Abstract: Brine-based well treatment compositions containing alkali nitrate exhibit greater thermal stability when used in deep wells than substantially similar brine-based well treatment compositions which do not contain an alkali nitrate. The brine is thickened with a water-soluble crosslinkable polymer and crosslinking agent. The enhanced thermal stability of the well treatment compositions allows use of the fluids at elevated temperatures, for instance as high as 400° F.

Abstract: The present invention relates to the use of chalcogen heterocyclic electron donating compounds as thermal decomposition reduction additives for gels used in well treatment fluids such as drilling fluids, fracturing fluids, and well completion and workover fluids.

Abstract: The invention discloses a cement slurry composition for cementing a well comprising: an hydraulic cement, water and a combination made of a hydroxyethyl cellulose and an acrylamido-methyl-propane sulfonate-acrylamide copolymer.

Abstract: Loss of wellbore fluids (such as drilling fluids, completion fluids and workover fluids) into the flow passages of a subterranean formation during well drilling, cementing, completion and workover operations may be reduced or eliminated by introducing into the wellbore in communication with the formation a suspension of a polysaccharide in a aqueous fluid. The aqueous fluid contains water and a delayed viscosification material or agent. Hydration of the polysaccharide may be delayed until after introduction of the composition into the formation. A fluid-impermeable barrier is thereby formed.

Abstract: Methods and compositions are provided for treating fluids, especially spacer fluids and cement compositions as well as drilling, completion and stimulation fluids including, but not limited to, drilling muds, well cleanup fluids, workover fluids, conformance fluids, gravel pack fluids, acidizing fluids, fracturing fluids and the like for introduction into a subterranean zone penetrated by a wellbore, wherein the treating fluid comprises zeolite and a carrier fluid. The treating fluid may additionally include one or more of a viscosifier, organic polymer, dispersants, surfactants and weighting materials.

Abstract: A method for pre-emptively reducing the production of water in an oil and gas well is provided. In one embodiment, a drill-in fluid having a relative permeability modifier (RPM) capable of impeding the production of water is introduced into the wellbore during drilling operations. In a second embodiment, a completion fluid having a relative permeability modifier (RPM) capable of impeding the production of water is introduced into the wellbore during completion operations. The drill-in fluid or completion fluid may further include an organosilicon compound to increase flow resistance and extend the effective RPM permeability application range.

Abstract: The present invention relates to compositions and use of fluidized polymer suspensions containing allyloxy linkage and its functional derivatives, and water soluble polymers for use in oil field applications as fluid additives for drilling and cementing processes.

Abstract: This invention relates to a composition and use application of aqueous fluidized polymer suspensions of hydroxyethyl cellulose (HEC) suspended in sodium thiosulfate for use in oil field applications such completion fluids, drilling fluids, fracturing fluids and oil well cement slurries as rheology/viscosity modifier and fluid loss reducer for use where the affect on the marine environment is to be minimized.

Abstract: Many methods and compositions are provided. One of the methods provided comprises the steps of: providing an aqueous treatment fluid that comprises a polysaccharide and a dual functional component, the aqueous treatment fluid having a first viscosity; allowing the dual functional component to interact with the polysaccharide such that the viscosity of the aqueous treatment fluid increases to a second viscosity, the second viscosity being greater than the first viscosity; placing the aqueous treatment fluid into a subterranean formation; and allowing the dual functional component to interact with the polysaccharide so as to reduce the second viscosity of the aqueous treatment fluid to a third viscosity, the third viscosity being less than the second viscosity. An example of a composition is a viscosified treatment fluid for treating subterranean formations comprising: an aqueous base fluid and an apparent cross linked reaction product of a polysaccharide and a dual functional component.

Abstract: A method of introducing an oil field or gas field production chemical into a hydrocarbon-bearing porous subterranean formation penetrated by a wellbore comprising: injecting a gelling composition comprising an aqueous liquid, an oil field or gas field production chemical, and a gellable polymer through the wellbore into the porous subterranean formation wherein the gellable polymer forms a gel within the pores of the subterranean formation thereby encapsulating the production chemical in the gel; and controllably releasing the production chemical from the gel into a formation fluid.

Abstract: Suspensions are provided of water-soluble materials in non-aqueous carrier fluids using suspension agents that include 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 method for minimizing the amount of metal crosslinked viscosifier necessary for treating a wellbore with proppant or gravel is given. The method includes using fibers to aid in transporting, suspending and placing proppant or gravel in viscous carrier fluids otherwise having insufficient viscosity to prevent particulate settling. Fibers are given that have properties optimized for proppant transport but degrade after the treatment into degradation products that do not precipitate in the presence of ions in the water such as calcium and magnesium. Crosslinked polymer carrier fluids are identified that are not damaged by contaminants present in the fibers or by degradation products released by premature degradation of the fibers.

