Abstract: A method of controlling leak-off and reducing the concentration of polymers (and/or other materials) in filter cakes formed when oilfield treatment fluids flow through subterranean formation faces involves adding large plate-like degradable and/or non-degradable, particles to polymer or VES-viscosified oilfield treatment fluids, at concentrations of such particles that are less than that required to cover the contacted formation face with a monolayer of such particles. When these large plate-like degradable and/or non-degradable particles are included in the fluid, polymer concentrates to form filter cake only in regions on the formation face (for example fracture faces) not shielded by the large plate-like particles, and the remaining formation face is not covered by concentrated polymer. As a result, the damage due to concentration of polymer and/or other materials in the filter cake during leak-off is reduced, and subsequent clean-up of the filter cake is easier.

Abstract: A fluid loss pill that includes a crosslinked polymer gel, a brine, and solid salt particles disposed in said gel is described. Further, a method for reducing fluid loss that includes pumping a selected amount of a fluid loss pill into a wellbore leading to an oil-condensate-, or gas-producing formation, the fluid loss pill including a crosslinked polymer gel, a brine, and solid salt particles disposed in said gel is described.

Abstract: A process of preparing a well servicing fluid comprising viscosifying a heavy brine by contacting with a cationic polysaccharide and a composition thereof.

Abstract: A drilling fluid includes a base fluid and a circulation loss reducing additive package having a polysaccharide, a cellulose derivative and a pH controlling component.

Abstract: The present invention relates to subterranean treatment fluids, and more particularly, the present invention relates to subterranean treatment fluids comprising relative permeability modifiers and methods for using such subterranean treatment fluids in subterranean operations to reduce the production of water from and stimulate hydrocarbon production in a subterranean formation. In certain embodiments, the methods of the present invention generally comprise the steps of providing a permeability-modifying aqueous treatment fluid comprising a relative permeability modifier and contacting a subterranean formation with the permeability-modifying aqueous treatment fluid. Optionally, the permeability-modifying aqueous treatment fluid may be injected in the subterranean formation at a pressure sufficient to create or enhance at least one fracture therein. In another embodiment, the relative permeability modifier may be provided by appropriate reaction in situ.

Abstract: The present invention relates to subterranean treatment fluids, and more particularly, the present invention relates to subterranean treatment fluids comprising relative permeability modifiers and methods for using such subterranean treatment fluids in subterranean operations to reduce the production of water from and stimulate hydrocarbon production in a subterranean formation. In certain embodiments, the methods of the present invention generally comprise the steps of providing a permeability-modifying aqueous treatment fluid comprising a relative permeability modifier and contacting a subterranean formation with the permeability-modifying aqueous treatment fluid. Optionally, the permeability-modifying aqueous treatment fluid may be injected in the subterranean formation at a pressure sufficient to create or enhance at least one fracture therein. In another embodiment, the relative permeability modifier may be provided by appropriate reaction in situ.

Abstract: The present invention relates to novel aqueous wellbore treatment fluids containing a gas component, a heteropolysaccharide, an electrolyte, and a surfactant, wherein the fluids may further include an organoamino compound. The fluids exhibit good rheological properties at elevated temperatures. Methods of use of fluids comprising at least an aqueous medium, a gas component, a heteropolysaccharide and a surfactant for hydraulically fracturing, well cleanup and gravel packing operations, are also disclosed.

Abstract: An exemplary method of the present invention for performing an injection operation includes providing a water-soluble relative permeability modifier, introducing the water-soluble relative permeability modifier into a subterranean formation; and injecting an aqueous injection fluid into the subterranean formation after introducing the water-soluble relative permeability modifier. An exemplary permeability-modifying injection fluid of the present invention contains water-soluble relative permeability modifier. The water-soluble relative permeability modifiers of the present invention include hydrophobically modified water-soluble polymers, hydrophilically modified water-soluble polymers, and water-soluble polymers without hydrophobic or hydrophilic modification.

