, and systems including the composition. In various embodiments, the present invention provides a method of treating a subterranean formation. The method can include obtaining or providing a composition including a crosslinkable ampholyte polymer. The crosslinkable ampholyte polymer can include an ethylene repeating unit including a —C(O)NH2 group, an ethylene repeating unit including a —S(O)2OR1 group, and an ethylene repeating unit comprising an —N+R23X? group. At each occurrence, R1 can be independently selected from the group consisting of —H and a counterion. At each occurrence, R2 can be independently substituted or unsubstituted (C1-C20)hydrocarbyl. At each occurrence, X? can be independently a counterion. The composition can also include at least one crosslinker.

Abstract: Methods of treating flowback water from a subterranean formation penetrated by a well bore are provided, comprising: (a) providing remediated flowback water having a ferrous iron (Fe+2) ion concentration of less than about 100 milligrams of ferrous iron ion per liter of flowback water, a barium ion (Ba+2) concentration of less than about 500 milligrams of barium ion per liter of flowback water, and a calcium ion (Ca+) concentration of at least about 1,000 milligrams of calcium ion per liter of remediated flowback water; and (b) treating the flowback water with: (i) at least one friction reducing agent; and (ii) at least one scale formation inhibiting agent and/or at least one iron precipitation control agent to provide treated flowback water which can be reused as fracturing fluid in a well drilling operation.

Abstract: A method of producing treated liquid hydrocarbons. The method begins by pressurizing a latex in a pressure vessel. This is followed by flowing the latex from the pressure vessel into a pipeline containing liquid hydrocarbons to produce treated liquid hydrocarbons. In this embodiment the latex comprises a drag reducing polymer.

Abstract: A copolymer and preparation method and application thereof are disclosed. The copolymer is random copolymer obtained from monomers consisting of acrylamide, acrylic acid, alkenyl sulfonate, 2-acrylamido-dodecyl sulfonate, p-styrene sulfonate or isoprene sulfonate and so on. The copolymer of present invention can be used as fluid loss additive and has good fluid loss properties, which would not make the drilling fluid thicken at high temperature of 200° C. and high salt conditions of saturated brine. It has a medium-pressure fluid loss after aging and rolling for 16 h at high temperature of 200° C., as measured in accordance with the American Petroleum Institute Standard Test at room temperature, and has good properties of high temperature-resisting and salt-resisting.

Abstract: A method begins by obtaining a slipstream of a liquid. The slipstream of liquid is then mixed upstream of an injection pump with a latex comprising a drag reducing polymer to produce a drag reducing mixture. The drag reducing mixture is then injected into a liquid hydrocarbon to produce a treated liquid hydrocarbon.

Abstract: A salt-tolerant, thermally-stable rheology modifier and, in particular, a rheology modifier for applications in oil-field well-bore fluids. In accordance with one aspect, the rheology modifier comprises a terpolymer of acrylamide, 2-acrylamido-2-methyl-propanesulfonic acid (AMPS) and a long-chain alkyl acrylate wherein the terpolymer is prepared by dispersion polymerization.

Abstract: A drilling fluid is provided that comprises a non-ionic or cationic polymer having general formula I or II. The drilling fluid may be used in drilling or other oilfield operations to prevent or limit the accretion of hydrocarbons to metal components when these are in contact with highly viscous hydrocarbons such as those present in formations containing heavy crude oil or tar sand.

Abstract: Methods of stabilizing water-sensitive clays in subterranean formations may include introducing a drill-in treatment fluid into at least a portion of a subterranean formation comprising water-sensitive minerals, where providing the drill-in treatment fluid comprises an aqueous-based fluid and a hydrophobically-modified cationic polymer; and allowing the hydrophobically-modified cationic polymer to at least partially coat the water-sensitive mineral.

Abstract: An inhibitive water-based polymer mud system and method for using the system in drilling and in stabilizing wellbores is disclosed for use in water sensitive formations as an alternative to oil-based muds. The system comprises a fresh water or salt water base thinned or dispersed with a water soluble, biodegradable polyamide-based copolymer having at least one grafted side chain formed from ethylenic unsaturated compounds. This system is effective and has stable rheology over a broad pH range, even at a near neutral pH of 8.0. The drilling fluids do not contain heavy metals and are rheologically tolerant to contaminants such as cement, anhydrite and sodium and temperatures as high as about 400° F.

