Abstract: A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid comprising at least one polymerizable monomer and at least one antistatic agent to control build up of static charge. The second fluid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

Abstract: Methods of improving shear recovery time of viscoelastic surfactant fluid systems are described, one method involving providing a viscoelastic surfactant fluid system comprising a major portion of a surfactant and a rheology enhancer in a concentration sufficient to shorten shear recovery time of the fluid system compared to shear recovery time of the fluid system absent the rheology enhancer, the rheology enhancer selected from aromatic sulfonates having a molecular weight of at least 500; and injecting the fluid system down a well. The rheology enhancer may be a lignosulfonate derived from wood pulping. Viscoelastic surfactant systems including the rheology enhancer are also described.

Abstract: In one embodiment, the present invention provides a drilling fluid composition that comprises a surfactant-free emulsion comprising an oleaginous fluid, a fluid that is at least partially immiscible with the oleaginous fluid, and emulsion facilitating particles. In another embodiment, the present invention provides a method of treating a subterranean formation comprising providing a treatment fluid that comprises a surfactant-free emulsion, the surfactant-free emulsion comprising an oleaginous fluid, a fluid that is at least partially immiscible with the oleaginous fluid, and emulsion facilitating particles; and treating the subterranean formation.

Abstract: Improved gelled hydrocarbon fracturing fluids include a gelling agent and a crosslinking composition including a crosslinking agent and a catalytic agent. The catalytic agent is a fatty quaternized amine, which includes monoalkyl benzyl quaternized amines.

Abstract: A method of controlling the pressure of a casing annulus in a subterranean well that includes injecting into the casing annulus a composition including a base fluid and a polymer coated colloidal solid material. The polymer coated colloidal solid material includes: a solid particle having an weight average particle diameter (d50) of less than two microns, and a polymeric dispersing agent coated onto the surface of the solid particle during the comminution (i.e. grinding) process utilized to make the colloidal particles. The polymeric dispersing agent may be a water soluble polymer having a molecular weight of at least 2000 Daltons. The solid particulate material may be selected from materials having of specific gravity of at least 2.68 and preferably the solid particulate material may be selected from barium sulfate (barite), calcium carbonate, dolomite, ilmenite, hematite, olivine, siderite, strontium sulfate, combinations and mixtures of these-and other similar solids.

Abstract: A method of reducing the viscosity of oil-based drilling fluids and well service fluids at low temperatures and a thinner compound for use in such drilling fluids and well service fluids is disclosed. The method comprises adding to said drilling fluids or well service fluids a thinner having the formula: R—(C2H4O)n(C3H6O)m(C4H8O)k-H where R is a saturated or unsaturated, linear or branched alkyl radical having about 8 to about 24 carbon atoms, n is a number ranging from about 1 to about 10, m is a number ranging form about 0 to about 10, and k is a number ranging from about 0 to about 10.

Abstract: Delayed breakers are given that break viscoelastic surfactant fluids inside the pores of formations into which the fluids have been injected. The breakers comprise proteins, proteins that contain breakers, or cells that contain breakers. Proteins become breakers, and proteins and cells release breakers, due to a triggering mechanism that may be, for example, a change in temperature, pH, or salinity.

Abstract: The handling, transport and delivery of particulate materials, particularly fine particles, may be difficult. Alkaline earth metal oxide particles such as magnesium oxide (MgO) may be suspended in glycerin and/or alkylene glycols such as propylene glycol up to loadings of 51 wt %. Such suspensions or slurries make it easier to deliver MgO and similar agents into fluids, such as aqueous fluids gelled with viscoelastic surfactants (VES). These concentrated suspensions or slurries may be improved in their stability by the inclusion of minor amounts of a vegetable oil and/or a fish oil. The MgO serves as stabilizers and/or fluid loss control agents for VES-gelled fluids used to treat subterranean formations, e.g. for well completion or stimulation in hydrocarbon recovery operations. The particle size of the magnesium oxide or other agent may be between 1 nanometer to 0.4 millimeter.

Abstract: The invention concerns an aqueous viscoelastic fluid for use in the recovery of hydrocarbons. According to the invention, the aqueous viscoelastic fluid comprises a monomer, a dimer or an oligomer of a viscoelastic surfactant able to form a viscoelastic gel under downhole conditions, said surfactant comprising a hydrophobic tail and a hydrophilic head, and being of the following formulae: R—X—Y-Z where R is the hydrophobic tail of the surfactant, Z is the hydrophilic head of the surfactant, said hydrophilic head being charged, X is a stabilising group and Y chain is a linear, saturated or unsaturated, hydrocarbon chain of 1, 2 or 3 carbon atoms or a branched, saturated or unsaturated hydrocarbon chain wherein the main chain is of 1, 2 or 3 carbon atoms, possibly incorporating an aromatic ring.

