Abstract: Surfactant based viscoelastic fluids for enhancing the productivity of a hydrocarbon-bearing formations have particular applicability in acid fracturing of subterranean formations surrounding oil and gas wells. The viscoelastic fluid contains an organic acid, an inorganic monovalent salt and a quaternary ammonium aromatic salt and water. The fluid may further be foamed or energized.

Abstract: The invention relates to corrosion inhibitor compositions comprising products of a reaction between aldehydes and amides for use in subterranean applications and methods related thereto. In general, the methods for inhibiting corrosion comprise providing a corrosive environment and adding a composition comprising a corrosion inhibitor to the corrosive environment. The corrosion inhibitor comprises a product of a reaction between at least one aldehyde and at least one amide that is not formamide or a formamide derivative.

Abstract: The use of free, aromatic acids which contain at least two aromatic ring systems or at least two acid functions, and/or salts thereof, for influencing rock formations in the exploitation of underground mineral oil and/or natural gas deposits is described. The free acids are used in particular for influencing and especially controlling the flow of acid into rock formations in so-called acidizing methods. Suitable salts of said aromatic acids serve for reducing the rock permeability and in particular reducing the inflow of water into the well bore. In addition to this use, corresponding methods are also claimed.

Abstract: Viscoelastic surfactant (VES) gelled aqueous fluids containing water, a VES, an internal breaker, a VES stabilizer, a fluid loss control agent and a viscosity enhancer are useful as treating fluids and particularly as fracturing fluids for subterranean formations. These VES-based fluids have faster and more complete clean-up than polymer-based fracturing fluids. The use of an internal breaker permits ready removal of the unique VES micelle based pseudo-filter cake with several advantages including reducing the typical VES loading and total fluid volume since more VES fluid stays within the fracture, generating a more optimum fracture geometry for enhanced reservoir productivity, and treating reservoirs with permeability above the present VES limit of approximately 400 md to at least 2000 md.

Abstract: A method for sealing a subterranean zone is disclosed. The method includes the steps of preparing a wellbore fluid, placing the wellbore fluid into at least a portion of an annular space between the sidewalls of a wellbore and the exterior of a casing string disposed in the wellbore, and allowing the wellbore fluid to solidify therein, wherein the wellbore fluid includes an oleaginous fluid as the continuous phase of the wellbore fluid, a non-oleaginous fluid as the discontinuous phase of the wellbore fluid, and about 5 to about 50 pounds per barrel of a thermally activated hydrocarbon gellant.

Abstract: An oil-in-water emulsion that includes a brine continuous phase; and an oleaginous discontinuous phase stabilized by an emulsifier blend, the emulsifier blend comprising: an emulsifier having an HLB greater than 11; and an amphoteric chemotrope is disclosed. Emulsifier blends comprising an emulsifier having an HLB greater than 11 and an amphoteric chemotrope and methods of using emulsifier blends are also disclosed.

Abstract: Emulsified acids have been used to increase production rates of oil and gas in carbonate reservoirs through acid fracturing and matrix acidizing operations. An emulsifier is used to emulsify the aqueous acid with an oil, usually diesel. Very small particles, such as colloidal clay particles and/or nanoparticles increase the stability of the emulsified acids over an elevated temperature range.

Abstract: An asphaltene and resin precipitation inhibiting solution formed of an asphaltene and resin precipitation inhibiting compound and a solvent miscible in a carbon dioxide liquid or supercritical fluid. The inhibiting compound includes a head region with an affinity for asphaltene and resin components of a hydrocarbon mixture that is greater than its affinity for water, carbon dioxide, and aliphatic components of the hydrocarbon mixture. The head region includes one or more unsaturated hydrocarbon groups or one or more nonionic dipolar groups. The inhibiting compound also includes a tail region with an affinity for carbon dioxide that is greater than its affinity for substantially all components of the hydrocarbon mixture and water. The tail region includes one or more nonionic quadrupolar groups. An effective amount of solution is added to a hydrocarbon mixture in an underground reservoir when employing a carbon dioxide fluid to flush the hydrocarbon mixture from the reservoir.

Abstract: A well servicing fluid is disclosed. The well servicing fluid is formulated with components comprising: an organic salt, the organic salt being the product of an organic acid and an organic amine base; and an aqueous based solvent. A method of servicing a well is also disclosed.