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 is given for reducing fluid loss in downhole operations such as drilling and completion. A composition containing a fusing solid is injected into the fluid loss flow path; the fusing solid fuses at formation temperature when the injection pressure is released and the formation matrix surfaces forming the flow path close on the composition. The fusing solid is gilsonite, or a similar material, or resin coated particles. The composition may optionally contain one or more of fibers, flakes, an activator, and a dispersant.

Abstract: Compositions relating to fluid loss control operations are provided. In some embodiments, fluid loss treatment fluid compositions are provided that may comprise ceramic particulate bridging agents, wherein at least a portion of the ceramic particulate bridging agents comprise chemically bonded particulates, a partially depolymerized starch derivative, and a base fluid are provided. In other embodiments, fluid loss treatment fluid compositions are provided comprising ceramic particulate bridging agents, wherein at least a portion of the ceramic particulate bridging agents are substantially insoluble in water; a partially depolymerized starch derivative, and a base fluid.

Abstract: A composition comprising a carboxylated, sulfonated polysaccharide and a wellbore servicing fluid. A wellbore servicing composition comprising a hydraulic cement and a carboxylated, sulfonated polysaccharide. A wellbore servicing composition comprising a polysaccharide having carboxylate and sulfonate groups.

Abstract: Novel cross-linked gels comprised of alkoxyetheramides grafted to polysaccharides that have superior viscosity properties have been made. By controlling the chain length of the alkoxyetheramides and the hydrophobic nature of the gel, these materials are ideal for many uses such as in hydraulic fracturing of oil-bearing geological formations, in the paint and dye industries, as dispersants, in personal care products and for carriers in controlled drug delivery.

Abstract: A cross-link delaying or retarding composition, a cross-linking system including the cross-link delaying or retarding composition, or a fracturing fluid including a cross-linking system and a cross-link delaying or retarding composition are disclosed along with methods for making and using the compositions.

Abstract: A monovalent cation containing well fluid composed of an aqueous brine containing at least 0.6 equivalents per liter of a water soluble monovalent cation salt, is substantially free of divalent cations, and an amount of a starch derivative selected such that the well fluid has the following characteristics: (a) a low shear rate viscosity greater than about 5,000 centipoise; (b) a high shear rate viscosity at 511 sec?1 in the range from about 15 to about 70 centipoise measured at 120° F. is described. The fluid may be formulated to be substantially free of xanthan gums and preferably has less than 0.25 lb/bbl of xanthan gum.

Abstract: The drilling mud with a lowered coefficient of friction having a silicate-based mud and a lubricant selected from the group consisting of: glycosides, alkylpolyalkoxyalcohols, alcohol ester polymers, amine phosphates, starch and combinations thereof.

Abstract: The invention provides for a composition for treating a subterranean formation, the composition comprising a water-swellable agent and a sealing agent. Preferably, the water-swellable agent: i) absorbs greater than 100 weight % of water; and ii) swells to greater than 100 weight % as it absorbs water. Preferably the sealing agent: i) is greater than 0.01 weight % soluble in water; and ii) forms a three dimensional gel structure in water. The invention also provides for a method of treating a subterranean formation penetrated by a wellbore, the method comprising the steps of: a) introducing a sealing agent into the subterranean formation; and b) introducing a water-swellable agent into the subterranean formation.

Abstract: Methods of cementing in a subterranean formation may include the steps of: providing a cement composition comprising a cement, water, and a dispersant comprising a low molecular weight starch that comprises anionic groups; placing the cement composition in the subterranean formation; and allowing the cement composition to set therein. In certain embodiments, improved biodegradable dispersants may include low molecular weight starches having anionic groups.