Abstract: An additive that increases the density of fluids used in a wellbore during the construction or repair of oil, gas, injection, water, or geothermal wells comprises In one illustrative embodiment the additive comprises a weighting agent, and more preferably an ultra-fine weighting agent. Another embodiment includes a wellbore fluid containing an ultra-fine weighting agent that has an increased density with improved suspension stability without a significant viscosity increase. The wellbore fluid as described herein has rheological properties comparable to a conventional wellbore fluid. An illustrative embodiment of the claimed subject matter is further directed to a method for making the ultra-fine weighting agent and a method for using such ultra-fine weighting agent in a wellbore fluid. In one preferred embodiment the additive has a particle diameter between 4 ?m to 15 ?m. In another preferred embodiment, the additive has a D50 of approximately 3 ?m (1 ?m to 6 ?m).

Abstract: Pumpable multiple phase vesicle compositions carry agents and components downhole or through a conduit, and controllably releasing them at a different place and time by breaking the compositions. In one non-limiting embodiment the pumpable multiple phase vesicles have a third phase containing a first phase which bears the agent to be controllably released. The first and third phases of the vesicles are separated by a surface active material bilayer that forms the second phase. The pumpable multiple phase vesicles may have internal and external phases that are both oil miscible, both aqueous miscible, or both alcohol miscible. The surface active material bilayer may be composed of compounds such as phospholipids, alkyl polyglycosides, gemini surfactants, sorbitan monooleate, sorbitan trioleate, and many others. The agent may be released by one or more of a variety of mechanisms.

Abstract: A wellbore servicing composition comprising a metal oxide, a soluble salt, a surfactant and an oleaginous fluid. A wellbore servicing composition comprising magnesium oxide, a chloride or phosphate salt, an organophilic surfactant and an oleaginous fluid. A wellbore servicing composition comprising magnesium oxide, magnesium chloride, an organophilic surfactant, water and an oleaginous fluid wherein the organophilic surfactant is present in an amount of from about 0.25% to about 5% base on the combined weight of the magnesium oxide and magnesium chloride, and the oleaginous fluid is present ratio of from about 95:5 cement:oleaginous fluid to about 50:50 cement:oleaginous fluid.

Abstract: A method of treating a well consists of introducing into the wellbore a biodegradable fluid system containing a fatty acid ester, such as methyl soyate. The fluid system may further contain a lactic acid ester, such as ethyl lactate, and/or a nonionic surfactant. The fluid system may be used in displacement, well remediation and stimulation as well as additional, alternative applications such as the cleaning of surface and/or downhole equipment.

Abstract: Fluids viscosified with viscoelastic surfactants (VESs) may have their viscosities reduced (gels broken) by the direct or indirect action of a breaker composition that contains at least one mineral oil, at least one polyalphaolefin oil, and/or at least one saturated fatty acid. The breaker may initially be dispersed oil droplets in an internal, discontinuous phase of the fluid. In one non-limiting embodiment, the breaker, e.g. mineral oil is added to the fluid after it has been substantially gelled. The breaking composition is believed to act possibly by rearranging, disaggregating or otherwise attacking the micellar structure of the VES-gelled fluid in a non-spontaneous, rate controlled manner at elevated fluid temperatures. In a specific, non-limiting instance, a brine fluid gelled with an amine oxide surfactant can have its viscosity broken with a light, low viscosity paraffinic mineral oil.

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: Disclosed is a microemulsion well treatment microemulsion that is formed by combining a solvent-surfactant blend with a carrier fluid. In preferred embodiments, the solvent-surfactant blend includes a surfactant and a solvent selected from the group consisting of terpenes and alkyl or aryl esters of short chain alcohols. The disclosed well treatment microemulsion can be used in well remediation, stimulation and hydrogen sulfide mitigation operations. Additionally, the well treatment microemulsion can be used in the production of benzothiophenes through interaction with hydrogen sulfide.

