Abstract: This invention is directed to a composition comprising expandable cross linked polymeric microparticles having an unexpanded volume average particle size diameter of from about 0.05 to about 10 microns and a cross linking agent content of about 1,000 to less than about 9,000 ppm of labile cross linkers and from 0 to about 300 ppm of non-labile cross linkers and to the use of the composition for modifying the permeability of subterranean formations and increasing the mobilization and/or recovery rate of hydrocarbon fluids present in the formations.

Abstract: A shale-stabilizing additive is described which comprises a copolymer of an olefinically unsaturated hydrocarbon and an ethylenically unsaturated carboxylic acid, carbocylic acid salt or carboxylic acid anhydride with alkylene oxide based side chains. The additive can be used for water-based service fluids (WBM) to facilitate the drilling or completion process in shales or clayey formations.

Abstract: Methods of cementing in wellbores using cement compositions having elasticity or high compressive strength and low permeability are provided. The cement compositions are basically comprised of particulate acid degradable glass, water, at least one water soluble polymerizable alkenoic acid monomer and a water soluble free-radical initiator.

Abstract: Methods and compositions for removing organics solubilized in a water-like fluid (WSO), such as the water produced in connection with the production of hydrocarbons from subterranean formations, are described. Hydrophilic &agr;-hydroxy-monocarboxylic acids (AHAs), such as hydroxyacetic (glycolic) acid, alone or optionally together with anionic polymers, have been found to be effective. The compositions and methods of this invention have reduced corrosion and scale formation problems as compared with other methods employing stronger acids to remove WSO. The AHAs have pKa's of greater than 3.8.

Abstract: It has been found that a large variety of solid chemicals available in a bulk powder form could be added to subterranean treatment fluids with delayed release when said chemicals are delivered as capsules consisting of encapsulated granulates obtained by aggregating the bulk powder under pressure to form a densified material and optionally, dry comminuting said densified material to produce granulates at the desired size. The invention is particularly useful for delivering new types of breaking agents for stimulation fluids or additives for wellbore cementing.

Abstract: A swellable polymer gel composition for use in subterranean formations. The composition comprises water, a water soluble polymer, a water soluble crosslinking system and a swelling agent. The crosslinking system may be either a redox system or a chelating system. The amounts of the polymer and the crosslinking system are effective to form a substantially uniformly reacted tri-dimensional gel structure. To the gel solution, is added a swelling agent in an amount sufficient to increase the volume of the gel a predetermined percentage. The swelling agent may be a natural or a synthetic agent. A strengthening agent may be added to increase the gel strength of the composition. The composition has numerous uses and is particularly useful in oil industry applications such as plugging wells, sealing casing leaks and reducing water production from water-bearing hydrocarbon formations.

Abstract: Methods of consolidating formations or forming chemical casing or both while drilling are provided. One method of the invention comprises drilling a well bore with a drilling fluid comprised of water, a polymeric cationic catalyst which is adsorbed on weak zones or formations formed of unconsolidated clays, shale, sand stone and the like, a water soluble or dispersible polymer which is cross-linked by a thermoset resin and causes the resin to be hard and tough when cured, a particulate curable solid thermoset resin, a water soluble thermoset resin, and a delayed dispersible acid catalyst for curing the solid and water soluble resins. The drilling fluid forms a filter cake on the walls of the well bore that cures and consolidates the unconsolidated weak zones and formations penetrated by the well bore so that sloughing is prevented and forms a hard and tough cross-linked chemical casing on the walls of the well bore.

Abstract: Cementing compositions which are particularly suitable for squeeze cementing operations, comprise an aqueous phase, and a micro-cement, the aqueous phase including an aqueous suspension comprising a vinyl acetate type polymer obtained by chemically cross-linking a polyvinyl compound, a nanolatex and an anionic surfactant with a cloud point of more than 80° C.

Abstract: This invention provides a water-free oil based fluid polymer suspension composition for use as a rheology modifier and fluid loss reducer in oil or gas well servicing fluids. It has been found that by using white medicinal oil as a carrier, high solids content and environmental friendly anhydrous fluidized polymer suspensions of xanthan gum, cellulose ethers, guar gum and derivatives thereof can be prepared. More specifically, in one aspect, an oil-based fluid polymer suspension (FPS) composition for use in oil or gas well servicing fluids is preferred containing: a) a hydrophilic polymer, b) an organophilic clay, c) a stabilizer, and d) a white medicinal oil having selected properties.

Abstract: This invention is directed to a composition comprising expandable cross linked polymeric microparticles having an unexpanded volume average particle size diameter of from about 0.05 to about 10 microns and a cross linking agent content of about 1,000 to less than about 9,000 ppm of labile cross linkers and from 0 to about 300 ppm of non-labile cross linkers and to the use of the composition for modifying the permeability of subterranean formations and increasing the mobilization and/or recovery rate of hydrocarbon fluids present in the formations.