Abstract: A method of preparing a drag reducing polymer wherein the drag reducing polymer is able to be injected into a pipeline, such that the friction loss associated with the turbulent flow through the pipeline is reduced by suppressing the growth of turbulent eddies. The drag reducing polymer is injected into a pipeline of liquid hydrocarbon hydrocarbon having an asphaltene content of at least 3 weight percent and an API gravity of less than about 26° to thereby produce a treated liquid hydrocarbon wherein the viscosity of the treated liquid hydrocarbon is not less than the viscosity of the liquid hydrocarbon prior to treatment with the drag reducing polymer. The drag reducing polymer has a solubility parameter within 4 MPa1/2 of the solubility parameter of the liquid hydrocarbon. The drag reducing polymer is also added to the liquid hydrocarbon in the range from about 0.1 to about 500 ppmw.

Abstract: A method of introducing a drag reducing polymer into a pipeline such that the friction loss associated with the turbulent flow though the pipeline is reduced by suppressing the growth of turbulent eddies. The drag reducing polymer is introduced into a liquid hydrocarbon having an asphaltene content of at least 3 weight percent and an API gravity of less than about 26° to thereby produce a treated liquid hydrocarbon. The treated liquid hydrocarbon does not have a viscosity less than the viscosity of the liquid hydrocarbon prior to treatment with the drag reducing polymer. Additionally, the drag reducing polymer is added to the liquid hydrocarbon in the range from about 0.1 to about 500 ppmw.

Abstract: A method of introducing a drag reducing polymer into a pipeline such that the friction loss associated with the turbulent flow though the pipeline is reduced by suppressing the growth of turbulent eddies. The drag reducing polymer is introduced into a liquid hydrocarbon having an asphaltene content of at least 3 weight percent and/or an API gravity of less than about 26° to thereby produce a treated liquid hydrocarbon. The treated liquid hydrocarbon does not have a viscosity less than the viscosity of the liquid hydrocarbon prior to treatment with the drag reducing polymer. Additionally, the drag reducing polymer is added to the liquid hydrocarbon in the range from about 0.1 to about 500 ppmw.

Abstract: Lubricants and drilling fluid systems comprising lubricants which form a coherent lubricating film on metal equipment, thereby prolonging equipment life even under a wide variety of conditions, including high temperature and/or high pressure conditions.

Abstract: A well treatment composition comprises: a water-soluble, organic liquid, wherein the organic liquid: (A) comprises the continuous phase of the well treatment composition; and (B) comprises a polyglycol or a derivative of polyglycol; a fluid loss additive, wherein the fluid loss additive: (A) is insoluble in the organic liquid; and (B) comprises a high molecular weight, water-swellable polymer; and a suspending agent, wherein the suspending agent comprises an organophilic clay, wherein the well treatment composition has an activity of at least 15%. A method of cementing in a subterranean formation comprises: introducing a cement composition into the subterranean formation, the cement composition comprising: (i) cement; (ii) water; and (iii) the well treatment composition; and allowing the cement composition to set after introduction into the subterranean formation.

Abstract: A method of formulating a wellbore fluid that includes precipitating a weighting agent from a solution; and adding the precipitated weighting agent to a base fluid to form a wellbore fluid is disclosed. Fluids and methods of formulating wellbore fluids that contain dispersant coated precipitated weighting agents are also disclosed.

Abstract: Disclosed herein is a curable composition excellent in workability, adhesion properties, rubber-like properties, storage stability, and quick curability. The curable composition comprises (A) a crosslinkable silyl group-containing organic polymer and (B) a (meth)acrylic polymer obtained by polymerizing a (meth)acrylic monomer having a polymerizable unsaturated bond in the presence of a metallocene compound and a crosslinkable silyl group-containing thiol compound, at least one end of the (meth)acrylic polymer being bonded to a residue, —S—R3 (where R3 represents a group having a crosslinkable silyl group) obtained by removing a hydrogen atom from the crosslinkable silyl group-containing thiol compound.

Abstract: What is proposed is the use of a water-soluble hydrophobically associating copolymer as an additive in the development, exploitation and completion of underground mineral oil and natural gas deposits and in deep drillings, wherein the copolymer comprises (a) at least one monoethylenically unsaturated monomer (a) selected from H2C?C(R1)—R4—O—(—CH2—CH2—O—)k—(—CH2—CH(R3)—O—)l—R5 ??(I), and/or H2C?C(R1)—O—(—CH2—CH2—O—)k—R2 ??(II), and (b) at least one monoethylenically unsaturated, hydrophilic monomer (b) different from monomer (a), wherein the copolymer is obtainable through copolymerization of the monomers (a) and (b) in the presence of at least one surfactant (c).