Abstract: Disclosed are drilling fluids suitable for use in connection with oil well drilling. The drilling fluids of the invention include in one embodiment a liquid base, an alkyl glucoside, such as methyl glucoside, and a borehole stability promoter that includes a maltodextrin, a carboxyalkyl starch, a hemicellulose-containing material, or a mixture of the foregoing. In another embodiment, the drilling fluid includes a liquid base and molasses solids, preferably in combination with an alkyl glucoside and more preferably in further combination with one of the aforementioned borehole stability promoters. The drilling fluids of the invention surprisingly have a reduced tendency to swell shale as compared with known drilling fluids. Also disclosed are a drilling apparatus and process. The drilling apparatus includes a drill string, which may be conventional, that is fluidically coupled to a source of drilling fluid, the source of drilling fluid including the drilling fluid of the invention.

Abstract: The subject of the present invention is the use of particular polysaccharides as admixtures for mineral materials, especially as admixtures for mineral binders. These polysaccharides have, characteristically: a weight-average molecular weight Mw of at least 500 g/mol and at most 9000 g/mol, especially between 700 and 7000 g/mol; and a degree of branching DB of at least 10%, especially between 10 and 40%. The invention also relates to the combined use, in mineral materials, including especially mineral binders, of these particular polysaccharides on the one hand and of certain other admixtures on the other hand, for example admixtures, of saccharidic or nonsaccharidic type, having a plasticizing, superplasticizing or other functionality.

Abstract: The invention provides well drilling and servicing fluids, and methods of drilling, completing, or working over a well therewith, preferred fluids comprise an aqueous liquid, a water soluble polymer viscosifier (preferably xanthan gum), a polymeric fluid loss control additive (preferably a partially depolymerized partially crosslinked hydroxyalkyl ether derivative of starch or a hydroxyalkyl ether derivative of a partially crosslinked and partially depolymerized starch), a bridging agent comprising a particulate calcined magnesia that has an Activity Index greater than about 800 seconds, and an additive selected from the group consisting of citric acid, alkali metal salts of citric acid, ammonium citrate, and mixtures thereof in an amount sufficient to increase the low shear rate viscosity of the fluids, preferably from about 0.05–5 ppb, most preferably from about 0.15–3 ppb.

Abstract: The invention provides well drilling and servicing fluids, and methods of drilling, completing, or working over a well therewith, preferred fluids comprise an aqueous liquid, a water soluble polymer viscosifier (preferably xanthan gum), a polymeric fluid loss control additive (preferably a partially depolymerized partially crosslinked hydroxyalkyl ether derivative of starch or a hydroxyalkyl ether derivative of a partially crosslinked and partially depolymerized starch), a bridging agent comprising a particulate calcined magnesia that has an Activity Index greater than about 800 seconds, and citric acid in an amount sufficient to increase the low shear rate viscosity of the fluids. The invention further provides a method of increasing the low shear rate viscosity of fluids which contain a water soluble polymer and a calcined magnesia bridging agent which has an Activity Index greater than about 800 seconds.

Abstract: Methods and compositions relating to fluid loss control operations are provided. More particularly, fluid loss treatment fluid compositions may comprise ceramic particulate bridging agents, a partially depolymerized starch derivative, and a base fluid. In some embodiments, the partially depolymerized starch derivative may include a crosslinked ether derivative of a partially depolymerized starch, a partially depolymerized crosslinked ether derivative of a starch, or a combination thereof.

Abstract: Disclosed herein is a method of treating a subterranean formation utilizing a fluid having a splittable foamer, i.e., a fluid that creates a stable foam when it contacts the formation but that loses its ability to foam as it remains in contact with the formation for extended time. The present method has the advantage that the fluid can be recovered from the well unhindered by the difficulties involved with recovering a foamed fluid from a well. The present method does not require the use of breakers, though the splitting of the foam can be accelerated by introducing an organic or inorganic acid into the well, if so desired.

Abstract: A material and a device for releasing chemicals in a fluid environment is disclosed, and a method for releasing substances into downhole fluid environments. The invention also relates to materials for sand control and hydraulic fracturing. The substance release device typically comprises a polymeric material for releasing a substance into a downhole fluid environment in a well, and in preferred embodiments the material comprises a spherical, plastic chemical release capsule which is hard, permeable and may encapsulate a range of solids and/or liquids for subsequent release. These solids or liquids can include inhibitors such as scale inhibitors and other oilfield production chemicals for release into the wellbore of an oil or gas producing well or a water injection well.