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

Abstract: 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: The invention includes a composition of matter for increasing the viscosity of an aqueous fluid and for recovering oil from a subterranean formation. It also includes methods for making and using the composition.

Abstract: Encapsulated water soluble chemicals for use in controlled time release applications, methods of encapsulating the chemicals and methods of using the encapsulated chemicals are provided. The methods of encapsulating the chemicals are basically comprised of forming a first coating of a dry hydrophobic film forming material or a sparingly soluble material which provides a dry shield on the chemical and then forming a second coating of a porous cross-linked hydrophilic polymer on the first coating which prevents the substantial dissolution of the resulting encapsulated chemical for a selected period of time.

Abstract: Encapsulated water soluble chemicals for use in controlled time release applications, methods of encapsulating the chemicals and methods of using the encapsulated chemicals are provided. The methods of encapsulating the chemicals are basically comprised of forming a first coating of a dry hydrophobic film forming material or a sparingly soluble material which provides a dry shield on the chemical and then forming a second coating of a porous cross-linked hydrophilic polymer on the first coating which prevents the substantial dissolution of the resulting encapsulated chemical for a selected period of time.

Abstract: This invention is directed to a composition comprising expandable cross linked polymeric microparticles having an unexpanded volume average particle size diameter of from about 0.05 to about 10 microns and a cross linking agent content of from about 9,000 to about 200,000 ppm of labile cross linkers and from 0 to about 300 ppm of non-labile cross linkers and to the use of the composition for modifying the permeability of subterranean formations and increasing the mobilization and/or recovery rate of hydrocarbon fluids present in the formations.

Abstract: Herein is described a method of consolidating a subterranean formation or repairing a gravel pack, comprising (i) providing a consolidating fluid, wherein the consolidating fluid comprises a gel component and a gel-forming agent; and (ii) injecting the consolidating fluid into the formation or gravel pack, under conditions wherein the gel component forms a flexible gel, thereby consolidating the formation.

Abstract: A new stable liquid suspension containing non-soluble particles dispersed in a non-aqueous liquid medium having a concentration of a suspension aid and a method of making and use thereof.

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

Abstract: The invention 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: A drilling fluid system for use in oil and gas well drilling operations is described having a rheological modifier/control agent comprising a polyalkyl methacrylate copolymer containing a small amount of vinyl pyrrolidone, a weighting agent, optionally an organophilic clay, with a base fluid making up the balance. The drilling fluid may be oil, invert emulsion, and in particular synthetic base fluid where the continuous phase may be synthetic esters olefins, paraffins, mineral oil or diesel oil, and the like. These copolymers prevent or reduce barite sag and provide cutting transport in these drilling systems.

Abstract: Methods and compositions for reducing the permeabilities of subterranean zones are provided. The methods of the invention are basically comprised of introducing an aqueous composition comprised of a chelated organic gelling agent and a copolymer of an ethylenically unsaturated polar monomer and an ethylenically unsaturated ester or a terpolymer or tetrapolymer of an ethylenically unsaturated polar monomer, an ethylenically unsaturated ester and a monomer selected from AMPS® and/or N-vinylpyrrolidone into the zone and then allowing the aqueous composition to form a cross-linked gel in the zone.

Abstract: A method for reducing the permeability of a region of an underground formation by injecting a gelant solution that forms a stable gel into the region is disclosed. The gelant solution includes an aqueous solvent, about 2% to about 16% by weight of a lignosulfonate-acrylic acid graft copolymer and a sufficient concentration of a crosslinking agent to crosslink the copolymer. The lignosulfonate-acrylic acid copolymer used in the invention has an acrylic acid content of about 10% to about 50% by weight and the crosslinking agent is a complex of one or more positively charged chromium (III) species and one or more negatively charged carboxylate species. Preferably, the chromium (III) species used in the invention has a concentration of about 0.1% to about 8.0% by weight. In one preferred embodiment, the carboxylate species of the crosslinker may be selected from formate, acetate, propionate, lactate, oxalate and malonate.

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

Abstract: Improved performance in the phase separation of aqueous brines from hydrocarbons within an electrostatic desalter operation is obtained by the addition to the crude oil emulsions entering the desalter of an effective asphaltene dispersing amount of an alkyl phenol-formaldehyde liquid resin polymer, optionally in the presence of a lipophilic/hydrophilic vinylic polymer. The preferred resin is a nonyl phenol-formaldehyde resin having a molecular weight of from 1,000-20,000, and the preferred vinylic polymer is a copolymer of lauryl (meth)acrylate and hydroxyethyl (meth)acrylate. Best results from the electrostatic desalter are obtained when also using a demulsifier chemical treatment along with the asphaltene dispersing treatments. Desalter efficiency is increased and desalter brine effluent quality is greatly increased.

