Abstract: An oxidative breaker system for use in reducing the viscosity of a polysaccharide-based or derivatized polysaccharide-based suspension includes a silicone carrier fluid, an oxidizer, and a suspension aid. The suspension aid is preferably fumed silica. The oxidizer may be selected from the group consisting of alkali metal peroxide, transition metal peroxide, persulfate compound, bromide compound, and bromate compound. In highly preferred embodiments, the oxidizer is magnesium peroxide or calcium peroxide. Alternative carrier fluids and suspension agents are also included in the art. Also disclosed is a method for breaking a polysaccharide-based suspension with the inventive oxidative breaker system.

Abstract: An oxidative breaker system for use in reducing the viscosity of a polysaccharide-based or derivatized polysaccharide-based suspension includes a silicone carrier fluid, an oxidizer, and a suspension aid. The suspension aid is preferably fumed silica. The oxidizer may be selected from the group consisting of alkali metal peroxide, transition metal peroxide, persulfate compound, bromide compound, and bromate compound. In highly preferred embodiments, the oxidizer is magnesium peroxide or calcium peroxide. Alternative carrier fluids and suspension agents are also included in the art. Also disclosed is a method for breaking a polysaccharide-based suspension with the inventive oxidative breaker system.

Abstract: An oxidative breaker system for use in reducing the viscosity of a polysaccharide-based or derivatized polysaccharide-based suspension includes a silicone carrier fluid, an oxidizer, and a suspension aid. The suspension aid is preferably fumed silica. The oxidizer may be selected from the group consisting of alkali metal peroxide, transition metal peroxide, persulfate compound, bromide compound, and bromate compound. In highly preferred embodiments, the oxidizer is magnesium peroxide or calcium peroxide. Alternative carrier fluids and suspension agents are also included in the art. Also disclosed is a method for breaking a polysaccharide-based suspension with the inventive oxidative breaker system.

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.).

Abstract: Selectively cross-linked starches are disclosed that are useful as fluid loss control additives in subterranean treatment fluids comprising starches that are 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.).

Abstract: Selectively cross-linked starches are disclosed that are useful as fluid loss control additives in subterranean treatment fluids comprising starches that are 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.).

Abstract: Rheologically modified compositions, and rheologically modified fluid compositions prepared therefrom, containing reticulated bacterial cellulose in a polyol base fluid, are disclosed. The amount of reticulated bacterial cellulose present in the composition is an amount effective to viscosify the polyol base fluid.

Abstract: A pH tolerant aqueous gel-forming composition for placement within a subterranean formation. The composition includes water, a viscosifying amount of a heteropolysaccharide prepared by growing Xanthomonas campestris NCIB 11854 in an aqueous nutrient medium by aerobic fermentation and recovering the heteropolysaccharide, and a crosslinking agent for the heteropolysaccharide in an amount sufficient to cause gelation of the aqueous solution of the Xanthomonas compestris NCIB 11854 heteropolysaccharide. Also described is a two-stage gel-forming composition for use in controlling the profile of a subterranean formation.

Abstract: A method for imparting selectivity to an in-situ gel-forming composition for placement within a subterranean oil-bearing formation having relatively high permeability zones and relatively low permeability zones, comprising the steps of: preparing an aqueous-based mixture, the mixture comprising: a first stage gel-forming composition in an amount effective to selectively enter the relatively high permeability zones of the formation, the first stage composition including a heteropolysaccharide prepared by growing Xanthomonas campestris NCIB 11854 in an aqueous nutrient medium by aerobic fermentation and recovering the heteropolysaccharide and a crosslinking agent for the heteropolysaccharide; and at least one second stage in-situ gel-forming composition comprising a water-dispersible polymer and a crosslinking agent for the water-dispersible polymer in an amount effective to form a stable gel; and gelling the first stage gel-forming composition ex-situ by reacting the Xanthomonas campestris NCIB 11854 heteropol

Abstract: Methods of inhibiting the flow of water into and from subterranean well formations wherein one or more gelling agents having the property of forming highly viscous gels in the presence of water are injected into the formation.