Abstract: A sand slurry composition and a method for making sand slurries are disclosed. The sand slurry composition is comprised of sand, an aqueous liquid and a chemical compound that renders the surface sand of hydrophobic. The method is comprised of rendering sand surface hydrophobic during or before making the slurry. This method and composition can find many applications in different industries, especially in various oil field applications.

Abstract: A method of creating a carbon dioxide hydrate is disclosed. The preferred steps include supplying liquid carbon dioxide and a dissociation agent to a hydrocarbon hydrate, decomposing the hydrocarbon hydrate by the dissociation agent into a hydrocarbon gas and liquid water, and forming the carbon dioxide hydrate from the liquid carbon dioxide and the liquid water. The dissociation agent preferably is at least one of an inorganic salt, a surface active agent, a hydrate inhibitor, and an absorption solution. Furthermore, a substance composition of liquid carbon dioxide and the dissociation agent is described, which is provided for depositing carbon dioxide hydrate in a subterranean geological formation. Furthermore, a deposition device is described, which is configured for depositing carbon dioxide hydrate in a subterranean geological formation.

Abstract: The present invention comprises fluorinated ethoxylated polyurethanes of formula [Rf—(X)n—(CH2CHR1—O)m—CH2CH2—O—C(O)—NH]p-A, wherein Rf is a C1 to C6 perfluoroalkyl; X is a divalent radical; n is 0 or 1; R1 is H or C1 to C4 alkyl; m is 1 to 20; p is a positive integer of at least 2; and A is the residue of a polyisocyanate, and methods for altering surface behavior of liquids using such compounds.

Abstract: Alkaline earth metal compounds may be fluid loss control (FLC) agents for viscoelastic surfactant (VES) fluids used for fluid loss control pills, lost circulation material pills and kill pills in hydrocarbon recovery operations. The FLC agents may include, but not be limited to oxides and hydroxides of alkaline earth metal, and in one case magnesium oxide where the particle size of the magnesium oxide is between 1 nanometer to 0.4 millimeter. The FLC agent may alternatively be transition metal oxides and/or transition metal hydroxides. The FLC agent appears to associate with the VES micelles and together form a novel pseudo-filter cake quasi-crosslinked viscous fluid layer that limits further VES fluid flow into the porous media. The FLC agent solid particles may be added along with VES fluids. The pills may also contain internal breakers to reduce the viscosity thereof so that the components of the pill may be recovered.

Abstract: Methods and compositions that include a method comprising: providing a treatment fluid comprising at least a plurality of degradable diverting agents that comprise at least one degradable material selected from the group consisting of a fatty alcohol, a fatty acid salt, a fatty ester, a proteinous material, and a combination thereof; and introducing the treatment fluid into a subterranean formation during a subterranean operation via a well bore.

Abstract: The present invention provides treatment fluids useful for subterranean operations, and more particularly, in at least one aspect, a treatment fluid that comprises a carrier fluid and a cationic surfactant comprising a cationic head group, a polar group attached to the head group, and a hydrophobic group that is either a saturated or unsaturated, branched or straight chain alkyl, and comprises about 6 carbons to about 22 carbons. The treatment fluids of the present invention are at least suitable for use as a remedial treatment for the reduction of existing water blocks, oil blocks, and/or gas condensates.

Abstract: A method of selectively blocking fractures in a subterranean formation by injecting a diversion agent into the well is disclosed. According to one embodiment, the method comprises injecting a diversion agent into a subterranean formation to form an alkaline-earth carbonate precipitate from decomposition of a carbonyl compound, wherein the diversion agent includes the carbonyl compound and an alkaline-earth halide salt.

Abstract: The invention concerns a treatment fluid for wells drilled in oil mud in the form of an emulsion of water in oil comprising: a continuous organic phase comprising at least one emulsion-breaking organo-soluble additive; a dispersed aqueous phase including at least one solid-dissolving agent for the controlled destabilization of the processing fluid; at least one emulsifying agent; at least one weight-increasing agent; the proportion and the nature of the hydrosoluble additive being chosen so as to obtain a delay effect for the destabilization of the emulsion so as to be compatible with the tank fluids. The invention also concerns a method of processing wells bored with oil-based muds, using said processing fluid.