Abstract: The present invention relates to improved methods and compositions for reducing the viscosity of subterranean servicing fluids where the servicing fluid has been cross-linked to increase its viscosity and that crosslinking can be reversed using a delayed release acid produced to reduce the fluid's pH.

Abstract: Methods for treating subterranean formations and aqueous treating fluid compositions are provided. The aqueous treating fluid compositions comprise water, a water soluble hydrophobically modified gelling agent polymer produced by grafting a low concentration of hydrophobic monomers thereon, and a low concentration of an ionic surfactant the hydrophobic chain portion of which is associated with the hydrophobic monomers grafted onto the gelling agent polymer resulting in gelling agent polymer molecules having increased radiuses of gyration.

Abstract: A method of treating a subterranean formation is provided, the method may comprise providing a fluid comprising an aqueous fluid, a gelling agent, and a zirconium triisopropylamine crosslinking agent; and introducing the fluid into a well bore that penetrates the subterranean formation. Also provided are methods of fracturing a subterranean formation.

Abstract: Improved methods for treating and for fracturing subterranean formations and the fluid compositions are provided. The viscosity of a treating fluid containing gelling agents is broken, even at temperatures of about 250° F. and lower, utilizing an oxidizing breaker and a reducing sugar to activate the breaker.

Abstract: Improved methods for treating and for fracturing subterranean formations and the fluid compositions are provided. A method presented herein is a method of reducing the viscosity of a viscosified treatment fluid that comprises providing a viscosified treatment fluid that comprises a basic fluid and a gelling agent, providing a breaker composition comprising an oxidizing breaker and a breaker activator that comprises a reducing sugar; and allowing the breaker composition and the viscosified treatment fluid to interact so as to reduce the viscosity of the viscosified treatment fluid.

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 process for enhancing the productivity of a formation consists of introducing into the formation a viscoelastic fluid which contains at least one surfactant, at least one quaternary amine polyelectrolyte, water, and a non-aqueous solvent. The surfactant forms aggregation structures or vesicles. The fluid, which significantly enhances fluid viscosity and thermal stability, is particularly effective as a diverting fluid to divert an acid treatment package from a high permeability or undamaged portion of a formation to a low permeability or damaged portion of a formation as well as a fracturing fluid. In addition, the fluid is useful for sand control completion.

Abstract: Methods for cementing in a subterranean zone, which use a cement composition that includes zeolite, cementitious material, proportioned fluid loss control additives and a mixing fluid. Cement compositions containing proportioned fluid loss control additives, and methods of making cement compositions containing proportioned fluid loss control additives.

Abstract: A process for stimulating a formation is disclosed wherein a diverting fluid is used to divert an acid treatment package from a high permeability or damaged portion of a formation to a low permeability or undamaged portion of a formation. The fluid, which preferably forms vesicles, comprises at least one surfactant, at least one quaternary amine polyelectrolyte, water, and a non-aqueous solvent.

Abstract: The present invention relates to subterranean fracturing operations, and more particularly to fracturing fluids that includes a fluid loss control additive, and methods of using such fracturing fluids in fracturing subterranean formations. In one embodiment, a fracturing fluid of the present invention includes a viscosifier; and a fluid loss control additive that includes a deformable, degradable material.

Abstract: The present invention provides compositions of treating subterranean zones penetrated by well bores in primary well cementing operations, well completion operations, production stimulation treatments and the like. The invention includes aqueous well treating fluids comprised of water and a water soluble polymer complex fluid loss control additive. Preferred polymer complexes comprise water-soluble polymers made in the presence of hydroxyethylcellulose.

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: The present invention discloses two stage subterranean zone fracturing fluids and methods. A two stage subterranean zone fracturing fluid of the invention comprises a first stage fluid comprising a foamed liquid containing a water soluble gel breaker and a second stage fluid that comprises a viscous liquid containing a metal cross-linked gelling agent. Another two stage subterranean zone fracturing fluid comprises a first stage fluid comprising a foamed liquid containing a water soluble gel breaker and a second stage fluid comprising a viscous liquid containing a borate cross-linked gelling agent.

Abstract: The present invention relates to methods and compositions for treating subterranean well formations, and more specifically, to improved subterranean formation treating fluid concentrates, treating fluids and methods of using such treating fluids in subterranean formations. The treating fluid concentrates generally comprise water and a substantially fully hydrated depolymerized polymer. The treating fluids which are formed by adding water to the treating fluid concentrates generally comprise water, a substantially fully hydrated depolymerized polymer and a crosslinking agent for crosslinking the hydrated depolymerized polymer.

