Abstract: The present invention relates to a method of breaking an aqueous fracturing fluid comprising introducing said aqueous fracturing fluid into contact with an encapsulated viscosity reducing agent said encapsulated viscosity reducing agent comprising an aqueous fluid soluble breaker for said fracturing fluid encapsulated within a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide, said membrane having an embrittlement effective amount of a micron sized particulate present therein and said membrane having been cured at a temperature of at least about 115° F., such that an aqueous fluid in said fracturing fluid can contact said breaker after fracture failure of said membrane to dissolve at least a portion of said breaker and break the fracturing fluid in contact therewith.

Abstract: The present invention provides methods and compositions for sealing subterranean zones. The methods of the invention basically comprise the steps of preparing a sealing composition comprised of an aqueous alkali metal silicate solution, a gelling agent and a delayed acid activator for causing the composition to set into a rigid mass, placing the sealing composition in said subterranean zone and allowing the sealing composition to set into a rigid sealing mass therein.

Abstract: The present invention provides borate cross-linked well treating fluids and methods of preparing and using the fluids in treating wells such as fracturing subterranean zones therein. The improved cross-linked treating fluids are basically comprised of water, a hydrated galactomannan gelling agent and a borate composition for buffering the treating fluid and cross-linking the hydrated galactomannan gelling agent comprised of water, a soluble boron source and an alkanolamine or alkylamine.

Abstract: A method of treating a subterranean formation penetrated by a wellbore utilizing a preformed high solids content slurry is prepared and transported to the wellsite. A portion of the slurry is admixed with a treatment fluid whereby the resultant solids content of the fluid is reduced and the fluid is introduced into a wellbore penetrating the subterranean formation. The high solids content slurry is substantially stable and the particulate does not substantially settle within the fluid prior to admixing with the treatment fluid thereby permitting large quantities of particulate to be rapidly admixed with a treatment fluid.

Abstract: The present invention provides methods of stimulating fluid production from an unconsolidated formation penetrated by a wellbore while preventing the migration of formation sands with fluids produced from the formation. The methods basically comprise the steps of injecting a hardenable resin composition into a portion of the formation surrounding the wellbore whereby that portion is consolidated into a hard permeable mass, forming an indentation in the wellbore to facilitate the initiation of a fracture in the consolidated portion of the formation, creating a fracture in the formation extending from the wellbore through the consolidated portion of the formation into an unconsolidated portion thereof and depositing hardenable resin composition coated proppant in the fracture whereby the proppant is consolidated into a hard permeable mass.

Abstract: The present invention relates to a method of preparing an encapsulated enzyme breaker and method of use in treating a subterranean formation. An encapsulated breaker is prepared by coating an enzyme on a cellulose substrate. A micron-sized particulate is admixed with the enzyme solution to prevent undesired agglomeration of the substrate. The enzyme solution coated substrate is covered with a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide. The membrane contains imperfections through which an aqueous fluid may pass into the breaker to contact the enzyme and diffuse the enzyme outward from the breaker particle.

Abstract: The present invention provides a method of treating a subterranean formation by rapidly viscosifying a normally liquid hydrocarbon. The method is accomplished by admixing (i) an alkyl orthophosphate acid ester and (ii) an alkali metal hydroxide present in an amount sufficient to at least partially neutralize said ester and (iii) a reaction product resulting from the reaction of a source of aluminum or ferric ions with a C.sub.8 -C.sub.18 surface active amine solubilized in the presence of an organic solvent such as a C.sub.2 -C.sub.4 monohydric alcohol with the normally liquid hydrocarbon. The mixture rapidly viscosifies to a level sufficient to transport proppant and then can be introduced into a subterranean formation to treat the formation in a desired manner.

Abstract: A gel fluid for treating a subterranean formation penetrated by a well bore including an aqueous liquid, an organic gelling agent and at least about 0.05% by weight, based on the weight of the aqueous liquid, of a broken gel fragment stabilizer. The gel fluid can optionally include crosslinking agents, proppant materials, pH buffers and other components. The broken gel fragment stabilizer is a dialkyl sulfosuccinate that has dispersing properties sufficient to diminish the propensity of broken gel fragments formed when the gel fluid breaks to agglomerate. Also provided is a method of treating a subterranean formation penetrated by a well bore. The inventive gel fluid and method are particularly suitable for fracturing a subterranean formation to stimulate the production of hydrocarbons therefrom.