Abstract: A process for recovering oil by injecting into a subterranean oil-bearing reservoir through one or more injection wells, an aqueous solution containing one or more amphoteric alkyl amido betaine surfactants that form a viscoelastic gel reducing interfacial tension and increasing the viscosity of the injection fluid simultaneously, displacing the solution into the reservoir, and recovering the oil from one or more production wells. These viscoelastic gels are tolerant to electrolytes and multivalent cations. They are shear reversible and adsorbed little onto the reservoir. Their viscosity is reduced when contacting certain hydrocarbons but remains high when contacting water or brine. This allows the fluid to preferentially penetrate the oil-bearing portions of the formation and resulting additional oil recovery.

Abstract: Coatings for well screens that protect the screens from damage as they are inserted into the wellbore and once in the well, release reactive materials to react with and degrade potentially plugging materials such as drill solids, fluid filtercakes, fluid loss additives, and drilling fluids. The coatings can be specifically designed for individual well conditions and are comprised of a binder that either melts or dissolves within the wellbore and one or more reactive materials such as acids, enzymes, surfactants, chelants, oxidizers or free radical generators and the like which are released into the screen and the near wellbore area and which are effective in degrading or dissolving materials which could potentially plug the screen.

Abstract: Pumpable multiple phase vesicle compositions carry agents and components downhole or through a conduit, and controllably releasing them at a different place and time by breaking the compositions. In one non-limiting embodiment the pumpable multiple phase vesicles have a third phase containing a first phase which bears the agent to be controllably released. The first and third phases of the vesicles are separated by a surface active material bilayer that forms the second phase. The pumpable multiple phase vesicles may have internal and external phases that are both oil miscible, both aqueous miscible, or both alcohol miscible. The surface active material bilayer may be composed of compounds such as phospholipids, alkyl polyglycosides, gemini surfactants, sorbitan monooleate, sorbitan trioleate, and many others. The agent may be released by one or more of a variety of mechanisms.

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: Delayed breakers are given that break viscoelastic surfactant fluids inside the pores of formations into which the fluids have been injected. The breakers comprise proteins, proteins that contain breakers, or cells that contain breakers. Proteins become breakers, and proteins and cells release breakers, due to a triggering mechanism that may be, for example, a change in temperature, pH, or salinity.

Abstract: Methods of servicing a wellbore in contact with a subterranean formation include passing an ester-based fluid into the wellbore and reducing a temperature of the ester-based fluid by an amount effective to cause the ester-based fluid to set, e.g., by from about 10° F. to about 20° F. The ester-based fluid includes a water in ester-based oil emulsion, a pH controlling additive, e.g., hydrated lime, in the water-phase, and an emulsifier to stabilize the pH controlling additive. Cooling the ester-based fluid causes the emulsion to destabilize, resulting in the release of the pH controlling additive. This release raises pH of the ester-based fluid by an effective amount to cause it to set. Wellbore servicing fluids comprising the foregoing ester-based fluid may be employed as environmentally friendly sealants or spotting fluids in wellbores.

Abstract: The present invention relates to a method and to a fluid for drilling or workover in a well running through a porous permeable formation, wherein a water-based well fluid circulates in said well. In the method, at most 3% by weight of a composition obtained from fat, or an oil, and an alcohol, is added to the fluid in addition to the conventional constituents for such a fluid, the chain lengths of the acid and alcohol parts being chosen such that the ester thus obtained has sufficient dispersion in water, compatibility with said constituents, does not form an emulsion with the reservoir oil and adsorbs sufficiently on the porous formation.

Abstract: A method of treating a well consists of introducing into the wellbore a biodegradable fluid system containing a blend of lactic acid ester, such as ethyl lactate, and a fatty acid ester, such as methyl soyate. The fluid system may be further in the form of a microemulsion that is formed by combining a blend with one or more emulsifiers, an alcohol, and water. The fluid system may be used in displacement, well remediation and stimulation as well as additional, alternative applications such as the cleaning of surface and/or downhole equipment.

Abstract: An organic based emulsion-breaking formulation for use in treating well bores drilled in oil-bearing mud that is not eco-toxic and is optimally compatible with formation fluids comprises: as the emulsion-breaking agent, at least one constituent selected from non-ionic amphiphilic compositions obtained by reacting at least one polymerized vegetable oil with at least one aminoalcohol and alkyl esters (for example C1 to C8) of fatty acids derived from natural, vegetable or animal oils; optionally, at least one wetting agent selected from anionic surfactants; and optionally at least one solvent; the assembly being as a mixture in an organic base. Such a formulation can be weighted by mineral fillers.

