Abstract: Methods and apparatus are disclosed for fracturing subterranean formations using fracturing fluids that are hydrated from dry mix blends. One aspect of the invention comprises a dry blended particulate composition for hydraulic fracturing comprising a particulate hydratable polysaccharide, a particulate crosslinking agent, and a slowly releasing particulate base. The compositions employ controlled release methods of particle dissolution. The invention reveals a dry blended particulate composition capable of significantly improved high temperature stability. Further, methods of fracturing and apparatus for rapidly hydrating and pumping the fracturing fluid into subterranean formations are disclosed.

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscoelastic surfactant fluid containing wormlike micelles are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The invention further relates to novel fracturing methods useful for increasing hydrocarbon production, limiting connate water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of micelles of surfactant in aqueous zones of the subterranean formation facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

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: 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: A method combining resin consolidation and placement of fibrous material in intimate mixture with particulates provides a means of stabilizing a formation respect to sand production while enhancing well productivity without requiring a gravel pack screen.

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: Prior to pumping completion brine fluid into a wellbore, an additive comprising two percent (2%) of a 0.25% solution of polyacrylamide is blended into the completion brine fluid thereby producing a treated brine fluid. This blending would be performed in tanks at the wellsite. The treated brine fluid is then pumed into the wellbore. In addition, or in the alternative, a new perforating gun stores the polyacrylamide additive composition. When the perforating gun detonates, the additive is disbursed into the completion brine fluid disposed in the annulus of the wellbore. For example, the new perforating gun may include a plurality of shaped charges coated with a lacquer of the polyacrylamide additive, or it may include one or more containers which contain the polyacrylamide additive. When the brine completion fluid is pumped into the wellbore annulus, a detonation wave conducts in a detonating cord of the perforating gun. The detonation wave passes through each of the containers.

Abstract: A novel method and device for manipulating ferrofluids for use in cementing wells are disclosed. The cementitious fluids may comprise: (a) a hydraulic cement, (b) finely divided magnetic particles, (c) a binding agent or a surfactant, and (d) a liquid medium. The binding agent or surfactant is present in the compositions in an amount sufficient to render the compositions stable in a magnetic field. When used in cementing wells, the cementitious ferrofluids are implaced in the annulus separating a casing from the formation in a wellbore by conventional techniques and the slurry is subsequently subjected to an activating alternating magnetic field that causes movement of the flurry. The non-cementitious ferrofluids comprise: (a) finely divided magnetic particles, (b) stabilizing agent, and (c) a liquid medium. The movement of the slurry results in a "scrubbing" action against the surface of the casing and formation surfaces, and a mixing of the slurry which helps displace any residual drilling mud.

Abstract: Novel cementitious and non-cementitious ferrofluids are disclosed which have properties making them suitable for use in cementing wells. The cementitious fluids comprise: (a) a hydraulic cement, (b) finely divided magnetic particles, (c) a bonding agent or a surfactant, and (d) a liquid medium. The binding agent or surfactant is present in the compositions in an amount sufficient to render the compositions stable in a magnetic field. When used in cementing wells, the cementitious ferrofluids are implaced in the annulus separating a casing from the formation in a wellbore by conventional techniques and the slurry is subsequently subjected to an activating magnetic field that causes movement of the magnetic particles in the slurry. The non-cementitious ferrofluids comprise: (a) finely divided magnetic particles, (b) stabilizing agent, and (c) a liquid medium.

Abstract: A salt water hydraulic cement slurry and method of use in oil and gas well cement jobs involving a novel fluid loss additive comprising an admixture of sulfonated aromatic polymers. An effective amount of an admixture of water soluble salts of a sulfonated styrene/maleic anhydride copolymer, sulfonated polystyrene, sulfonated polyvinyltoluene and sulfonated polynaphthalene/formaldehyde condensate when added to a salt water/Portland cement slurry provides fluid loss control to the Portland cement slurry at bottomhole circulating temperature between 80.degree. and 210.degree. F. Further, addition of and/or the replacement of the sulfonated polystyrene by a water soluble lignosulfonate further enhances the high temperature properties of the salt water cement slurry.One exception to this appears in British Pat. No.

Abstract: Cement slurries comprising (a) iron (II) sulfate, or hydrate thereof, (b) aluminum sulfate, or a hydrate thereof, (c) a hydraulic cement comprising calcium hydroxide or a hydrolyzable calcium oxide (e.g., a Portland cement), and (d) water, are described. These cement slurries are pumpable and thixotropic and have particular utility in cementing pipe into the borehole of a petroleum well.

Abstract: A hydratable cement composition useful for preparing a pectolite-containing expanding cement at temperatures above about 150.degree. C. comprising a water soluble sodium salt of a weak acid, a 0.1 molar aqueous solution of which salt has a pH of between about 7.5 and about 11.5, a calcium source, and a silicon source, where the atomic ratio of sodium to calcium to silicon ranges from about 0.3:0.6:1 to about 0.03:1:1; aqueous slurries prepared therefrom and the use of such slurries for plugging subterranean cavities at a temperature of at least about 150.degree. C.The invention composition is useful for preparing a pectolite-containing expansive cement having about 0.2 to about 2 percent expansion, by volume, when cured at at least 150.degree. C.

Abstract: A method combining resin consolidation and placement of fibrous material in intimate mixture with particulates provides a means of stabilizing a formation respect to sand production while enhancing well productivity without requiring a gravel pack screen.