Abstract: Methods and compositions for controlling iron in aqueous well fracturing fluids are disclosed. In accordance with the methods, ferric iron contained in a fracturing fluid is prevented from precipitating or otherwise disadvantageously reacting by adding a thioalkyl acid or derivative thereof to the fracturing fluid. The thioalkyl acid or derivative reduces ferric ion to ferrous ion which remains in solution at pH levels below about 7.5.

Abstract: Water-soluble, polymer viscosifiers of aqueous solutions, also known as gelling agents, can be suspended in a hydrocarbon carrier fluid, such as, diesel to prepare a liquid gel concentrate. When a liquid gel concentrate is added to an aqueous solution the gelling agent disperses into it and viscosifies it. To make an improved performance admixture for preparation of liquid gel concentrates and render the gelling agent suspendable in the hydrocarbon carrier fluid, it is first coated with a mixture of an oil-compatible polymer suspending agent, such as a polymer suspension, comprising a branched chain alkyl acrylate monomer copolymerized with a minor amount of hydrophilic monomer such as acrylic acid with an appropriate amount of internal crosslinking agent to control polymer particle size, and a surfactant such as a nonylphenol reacted with several moles of ethylene oxide, styrenated phenol ethoxylate, or a phosphate ester of styrenated phenol ethoxylate.

Abstract: A method of treating a subterranean formation utilizing a first acidic crosslinked aqueous gel followed by a second alkaline crosslinked aqueous gel having a different crosslinking agent. The first fluid assists in breaking the viscosity of the second fluid upon completion of the treatment. The first fluid may contain a gasifiable fluid which will provide a gas assist to the return of the first and second fluids upon completion of the treatment.

Abstract: The present invention provides a method for treating coal seams to improve dewatering to enhance gas production therefrom. The treatment is effected by contacting the coal with an effective amount of a selected additive comprises at least one member selected from the group consisting of benzyl coco di-(hydroxyethyl) quaternary amine, p-T-amyl-phenol condensed with formaldehyde and a copolymer comprising from about 80 to about 100% C.sub.1-30 alkyl methacrylate monomers and from about 0 to about 20% hydrophilic monomers.

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 persulfate/catalyst breaker system is disclosed which effects controlled breaks of polysaccharide gelled fluids in the ambient temperature range without interfering with fluid performance. The catalyzing constituent of the breaker system comprises at least one member selected from the group of erythorbic acid or its salts, hydroxylamine hydrochloride, dihydroxymaleic acid and its salts, citric acid and its salts and a copper ion releasing compound.

Abstract: The present invention relates to novel crosslinkable interpolymers and methods of use in treating subterranean formations. The novel interpolymers comprise a water soluble monomer, a hydrophobe monomer, and vicinal diol monomer polymerized to form high molecular weight polymers which viscosify aqueous liquids. The solution viscosity may be enhanced by the addition of a surfactant having an HLB value of about 10 or less. The interpolymers are readily crosslinkable with polyvalent metal ions, such as titanium and zirconium to form thermally stable viscoelastic gels. The gels provide viscosity and solids transport characteristics that are useful in stimulating, gravel packing and polymer flooding operations.

Abstract: Novel treating fluid compositions containing crosslinkable non-ionic cellulose derivatives and methods of use in petroleum recovery operations are disclosed. The treating fluid polymers are prepared by reacting vinyl or allyl monomers having a crosslinkable substitutent with a cellulose derivative using a ceric ion redox system. Treatment of a non-ionic cellulose derivative with a ceric ion redox system also yields a crosslinkable polymer. The polymers readily crosslink with polyvalent metal ions, such as zirconium and titanium, to form temperature-stable gels useful in petroleum recovery operations.

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: Several new treatment processes and compositions for practicing these processes are provided which substantially alter the fluid flow and surface characteristics of porous permeable particulate formations, especially subterranean formations intersected by an oil well. The compositions of this invention also provide methods of increasing viscosity or gelling aqueous fluids, especially acids, which can be used to treat such earthen formations. Treatment of the earthen formations with the compositions of this invention can substantially modify the permeability and surface characteristics of the formation to prevent or reduce the flow of aqueous fluids, especially water and formation brines through that portion of the formation, thereby reducing the water-oil ratio of fluid flowing through or produced from that formation and in some cases enhancing the hydrocarbon production. The treatment of this invention uses branched organic polymers of a wide molecular weight range.

Abstract: Several new treatment processes and compositions for practicing these processes are provided which substantially alter the fluid flow and surface characteristics of porous permeable particulate formations, especially subterranean formations intersected by an oil well. The compositions of this invention also provide methods of increasing viscosity or gelling aqueous fluids, especially acids, which can be used to treat such earthen formations. Treatment of the earthen formations with the compositions of this invention can substantially modify the permeability and surface characteristics of the formation to prevent or reduce the flow of aqueous fluids, especially water and formation brines through that portion of the formation, thereby reducing the water-oil ratio of fluid flowing through or produced from that formation and in some cases enhancing the hydrocarbon production. The treatment of this invention uses branched organic polymers of a wide molecular weight range.