Abstract: Coil tubing cleanout fluids comprising a clay are provided. A method may comprise introducing a cleanout fluid into a wellbore wherein the cleanout fluid comprises a carrier fluid and a clay; and entraining solid particles in the cleanout fluid wherein the solid particles are disposed in the wellbore.

Abstract: The present disclosure relates to systems and methods for wellbore pressure control with separated fluid columns. One embodiment is a composition comprising: a base fluid, a hectorite clay, a secondary clay comprising at least one clay selected from the group consisting of an attapulgite clay, a sepiolite clay, a palygorskite clay, and any combination thereof, and a plurality of fibers. Another embodiment is a method comprising: introducing a first fluid into a wellbore; introducing a barrier pill into the wellbore, wherein the barrier pill comprises: a base fluid, a hectorite clay, and a plurality of fibers; and introducing a second fluid into the wellbore.

Abstract: A well treatment fluid comprising a 2-oxo-aldehyde having 3 or more carbon atoms is disclosed herein. Methods to prepare and to utilize the fluid, and to inhibit biological degradation of a well treatment fluid, are also disclosed.

Abstract: The disclosure is directed to polyelectrolyte complex nanoparticles that can be used to deliver agents deep into hydrocarbon reservoirs. Methods of making and using said polyelectrolyte complex nanoparticles are also provided.

Abstract: Water-soluble, hydrophobically associating copolymers which comprise new types of hydrophobically associating monomers. The monomers comprise an ethylenically unsaturated group and a polyether group with block structure comprising a hydrophilic polyalkylene oxide block which consists essentially of ethylene oxide groups, and a terminal, hydrophobic polyalkylene oxide block which consists of alkylene oxides with at least 4, preferably at least 5 carbon atoms.

Abstract: The present invention relates to hollow hydrogel capsules. In various embodiments, the present invention provides a method of treating a subterranean formation with a hollow hydrogel capsule including a hydrogel shell including a hydrolyzed and crosslinked polymerized composition. The hollow hydrogel capsule also includes a hollow interior including at least one component of a downhole composition for subterranean petroleum or water well drilling, stimulation, clean-up, production, completion, abandonment, or a combination thereof. In various embodiments, the present invention provides compositions comprising the hollow hydrogel capsules and methods of making the hollow hydrogel capsules.

Abstract: Methods comprising: providing an aqueous treatment fluid comprising an aqueous fluid, a friction reducing polymer, and an antiflocculation additive; and introducing the treatment fluid into a subterranean formation. Methods of fracturing a subterranean formation comprising: providing an aqueous treatment fluid comprising an aqueous fluid, a friction reducing polymer, and an antiflocculation additive; and introducing the treatment fluid into a well bore penetrating the subterranean formation at rate in the range of from about 30 barrels to about 250 barrels per minute so as to create or enhance one or more fractures in the subterranean formation. Aqueous treatment fluids comprising: an aqueous fluid, a friction reducing polymer in an amount sufficient to reduce friction without forming a gel, and an antiflocculation additive.

Abstract: A particulate suspending agent may be useful for mitigating particulate settling in wellbore applications with high-temperature and/or at near-neutral and higher pH values. Methods of treating a wellbore may include providing a treatment fluid comprising an aqueous liquid, a plurality of particulates, and a particulate suspending agent, wherein the particulate suspending agent comprises a crosslinked polymer particulate formed by a reaction comprising a first monofunctional monomer and an orthoester crosslinker, the orthoester crosslinker comprising an orthoester linkage and at least two crosslinking moieties; and placing the treatment fluid in a wellbore penetrating a subterranean formation.

Abstract: Of the many methods and compositions provided herein, one method includes a method comprising introducing a sealant composition into a well bore that penetrates a subterranean formation, wherein the sealant composition comprises a base fluid, a binder material, and a filler material; and allowing the sealant composition to form a cohesive sealant. One composition provided herein includes a sealant composition comprising a base fluid, a binder material, and a filler material, wherein the sealant composition will form a cohesive sealant.

