Abstract: The present invention provides seawater-based cross-linked fracturing fluids and methods of preparing and using the fluids in fracturing subterranean formations penetrated by well bores and having temperatures above about 200° F. The improved cross-linked fracturing fluids are basically comprised of a gelling agent, seawater present in an amount sufficient to hydrate the gelling agent and to form a gelled aqueous fluid, and a delayed cross-linking agent, capable of causing delayed cross-linking of the gelling agent in the gelled aqueous fluid at a pH below the threshold for precipitate formation in seawater.

Abstract: Improved aqueous fracturing fluids are disclosed that are particularly useful as well stimulation fluids to fracture tight (i.e., low permeability) subterranean formations. Gas wells treated with these fracturing fluids have rapid cleanup and enhanced well production. The fluids contain small but sufficient amounts of certain amine oxides to aid in the removal of the fracturing fluid from the formation. By facilitating the removal of fluid from the invaded zones, the amount of damage to the fracture faces in the formation is thereby minimized. The amine oxides correspond to the formula I, wherein R1 is an aliphatic group of from 6 to about 20 carbon atoms, and wherein R2 and R3 are each independently alkyl of from 1 to about 4 carbon atoms. The amine oxides in which R1 is an alkyl group are preferred, and those in which R1 is an alkyl group of from 8 to 10 carbon atoms and R2 and R3 are each methyl or ethyl groups are most preferred.

Abstract: This invention provides a water-free oil based fluid polymer suspension composition for use as a rheology modifier and fluid loss reducer in oil or gas well servicing fluids. It has been found that by using white medicinal oil as a carrier, high solids content and environmental friendly anhydrous fluidized polymer suspensions of xanthan gum, cellulose ethers, guar gum and derivatives thereof can be prepared. More specifically, in one aspect, an oil-based fluid polymer suspension (FPS) composition for use in oil or gas well servicing fluids is preferred containing: a) a hydrophilic polymer, b) an organophilic clay, c) a stabilizer, and d) a white medicinal oil having selected properties.

Abstract: Subterranean formation treating fluid concentrates, treating fluids and methods are provided by the present invention. The treating fluid concentrates are basically comprised of water and a substantially fully hydrated depolymerized polymer. The treating fluids which are formed by adding water to the treating fluid concentrates are basically comprised of water, a substantially fully hydrated depolymerized polymer and a crosslinking agent for crosslinking the hydrated depolymerized polymer.

Abstract: A new stable liquid suspension containing non-soluble particles dispersed in a non-aqueous liquid medium having a concentration of a suspension aid and a method of making and use thereof.

Abstract: The present invention provides environmentally safe foamed fracturing fluids, additives for foaming and stabilizing foamed fracturing fluids and methods of fracturing subterranean zones. The foamed fracturing fluids of this invention are basically comprised of water, a gelling agent for forming the water into gelled water and increasing the viscosity thereof, sufficient gas to form a foam, and an effective amount of an additive for foaming and stabilizing the gelled water comprised of hydrolyzed keratin.

Abstract: Polymers are derivatized and then may be introduced into a wellbore, such as in a hydraulic fracturing treatment. A polymer may be a guar powder that is mixed with a organic solvent and derivatized using a derivatizing agent, such as sodium chloroacetate. The polymer is typically derivatized in bulk prior to introduction into the wellbore. The derivatized polymer may be hydrated and/or crosslinked prior to introduction into the wellbore.

Abstract: The present invention relates to methods of treating subterranean formations with viscosified aqueous well treating compositions which break into thin fluids at static temperatures in the range of from about 150° F. to about 200° F. A breaker system is included in the compositions comprised of an alkali metal or ammonium persulfate breaker and a breaker activity delaying agent comprised of an alkali metal chlorite or hypochlorite.

Abstract: The present invention provides improved methods of treating subterranean formations using borate cross-linking compositions and borate cross-linked well treating fluids. The borate cross-linking compositions are basically comprised of a low viscosity hydrocarbon liquid, an organophillic clay, a slightly water soluble borate, a buffer and a dispersing agent.

