Abstract: The present disclosure is directed to compositions and methods for enhanced oil recovery, for modifying the permeability of subterranean formations and for increasing the mobilization and/or recovery rate of hydrocarbon fluids present in the formations. The compositions may include, for example, expandable cross-linked polymeric microparticles having unexpanded volume average particle size diameters of from about 0.05 to about 5,000 microns and cross linking agent contents of from about 100 to about 200,000 ppm of labile cross linkers and from 0 to about 300 ppm of non-labile cross linkers that may be used in combination with other components such as, for example, a second and different polymeric microparticle, a viscosified aqueous solution, a subterranean reservoir treatment, or combinations thereof.

Abstract: A fluid loss control pill or solution includes a polymer having a functional group that can be hydrolyzed by a base or a nucleophile. A method for fluid loss control in a subterranean formation includes placing a fluid loss control pill or solution in a wellbore penetrating the subterranean formation, wherein the fluid loss control pill or solution comprises a polymer having a functional group that can be hydrolyzed by a base or a nucleophile; and converting the polymer into a soluble form by hydrolyzing the functional group with a base or a nucleophile, when fluid loss control is no longer needed.

Abstract: Phosphate esters useful for gelling hydrocarbons in combination with a metal source are disclosed along with methods of preparation of the phosphate esters. Fouling in oil refinery towers has been attributed due to distillation of impurities present in phosphate esters used to gel hydrocarbons for oil well fracturing. The improved method of preparation of the phosphate ester results in a product that substantially reduces or eliminates volatile phosphorus, which is phosphorus impurities that distill up to 250° C., and increases the high temperature viscosity of the hydrocarbon gels formed using the phosphate esters.

Abstract: An acidizing fluid for sandstone formations is provided, along with methods of acidizing a sandstone formation penetrated by a wellbore. The aqueous acid treatment is a mixture of an aqueous liquid, a fluoride source, and an effective amount of at least one homopolymer or copolymer of a polycarboxylic acid, salt thereof or derivative thereof, which is introduced into the wellbore, and allowed to acidize the formation and concurrently inhibit calcium fluoride formation and impart calcium tolerance to the fluid.

Abstract: Wellbore fluid having a continuous aqueous phase, and containing at least one polymer which (a) has a number average molecular weight in the range of from 10,000 to less than 100,000; (b) contains hydrophilic units such that the polymer is at least 2% soluble in water at a temperature of 20° C. wherein none of said hydrophilic units comprise —CH2.CH2.O— units; and (c) contains pendant alkyl groups having at least 10 carbon atoms. The combined molecular weight of the pendant alkyl groups is in the range of from 15 to 70% by weight based on the weight of the polymer.

Abstract: The invention relates to a water-based drilling fluid composition comprising a carboxymethyl cellulose (CMC), wherein the CMC is characterized by forming a gel at 25° C. after high-shear dissolution in a 0.3 wt % aqueous sodium chloride solution, the final content of the CMC in the aqueous sodium chloride solution being I wt % for a CMC having a degree of polymerization of >4,000, 1.5. wt % for a CMC having a DP of >3,000-4,000, 2 wt % for a CMC having a DD of 1,500-3,000, and 4 wt % for a CMC having a DP of <1,500, the gel being a fluid having a storage modulus (G?) which exceeds the loss modulus (G?) over the entire frequency region of 0.01-10 Hz when measured on an oscillatory rheometer operating at a strain of 0.2.

Abstract: Fluids viscosified with viscoelastic surfactants (VESs) may have their viscosities reduced (gels broken) by the direct or indirect action of a composition that contains at least one metal ion source and optionally at least one second source. An optional second source may be a chelating agent where at least one reducing agent source may be additionally optionally used. Another optional component with the metal ion source includes a second, different metal ion source. The breaking composition is believed to directly attack the VES itself, possibly by disaggregating or otherwise attacking the micellar structure of the VES-gelled fluid, and/or possibly by changing the chemical structure of the VES to give two or more products.

Abstract: An invert emulsion drilling fluid, and a method for the use thereof in drilling wellbores, with good rheological properties at high temperatures and pressures. One embodiment of the drilling fluids are free of organophilic clays and lignites, free of calcium chloride, and comprise an alcohol in the internal phase, a quaternary ammonium emulsifier, and argillaceous solids. In one embodiment, the alcohol is a glycerol, a polyglycerol, or a mixture thereof. In one embodiment, the base oil for the emulsion is a paraffin and/or mineral oil. The drilling fluids provide good lubricity and high rates of penetration.

Abstract: Among many things, in some embodiments, improved viscoelastic surfactant gels that comprise non-aqueous tackifying agents, and their associated methods of use, are provided. In one embodiment, the methods comprise: providing a treatment fluid that comprises an aqueous base fluid, a non-aqueous tackifying agent, and a viscoelastic surfactant; and introducing the treatment fluid into a subterranean formation.