Abstract: The invention is directed to stable crosslinked water-soluble swellable polymers and methods for making same. More particularly, the invention relates to a composition comprising expandable polymeric particles having anionic sites and labile crosslinkers and stable crosslinkers, said particle mixed with a fluid and a cationic crosslinker that is capable of further crosslinking the particle on degradation of the labile crosslinker and exposure of the anionic sites so as to form a gel. A particularly important use is as an injection fluid in petroleum production, where the expandable polymeric particles are injected into target zone and when the heat and/or suitable pH of the target zone cause degradation of the labile crosslinker and the particle expands, the cationic crosslinker crosslinks the polymer to form a gel, thus diverting water to lower permeability regions and improving oil recovery.

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: Water-soluble, hydrophobically associating copolymers which comprise new types of hydrophobically associating monomers. The monomers comprise an ethylenically unsaturated group and a polyether group with block structure comprising a hydrophilic polyalkylene oxide block which consists essentially of ethylene oxide groups, and a terminal, hydrophobic polyalkylene oxide block which consists of alkylene oxides with at least 4, preferably at least 5 carbon atoms.

Abstract: A method for preventing scale formation during an alkaline hydrocarbon recovery process is disclosed. An aqueous solution (e.g., recovered sea water, water produced from the subterranean reservoir, or a combination thereof) having a concentration of metal cations (e.g., calcium, magnesium) is provided. A stoichiometric amount of an organic complexing agent relative to the concentration of metal cations is introduced into the aqueous solution such that the organic complexing agent forms aqueous soluble cation-ligand complexes with the metal cations. At least one alkaline is introduced into the aqueous solution to form an injection fluid having a pH value of at least 10. The cation-ligand complexes remain soluble in the injection fluid such that scale formation is prevented when the injection fluid is injected into a subterranean reservoir.

Abstract: Methods of using relative permeability modifiers for the diversion of aqueous fluids during subterranean operations are provided. An embodiment of the present invention provides a method of diverting fluids in a subterranean formation that may comprise providing a treatment fluid comprising an aqueous fluid and a relative permeability modifier that comprises water-soluble polymer with hydrophobic or hydrophilic modification; introducing the treatment fluid into a well bore that penetrates the subterranean formation; and at least a first portion of the treatment fluid to penetrate into a portion of the subterranean formation so as to substantially divert a second portion of the treatment fluid or another aqueous treatment fluid to another portion of the subterranean.

Abstract: A process for achieving enhanced levels of friction reduction in high salinity conditions, particularly suited to slick-water hydraulic fracturing and coiled tubing applications, uses low charge and preferably uncharged water soluble high molecular weight polymers. A fracturing fluid is injected into a conduit. The fracturing fluid is an aqueous solution comprising at least one water soluble (co)polymer comprising less than 10 mol % ionic monomer(s), and the aqueous solution comprises total dissolved salts concentration ranging from 100,000 mg/L to up to the salt concentration at which the aqueous solution becomes saturated in salts.

Abstract: Methods for scale inhibition treatment of oil or gas production wells generally include injecting a scale inhibition composition into the oil or gas production well, wherein the scale inhibition composition comprises one or more polymers, each polymer comprising recurring units of a first monomer and a second monomer, wherein: (i) the first monomer is selected from maleic acid, maleic anhydride, fumaric acid, acrylic acid, salts thereof, or combinations thereof; and (ii) the second monomer is selected from vinyl sulfonic acid, allyl sulfonic acid, methallylsulfonic acid, salts thereof, or combinations thereof; wherein the concentration of the polymers in the composition is about 10 to about 60 percent of the polymers by weight of the composition; and wherein the composition has a pH of about 7 to about 8.5.