Abstract: An aqueous external dispersion comprising a wax dispersant and an organic crystal modifier composition dispersed through a continuous water phase is useful as a crystal modifier for petroleum or a petroleum-derived liquid. The dispersant comprises a non-ionic surfactant and is present in the dispersion in an amount sufficient to impart at least meta-stability to the dispersion. The dispersion has a viscosity at 25.degree. C. of less than about 50,000 centipoise.

Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.

Abstract: Polymeric well completion and remedial compositions which form highly pliable impermeable masses of desired rigidity and methods of using the compositions are provided. The compositions are basically comprised of water, a water soluble polymerizable monomer, a polymerization initiator and an oxygen scavenging agent. The composition is usually foamed and contains a gelling agent and a solid filler material to increase the density and/or rigidity of the impermeable mass formed.

Abstract: Polymeric well completion and remedial compositions which form highly pliable and durable impermeable masses of desired rigidity and methods of using the compositions are provided. The compositions are basically comprised of water, a water soluble polymerizable monomer, a polymerization initiator and an oxygen scavenging agent. The compositions are usually foamed and can contain a gelling agent and a solid filler material to increase the density and/or rigidity of the impermeable mass formed and/or a vulcanizable rubber latex, vulcanizing agent and vulcanizing activator to provide durability and other properties.

Abstract: A method and a drilling fluid/cement slurry composition for cementing a wellbore. The drilling fluid/cement slurry composition comprises A cement slurry composition comprising:a) a cementitious material;b) a drilling fluid; andc) 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, acrylamidopropanephosphonate, vinyl alcohol, sulfonated or phosphonated propene and alkali, alkaline earth and ammonium salts thereof.

Abstract: An aqueous external dispersion comprising a wax dispersant and an organic crystal modifier composition dispersed through a continuous water phase is useful as a crystal modifier for petroleum or a petroleum-derived liquid. The dispersant comprises a non-ionic surfactant and is present in the dispersion in an amount sufficient to impart at least meta-stability to the dispersion. The dispersion has a viscosity at 25.degree. C. of less than about 50,000 centipoise.

Abstract: The present invention provides compositions useful for viscosifying aqueous fluids, methods for making them and methods for using them. In one aspect of the invention, inventive compositions comprise a prehydrating alcohol having at least two hydroxyl groups and having a molecular weight of from about 60 to about 600; an inorganic salt; and a polymer. In a preferred aspect of the invention, the viscosifier composition additionally comprises a solvent having a molecular weight of from about 75 to about 1000. According to another aspect of the invention, inventive compositions comprise a prehydrating alcohol; an inorganic salt; and a polymer; and the composition is essentially free from water. Inventive compositions find advantageous use in viscosifying fluids utilized in subterranean drilling activities such as, for example, drilling, drill-in, completion, hydraulic fracturing, work-over, packer, well treating, testing, spacer, or hole abandonment fluids.

Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.

Abstract: The present invention relates to a method of stabilizing argillaceous rocks containing reactive clays in the presence of water, wherein said argillaceous rocks are placed in contact with an aqueous solution containing a polymer with hydrophilic groups and hydrophobic groups.

Abstract: The invention involves biopolymer/oil suspension compositions for the oil service industry, most particularly drilling and completion fluids, which provide such fluids a variety of desirable properties. Biopolymers include water soluble polymers and water swellable polymers. Such biopolymer/oil suspension compositions are essentially mixtures of biopolymers such as cellulosics in an oil medium with a specific anti-settling additive. The invention is particularly directed to providing enhanced anti-settling properties to such biopolymer/oil compositions; that is, the ability of the biopolymer/oil composition to retain the biopolymers in suspension prior to the composition being introduced into drilling and completion fluids. The invention in one embodiment is described as a liquid biopolymer-in-oil additive compositions for use in aqueous-based completion fluids, containing an agent comprising: a) one or more polyamides, and b) hydrogenated caster oils including castorwax.

Abstract: This invention relates to a composition comprising: a mixture of a brine and a liquid oil, and (A) an emulsifying amount of (i) at least one reaction product of a hydrocarbyl-substituted succinic acylating agent, and at least one of (a) ammonia, (b) an alcohol, (c) an amine, (d) or mixtures thereof, or at least one salt of the reaction product; or (ii) at least one reaction product of a hydroxyaromatic compound, an aldehyde, and an amine. The compositions of the present invention have beneficial emulsification properties. These compositions are useful in drilling, working over and completing well-bore holes. The well-drilling compositions of the present invention have beneficial viscosity, pumping and suspension properties.