Abstract: A method for removing drilling damage from a formation in a wellbore that has not been produced includes injecting a chemical-acting cleanup fluid and contacting it with a filtercake on a face of a formation of interest for a period of time sufficient to loosen some of the solids embedded in the filtercake. The method further includes circulating a solids removal fluid at a high rate through the wellbore across the face of the formation of interest, the solids removal fluid including a viscosifier, and positioning a second treatment fluid having a fluid loss control pill in the wellbore at the formation of interest. The method further includes degrading particles of the fluid loss control pill and degrading remaining bridging agent from the drilling fluid.

Abstract: Disclosed are novel Mannich bases which are produced by using at least one phenolic compound of formula (I): formaldehyde, and at least one polyamine. Also disclosed is a two-step method for producing Mannich bases, by means of which low viscous Mannich bases are obtained.

Abstract: A substantially liquid gellant formed as one or more reaction products of a metal carboxylate or metal carboxylate amine salt, one or more organic acids, an ester which drives the reaction so that the reaction products are asymmetrical in structure, and a rheology modifier which preferentially interacts between the reaction products for prevent solidifying of the gellant reaction products until such time as the gellant is mixed with the fracturing fluid containing an activator after which the reaction products preferentially interact with the activator to gel the fracturing fluid. The resulting gellant is capable of gelling a hydrocarbon base fluid in less than about 30 seconds.

Abstract: An aqueous, foamable composition useful for formation fracturing is disclosed, which includes an ionically coupled gel system. These compositions are well suited in fracturing formation where there are insufficient or non-existent hydration units. Methods for making the compositions and methods using the foamable compositions to fracture formation with insufficient hydration units.

Abstract: Methods for treating a portion of a well include the steps of: (a) forming a treatment gel comprising a polymer or a polymer system of a mixture of two or more polymers, wherein the polymer or the polymer system is capable of each of the following, when tested at at least one concentration in the range of 2-10 times C* in deionized water, at about 22° C., and at about 1 atmosphere pressure: (i) forming a polymer gel of the polymer and water at at least one pH in the range of 4-9, wherein a bulk form of the polymer gel has a G? greater than G? at all frequencies in the range of 1 rad/sec-100 rad/sec; (ii) dissolving at at least one pH in the range of 2-4; and (iii) dissolving at at least one pH in the range of 9-12; (b) dispersing the treatment gel in a fluid to form a treatment fluid; (c) introducing the treatment gel in a treatment fluid into a portion of a well; and (d) after the step of introducing the treatment gel, adjusting the pH of the treatment gel to at least one pH in the range of 2-4 or 9-12.

Abstract: This invention is directed to a composition comprising expandable polymeric microparticles comprising an interpenetrating polymer network (IPN). The IPN constrains the microparticle to an unexpanded volume average particle size diameter of from about 0.05 to about 5,000 microns. Labile cross-links in the polymers of the IPN are subject to degradation, which results in release of the expandable microparticle so that the microparticle expands. The invention is further directed 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: Methods for treating a portion of a well include the steps of: (a) forming a treatment gel comprising a polymer or a polymer system of a mixture of two or more polymers, wherein the polymer or the polymer system is capable of each of the following, when tested at least one concentration in the range of 2-10 times C* in deionized water, at about 22° C., and at about 1 atmosphere pressure: (i) forming a polymer gel of the polymer and water at least one pH in the range of 4-9, wherein a bulk form of the polymer gel has a G? greater than G? at all frequencies in the range of 1 rad/sec-100 rad/sec; (ii) dissolving at least one pH in the range of 2-4; and (iii) dissolving at least one pH in the range of 9-12; (b) dispersing the treatment gel in a fluid to form a treatment fluid; (c) introducing the treatment gel in a treatment fluid into a portion of a well; and (d) after the step of introducing the treatment gel, adjusting the pH of the treatment gel to at least one pH in the range of 2-4 or 9-12.

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: This invention relates to methods for reducing the viscosity of hydrocarbon liquids encountered in petroleum operations. The method includes forming a low viscosity emulsion by contacting hydrocarbon liquids with an effective amount of a water-soluble polymer having pendant methyl ether groups.

Abstract: A composition for reducing lost circulation in a well, while drilling the well with a drilling mud, which is composed of a base fluid, a mixture of particles, and a blend of fibers. The composition is used by stopping drilling with the mud, injecting a spacer, injecting the water-based composition, injecting a spacer, and resuming drilling with the oil-based mud.

Abstract: Embodiments of this invention relate to a composition and a method for tailoring the rheology of a fluid for use in the oil field services industry including forming a fluid comprising a tetrakis(hydroxyalkyl) phosphonium salt and a polymer, and exposing the fluid to a temperature of about 20° C. to about 200° C., wherein a viscosity is observed that is at least about 5 percent different than if no salt were present. Embodiments of this invention also relate to a composition and a method for tailoring the rheology of a fluid for use in the oil field services industry including forming a fluid comprising a tetrakis(hydroxyalkyl) phosphonium salt and diutan and/or guar and/or guar derivatives and/or a combination thereof, and exposing the fluid to a temperature of about 20° C. to about 163° C., wherein a viscosity is observed that is at least about 5 percent lower than if no salt were present.