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: The invention relates to a copolymer having: A) at least one monomer unit a) derived from at least one ethylenically unsaturated aliphatic monocarboxylic or polycarboxylic acid, a corresponding anhydride, or a corresponding water-soluble salt; B) at least one monomer unit b) derived from a particular sulfonated or sulfated ethylenically unsaturated ether or at least one monomer unit (b?) derived from a sulfonated ethylenically unsaturated monomer other than (b), C) at least one monomer unit (c) derived from a monomer with the average general formula [CH2?CH—CH2—R6—O—]xP(?O)(OM)3-x. The invention also relates to a method for preparing such a copolymer, an inhibitor composition including such a copolymer, and a method for inhibiting inorganic deposits in a petroleum reservoir by means of said inhibitor composition.

Abstract: A process is proposed for blocking underground formations in the extraction of fossil oil and/or gas, a first step involving introducing water-absorbing particles into liquid-bearing and porous rock formations, said particles being water-swellable, crosslinked and water-insoluble polymers, said particles in the water-bearing rock formation finally preventing liquid flow through the rock layers by water absorption. This process is characterized in that the absorbing particles comprise a superabsorbent polymer with anionic and/or cationic properties and a retarded swelling action. This process, which can also be carried out in saline formation waters, is notable in that the swelling of the superabsorbents used begins no earlier than after five minutes and in that the superabsorbents are obtainable by four proposed process variants and any combination thereof.

Abstract: Methods and compositions are provided that relate to well bore treatments that comprise swellable particles. An embodiment includes a method that comprises introducing a fluid comprising a dual oil/water-swellable particle into a subterranean formation. Another embodiment includes a method of cementing that comprises: introducing a cement composition comprising cement, water, and a dual oil/water-swellable particle into a space between a pipe string and a subterranean formation; and allowing the cement composition to set in the space. Another embodiment includes a well treatment composition comprising a dual oil/water-swellable particle.

Abstract: Methods for treating formations bearing brine and at least one of black oil or volatile oil using a composition containing a nonionic polymer and solvent. The solvent at least one of solubilizes or displaces at least one of brine or oil in the formation. Methods for making a composition for treating a formation bearing brine an at least one of black oil or volatile oil are also disclosed.

Abstract: A fluid comprising a viscous hyposaline aqueous solution of first and second cationic polymers comprising quaternized ammonium groups, wherein the first cationic polymer comprises a hydrophilic base polymer structure and the second cationic polymer comprises a lipophilic base polymer structure, and a method comprising introducing the viscous fluid into an initial first interval of a subterranean formation, and diverting with the viscous fluid a treating fluid from the initial first interval to an initial second interval. The fluid and method are useful to modify a hydrocarbon reservoir formation for improved relative permeability of oil with respect to water to enhance hydrocarbon production from the reservoir.

Abstract: A method of reducing fluid loss from a wellbore that includes emplacing a fluid loss pill in the wellbore, the fluid loss pill comprising: a base fluid; a hydratable or solvatable synthetic copolymer having at least one crosslinkable comonomer; and a crosslinking agent is disclosed.

Abstract: A fluid loss pill that includes a crosslinked polymer gel, a brine, and solid salt particles disposed in said gel is described. Further, a method for reducing fluid loss that includes pumping a selected amount of a fluid loss pill into a wellbore leading to an oil-condensate-, or gas-producing formation, the fluid loss pill including a crosslinked polymer gel, a brine, and solid salt particles disposed in said gel is described.

Abstract: A method of recovering crude oil from a subterranean hydrocarbon containing formation which comprises (a) injecting into said formation an aqueous solution containing an effective amount alkali metal, alkaline-earth or ammonium salts of alcohol ether sulfonates derived from unsaturated alcohol ethers, and (b) displacing said solution into one or more injection wells and recovering the oil from one or more production wells. The unsaturated alkoxylated alcohol contain various amounts of ethylene oxide, propylene oxide and butylene oxides elected to optimize their interfacial properties with different types of crude oil with different brines.