Abstract: Using a complex emulsion for treating a subterranean formation, such as to dissolve minerals therein (e.g. carbonates, scales, and/or filter cake) to improve permeability, substantially improves post treatment fluid clean-up for improved hydrocarbon production. The complex emulsion is made by mixing an acid aqueous phase with an oil external microemulsion to give an initial product, where the acid aqueous phase is an external phase and the microemulsion is an internal phase. Then the initial product is mixed with a second oil (e.g. xylene, diesel, toluene, kerosene, other aromatics, refined hydrocarbons and the like) containing an emulsifier to make a complex emulsion.

Abstract: This invention relates to an aqueous-swellable and degradable diverting system and the use of the system in treating a subterranean formation penetrated by a wellbore. The diverting system comprises a carrier fluid and a partially dehydrated or anhydrous borate source material that does not swell or does not swell substantially when placed in contact with the carrier fluid. The carrier fluid is capable of carrying and placing the borate source material into a stimulation network substantially distanced from a wellbore. The carrier fluid may be a non-aqueous fluid, or when the average size of the borate source material is sufficient large, the carrier fluid may also be an aqueous fluid. Exposure of the diverting composition to sufficient amount of aqueous fluid swells the borate source material, bridges a desired portion of the stimulation network and then dissolves at least a portion of the diverting composition.

Abstract: Sealant compositions comprising a colloidally stabilized latex and methods of using the same to service a wellbore are provided. The sealant compositions may include: an aliphatic conjugated diene monomer; an additional monomer comprising a non-aromatic unsaturated mono- or di- carboxylic ester monomer, an aromatic unsaturated monomer, a nitrogen-containing monomer, or combinations thereof; and a protective colloid. The foregoing sealant composition may be displaced into the wellbore to isolate the subterranean formation from a portion of the wellbore, to support a conduit in the wellbore, to plug a void or crack in the conduit, to plug a void or crack in a cement sheath disposed in an annulus of the wellbore, to plug an opening between the cement sheath and the conduit, or combinations thereof. The colloidally stabilized latex remains substantially stable when exposed to salt, which may be present in the wellbore and/or in the sealant composition itself.

Abstract: The invention relates to methods and compositions for producing or recovering an aqueous-based fluid to be utilized or injected in a wellbore or surrounding subterranean formation. The method comprises the step of contacting an aqueous-based fluid with an aqueous-soluble breaker composition comprising an oxidizing agent and a catalyst for a time sufficient to reduce or eliminate one or more deleterious substances in the aqueous-based fluid to produce a treated aqueous-based fluid suitable for use or injection in a wellbore or surrounding subterranean formation.

Abstract: This invention relates to compositions and methods of treating a subterranean formation penetrated by a well bore including providing a treatment composition comprising a rheological polymer, a partitioning agent, a charged polyelectrolyte, and a first liquid medium, forming a stabilized heterogeneous mixture comprising a dispersed rheological polymer-rich phase and a partitioning agent-rich phase, and injecting the treatment fluid into the well bore. The invention relates to methods and compositions for preparing a well treatment fluid, including mixing polyethylene glycol partitioning agent, a charged polyelectrolyte, a first aqueous medium, and one or more rheological polymers selected from the group consisting of guar, modified guar, cellulose, modified cellulose, heteropolysaccharide, heteropolysaccharide derivative, or polyacrylamide, to hydrate the one or more polymers and form a water-in-water emulsion, and mixing the water-in-water emulsion with a second aqueous medium to form a well treatment fluid.

Abstract: This invention relates to compositions and methods for treating subterranean formations, in particular, oilfield stimulation compositions and methods using water-in-water polymer emulsions to uniformly dissolve a rheologically active polymer, such as a thickener or friction reducer, in the treatment fluid. The emulsions have a low viscosity and are easily pumped for mixing into a treatment fluid, where upon dilution with an aqueous medium, the polymer is easily hydrated without forming fish-eyes. The partitioning agent in the water-in-water emulsion does not generally affect the rheology of the treatment fluid. The invention also relates to further processing of the emulsion by wet grinding, high shear mixing and/or heating to enhance the hydration rate in the preparation of the well treatment fluid.