Abstract: A copolymer containing, as monomer components, a) at least one sulfonic acid-containing compound, b) at least one nitrogen-containing N-vinylamide, one acrylamide or methacrylamide and c) at least one bifunctional or higher-functional vinyl ether is proposed. These copolymers are suitable in particular as thixotropic agents, antisegregation agents and water retention agents and overall as an additive in cement-containing but also gypsum-based systems. Such copolymers having a molecular weight of >40 000 g/mol can be used in particular as admixtures in the exploration of mineral oil and natural gas deposits.

Abstract: A copolymer and preparation method and application thereof are disclosed. The copolymer is random copolymer obtained from monomers consisting of acrylamide, acrylic acid, alkenyl sulfonate, 2-acrylamido-dodecyl sulfonate, p-styrene sulfonate or isoprene sulfonate and so on. The copolymer of present invention can be used as fluid loss additive and has good fluid loss properties, which would not make the drilling fluid thicken at high temperature of 200° C. and high salt conditions of saturated brine. It has a medium-pressure fluid loss after aging and rolling for 16 h at high temperature of 200° C., as measured in accordance with the American Petroleum Institute Standard Test at room temperature, and has good properties of high temperature-resisting and salt-resisting.

Abstract: The invention relates to the use of vinyl phosphonic acid or a salt thereof for improving the biodegradability of mixed polymers, comprising 25 to 99.5% by weight of structural units of one or more monomers selected from the group made of compounds of formula (1) and formula (3), where R1 and R2 independently are hydrogen or C1-C4-alkyl, formula (4), where n is 3, 4, or 5, and formula (5), where X is OH or for NR3R4, and R3 and R4 independently are H or C1 to C4-alkyl, in that 0.5 to 25% by weight of vinyl phosphonic acid is polymerized into the mixed polymer.

Abstract: A system for reducing pressure drop associated with the turbulent flow of asphaltenic crude oil through a conduit. The crude oil has a high asphaltene content and/or a low API gravity. Such reduction in pressure drop is achieved by treating the asphaltenic crude oil with a high molecular weight drag reducing polymer that can have a solubility parameter within about 20 percent of the solubility parameter of the heavy crude oil. The drag reducing polymer can also comprise the residues of monomers having at least one heteroatom.

Abstract: The invention relates to a copolymer including betaininc units and hydrophobic and/or amphiphile units. The invention also relates to a method for preparing a copolymer including betaininc units and hydrophobic and/or amphiphile units, by controlled micellar polymerisation. The invention further relates to the uses of the copolymer. The copolymer is particularly used for increasing the viscosity of saline aqueous compositions.

Abstract: The invention relates to a copolymer containing: i) 80-90% by weight of one or more structural units of the formula A, where R1 is hydrogen or methyl, R2 is C2-C10-alkylene, and Me+ is an ammonium or an alkali metal ion; ii) from 1 to 10% by weight of one or more structural units of the formula B where R3 and R4 are each independently hydrogen, methyl or ethyl; iii) from 1 to 10% by weight of one or more structural units of the formula C, where n is a number from 1 to 6; iv) from 0.1 to 5% by weight of structural units of the formula D where X is hydrogen, an ammonium ion or an alkali metal ion; and optionally, v) from 0 to 10% by weight of one or more structural units of the formula E, where R5 is hydrogen, methyl and/or ethyl, with the proviso that the content in the copolymers of structural units B) and C) is from 6 to 15% by weight.

Abstract: A copolymer based on olefinic sulphonic acids as monomer component a) and an organosilicone-containing compound as reactive component b) is proposed, for which in particular 2-acrylamido-2-methylpropanesulphonic acid (AMPS®) is suitable as component a) and vinyltrimethoxysilane, vinyltriethoxysilane and trichlorosilane as component b). This copolymer, which may have a molecular weight of from 5,000 to 5,000,000 g/mol, may also comprise further reaction components c) and d) in addition to the two main components for which further reaction components (meth)acrylamides or vinyl ethers are suitable. These copolymers, which are obtainable in particular by precipitation or gel polymerizations, are used in particular in applications in construction chemistry and here especially as water retention agents and fluid loss additives in drilling fluids and for well cementing.

Abstract: There is provided a wellbore fluid having a continuous aqueous phase, and comprising at least one polymer which contains both hydrophilic units and hydrophobic units, at least some of said hydrophilic units containing sulfonate groups, and less than 50% by weight of said hydrophilic units comprising —CH2.CH2.O— units; and at least some of said hydrophobic units containing pendant alkyl groups having at least 8 carbon atoms. Such aqueous based wellbore fluids exhibit significantly improved fluid loss properties when used in wellbore operations, such as drilling, completion or workover.