Abstract: A downwell packer assembly includes a tubular member and a packer element mounted on the tubular member. The packer element comprises a composition that includes a polymer. The packer element includes micropores (typically created via a blowing agent). When the packer element is exposed to a swelling fluid, such as water or hydrocarbon, the micropores can help to control and, in some instances, increase the rate of swelling. Such swelling enables the packer element to form a seal against the walls of the wellbore.

Abstract: This invention is based upon the finding that certain chlorosulfonated ?-olefin copolymers can be beneficially utilized in drilling fluids that are utilized in drilling subterreanean wells. For instance, it has been unexpectedly found that certain chlorosulfonated ?-olefin copolymers can be beneficially used as total or partial replacements for organoclays in oil based drilling fluids. The chlorosulfonated ?-olefin copolymers that are useful in the practice of this invention are typically chlorosulfonated ethylene/octene copolymers or chlorosulfonated ethylene/butene copolymers. The chlorosulfonated ?-olefin copolymers will contain from 0.2 to 5 weight percent sulfur. The utilization of chlorosulfonated ?-olefin copolymers in oil-based drilling fluids offers (1) long service life at high operating temperatures, (2) minimal formation damage, (3) improved filtration behavior, and (4) highly effective performance at low viscosifier levels.

Abstract: A method of treating a hydrocarbon containing formation is described. The method includes providing a hydrocarbon recovery composition to the hydrocarbon containing formation. The hydrocarbon recovery composition includes a branched internal olefin sulfonate having an average carbon number of at least 15 and an average number of branches per molecule of at least about 0.8.

Abstract: A water-based drilling fluid having a polymer latex capable of providing a deformable latex film on at least a portion of a subterranean formation has been discovered to provide reduced drilling fluid pressure invasion when used to drill in shale formations for hydrocarbon recovery operations. A precipitating agent such as a silicate or an aluminum complex (e.g. sodium aluminate) is preferably used in conjunction with the polymer. Typically, the water present contains a salt to form a brine, often to saturation, although the invention may be practiced with fresh water. If a salt is employed, it is often helpful to additionally employ a surfactant, such as a betaine, for example.

Abstract: Compositions comprise nonionic fluorinated polymeric surfactants and solvent. The solvent comprises: at least one of a polyol or polyol ether, wherein the polyol and polyol ether have from 2 to 10 carbon atoms; and at least one monohydroxy alcohol, ether, or ketone having from 1 to 4 carbon atoms, or a mixture thereof, wherein the solvent is capable of at least one of solubilizing or displacing brine or condensate in the hydrocarbon-bearing clastic formation. Embodiments of the compositions are useful in recovery of hydrocarbons from hydrocarbon-bearing clastic formations that contain brine and/or condensate.

Abstract: A method of inhibiting scale formation in a subterranean formation comprising: (a) injecting a suspension comprising particles of a controlled release scale inhibitor suspended in an aqueous medium into a formation through an injection well wherein the particles have a mean diameter of less than 10 microns, preferably less than 5 microns, more preferably less than 1 micron; (b) allowing the suspension to percolate through the subterranean formation towards a production well; and (c) controllably releasing the scale inhibitor from the particles in the near well bore region of the production well. Suitably, the particles of the controlled release scale inhibitor comprise an esterifiable scale inhibitor cross-linked with a polyol via ester cross-links.

Abstract: Water soluble associative polymers and compositions comprising them together with alkali metal salts of carboxylic acid are disclosed. Methods comprise introducing into a wellbore a fluid comprising such associative polymers and alkali metal salts of carboxylic acid, e.g., cesium formate. Disclosed water soluble associative polymers have functionality including at least sulfonate groups, carboxylate groups and hydrophobes associative with one another in a saturated aqueous solution of an alkali metal salt of a carboxylic acid.