Abstract: This invention relates to divinyl sulfone crosslinking agents, viscosified treatment fluids, and methods of using these compositions in applications wherein viscosified treatment fluids may be used. In one embodiment, this invention provides a method of treating a portion of a subterranean formation comprising: providing a viscosified treatment fluid that comprises an aqueous base fluid and a crosslinked gelling agent, the crosslinked gelling agent comprising at least one alkyl sulfone bridge, and treating the portion of the subterranean formation.

Abstract: Methods and compositions relating to fluid loss control operations are provided. Examples of compositions may comprise ceramic particulate bridging agents and improved fluid loss control additives, and methods of using those compositions to provide fluid loss control. An embodiment of a method of providing fluid loss control from a first location to a second location may comprise the steps of: providing a treatment fluid comprising ceramic particulate bridging agents, a modified starch composition, and a base fluid; introducing the treatment fluid to the first location; and allowing the treatment fluid to form a filter cake to prevent fluid loss from the first location to the second location.

Abstract: The present invention generally relates to compositions of matter and methods of using those compositions. More particularly, and as part of one of the preferred embodiments, the present invention relates to compositions and methods of use of fluids useful for sealing formation fractures and/or inhibiting downhole fluid loss. The present invention is useful as a pill or series of pills that can be formulated and spotted to a particular formation zone.

Abstract: A new fluid system additive is provided that serves to disperse and maintain fluid system solids in a stabilized condition and also “toughen” the filter cake. Fluid systems containing this additive also tolerate calcium contamination better than existing additives, and in laboratory tests simulating well conditions, the treated fluid systems demonstrate good fluid properties at high temperatures (e.g. 250° F.) in contrast to similar fluid systems treated with conventional, more costly additives. In a preferred embodiment, a composition or additive for use in hydrocarbon exploitation includes a biopolymer derived from at least one species of the family Musaceae.

Abstract: It is proposed a method for completing an unconsolidated interval, including particulates, in a subterranean formation, including a consolidation steps. The consolidation step is performed by injection of an aqueous solution of colloidal particles with a pH modifier and/or an ionic-strength modifier. A hard gel is formed that holds the particulates together. The consolidation is followed by hydraulic fracturing. Diversion towards area of less permeability may be enhanced by the use of micrometric particles.

Abstract: A method for producing a precursor polymer dispersion for addition to a brine for use in drilling and completion operations comprising providing a precursor brine having a first salt content, and mixing a water-soluble polymer with the precursor brine at a sufficient concentration and under conditions sufficient to produce a precursor polymer dispersion effective at a sufficient concentration in a final brine having a second salt content to improve the rheology and/or fluid loss control properties of the final brine.

Abstract: Viscous well treating fluids and methods of treating subterranean zones penetrated by well bores are provided. The viscous fluids are basically comprised of water, a gelling agent and a delayed viscosity breaker comprising pentanedione peroxide.

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: A water-base fluid for use in drilling wells and other drilling operation includes a shale clay which swells in the presence of water. The fluid preferably includes: an aqueous based continuous phase, and a shale hydration inhibition agent having the formula: wherein R and R′ are independently selectable alkylene groups having 2 to 4 carbon atoms, and wherein x and y have independently selected values such that the sum of x and y is at least 1. The shale hydration inhibition agent should be present in sufficient concentration to reduce the swelling of the shale clay. The fluid may be used for formulating drilling fluids such as water-base drilling muds or clear brine drilling fluids. The fluid may also be used in the slurrification and disposal of drill cuttings that contain water swellable clays or shale clays.

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: Biodegradable dispersants for cement slurries, well cement compositions comprising such biodegradable dispersants, and methods of using such well cement compositions are provided. The biodegradable dispersants of the present invention comprise low molecular weight starches that comprise anionic groups.