Abstract: An acid-in-oil emulsion having a corrosion inhibitor as the external phase has been found to prevent downhole corrosion when acidizing carbonate formations to enhance hydrocarbon recovery.

Abstract: The present invention relates to an additive, and its use for inhibiting nucleation, growth and agglomeration of gas hydrates by adding an effective amount of an inhibitor to a multiphasic mixture which tends to hydrate formation and consists of water, gas and optionally condensate, or to a drilling fluid which tends to form gas hydrates. Said inhibitor comprising dialkoxylated quaternary ammonium compounds of the formula 1 where R1, R2 are each independently radicals of the formulae -(A-O)n—(C)—CO—O—R5, R3 is C1- to C30-alkyl or C2- to C30-alkenyl, R4 is an organic radical which optionally contains heteroatoms and has from 1 to 100 carbon atoms, R5 is an alkyl or an alkenyl, n is a number from 1 to 20, A is an alkylene group, B is an alkylene group, C is a C1- to C6-alkylene group and X is an anion, are used as gas hydrate inhibitors.

Abstract: The invention discloses a foam composition comprising a self-assembled, force-transmitting peptide network prepared by: a) dissolving or dispersing a peptide surfactant in a liquid to form a solution; and b) mixing the solution with a gas (e.g., nitrogen, carbon dioxide) to form a foam.

Abstract: An acid treatment composition is provided including an alkyl sarcosinate as corrosion inhibitor and an optional corrosion inhibitor intensifier in an acidic solution. Methods for treating wells with these acid treatment compositions are also provided that help control corrosion of the alloy surfaces used in the wells during the acid treatment.

Abstract: The present invention provides drilling fluids that comprise a base fluid and a water-soluble relative permeability modifier. In addition, the present invention provides methods of reducing the permeability of a subterranean formation to aqueous-based fluids during the drilling phase that comprises providing a water-soluble relative permeability modifier; and placing the water-soluble relative permeability modifier into the subterranean formation during the drilling phase. The present invention provides methods of drilling a well bore in a subterranean formation comprising providing a drilling fluid that comprises a base fluid and a water-soluble relative permeability modifier, and placing the drilling fluid in the subterranean formation. The water-soluble relative permeability modifiers of the present invention generally may comprise hydrophilically modified polymers, hydrophobically modified polymers, or water-soluble polymers without hydrophobic or hydrophilic modification.

Abstract: An acid treatment composition is provided including a corrosion inhibitor and an optional corrosion inhibitor intensifier in an acidic solution. More specifically, the composition includes an anionic surfactant. Methods for treating wells with these acid treatment compositions are also provided that help control corrosion of the steel used in the wells during the acid treatment.

Abstract: A method for reducing the toxicity of an invert emulsion wellbore fluid is disclosed. The method comprises forming an invert emulsion wellbore fluid comprising an oleaginous continuous phase, an aqueous discontinuous phase, and an emulsifying fluid, wherein the emulsifying fluid comprises a nitrogen-containing emulsifying agent and an alkalinity agent, and wherein the invert emulsion wellbore fluid produces an LC50 (SSP) of at least 30,000 parts per million at 3000° F.

Abstract: A method of treating a subterranean formation penetrated by a wellbore involves introducing an acid treatment fluid through the wellbore into the formation. The treatment fluid is formed from a zwitterionic viscoelastic surfactant, an acid in an amount to provide the treatment fluid with an initial pH of ?0 and a rheology enhancer. The treatment fluid has a high viscosity at the initial pH and a lower viscosity when the pH of the treatment fluid is raised to an intermediate pH of from greater than 0 to about 5.

Abstract: Methods are provided that include a method comprising providing a acidic treatment fluid that comprises a base fluid, an acid composition, and a gelling agent that comprises clarified diutan; and introducing the acidic treatment fluid into at least a portion of a subterranean formation. In some embodiments, the acidic treatment fluid may be allowed to interact with a component of the subterranean formation so that the component is at least partially dissolved. In some embodiments, the acidic treatment fluid may be introduced into a pipeline. Additional methods are also provided.