Abstract: Methods of fracturing a subterranean formation include providing a fracturing fluid having a first pH. The fracturing fluid may be made by combining a gelling agent, a surfactant, and a proppant. The surfactant is capable of facilitating foaming of the fracturing fluid at the first pH and defoaming of the fracturing fluid when its pH is changed to a second pH. The methods of fracturing the subterranean formation further include foaming the fracturing fluid having the first pH and subsequently pumping it to the subterranean formation to fracture the formation. The pH of the fracturing fluid changes to a second pH, for example via in situ contact with an acidic material, causing the level of foam in the fracturing fluid to be reduced. As a result of the reduction of the foam, the fracturing fluid deposits the proppant into the fractures formed in the subterranean formation.

Abstract: Methods and compositions for treating subterranean zones penetrated by well bores utilizing environmentally safe viscous fluids including a solubility increasing boron complex or ester forming compound. A method of the invention comprises the following steps. A viscous treating fluid composition is provided comprising water, a viscosity increasing polymer and a water soluble delayed polymer breaker that comprises a mixture of sodium perborate tetrahydrate and a solubility increasing boron complex or ester forming compound. The viscous treating fluid composition is introduced into the subterranean zone wherein the viscous treating fluid is allowed to break into a thin fluid of reduced viscosity.

Abstract: The present invention provides oil based compositions and methods of using the compositions for temporarily sealing subterranean zones. The compositions are basically comprised of oil, a hydratable polymer, an organophilic clay, a water-swellable clay, and an acid soluble material such as calcium carbonate. These compositions will form a viscous gel when contacted with water. The gelled mass may then be dissolved with an acidic fluid, such as 15% hydrochloric acid.

Abstract: The invention relates to water based wellbore fluids used during a hydrocarbon recovery process, such as drilling, fracturing, gravel packing and wellbore workover. According to the present invention, said wellbore fluid comprises a fluid loss additive and a bridging material that are hydrophobic in nature, hydrophobically modified or oil wettable. The wellbore fluid generates an active filter cake that once formed, is impermeable to an aqueous phase, thus reducing fluid loss and ensuring reduced damage to the formation, yet simultaneously is permeable to the back flow of hydrocarbons during a hydrocarbon recovery process.

Abstract: Well completion foamed spacer fluids and methods of using the foamed spacer fluids are provided. A method of the invention for displacing a first fluid from a well bore with an incompatible second fluid comprises the following steps. A foamed spacer fluid is placed between the first and second fluids to separate the first and second fluids and to remove the first fluid from the walls of the well bore. Thereafter, the first fluid and the foamed spacer fluid are displaced from the well bore with the second fluid.

Abstract: Methods of fracturing subterranean zones with less pumping are provided. The methods basically comprise the steps of providing an aqueous fracturing fluid comprised of a brine having a density in the range of from about 9 to about 19 pounds per gallon, pumping the aqueous fracturing fluid into the subterranean zone at a rate and pressure sufficient to fracture the subterranean zone and recovering the aqueous fracturing fluid from the subterranean zone.

Abstract: Methods of treating subterranean zones penetrated by well bores wherein the static temperatures of the zones are as high as 400° F. and greater include using aqueous treating fluids comprised of an aqueous liquid containing one or more inorganic monovalent salts, multivalent salts or both in an amount no greater than about 5% by weight of the aqueous liquid and one or more specific synthetic hectorite clay gelling and thixotropy imparting agents.

Abstract: A plugging fluid for plugging a subterranean formation zone surrounding a drill hole comprises an emulsion comprising a dispersed aqueous phase containing an aqueous base and a continuous hydrophobic phase containing a polymer consisting of a grafted cellulose ether derivative, a surfactant and a crosslinking activator of the polymer. The polymer is preferably 2-hydroxyethyl cellulose grafted with vinyl phosphonic acid. Upon shearing, preferably through the drilling bit, the emulsion inverts so that the rupture of the emulsion droplets releases the crosslinking activator into the water phase thus forming a gel structure.

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: The present invention provides methods and compositions for treating subterranean zones penetrated by well bores utilizing environmentally safe viscous fluids. A method of the invention comprises the following steps. A viscous treating fluid composition is provided comprised of water, a viscosity increasing polymer and a water soluble delayed polymer breaker that comprises a mixture of sodium perborate tetrahydrate and a solubility increasing boron complex or ester forming compound. The viscous treating fluid composition is introduced into the subterranean zone wherein the viscous treating fluid is allowed to break into a thin fluid of reduced viscosity.