Abstract: Methods of inhibiting the flow of water into and from subterranean well formations wherein one or more gelling agents having the property of forming highly viscous gels in the presence of water are injected into the formation.

Abstract: An improvement in the method of transporting viscous hydrocarbons through pipes is disclosed. Briefly, the method comprises adding water containing an effective amount of (a) an anionic alkyl polyether ethoxylated sulfate or (b) a combination of this material with an alcohol ether sulfate. The resulting oil-in-water dispersion has a lower viscosity and is more easily transported.

Abstract: An improvement in the method of transporting viscous hydrocarbons through pipes is disclosed. Briefly, the method comprises adding water containing an effective amount of a combination of (a) a sodium or ammonium salt of an ethoxylated alcohol sulfate and (b) a surfactant selected from the group consisting of certain polyoxyethylene-polyoxypropylene block polymers and certain oxyethylated alcohols. The resulting oil-in-water emulsion has a lower viscosity and is more easily transported.

Abstract: A method and composition is provided for positioning a polymeric material having particulate matter disposed therein in a subterranean formation penetrated by a wellbore. The composition consists essentially of a hydrocarbon oil, a quaternary salt of an essentially undegraded, cellulose sulfate, solid particulate matter in an amount equal to from about 0.25 to about 22 pounds of particulate matter per gallon of hydrocarbon oil and an acid-settable thermosetting resin in an amount equal to from about 0.1 to about 5.0 gallons per cubic foot of particulate material. The composition is placed in contact with a subterranean formation in a wellbore by a method comprising injecting a first mixture consisting essentially of said quaternary salt of an essentially undegraded cellulose sulfate mixed with hydrocarbon oil followed by the injection of the composition with a post injection of an additional quantity of the quaternary salt in oil.

Abstract: Sand control in an incompetent formation is effected by squeezing a thickened composition [comprising a hydrocarbon oil carrier, particulate matter (e.g. sand) a base-settable thermosetting resin, a neutralizing agent (e.g. lauryl amine), a miscible polar solvent (e.g. ethanol), and a carboxy vinyl polymer (e.g. CARBOPOL 934)] in contact with the incompetent formation and curing with a basic catalyst.

Abstract: A method and composition is provided for positioning a polymeric material having particulate matter disposed therein in a subterranean formation penetrated by a wellbore. The composition consists essentially of a hydrocarbon oil, a quaternary salt of an essentially undegraded, cellulose sulfate, solid particulate matter in an amount equal to from about 0.25 to about 22 pounds of particulate matter per gallon of hydrocarbon oil and an acid-settable thermosetting resin in an amount equal to from about 0.1 to about 5.0 gallons per cubic foot of particulate material. The composition is placed in contact with a subterranean formation in a wellbore by a method comprising injecting a first mixture consisting essentially of said quaternary salt of an essentially undegraded cellulose sulfate mixed with hydrocarbon oil followed by the injection of the composition with a post injection of an additional quantity of the quaternary salt in oil.

Abstract: Sand control in an incompetent formation is effected by squeezing a thickened composition [comprising a hydrocarbon oil carrier, particulate matter (e.g. sand) a base-settable thermosetting resin, a neutralizing agent (e.g., lauryl amine), a miscible polar solvent (e.g. ethanol), and a carboxy vinyl polymer (e.g. CARBOPOL 934)] in contact with the incompetent formation and curing with a basic catalyst.

Abstract: native bottomhole samples of very viscous crude oil (bitumen, tar) are obtained by injecting water plus a suitable surfactant mixture down a hollow sucker rod whereby mixing occurs downhole, producing a resultant oil-in-water emulsion, and recovering the crude oil from the emulsion. Contamination of the crude oil sample with light hydrocarbons is avoided.