Abstract: Oil degradable granules containing particulate breaker chemical is used in fracturing operations to break hydrocarbon liquid gelled with salts of alkyl phosphate esters. The preferred breaker chemical is powdered Ca(OH).sub.2.

Abstract: This invention relates to improved hydrocarbon gels which find use in the fracturing of petroleum producing formations. In particular it relates to the use of a define class of gelling agents for hydrocarbons which provide excellent results in such fracturing. The gelling agents comprise combinations of (1) selected orthophosphate esters and (2) a composition comprising a source of ferric ions, an amine, and a polycarboxylic acid or salt thereof.

Abstract: A high internal phase ratio water-in-oil emulsion containing an emulsifier comprising a block or graft copolymer the general formula (A-COO).sub.mB or a reaction product of a polyalk(en)yl succinic anhydride and a polar compound having at least one hydroxyl or amino group demonstrates surprisingly low pumping friction pressure losses, high temperature stability and excellent proppant carrying capacity for use as a fracturing fluid in the hydraulic fracturing of subterranean formation.

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: Disclosed is an improvement in a method for propping a fracture adjacent a wellbore formed by injecting in said fracture a carrier fluid containing proppant coated with a curable resin which improvement comprises:a) using proppant coated with a resin fluid containing a polymerizable oligomer of furfuryl alcohol resin, a catalyst comprising an oil soluble, slightly water soluble organic acid and an ester of a weak organic acid to consume water produced by the polymerization of resin;b) using as a carrier an aqueous saline fluid comprising water which is 70% to 100% saturated with sodium chloride,c) suspending said resin-coated proppant in the carrier fluid, forming a fluid mixture of resin-coated proppant and carrier fluid; and injecting said mixture into said fracture, wherein the timing of the addition of the catalyst can be varied.

Abstract: This invention relates to improved hydrocarbon gels which find use in the fracturing of petroleum producing formations. In particular it relates to the use of a define class of gelling agents for hydrocarbons which provide excellent results in such fracturing. The gelling agents comprise combinations of selected orthophosphate esters and ferric ammonium citrate or lower alkyl amine derivative thereof. The lower alkyl amine derivatives are referred to as ferric alkylamine citrates.

Abstract: An aqueous foamed fracturing fluid composition and method for using the foamed fracturing fluid for fracturing subterranean formations that have been penetrated by a wellbore wherein the foamed fracturing fluid comprises: (a) a viscosifier which is preferably either hydrophobically modified guar or hydrophobically modified hydroxymethylcellulose; (b) a surfactant which is preferably alpha olefin sulfonate; and (c) the gas phase includes either nitrogen or carbon dioxide.

Abstract: A stable, non-aqueous liquid suspension of delayed boron cross-linkers comprises an anhydrous boron compound or a sparingly soluble borate suspended in a mixture of mineral spirits (commonly termed as naphtha) and a resin. Anhydrous boron compounds suitable for suspension include, but are not limited to, anhydrous borax, anhydrous boric acid, or a mixture of both the anhydrous borax and anhydrous boric acid. Sparingly soluble borates suitable for suspension include, but are not limited to, alkaline earth metal borates, alkali metal borates, or a mixture thereof. The mixture between the mineral spirits and resin produces a mineral spirits-resin solution. Alternatively, the mineral spirits may be replaced with a suitable oil which forms an oil-resin solution when mixed with the resin. The oil-resin solution suspends the anhydrous boron compound or the sparingly soluble borate to produce a stable, non-aqueous liquid suspension of delayed boron cross-linkers.

Abstract: A composition of matter for matrix conformance formed from an aqueous solution of an alginate polysaccharide and a method of forming an alginate polysaccharide gel. A Group IIA cation, Fe.sup.2+, Fe.sup.3+, Al.sup.3+, Mn.sup.2 +, Zn.sup.2+, a dialdehyde, or a diamine may be used to crosslink the resulting alginate gel. The gel may also comprise a modifier, such as a polyvinyl alcohol, a polycarboxylic acid, or a polyacrylamide. The rate and extent of crosslinking are controlled by varying the alginate molecular weight, the alginate concentration, or the type and concentration of crosslinker, or by adding a sequestering agent such as EDTA or citrate.