Abstract: Subject matter of the present invention is a drilling fluid additive based on sulfonated asphalt, which comprises a water soluble and anionic polymer component in quantities of 0.1 to 20 wt. %, with respect to the total additive in addition to the asphalt component. With this additive the water solubility of sulfonated asphalt can be markedly increased. This additive, whose polymer component is thermally highly stable, is utilized primarily in water- and/or oil-based drilling fluids and in particular in the exploration of subterraneous petroleum and natural gas deposits. Typical polymer components to consider are representatives of polycondensation products, such as phenol resins, ketone resins and sulfonated naphthalene, acetone and amino plasticizer resins (for example urea and melamine resins).

Abstract: Films that may be created and/or placed in a well bore that prevent the flow of fluid into cracks or fractures in a portion of a subterranean formation penetrated by the well bore, and associated methods of use, are provided. In one embodiment, the methods comprise: providing a treatment fluid that comprises a base fluid and a film-forming polymer; introducing the treatment fluid into a portion of a well bore penetrating a portion of a subterranean formation, the well bore comprising an interior wall; and allowing the film-forming polymer to electrostatically interact with a surface of the interior wall of the well bore to form a substantially continuous film along a portion of the interior wall of the well bore, the substantially continuous film being capable of hindering the flow of a fluid therethrough.

Abstract: A drilling fluid system comprising a brine and a quantity of cationic copolymers comprising a ratio of acrylamide monomers to cationic derivatives of acrylamide monomers, wherein the quantity and the ratio are effective to maintain effective rheology and fluid loss control in said drilling fluid system at temperatures of at least about 250° C. for at least about 16 hours.

Abstract: Provided herein are methods that include In one embodiment, the present invention provides a method comprising: providing an annulus between a first tubing and a second tubing; providing an aqueous-based insulating fluid that comprises an aqueous base fluid, a water-miscible organic liquid, and a synthetic polymer; and placing the aqueous-based insulating fluid in the annulus. Another method provided is a method comprising: providing a tubing comprising a first fluid located within a well bore such that an annulus is formed between the tubing and a surface of the well bore; providing an aqueous-based insulating fluid that comprises an aqueous base fluid, a water-miscible organic liquid, and a synthetic polymer; and placing the aqueous-based insulating fluid in the annulus.

Abstract: The invention relates to novel polymers comprising betaine-type units and to the use of zwitterionic polymers in drilling fluids, for example, as a clay swelling inhibitor and/or as an accretion-inhibiting agent and/or as a fluid-rheology-controlling agent and/or a filtrate-reducing agent and/or a lubricant.

Abstract: The invention concerns modified hydrophobic polyelectrolytes by amide formation of a hydrophilic skeleton by n-alkylamines whereof the alkyl chain comprises 6 to 22 carbon atoms. Preferably, the amide formation is obtained by di-n-dodecylamine. The hydrophilic skeleton is preferably a sodium polyacrylate or polyacrylic acid corresponding to a statistical acrylate-AMPS copolymer. Said polymers can be used for stabilizing direct or invert emulsions likely to be destabilized or inverted by a modification in the degree of salinity of the aqueous phase or a pH modification. The invention is particularly useful for stabilizing oil drilling fluids or the like in particular drilling, fracturation, acidification or completion fluids.

Abstract: Methods of reducing the fluid loss from a wellbore servicing fluid include combining a terpolymer with the wellbore servicing fluid to reduce the fluid loss from the fluid, followed by displacing the fluid into a wellbore. In an embodiment, the following monomers are used to make the terpolymer: from about 75 wt. % to about 95 wt. % of 2-acrylamido-2-methylpropanesulfonic acid or an alkali salt thereof; from about 3 wt. % to about 15 wt. % of acrylamide; and from about 3 wt. % to about 15 wt. % of N-vinyl-2-pyrrolidone, all weight percentages being based on a total weight of the monomers. The wellbore servicing fluid may comprise water or an aqueous salt solution such as a formate solution. The wellbore servicing fluid may also comprise clay such as montmorillonite and attapulgite clay.

Abstract: New polymers, and their applications in water-based wellbore service fluids, such as, for example, drilling fluids, yield desirable filtration control and rheological properties to such fluids even after exposure to HTHP aging. Typical temperatures encountered during such aging are around 350–400° F. and the duration of the exposure is some significant time such as 16 hours or longer. Preferably, the polymers are random terpolymers of N-vinylcaprolactam, vinyl sulfonate monomer 2-acrylamido-2-methyl-1-propanesulfonic acid, and monomer acrylamide, most preferably in a molar ratio of 15:20:65 respectively. The polymers reduce HTHP filtration volumes in fresh water, sea water, potassium chloride, and lime mud systems. The polymers may also be used to inhibit or reduce shale erosion.