Abstract: A packer fluid is provided for use with a wellbore fluid in an annulus or casing bore, having an aqueous portion which contains additives for preventing corrosion, microbiological activity, salt and scale deposition, and an environmentally-acceptable capping fluid which resides at a top of the wellbore to act as freeze protection and as thermal insulation in a the frost penetration layer. The additives in the packer fluid are particularly selected to exist in the aqueous additive fluid and in the wellbore fluid and to be substantially immiscible with the capping fluid and thereby prevent significant migration of the additives into the capping fluid which would compromise its environmental acceptability.

Abstract: A method is given for treating a subterranean formation penetrated by a wellbore with a viscosified fluid. The fluid contains a solid hydrolysable polyacid that upon dissolution and hydrolysis releases an acid that is a breaker for the viscosifying system. Suitable solid hydrolysable polyacids include polylactic acid and polyglycolic acid. The fluid also contains a pH control agent, present in an amount sufficient to neutralize any acid present in the solid hydrolysable polyacid before the injection and to neutralize any acid generated by the solid hydrolysable polyacid during the injection, so that the acid breaker is not available to break the fluid during the injection. In one embodiment the viscosifier is a viscoelastic surfactant fluid system and the solid hydrolysable polyacid is of a size selected to be a fluid loss additive, for example in fracturing or gravel packing.

Abstract: The present invention generally relates to a method for treating a subterranean formation with an aqueous viscoelastic treating fluid that an aqueous base fluid and one or more non-ionic amido amine oxide surfactant gelling agents. The treatment method comprises injecting the aqueous viscoelastic surfactant treating fluid through a wellbore and into the subterranean formation under conditions effective to control fluid loss, and breaking the gel of the aqueous viscoelastic treating fluid subsequent to treating said formation.

Abstract: Suspensions are provided of water-soluble materials in non-aqueous carrier fluids using suspension agents that include thixotropic agents and, optionally, organophilic clays. Methods of forming such suspensions are provided. Methods are also provided for using such suspensions to prepare aqueous solutions, in particular thickened aqueous solutions, in particular for use in oilfield treatments.

Abstract: A surfactant has the formula (R1—X)nZ, where R1 is an aliphatic group comprising a C10–C25 principal straight chain bonded at a terminal carbon atom thereof to X, and comprising at least one C1–C6 side chain. X is a charged head group, Z is a counterion, and n is an integer which ensures that the surfactant is charge neutral.

Abstract: The present invention relates to methods and compositions for degrading filter cakes in subterranean formations, and more specifically, to improved methods and compositions for degrading filter cakes that comprise acid-soluble portions and polymeric portions.

Abstract: A non-aqueous suspension including boron-containing particulates, a low molecular weight polyalkylene glycol and a suspension stabilizer is provided. Methods of crosslinking water soluble polymers and of fracturing a subterranean formation are also provided.

Abstract: It was found that the addition of polymers to viscoelastic surfactant base system allows to adjust the rheological properties of the base fluid. Depending in particular on one side of the ratio of the concentration of added polymer and the concentration of viscoelastic surfactant and on the other side of the molecular weight of the added polymer, the same polymer—or the same type of polymer—may perform different functions such as viscosity enhancer, viscosity breaker or viscosity-recovery enhancer.

Abstract: Methods are presented to induce a screenout during a subterranean formation fracturing or combined fracturing and gravel packing treatment having a viscoelastic surfactant-based carrier fluid by laying down a filter cake at least a portion of which is a base-soluble material, injecting proppant slurry, and causing hydrolysis and dissolution of the solid base-soluble material by adding base so that leak-off increases, the concentration of proppant in the fracture increases, and the proppant screens out. A method of gravel packing with a viscoelastic surfactant-based carrier fluid by laying down a filter cake at least a portion of which is a base-soluble material, injecting gravel, and causing hydrolysis and dissolution of the solid base-soluble material by adding base. Methods of slowing or accelerating the hydrolysis and dissolution are given, and addition of bridging-promoting materials is included.

Abstract: It has been discovered that solid, particulate dicarboxylic acids are useful as diverting agents in methods for acidizing subterranean formations to improve the uniformity of the acid treatments (acid displacement) by diverting acid to intervals of relatively less permeability. Particularly suitable solid, particulate dicarboxylic acids include, but are not necessarily limited to, those insoluble in both aqueous and hydrocarbon liquids, but which are soluble in mutual solvents or alcohol blends. These acids may have melting points of from about 180 to about 300° F. (about 82 to about 149° C.), formula molecular weights of from 146 to 400, and mesh sizes of from about 20 mesh to about 400 mesh (about 841 to about 38 microns). Particular dicarboxylic acids that fit this description include, but are not necessarily limited to, dodecanedioic acid, undecanedioic acid, decanedioic acid, azelaic acid, suberic acid, and mixtures thereof.