Abstract: A chemical system and method to stop or minimize fluid loss during completion of wells penetrating hydrocarbon formations are provided. The inventions relates to formulating a highly stable crosslinked hydroxyethyl cellulose (HEC), control released viscosity reduction additives, and user friendly packaging. The chemical system contains a linear HEC polymer solution, a low solubility compound which slowly raises the fluid pH, a chelating agent which further increases the pH level beyond the equilibrium achievable by the low solubility compound, a metal crosslinker which crosslinks HEC at elevated pH, a crosslink delaying agent which allows fluid viscosity to remain low until the fluid reaches the subterranean formation, and optionally an internal breaker. The chemical additives are packaged as an integrated pallet and transported to a field location which allows operators to conveniently mix them before pumping.

Abstract: A method is provided for controlling the delay time of aqueous borate-crosslinked polysaccharide-based fluids for hydraulic fracturing and related applications which allows on-the-fly control of the delay time without comprising overall fluid integrity. Without having to modify the total boron content nor pH of the fracturing fluid, the delay time is controlled by adding a polyol to the fracturing fluid at a first rate, determining the resulting delay time and then adjusting the rate of the polyol addition to the fracturing fluid until the desired delay time is achieved.

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: The present invention provides compositions useful for viscosifying aqueous fluids, methods for making them and methods for using them. In one aspect of the invention, inventive compositions comprise a prehydrating alcohol having at least two hydroxyl groups and having a molecular weight of from about 60 to about 600; an inorganic salt; and a polymer. In a preferred aspect of the invention, the viscosifier composition additionally comprises a solvent having a molecular weight of from about 75 to about 1000. According to another aspect of the invention, inventive compositions comprise a prehydrating alcohol; an inorganic salt; and a polymer; and the composition is essentially free from water. Inventive compositions find advantageous use in viscosifying fluids utilized in subterranean drilling activities such as, for example, drilling, drill-in, completion, hydraulic fracturing, work-over, packer, well treating, testing, spacer, or hole abandonment fluids.

Abstract: Improved high viscosity well treating fluids for use at temperatures above about 200.degree. F., gel breaking additives for the treating fluids and methods of using the treating fluids are provided by the present invention. The high viscosity well treating fluids are basically comprised of an aqueous liquid, a polysaccharide gelling agent to increase the viscosity of the aqueous liquid and a gel breaker comprised of a bromate ion releasing compound to reduce the viscosity of the aqueous liquid after a desired period of time.

Abstract: The invention involves biopolymer/oil suspension compositions for the oil service industry, most particularly drilling and completion fluids, which provide such fluids a variety of desirable properties. Biopolymers include water soluble polymers and water swellable polymers. Such biopolymer/oil suspension compositions are essentially mixtures of biopolymers such as cellulosics in an oil medium with a specific anti-settling additive. The invention is particularly directed to providing enhanced anti-settling properties to such biopolymer/oil compositions; that is, the ability of the biopolymer/oil composition to retain the biopolymers in suspension prior to the composition being introduced into drilling and completion fluids. The invention in one embodiment is described as a liquid biopolymer-in-oil additive compositions for use in aqueous-based completion fluids, containing an agent comprising: a) one or more polyamides, and b) hydrogenated caster oils including castorwax.

Abstract: The present invention relates to a method of breaking an aqueous based viscosified fluid having potassium ions present therein with a breaker comprising an alkali metal chlorite or hypochlorite through use of a breaker activator comprising a source of ammonium ion in the aqueous fluid. 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 100.degree. F. to about 300.degree. F. In some instances, a second breaker activator comprising a source of thioglycolate ion also may be admixed with the viscosified fluid to further accelerate breaker activation at temperatures below about 200.degree. F.

Abstract: The present invention relates to a method of breaking an aqueous based viscosified fluid containing a breaker comprising an alkali metal chlorite or hypochlorite through use of a breaker activator comprising thioglycolate ion or a compound capable of producing thioglycolate ion in the aqueous fluid. 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 100.degree. F. to about 200.degree. F.

Abstract: A method is shown for fracturing a subterranean formation in which a hydratable polymer, crosslinking agent and breaker are combined in an aqueous carrier to form a gelled fracturing fluid. The breaker is comprised of a substantially insoluble oxidant which is granulated and formed into a pellet or prill with a suitable binder. The pellet so formed can also contain a chelating agent and an activator in order to enhance the rate of breaking. The substantially insoluble oxidant is selected from the group consisting of alkaline earth and zinc salts of peroxide, perphosphate, perborate, and percarbonate.

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: 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.