Abstract: A method of forming in a desired location in a well bore a dual-state composite of a hardened hydraulic cement and a solid rubber which features the use of a composition consisting essentially of a mixture of a slurry of a hydraulic cement and a vulcanizable rubber latex.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: A pH tolerant aqueous gel-forming composition for placement within a subterranean formation. The composition includes water, a viscosifying amount of a heteropolysaccharide prepared by growing Xanthomonas campestris NCIB 11854 in an aqueous nutrient medium by aerobic fermentation and recovering the heteropolysaccharide, and a crosslinking agent for the heteropolysaccharide in an amount sufficient to cause gelation of the aqueous solution of the Xanthomonas compestris NCIB 11854 heteropolysaccharide. Also described is a two-stage gel-forming composition for use in controlling the profile of a subterranean formation.

Abstract: Gels containing gas precursors and/or pathways are used to selectively reduce the flow of aqueous fluids with respect to the flow of nonaqueous fluids to enhance the recovery of the nonaqueous fluids from subterranean formations. The gels, while stable at reservoir conditions, are also readily degraded by gel degrading agents such as acids and therefore are also employed as fail-safe gels in subterranean gel treatments. In another embodiment, selective permeability is restored to a previously treated well by injecting a gas into the previous treated portions of the subterranean formation to displace any aqueous fluid obstructing the passage of the nonaqueous fluid through the polymer-coated pores or gel.

Abstract: The present invention provides set retarding additives, set retarded hydraulic cement compositions including such additives and methods of using the cement compositions for cementing zones in wells. The set retarding additives are graft polymers comprised of a backbone sugar having one or more pendant polymerized or copolymerized vinyl compounds grafted thereto.

Abstract: An oil and gas well cementing composition has styrene/butadiene latex and a combination of nonionic and anionic surfactants for improved physical properties, especially fluid loss.

Abstract: A unique tetrapolymer and an additive package for reducing water loss from cement comprising a tetrapolymer, base, and electrolyte, at least one surfactant, and water is disclosed. A process for producing cement slurries with improved water loss properties, as well as an improved method for cementing gas and oil wells is also disclosed.

Abstract: An oil and gas well cementing composition has styrene/butadiene latex and a combination of nonionic and anionic surfactants for improved physical properties, especially fluid loss.

Abstract: Gellable compositions containing:(a) water;(b) a water-soluble organic polymer bearing special chelating functional groups;(c) a multi-valent metal ion capable of causing the polymer to crosslink,are useful to recover oil from a oil field.Said compositions make it possible gels to be obtained which are endowed with improved physical properties and show a higher stability under the conditions prevailing in the oil field.

Abstract: Gels stable in a subterranean formation at a temperature greater than about 175.degree. F. are formed using, inter alia, a stabilizing agent (e.g., a buffer having a buffering capacity at a pH of at least about 8 and/or a chelating agent).

Abstract: An aqueous polymeric gel-forming composition capable of selectively plugging highly permeable zones in subterranean oil-bearing formations. The composition comprises an aqueous solution of an anionic acrylamide copolymer of high molecular weight, comprising about 5 to 95 weight percent of 2-acrylamido-2-methylpropanesulfonic acid, about 2 to 95 weight percent of N-vinyl-N-methyl acetamide and about 5 to 93 weight percent of acrylamide, and a crosslinking agent selected from the group consisting of transition metal ions, phenolic resins and amino resins. The compositions of this invention will form stable gels in brines of wide-ranging salinity and are effective at the pH levels encountered in carbon dioxide and water flooding operations. Also provided is a process for selectively plugging regions of higher permeability within an oil-bearing formation to improve sweep efficiency during a fluid flood oil recovery operation.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: Visible gels are formed by mixing an inorganic crosslinking agent with a low viscosity aqueous solution having a low polyacrylamide content. The visible gels are employed to reduce the water/hydrocarbon permeability ratio of subterranean formations.

Abstract: The permeability of high-permeability zones in a oil reservoir can be reduced by using a gellable aqueous composition with delayed gelation. The composition comprises:a) water;b) a high-molecular weight natural or synthetic water-soluble polymer cross-linkable by means of Cr.sup.3+ ions;c) a water-soluble inorganic Cr.sup.

Abstract: An aqueous gellable composition having a delayed gelling time is disclosed, which contains a water-soluble polymer crosslinkable with Cr.sup.3+ and a crosslinking/retardant system containing a Cr.sup.3+ ion and a salicylic acid ligand, wherein said ligand can be in free form, or in the form of a complex with Cr.sup.3+, or partially in free form and partially in complexed form.Such a composition is useful for modifying the permeability in petroleum reservoirs, within a wide range of temperatures, of from about 60.degree. C. to 120.degree. C., or higher temperatures.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: The invention relates to aqueous preparations of acid-catalyzed melamine resins and/or urea-formaldehyde condensates which contain an addition of zeolite NaA and/or hydroxysodalite to increase their usefulness. The preparations in question are particularly suitable for use in the stabilization of rock and/or plugging of cavities, for example in tunneling and mining. Accordingly, the invention also relates to a process for stabilizing rock, for example in tunneling and mining, by injection of corresponding preparations together with an acidic catalyst.

Abstract: A novel composition and process are disclosed for forming crosslinked gels at elevated temperatures utilize a novel crosslinking agent comprising at least one aminobenzoic acid compound and a water dispersible aldehyde or aldehyde generating compound.

Abstract: Water production from a wellbore is reduced by sequentially or simultaneously injecting (a) a hydrophilic polymer-containing organic carrier fluid and (b) a crosslinking agent-containing fluid into at least a portion of a subterranean formation. The cross-linking agent reacts with the polymer in the presence of water to form a gel in at least a portion of the subterranean formation. The gel obstructs the flow of water in the subterranean formation, thereby reducing the production of water from the wellbore.