Abstract: Acid based micro-emulsions are disclosed comprising water, an acid blend, an anionic surfactant, a nonionic surfactant, a co-solvent, a solvent and an oxidizer. The micro-emulsions have particular utility in cleaning oil sludges and drilling mud residues from well cuttings, well formations and down hole and surface oil well drilling and production equipment.

Abstract: Gelled organic compositions and methods for using same. The gelled compositions may be liquid organic fluids, such as gelled liquid hydrocarbons, formed from a mixture of an organic-base fluid, a carboxylic acid, and one or more metal source compounds, such as a metal salt of carboxylic acid. The gelled compositions may be used in variety of applications including, but not limited to, oil field, pipeline and processing facility applications.

Abstract: Stimulation, particularly fracturing or acidising, of hydrocarbon wells having bores leading to hydrocarbon bearing uses a fluid including a continuous phase of or including a compound of the formula (1): (R2)p—Ph—(CH2)m—COO—(AO)n—R1 where R1, AO, n, m, Ph, R2 and p having defined meanings and particularly where the esters are alkyl or alkenyl benzoate esters. These esters are beneficial by having a range of viscosities, especially extending to low viscosities, and attractive toxicological and environmental profiles for use in well stimulation.

Abstract: It has been discovered that solid, particulate dicarboxylic acids are useful as diverting agents in methods for acidizing subterranean formations to improve the uniformity of the acid treatments (acid displacement) by diverting acid to intervals of relatively less permeability. Particularly suitable solid, particulate dicarboxylic acids include, but are not necessarily limited to, those insoluble in both aqueous and hydrocarbon liquids, but which are soluble in mutual solvents or alcohol blends. These acids may have melting points of from about 180 to about 300° F. (about 82 to about 149° C.), formula molecular weights of from 146 to 400, and mesh sizes of from about 20 mesh to about 400 mesh (about 841 to about 38 microns). Particular dicarboxylic acids that fit this description include, but are not necessarily limited to, dodecanedioic acid, undecanedioic acid, decanedioic acid, azelaic acid, suberic acid, and mixtures thereof.

Abstract: Coatings for well screens that protect the screens from damage as they are inserted into the wellbore and once in the well, release reactive materials to react with and degrade potentially plugging materials such as drill solids, fluid filtercakes, fluid loss additives, and drilling fluids. The coatings can be specifically designed for individual well conditions and are comprised of a binder that either melts or dissolves within the wellbore and one or more reactive materials such as acids, enzymes, surfactants, chelants, oxidizers or free radical generators and the like which are released into the screen and the near wellbore area and which are effective in degrading or dissolving materials which could potentially plug the screen.

Abstract: Liquid water soluble polymer suspensions in non-aqueous solvents are extremely stable over long periods of time with minimum separation of the solvent and no hard packing of the dispersed water soluble polymer. The suspensions enable a user to rapidly add the suspension to water, being mixed at low speeds, without the formation of lumps or fisheyes and without generating fugitive dust in the process. The suspensions are environmentally safe and biodegradable. Unlike many other liquid polymer suspensions, the suspensions exhibit minimal oil or grease upon dilution. They contain no surfactants that can add to the oil and grease determination. The suspensions and the fluids produced by diluting the fluids to a working concentration of the water soluble polymer exhibit low toxicity to marine organisms and to humans. The suspensions can be manufactured from ingredients suitable for use in personal care applications such as cosmetics, shampoos and the like.

Abstract: Disclosed is a hydrophilic, water soluble polymer concentrate for addition to aqueous liquids to enhance the properties thereof, particularly to increase the viscosity or decrease the fluid loss of well drilling and servicing fluids, the concentrate comprising a hydrophobic, water insoluble liquid, an organophilic clay suspension agent, the water soluble polymer, and a stabilizing agent comprising one or more acids in an amount from about 0.001% to about 1.5%, one or more anionic surfactants in an amount from about 0.001% to about 1.0%, one or more nonionic surfactants in an amount from 0.001% to about 0.625% and, from about 0% to about 0.75% of one or more water soluble organic liquids, wherein the total concentration of the stabilizing agent is from about 0.1% to about 2.5%, these percentages being based on the weight of the concentrate.