Abstract: Methods of treating articles using a compound represented by formula: (I) wherein each of X and Y is independently a thiol, a halogen, a hydrogen, a hydroxyl, a hydroalkyl, a carboxylic acid, an aldehyde, a carboxylic ester, or a carboxamide; R? is hydrogen, alkyl, or aryl; and x and y are each independently 0 to 10, wherein x+y is at least 1 and articles treated by such methods. In some embodiments, the article is a hydrocarbon-bearing formation. In some embodiments, the article is a particle, and the method further comprises treating the article with a fluorochemical comprising at least one fluoroaliphatic segment and at least one hydrophilic segment. In some embodiments, the method is used to treat a well bore.

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: Wellbore treatment kits are provide that include a polymeric solution for placement in a wellbore that penetrates a subterranean formation and an activator for causing a polymer to precipitate out of the polymeric solution when it contacts the polymeric solution, wherein the resulting precipitate is capable of at least partially blocking a flow of a wellbore servicing fluid into the subterranean formation. The wellbore servicing fluid may be, for example, a drilling fluid, a cement composition, a workover fluid, or combinations thereof. The polymeric solution may comprise, for example, a poly vinyl pyrrolidone aqueous solution, and the activator may comprise, for example, a formate brine. When desirable, the precipitate may be easily and quickly removed from the subterranean formation by dissolving it in fresh water.

Abstract: A gelled organic-based fluid system and method of forming and using the system. The fluid system is prepared by gelling an organic solvent, a viscoelastic surfactant, and a nitrogen compound having a free electron pair such as urea in an amount effective to both increase viscosity and increase a rate of breaking the viscosity, relative to the gelled system without the nitrogen compound. In a further aspect, the method is used to treat a well penetrating a subterranean formation, for example, in a coiled tubing cleanout, or the like.

Abstract: A low toxicity composition and method of reducing the swelling of clay in well comprising circulating in the well a water-based fluid comprising a functionally effective concentration of the additive formed from the following reaction of a tertiary amine of the following general formula: wherein R1 and R2 are alkyl or hydroxyalkyl groups with one to three carbon atoms or combinations thereof, and R3 is a hydroxyalkyl group with one to three carbon atoms, with an alkylating agent of the following general formula: R-A wherein R is an alkyl radical with one to three carbon atoms, and A is an organic or inorganic anion selected from the group consisting of sulfate, phosphate, carbonate, and combinations thereof.

Abstract: The invention is directed to methods for treating a portion of a well. The methods include the steps of: (A) forming a viscoelastic treatment fluid, wherein the treatment fluid comprises: (i) water; (ii) a viscoelastic surfactant (“VES”), wherein the VES is soluble in the water and wherein the VES is in the form of micelles; and (iii) a cross-linking agent for the VES molecules, wherein: (a) the cross-linking agent comprises cross-linking agent molecules having at least one complexed transition metal, wherein the transition metal has a valence state of at least three; and (b) the cross-linking agent is soluble in the water; and (B) introducing the treatment fluid into a portion of the well. According to a first aspect of the invention, (a) the VES comprises VES molecules having an alkyl group of greater than 14 carbon atoms and (b) the VES comprises VES molecules having at least one functional group selected from a carboxylate group, an amino group, an alcohol group, and an ether group.

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: 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: A composition for treating a portion of a wellbore or a portion of a subterranean formation is provided, the composition comprising: (a) water; (b) a source of hydrogen peroxide, and (c) an activator for the source of hydrogen peroxide; wherein the pH of the composition is adjusted to be within an appropriate range for the type of activator. A method for treating a portion of a wellbore or a portion of a subterranean formation, the method comprising the steps of: forming or providing a composition comprising: (a) water; (b) a source of hydrogen peroxide, and (c) an activator for the source of hydrogen peroxide; wherein the pH of the composition is adjusted within an appropriate range for the type of activator; and introducing the composition through a wellbore to treat a portion of a wellbore or a portion of a subterranean formation. The activator can be a water-soluble alkanoyl-donor compound or a chelated transition metal. Preferably, the composition further comprises an iron chelating agent.