Abstract: A method for controlling phosphonates which tend to precipitate with metal ions in water treatment operations comprising, adding to the water a water-soluble copolymer containing one or more of the following monomeric units: ##STR1## in which: R is hydrogen or an alkyl group, R.sub.1 is an alkyl group and X is hydrogen, NH.sub.4.sup.+, a water soluble metal ion or organic base; and[b] a monocarboxylic acid monomer; and adding the copolymer to the water to be treated in an amount sufficient to prevent precipitation of said phosphonates.

Abstract: An improvement in a method for the inhibition of scale deposition on the surfaces of a well coproducing oil and scale forming brines, said method comprising injecting into the well reservoir an acidic aqueous solution at a first pH containing dissolved therein a scale inhibitor, multivalent metal cations, and a heat-sensitive pH-increasing substance which decomposes at elevated temperatures liberating an alkaline compound such that the solution is inherently heated by the higher ambient reservoir temperature to a temperature at which the alkaline compound is liberated from the heat-sensitive substance thus raising the pH of the solution to a point at which a sparingly soluble multivalent metal salt of the scale inhibitor is phase separated from the solution on the porous surfaces of the reservoir rock formation, providing for a slow release of inhibitor into the produced brines when the well is in its production phase.

Abstract: A water-base fluid of optimized composition for solving problems encountered during operations such as drilling, completion or workover operations in a well crossing at least one permeable geologic formation contains (i) a hydrophilic/hydrophobic polymer, (ii) an acrylamide-base polymer of hydrophobic unit, (iii) a hydrophobically modified cellulose derivative, and (iv) a polysaccharide type polymer.The fluid can be used in a process implemented in a well drilled through at least one formation having a given permeability and is for particular application to slim-hole and/or deviated drilling.

Abstract: A composition of matter for matrix conformance formed from an aqueous solution of an alginate polysaccharide and a method of forming an alginate polysaccharide gel. A Group IIA cation, Fe.sup.2+, Fe.sup.3+, Al.sup.3+, Mn.sup.2 +, Zn.sup.2+, a dialdehyde, or a diamine may be used to crosslink the resulting alginate gel. The gel may also comprise a modifier, such as a polyvinyl alcohol, a polycarboxylic acid, or a polyacrylamide. The rate and extent of crosslinking are controlled by varying the alginate molecular weight, the alginate concentration, or the type and concentration of crosslinker, or by adding a sequestering agent such as EDTA or citrate.

Abstract: A method for controlling phosphonates which tend to precipitate with metal ions in water treatment operations comprising, adding to the water a water-soluble copolymer containing one or more of the following monomeric units:[a] ##STR1## in which: R is hydrogen or an alkyl group, R.sub.1 is an alkyl group and X is hydrogen, NH.sub.4.sup.+, a water soluble metal ion or organic base; and[b] a monocarboxylic acid monomer; and adding the copolymer to the water to be treated in an amount sufficient to prevent precipitation of said phosphonates.

Abstract: A blended additive composition, which is useful for thinning aqueous drilling fluids, is disclosed. The composition includes a first component selected from the group including: a modified tannin, a modified lignite and sodium lignosulfonate; a second component being a polymer prepared from acrylic acid; and a third component being a metal compound selected from the group of metals including iron, tin, chromium, manganese, titanium, aluminum and zinc.

Abstract: A method for the inhibition of scale deposition on the surfaces of a well coproducing oil and scale forming brines comprising injecting into the well reservoir an acidic aqueous solution at a first pH containing dissolved therein a scale inhibitor, multivalent metal ions, and a heat-sensitive pH-increasing substance containing no more than 10 carbon atoms, which decomposes at elevated temperatures liberating an alkaline compound such that the solution is inherently heated by the higher ambient reservoir temperature to a temperature at which the alkaline compound is liberated from the heat-sensitive substance thus raising the pH of the solution to a point at which a sparingly soluble multivalent metal salt of the scale inhibitor is phase separated from the solution on the porous surfaces of the reservoir rock formation, providing for a slow release of inhibitor into the produced brines when the well is in its production phase.

Abstract: A gelable composition and process are disclosed that delay the gelation and increase the gel strength of gelled water soluble acrylamide-containing polymers contains: (1) a water dispersible first crosslinking compound selected from the group consisting of p-aminosalicylic acid, furfuryl alcohol, RArOC(O)R' and HOArC(O)OR" wherein Ar represents a phenyl group which can be substituted or non-substituted; R is a hydrogen or a carboxylic group; R' is a C.sub.1 -C.sub.6 alkyl; R" is a hydrogen, a phenyl group, or a C.sub.1 -C.sub.6 alkyl; and when R is a carboxylic group, R and C(O)OR" can be at ortho, meta, or para position with respect to the OC(O)R' group and the OH group, respectively; (2) a water dispersible second crosslinking compound selected from the group consisting of aldehydes and aldehyde-generating compounds; (3) a water soluble acrylamide-containing polymer; and (4) water.