Abstract: A wellbore fluid having a non-aqueous continuous liquid phase that exhibits an electrical conductivity of not less than 10 &mgr;S m−1 at 1 kHz comprises a polar organic liquid (POL) which exhibits a dielectric constant of at least about 5.0 and a Hildebrand Solubility Parameter of at least about 17 (J cm−3)1/2. Oils or other organic liquids (OL) known to be suitable as the continuous liquid phase of wellbore fluids, may be used in admixture with POL component. Certain inorganic salts, organic bases, quaternary ammonium salts or hydroxides (the dissolved component, DC), display sufficient solubility (and current carrying abilities) in POL, OL or in mixtures of liquid (POL) and liquid (OL) to further improve the electrical conductivity of the mixture. The wellbore fluid can be used for providing enhanced information from electrical logging tools, measurement while drilling, logging while drilling, geosteering and the like.

Abstract: A wellbore fluid having a non-aqueous continuous liquid phase that exhibits an electrical conductivity increased by a factor in order of 104 to 107 compared to conventional invert emulsion comprises from about 0.2% to about 10% by volume of carbon black particles and one or more emulsifying surfactant(s) selected from the class including nonionic emulsifiers of Hydrophilic-Lipophilic Balance (HLB) less than about 12, and anionic surfactants wherein the counter-ion (cation) is any of alkali metal, ammonium, or hydrogen ions. This wellbore fluid can be used for drilling or completing a well and can be used for providing enhanced information from electrical logging tools, measurement while drilling, logging while drilling, geosteering and the like.

Abstract: The present invention relates to a borehole fluid comprising a lubricating compound containing at least one amphiphilic non-ionic compound obtained by reacting at least one vegetable oil or fatty acid as such or in a polymerized state on at least one amino alcohol. In one variant, the compound can be mixed with a solvent. The invention also relates to a method for verifying the lubrication power of a water-based fluid. The invention further relates to the application of said method to borehole fluids with a high pH.

Abstract: Liquid suspensions of particles in non-aqueous solvents are extremely stable over long periods of time with minimum separation of the solvent and no hard packing of the dispersed particles. The suspensions enable a user to rapidly add the suspension to water and to mix at low speeds without generating fugitive dust in the process. In addition, a liquid dispersion can provide an easy to use liquid containing higher concentrations of the active dispersed phase than can be accomplished by simply preparing an aqueous solution of the dispersed phase. Alternatively, highly water-soluble particles may also be suspended which have poor storage, freeze/thaw, or heat/cool stability. In some cases, liquid dispersions can yield controlled release of the dispersed phase because the dispersed phase is not in aqueous solution. The suspensions are environmentally safe and biodegradable and may be used in environmentally sensitive applications, such as for oil well treating fluids for offshore areas.

Abstract: The present invention relates to a method and a fluid for drilling or intervening in a well passing through a porous, permeable formation, wherein a water-based well fluid is circulating in said well. In this method, there is added to the fluid not only the conventional ingredients for such a fluid but also a maximum of 10 wt. % of a composition obtained from a grease or oil and an alcohol, with the chain lengths of the acid and alcohol parts being chosen such that the ester thus obtained has sufficient dispersion in water, compatibility with said ingredients, does not form an emulsion with the reservoir oil, and adsorbs sufficiently on the porous formation.

Abstract: A method of treating a hydrocarbon-containing formation is disclosed.

Abstract: This Invention relates to a novel reversible thickener, i.e., a fluid whose viscosity can be carefully modulated—from very low viscosity to sufficient viscosity to act as a barrier to further flow; particularly preferred embodiments are directed to fluids and methods for stimulating hydrocarbon low viscosity to sufficient viscosity to act as a barrier to further flow; particularly preferred—bearing formations—i.e., to increase the production of oil/gas from the formation. In particular, the Present Invention is directed to a family of fluids (and methods incorporating those fluids) intended to be pumped through a wellbore and into the hydrocarbon-bearing formation.

Abstract: A new composition for a spotting fluid and a method of using such spotting fluid for freeing differential stuck pipe in a subterranean well drilling operation is disclosed. The composition comprises an invert water-in-oil emulsion comprising iso-butyl oleate as its external phase and glycerin as the internal phase. In an alternative embodiment, calcium chloride and water may be substituted for glycerin.