Abstract: A composition for treating a portion of a wellbore or a portion of a subterranean formation is provided, the composition comprising: (a) water; (b) a source of hydrogen peroxide, and (c) an activator for the source of hydrogen peroxide; wherein the pH of the composition is adjusted to be within an appropriate range for the type of activator. A method for treating a portion of a wellbore or a portion of a subterranean formation, the method comprising the steps of: forming or providing a composition comprising: (a) water; (b) a source of hydrogen peroxide, and (c) an activator for the source of hydrogen peroxide; wherein the pH of the composition is adjusted within an appropriate range for the type of activator; and introducing the composition through a wellbore to treat a portion of a wellbore or a portion of a subterranean formation. The activator can be a water-soluble alkanoyl-donor compound or a chelated transition metal. Preferably, the composition further comprises an iron chelating agent.

Abstract: Treatment fluids are provided that include a treatment fluid comprising a base fluid and a gelling agent that comprises clarified diutan. In some embodiments, the treatment fluid is a subterranean treatment fluid. In some embodiments, the treatment fluid is a subterranean treatment fluid comprising a base fluid, a gelling agent that comprises clarified diutan, and at least a plurality of particulates. Additional treatment fluids are also provided.

Abstract: A packer or annular fluid includes a hydrocarbon fluid; and a gelling agent; wherein the packer fluid is a yield power law fluid. A method for preparing a packer fluid includes preparing a mixture of a hydrocarbon fluid, and a gelling agent; heating the mixture to a selected temperature; and shearing the mixture. A method for emplacing a packer fluid into an annulus includes preparing the packer fluid that includes a hydrocarbon fluid and a gelling agent, wherein the packer fluid is a yield power law fluid; and pumping the packer fluid into the annulus.

Abstract: The invention relates to a class of novel surfactants that have utility in the recovery and/or extraction of oil.

Abstract: A method for shortening the shear recovery time of cationic, nonionic, anionic, zwitterionic, and amphoteric viscoelastic surfactant fluid systems by adding an effective amount of an amphiphilic polymeric rheology enhancer. The rheology enhancer is a grafted polymer of polydimethylsiloxane, for example polydimethylsiloxanes grafted with ethylene/propylene glycol. The rheology enhancer also increases fluid viscosity and very low rheology enhancer concentration is needed.

Abstract: Biocidal compositions and their use in aqueous media, such as metalworking fluids, the compositions comprising a biocidal agent; and a non-biocidal primary amino alcohol compound of the formula (I): wherein R1, R2, R3, R4, and R5 are as defined herein.

Abstract: A well treatment microemulsion for use in a subterranean formation is disclosed, the microemulsion comprises a solvent blend comprising a solvent and a co-solvent; a surfactant blend comprising a surfactant, wherein the surfactant blend is able to give formation intermediate wettability properties; an alcohol; and a carrier fluid; wherein the alcohol, the solvent and surfactant blends are combined with the carrier fluid to produce the well treatment microemulsion. By intermediate wettability it is meant that the water has an advancing contact angle on the surface between 62 and 133 degrees. The associate method of treating a subterranean formation of a well with the microemulsion and the associate method of modifying the wettability of the formation with the microemulsion are also disclosed.

Abstract: An aqueous, viscoelastic fluid gelled with a viscoelastic surfactant (VES) is inhibited against hydrate formation with an effective amount of an additive that could be one or more halide salts of alkali metals and alkali earth metals, formate salts, alcohols, glycols, glycol amines, sugars, sugar alcohols, amidoamine oxides, polymers such as polyamines, polyvinylpyrrolidones and derivatives thereof, polyvinyl alcohols and derivatives thereof, polycaprolactams and derivatives thereof, hydroxyethylcellulose, and mixtures thereof. These fluids are inhibited against hydrate formation and may have increased viscosity as well. The additives may increase viscosity to the point where less VES is required to maintain a given viscosity. These inhibited, aqueous, viscoelastic fluids may be used as treatment fluids for subterranean hydrocarbon formations, such as in stimulation treatments, e.g. hydraulic fracturing fluids.

Abstract: The invention provides a method for treating tight gas sand and shale subterranean formations, the method comprising: forming a solvent-surfactant blend by combining a solvent, a surfactant and a co-surfactant; adding a diluent to the solvent-surfactant blend to form a micro emulsion; wherein the wettability of the formation altered from water-wet to gas-wet, and the amount of water imbibed into the formation is reduced.