Abstract: Fracturing fluids for hydraulically fracturing oil and gas bearing subterranean formations to increase flow of formation fluids into wells using a periodate or a metaperiodate salt as the viscosity breaker. The fracturing fluids are particularly advantageous when used in conjunction with curable resin-coated proppants and for fracturing subterranean formations which are at temperatures between about 50.degree. F. and about 120.degree. F., in conjunction with both uncured resin-coated proppants and other types of proppants.

Abstract: The present invention relates to a method of breaking an aqueous fracturing fluid comprising introducing said aqueous fracturing fluid into contact with an encapsulated breaker said encapsulated breaker comprising an aqueous fluid soluble breaker for said fracturing fluid encapsulated within a membrane comprising a partially hydrolyzed acrylic crosslinked with either an aziridine prepolymer or a carbodiimide, said membrane having imperfections through which an aqueous fluid can diffuse, such that an aqueous fluid in said fracturing fluid can diffuse through said membrane, dissolve at least a portion of said breaker and diffuse outward from said encapsulated breaker to contact and break the fracturing fluid in contact therewith.

Abstract: An apparatus and method for continuously mixing well treatment fluids, such as fracturing gels and the like. Dry polymer is fed into a metering feeder which accurately meters the rate of polymer fed into a water spraying mixer. A vent is provided so that air can enter with the polymer as necessary. Water, with or without a buffering compound therein, is flowed through a water inlet of the mixer. The water is jetted into a spiraling flow pattern through which the polymer falls and is substantially wetted. Auxiliary water inlets may be used to add additional water to the water-polymer slurry to increase mixing energy and increase the amount of slurry produced. The slurry is discharged into a mixing tank with an agitator and then into a holding tank. The slurry may also pass through a shear device to further increase the rate of viscosification of the slurry.

Abstract: The present invention provides a method of treating a subterranean formation utilizing a gelled fluid containing a galactomannan gum and a crosslinking agent comprising a source of borate ions and a delayed crosslinker comprising a source of Ti(+4) or Zr(+4) ions. The combination of crosslinking agents yields a viscous fluid at elevated temperatures having a viscosity higher than attainable by either crosslinking agent alone or as the result of the additive effects of the crosslinking agents. The enhanced viscosity facilitates transport and placement of proppant material in a subterranean formation.

Abstract: A method of increasing the production of hydrocarbons from a subterranean formation wherein an undesirable filter cake is present, resulting from the introduction of gelled polysaccharide containing fluids into the formation, comprising contacting the formation with an effective amount of a treatment fluid comprising a soluble source of fluoride ions present in an amount sufficient to provide a molar concentration of from about 0.01 about 0.5, having a pH in the range of from about 2 to about 4, whereby at least a portion of the filter cake is caused to dissolve.

Abstract: The present invention relates to a liquid suspension of a high molecular weight, water-soluble polymer or water-soluble salt prepared by admixing and water-soluble polymer with a hydrocarbon carrier fluid and a suspending agent comprising an aqueous emulsion of a copolymer comprising a water-insoluble and substantially hydrocarbon-insoluble polymer consisting of particles having a dry weight average particle size of below 10 .mu.m and which is formed from monomers of which 80% to 100% are hydrophobic, 30 to 100% are polar and 0% to 20% are hydrophilic. More particularly, the copolymer comprises from about 80% to about 100% C.sub.1-30 alkyl methacrylate monomers and from about 0% to about 20% hydrophilic monomers. Preferably, the copolymer comprises 90% to 100% 2-ethylhexylacrylate and from about 0.5% to about 10% acrylic acid. The liquid suspension is capable of supporting about 5 pounds of water-soluble polymer per gallon of suspension.

Abstract: A method of treating a subterranean formation penetrated by a well bore comprising injecting a gelled foamed fluid into said formation. The gelled foamed fluid is prepared by foaming an admixture of a fluid and a surface active foaming agent and admixing the foamed fluid with a gelled fluid whereby the foamed fluid is diluted by the gel to form the gelled foamed fluid.

Abstract: Foamed high viscosity aqueous inorganic acid solutions and methods of treating subterreanean well formations using such solutions are provided. The foamed acid solutions are comprised of water, at least one water soluble inorganic acid, a gelling-foaming agent comprised of a solution of a water soluble organic solvent and an ethoxylated fatty amine or a mixture of such amines and an inert gas.

Abstract: A method of treating a subterranean well formation wherein a low pH highly viscous thixotropic treating fluid is introduced into the formation. The treating fluid is formed by combining an aqueous acid solution with an aqueous alkali metal silicate solution and a gelling agent whereby a highly viscous polymerized alkali metal silicate gel of low pH is produced followed by shearing of the gel to impart thixotropic properties thereto.