Abstract: Barium sulfate and/or calcium carbonate scale inhibitor composition composed of a water-soluble polymer having incorporated phosphate functionality, the polymer being formed from at least one ethylenically unsaturated carboxylic acid monomer, at least one ethylenically unsaturated vinyl sulfonate monomer, or a mixture thereof. The scale inhibitor composition can be used as a means of detecting inhibitor composition in downhole and topside oilfield treatments by means that are faster and more accurate than turbidometric measurement.

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: Methods and compositions for cementing subterranean zones penetrated by well bores are provided. The methods are basically comprised of the steps of providing a cement composition which comprises a hydraulic cement, sufficient water to form a slurry and a dispersing agent comprising a tetrapolymer formed of methacrylic acid, methacrylate, methallyl sulfonic acid and ethoxylated acrylic acid. The cement composition is placed in the subterranean zone to be cemented and allowed to set into an impermeable solid mass therein.

Abstract: The present invention relates to an aqueous fluid useful for the recovery of a liquid hydrocarbon from subterranean reservoirs comprising an aqueous media and a surfactant blend. The aqueous fluid has an alkaline pH. The surfactant blend comprises at least one synthetic polyisobutylene surfactant and at least one secondary surfactant selected from the group consisting of sulfonate surfactants, alcohols and nonionic surfactants. The surfactant blend lowers the interfacial tension between hydrocarbon oil and the aqueous fluid.

Abstract: An oil field production chemical, especially a scale inhibitor, is in the form of particles thereof carrying a coating e.g. of a dispersing agent. The coating may be polymeric such as an oligomeric polyacid polyester, a polymeric alkoxylated alcohol or a fatty acid polyamine condensate or it may also be a surfactant and may be used in the form of a suspension in an inert oil, such as diesel oil or kerosene which may be injected into a subterranean formation to inhibit the formation of deposits, e.g. scale in oil wells over a longer period than compounds free of the coating.

Abstract: The present invention provides methods of preventing the flow of water or gas or both through a subterranean zone having a high temperature and a depth such that a long pumping time is required to place a sealing composition therein. The methods basically comprise the steps of preparing a polymeric sealing composition comprised of water, a cross-linking agent and a selected water-soluble polymer which reacts with the cross-linking agent and forms a sealing gel which is stable for a desired period of time at the temperature of the zone and has a pumping time before gelation in the presence of the cross-linking agent whereby the composition can be pumped to the depth of the zone and placed therein. Thereafter, the sealing composition is pumped into the zone and allowed to form a sealing gel therein.

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: Methods and compositions for cementing subterranean zones penetrated by well bores are provided. The methods are basically comprised of the steps of providing a cement composition which comprises a hydraulic cement, sufficient water to form a slurry and a dispersing agent comprising a tetrapolymer formed of methacrylic acid, methacrylate, methallyl sulfonic acid and ethoxylated acrylic acid. The cement composition is placed in the subterranean zone to be cemented and allowed to set into an impermeable solid mass therein.

Abstract: The present invention provides a water-based fluid, in particular for drilling, completion or for any other intervention in a well such as a hydrocarbon well, in which the viscosity is controlled by a system constituted by precipitated silica nanoparticles (A) associated with a water-soluble copolymer (B) comprising one or more water-soluble co-monomers (I) having little or no affinity for silica and one or more co-monomers (II) which absorb onto the silica. The invention is of particular application to the secondary recovery of hydrocarbons.

Abstract: A barium sulfate and/or calcium carbonate scale inhibitor composition is presented composed of a water-soluble polymer having incorporated phosphate functionality, the polymer being formed from at least one ethylenically unsaturated carboxylic acid monomer, at least one ethylenically unsaturated vinyl sulphonate monomer, or a mixture thereof. The scale inhibitor composition can also be used as a means of detecting the inhibitor composition in downhole and topside oilfield treatments by means that are faster and more accurate than turbidometric measurement.