Abstract: Borated starch compositions useful for controlling the rate of crosslinking of hydratable polymers in aqueous media for use in drilling fluids.

Abstract: In one embodiment, an epoxy resin composition is provided comprising: an epoxy resin and a partially reduced aromatic amine hardening agent. In another embodiment, a well treating composition is provided comprising: an epoxy resin; a partially reduced aromatic amine hardening agent; a solid particulate material; and a carrier fluid. In yet another embodiment, a method of treating a subterranean formation is provided. The inventive method comprises the step of placing the inventive well treating composition into the formation.

Abstract: Soil bacteria can be isolated which produce an enzyme capable of catalyzing the degradation of mannan-containing hemicellulose under conditions combining high pH and high temperature. Such bacteria can be cultured or used as sources of genetic information with which to engineer other microorganisms to produce the enzyme. Commercially useful quantities of native or recombinant hemicellulase can thus be produced by cultures consisting essentially of microorganisms capable of producing the enzyme.

Abstract: Viscoelastic surfactant based aqueous fluid systems are described that are useful in fracturing subterranean formations penetrated by a wellbore. The preferred thickening agents are quaternary ammonium halide salts derived from certain waxes, fats and oils. The thickening agent is used in conjunction with an inorganic water soluble salt such as ammonium chloride or potassium chloride, and an organic stabilizing additive selected from the group of organic salts such as sodium salicylate. The resulting fluids are stable to a fluid temperature of about 225.degree. F.

Abstract: The present invention relates to resin coated particulates, the process of forming the particulates, and the particulates' utilization in petroleum well completions. More particularly, the present invention comprises the resin coated particulates and the process whereby the high strength particulate substrates are coated with a heat curable resin which is reacted with a formaldehyde source-metal compound (FS-MC) complex. The resultant resin coated particulates are less reactive or interactive with the fluids employed to convey those particulates during petroleum well completion operations.

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 method of gelling a guar or derivatized guar polymer solution utilized to perform a hydraulic fracturing operation includes the step of adjusting the pH of the guar or derivatized guar polymer solution to between about 8.5 and 12.5. After adjusting the pH, an anhydrous boron compound or a sparingly soluble borate suspended in a mineral spirits-resin solution or an oil-resin solution is added to the guar or derivatized guar polymer solution. The guar or derivatized guar polymer solution and the anhydrous boron compound or the sparingly soluble borate solution suspended in the mineral spirits-resin solution or the oil-resin solution is then pumped into a subterranean formation under sufficient pressure to cause a fracture in the formation rock.

Abstract: A method is provided to fracture a subterranean formation along with a fracturing fluid useful in this method, the method comprising the steps of: a) providing a fracturing fluid, the fracturing fluid is an aqueous solution having an initial pH greater than about 8 and comprising a polysaccharide, a source of borate in an amount that is effective to crosslink the polysaccharide at a pH greater than 8, an oxidative breaker, and a precursor that hydrolyzes in an amount that is effective to lower the pH of the fracturing fluid after a time period that is greater than about one half hour and less than about two days; b) injecting the fracturing fluid into the formation at a pressure the is effective to fracture the formation and force at least a portion of the fracturing fluid into the fracture; and c) permitting the precursor to hydrolyze and thereby lowering the pH of the fracturing fluid to a pH that is less than about 8.

Abstract: A method of fracturing a subterranean formation in a well bore is shown in which a gellable fracturing fluid is first formed by blending together an aqueous fluid, a hydratable polymer, a suitable crosslinking agent for crosslinking the hydratable polymer to form a polymer gel and a breaker comprising a slightly water soluble, organic peroxide. The crosslinked polymer gel is pumped into the well bore under sufficient pressure to fracture the surrounding formation. The breaker is allowed to degrade the crosslinked polymer with time to reduce the viscosity of the fluid so that the fluid can be pumped from the formation back to the well surface.