Abstract: Well-working fluid compositions containing certain processed inorganic, oil and water wettable ground elastomeric crumb rubber materials to decrease the seepage loss of various fluids to subterranean formations in which these well working fluids are required and utilized are disclosed. Also disclosed is a method of reducing the seepage and whole mud loss of these well working fluids utilizing such ground elastomeric crumb rubber materials.

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: 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: The present invention provides a well treatment fluid that contains water, an oxidized chitosan-based compound, and a water-soluble compound having carbonyl groups, wherein the oxidized chitosan-based compound has the property of being soluble in water up to about 2 wt % while maintaining a viscosity of less than about 1000 cp. The water used for the well treatment fluid is selected from the group consisting of fresh water, seawater, natural brine, formulated brine, 2% KCl solution, and any mixtures in any proportion thereof. 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: The present invention generally relates to compositions of matter and methods of using those compositions. More particularly, and as part of one of the preferred embodiments, the present invention relates to compositions and methods of use of fluids useful for sealing formation fractures and/or inhibiting downhole fluid loss. The present invention is useful as a pill or series of pills that can be formulated and spotted to a particular formation zone.

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: The present invention relates to biodegradable chemical compositions wherein core substrates, particularly oil well chemicals, are adsorbed onto particulate starch, particularly granular starch, providing a stable, controlled release formulation suitable for use in oil field applications. The invention further relates to the process of preparing obtaining these compositions.

Abstract: The present invention generally relates to compositions of matter and methods of using those compositions. More particularly, and as part of one of the preferred embodiments, the present invention relates to compositions and methods of use of fluids useful for sealing formation fractures and/or inhibiting downhole fluid loss. The present invention is useful as a pill or series of pills that can be formulated and spotted to a particular formation zone.

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

Abstract: Herein is disclosed a well completion or stimulation fluid, comprising (i) a carrier fluid; (ii) a viscoelastic surfactant; and (iii) a fluid loss control additive (FLA) comprising at least one polymer and at least one crosslinker. The fluid may further comprise proppant or gravel, if it is intended for use as a fracturing fluid or a gravel packing fluid, although such uses do not require that the fluid comprise proppant or gravel. Also disclosed herein are methods of fracturing a subterranean formation, comprising (i) providing a fracturing fluid discussed above and (ii) injecting the fracturing fluid into the formation at a pressure sufficiently high to fracture the formation. In addition, disclosed herein are methods of gravel packing a wellbore, comprising (i) providing a gravel packing fluid discussed above and (ii) injecting the gravel packing fluid into the wellbore.

Abstract: Disclosed is a method of increasing the low shear rate viscosity and the shear thinning index of aqueous fluids containing a divalent cation salt, a crosslinked amylopectin starch which functions as both a viscosifier/suspending agent and as a fluid loss control additive, and a bridging agent, the fluids resulting from the method, and the use of the fluids in drilling a well, wherein the bridging agent is a sized particulate magnesium carbonate or a mixture of sized magnesium carbonate and sized calcium carbonate. The median (D50) particle size of the magnesium carbonate is from about 2 &mgr;m to about 10 &mgr;m. The weight ratio of calcium carbonate to magnesium carbonate is from about 70/30 to about 0/100.

Abstract: The present invention relates to biodegradable chemical compositions wherein core substrates, particularly oil well chemicals, are adsorbed onto particulate starch, particularly granular starch, providing a stable, controlled release formulation suitable for use in oil field applications. The invention further relates to the process of preparing obtaining these compositions.

Abstract: Selectively cross-linked starches are disclosed that are useful as fluid loss control additives in subterranean treatment fluids comprising starches that cross-linked to a Brabender peak viscosity of about 800 to about 1250 Brabender units after about 40 to about 70 minutes at about 92° C. and provide good fluid loss control over a temperature range of from about 20° C. to about 160° C. (68° F. to 320° F.).