Abstract: A low residue well treatment fluid comprises: an aqueous solvent; a gelling agent comprising one or modified polysaccharides, the modified polysaccharides having hydrophilic groups; and a crosslinking composition. The fluid may optionally further comprise a gel breaker, a buffer and/or a proppant. The fluids generate no or minimal residue upon being broken, and are particularly useful in well fracturing operations.

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: The present invention provides a well treatment fluid containing water, a amine-based polymer, and an oxidized polysaccharide-based polymer. The oxidized polysaccharide-based polymer is able to crosslink with the amine-based polymer and produce a gel having a viscosity of greater than about 20 cp, measured at a pH of about 4 to about 7 and at STP. The present invention also provides a method of treating a subterranean formation penetrated by a wellbore comprising the steps of: (a) forming the well treatment fluid, and (b) contacting the subterranean formation with the fluid.

Abstract: Methods of fracturing subterranean zones to produce maximum hydrocarbon productivity are provided. The methods are basically comprised of providing a fracturing fluid comprised of water, a gelling agent present in an amount in the range of from about 0.06% to about 0.3% by weight of the water and an inorganic salt for preventing clay swelling present in an amount in the range of from about 0.01% to about 1% by weight of the water. The fracturing fluid is introduced into the subterranean zone at a rate and pressure sufficient to form fractures and the fracturing fluid is recovered from the zone.

Abstract: A method of treating a well including injecting a thermally stable, substantially water-free well-treating fluid into the well, wherein the well-treating fluid comprises a polymer, a glycol compound, and a salt is disclosed. In another embodiment, a thermally stable, substantially water-free well fluid including a polymer, a diol compound, and a salt is disclosed.

Abstract: Methods and compositions for sealing subterranean zones having temperatures in the range of from about 80° F. to about 300°F. are provided. A method of the invention is basically comprised of the steps of providing a subterranean zone sealing composition that becomes substantially rigid when exposed to subterranean zone temperatures above about 80° F. and has a pH above about 8.5 comprised of water, a substantially fully hydrated depolymerized polymer and a cross-linking agent. The sealing composition is introduced into the subterranean zone whereby it becomes rigid and seals the zone. The sealing composition can subsequently be removed by contact with a fluid having a pH below about 8 when a boron compound is utilized as the cross-linking agent.

Abstract: The invention provides a method and fluid for drilling or servicing a well in a subterranean formation containing lost circulation zones or depleted, low pressure reservoirs. The fluid comprises an aqueous liquid having dispersed therein a viscosifier which increases the low shear rate viscosity of the fluid to at least 10,000 centipoise, an aphron-generating surfactant, and aphrons, wherein the fluid contains less than about 20% by volume of aphrons preferably generated by the turbulence and pressure drop as the fluid exits the drill bit in the vicinity of the formation. The method of drilling a wellbore in a subterranean formation comprises continuously re-circulating, while drilling, such a drilling fluid.

Abstract: The present invention provides methods of treating subterranean zones penetrated by well bores in primary well cementing operations, well completion operations, production stimulation treatments and the like. The methods are basically comprised of introducing into the subterranean zone an aqueous well treating fluid comprised of water and a water soluble polymer complex fluid loss control additive.

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: Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid comprised of water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solid suspending agent and a particulate solid bridging agent which is soluble in an aqueous ammonium salt solution. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with a clean-up solution comprised of water and an ammonium salt for a period of time such that the bridging agent is dissolved thereby.

Abstract: Environmentally acceptable well cement fluid loss control additives, cement compositions including the additives and methods of using the compositions are provided. The environmentally acceptable fluid loss control additives are comprised of ethoxylated hydroxyethylcellulose having a reduced molecular weight.

Abstract: A well treatment fluid composition that comprises a carrier fluid and an amphoteric surfactant, and optionally a viscosifying agent and proppant, is well suited for use in fracturing coal beds to stimulate methane production. The composition preferably is a foam that comprises a gas such as nitrogen or air. Preferably, the surfactant has the formula R—NH2—(CH2)n—C(O)OX wherein R is a saturated or unsaturated alkyl group having from 6-20 carbon atoms, n is from 2-6, and X is hydrogen or a salt forming cation.

Abstract: The present invention provides improved well drilling fluids containing hardenable furan sealant compositions and methods of drilling well bores and sealing pipe strings therein utilizing the drilling fluids. The drilling fluids are basically comprised of a base fluid, a viscosity increasing material and a hardenable furan sealant composition which becomes part of the filter cake formed on the walls of the well bore and hardens therein.

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.