Abstract: The crosslinking of galactomannan gum fracturing fluids by borate ion is delayed for high-temperature applications by encapsulating the boron with a polymer coating. The crosslink-delay time is further adjusted by varying the concentration of an organic polyol. The polyol also acts as a stabilizer for the crosslinked fluid at elevated temperatures. Low pumping friction pressures are achieved by the delay in the crosslinking with the boron available at high temperatures to add high temperature stability to the fracturing fluid at temperatures ranging up to about 350.degree. F.

Abstract: The present invention is directed to new enzyme breakers for breaking fracturing fluids or blocking gels, wherein the enzyme breakers only have activity above a selected temperature, i.e., no activity below the selected temperature or only active in a narrow temperature range. The present invention is preferably specifically directed to hemicellulase enzyme breakers only having activity above 100.degree. F., 150.degree. F., 200.degree. F., or 250.degree. F. and the method of making and use thereof.

Abstract: A composite fracturing fluid consisting of a mixture of carbon dioxide liquid, nitrogen gas and an aqueous media. Nitrogen is present in the mixture in an amount from about 1.25 to about 15 parts by volume to about 1 part by volume carbon dioxide, and nitrogen and carbon dioxide are present in the mixture from about 1 to about 24 parts by volume to about 1 part by volume water at bottom hole conditions in a subterranean formation. Thickening agents, gelling agents, foaming agents, surfactants, cross-linking agents, proppants, and other additives may be mixed with the fluid to achieve fluid properties desired for various types of subterranean formations.

Abstract: A method of fracturing a subterranean formation which surrounds a well bore comprises the steps of providing a fracturing fluid, and injecting the fracturing fluid into the well bore at a pressure sufficient to form fractures in the subterranean formation which surrounds the well bore. The pressure is then released from the fracturing fluid, after which the fluid may be removed from the well and the well placed into production. The fracturing fluid comprises an aqueous liquid, a polysaccharide soluble or dispersible in the aqueous liquid in an amount sufficient to increase the viscosity of the aqueous liquid, an enzyme breaker which degrades said polysaccharide at a temperature above 180.degree. F. Fracturing fluid compositions and enzyme breaker systems useful for carrying out the invention are also disclosed.

Abstract: This invention relates to improved hydrocarbon gels which find use in the fracturing of petroleum producing formations. In particular it relates to the use of a defined class of gelling agents for hydrocarbons which provide excellant results in such fracturing. The gelling agents comprise combinations of ferric salts and selected orthophosphate esters.

Abstract: The present invention relates to a method of controllably breaking an aqueous based viscosified fluid containing a gel stabilizer such as sodium thiosulfate, when the fluid is within a subterranean formation having a temperature above about 175.degree. F. The method is accomplished by the incorporation of a particular selected breaker comprising an alkali metal chlorite or hypochlorite in the viscosified fluid containing the gel stabilizer. The method is particularly effective in providing a controlled break in a treatment fluid introduced into a subterranean formation having a static temperature in the range of from about 200.degree. F. to about 300.degree. F.

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: Disclosed herein is a delayed crosslinking agent. This crosslinking agent contains a borate source and a water-soluble polysaccharide. Suggested borate sources include borax, boric acid, and sodium tetraborate. Guar gum, carboxymethylhydroxypropylguar, and hydroxypropylguar are recommended water-soluble polysaccharides. The borate source is present in an amount of from about 5 to about 30% percent by weight, calculated as B.sub.2 O.sub.3, of the water-soluble polysaccharide.These delayed crosslinking agents are transported to the well site and admixed with an aqueous solution containing additional water-soluble polysaccharide. The delayed crosslinking agents re-equilibrate in the aqueous solution of the water-soluble polysaccharide. The resulting compositions are useful as fracturing fluids.