Abstract: What is disclosed is the preparation and use of synthetic water soluble copolymers useful in modifying the water permeability characteristics of subterranean hydrocarbon producing formations. The copolymers are in the form of dilute, pumpable, homogeneous, aqueous solutions and comprise a crosslinked synthetic copolymerizate with intramolecular and intermolecular crosslinking in a non-gelled state and a molecular size/shape corresponding to a K-value of 220-450.

Abstract: An oil field production chemical, especially a scale inhibitor, is in the form of particles thereof carrying a coating e.g. of a dispersing agent. The coating may be polymeric such as an oligomeric polyacid polyester, a polymeric alkoxylated alcohol or a fatty acid polyamine condensate or it may also be a surfactant and may be used in the form of a suspension in an inert oil, such as diesel oil or kerosene which may be injected into a subterranean formation to inhibit the formation of deposits, e.g. scale in oil wells over a longer period than compounds free of the coating.

Abstract: A composition containing a chelating agent and an amino carboxylic acid and a method for breaking a gel formed by a crosslinkable polymer and a crosslinking agent. The composition may also be used for selectively removing crosslinked polymer gels from an oil-bearing zone in a subterranean formation in the presence of a water formation plugged by a crosslinkable polymer and a crosslinking agent. Aqueous solutions of phosphonates and sulfonates are also useful in the method.

Abstract: The invention concerns a water-based additive for well fluid, comprising an acrylamide and branched styrene sulphonate copolymer. It also concerns a water-based fluid comprising an acrylamide and branched styrene sulphonate copolymer. The additive is useful for controlling the filtering of a well fluid through the wall. The invention is advantageously applicable to drilling and/or completion of oil wells having a temperature higher than 120° C.

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

Abstract: Spacer fluids comprising a dispersant selected from the group consisting of water soluble polymers comprising allyloxybenzene sulfonate or allyloxybenzene phosphonate polymerized with at least one of acrylic acid, acrylamides, alkyl acrylamides, maleic anhydride, itaconic acid, sulfonated or phosphonated styrene, sulfonated or phosphonated vinyl toluene, sulfonated or phosphonated isobutylene, acrylamidopropane sulfonate or acrylamidopropanephosphonate, vinyl alcohol, sulfonated or phosphonated propene and alkali metal, alkaline earth metal and ammonium salts thereof and water with optional additional components such as surfactants, viscosifiers and wetting materials to form a rheologically compatible spacer fluid for use between a drilling fluid and a cement slurry and a method for using such spacer fluids to displace drilling fluids from a wellbore space with a cement slurry.

Abstract: For controlling the dispersion of solids, e.g., cuttings, in water-based fluid used during operations such as drilling, completion or workover operations in a well crossing at least one permeable geologic formation, there is added to the fluid an optimized amount of a water soluble polymer HM PAM based on acrylamide and hydrophobic units. In a variant, a useful amount of hydrophobically modified cellulose derivative, e.g., modified hydroxyethylcellulose, HMHEC, is also added, thus forming a fluid containing HM PAM and HM HEC. The process has particular application to slim-hole and/or strongly deviated drilling.

Abstract: Oil or water based drilling muds, together with other wellbore contaminants such as pipe thread sealants and lubricants are displaced from the well and the wellbore surfaces are cleaned by a system of four serially pumped fluid pills. The first stage fluid pill is a weighted spacer having an alkyl polyglycoside surfactant, a dispersant, a weighting agent and a viscosifier. The second stage pill is a drive fluid formed by water and a viscous polymer gel such as clarified xanthan gum having a viscosity/shear rate characteristic which minimizes mixing of the drive fluid pill with the displacement fluid pill. A buffer fluid pill comprising completion brine is interposed between the drive fluid pill and a fourth stage comprising a wash fluid pill using an organic solvent or a caustic alkyl polyglycoside as a final cleaning stage. The densities of the pills are controlled to minimize mixing and fingering of one pill into the other.