Abstract: Well completion methods utilizing rubber latex compositions are provided. The compositions are comprised of an aqueous suspension of rubber, a vulcanizing agent and a vulcanization activator, and are placed in a subterranean formation or a well bore at a desired location therein and allowed to vulcanize whereby a solid rubber plug or seal is formed.

Abstract: A method for imparting selectivity to an in-situ gel-forming composition for placement within a subterranean oil-bearing formation having relatively high permeability zones and relatively low permeability zones, comprising the steps of: preparing an aqueous-based mixture, the mixture comprising: a first stage gel-forming composition in an amount effective to selectively enter the relatively high permeability zones of the formation, the first stage composition including a heteropolysaccharide prepared by growing Xanthomonas campestris NCIB 11854 in an aqueous nutrient medium by aerobic fermentation and recovering the heteropolysaccharide and a crosslinking agent for the heteropolysaccharide; and at least one second stage in-situ gel-forming composition comprising a water-dispersible polymer and a crosslinking agent for the water-dispersible polymer in an amount effective to form a stable gel; and gelling the first stage gel-forming composition ex-situ by reacting the Xanthomonas campestris NCIB 11854 heteropol

Abstract: An electrically conductive polymer composition containing a nonconjugated polymer and a salt is prepared by admixing a sol or gel composition containing the salt with a polymer. A novel sol or gel composition containing a nonionic surfactant stabilizer is useful for preparing the electrically conductive composition. An intermediate mixture of salt, stabilizer and solvent are heated to prepare a sol or gel which is typically admixed with a latex to produce a product admixture containing the salt and a latex polymer. The product admixture is dried to produce a resultant latex polymer/salt composition having electrically conductive properties useful, as for example, as an antistatic carpet coating.

Abstract: The permeability of high-permeability zones in a oil reservoir can be reduced by using a gellable aqueous composition with delayed gelation.The composition comprises:a) water;b) a high-molecular weight natural or synthetic water-soluble polymer cross-linkable by means of Cr.sup.3+ ions;c) a water-soluble inorganic Cr.sup.

Abstract: A gel-forming composition capable of plugging highly permeable zones in a subterranean formation. The composition comprises water, a viscosifying amount of a water-dispersible polyvinyl amine copolymer and a crosslinking agent which is a mixture of an aldehyde and a phenolic component in an amount effective to cause gelation of the aqueous solution of the copolymer. The resultant gel is exceptionally thermally stable and, therefore, can be used as an effective profile control agent in all enhanced oil recovery operations, including steam flooding.

Abstract: A gellable aqueous compositions able to reduce the permeability of high-permeability zones in an oil reservoir is a aqueous solution containing metered quantities of:a) a water-soluble organic polymer cross-linkable by the effect of a polyvalent metal ion cross-linking agent;b) a Cr(III) ion cross-linking agent; andc) a ligand for the cross-linking agent chosen from water-soluble organic alpha-hydroxy acids and alpha-amino acids.

Abstract: A method for reducing the permeability of a high-permeability zone in a high-temperature oil reservoir comprises:preparing a gellable polymeric aqueous solution, operating on the surface under controlled conditions;injecting said gellable solution into the oil reservoir through a well;moving the solution through the reservoir until it reaches and substantially fills the high-permeability zone to be treated; andgelling the solution in situ with consequent lowering of the permeability in said high-permeability zone, and is essentially characterized in that the gellable solution is an aqueous solution containing a Cr(III) ion cross-linking agent and a water-soluble organic polymer cross-linkable by the effect of said cross-linking agent, said solution being free or substantially free of ligands for the cross-linking agent and having a pH adjusted to a value within the range of 1.5 to 5.5, depending on the desired gelling time.

Abstract: Improved methods of forming and suspending consolidatable resin composition coated particulate materials in gelled aqueous carrier liquids are provided. In accordance with the methods, a gelled aqueous carrier liquid, uncoated particulate material, a resin composition which will subsequently harden and a surface active agent are admixed whereby the particulate material is coated with the resin composition and suspended in the gelled aqueous carrier liquid.

Abstract: Visible gels are formed by mixing an inorganic crosslinking agent with a low viscosity aqueous solution having a low polyacrylamide content. The visible gels are employed to reduce the water/hydrocarbon permeability ratio of subterranean formations.

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 monomers having a crosslinkable substituent with a cellulose derivative using a redox system comprising the reaction product of hydrogen peroxide with ferrous salt. The polymers readily crosslink with polyvalent metal ions, such as zirconium and titanium, to form temperature-stable gels useful in petroleum recovery operations.

Abstract: A process is provided for feeding cables, wires, pipes etc. through a wall in such a way that the water- and/or gas resistance of the wall is maintained and that later on additional cables etc. can be passed through. The process uses a sealing agent comprising an intimate mixture of a water-swellable substance such as a clay and a hydrophobic substance such as vaseline. The sealing agent can be placed in a tubular device for providing water-tightness when making a bushing in a partially porous wall.

Abstract: A fluid is provided for the drilling, workover or completion of a subterranean well comprising an aqueous base, the browning reaction product of a carbohydrate, and a cation. Inversion of non-reducing sugars is effected on selected carbohydrates, with the inversion also catalyzing the browning reaction. Inhibition of continued in-situ browning reaction is provided by the addition of a stabilizer.

Abstract: A foam is provided having utility for improving sweep efficiency in subterranean oil-bearing formations and having specific utility for conformance improvement treatments and mobility control in such formations. The foam is a gel medium having a gas dispersed therein. The gel medium is made up of a crosslinkable polymer, a crosslinking agent, a surfactant and a liquid solvent.

Abstract: A fluid is provided for the drilling, workover or completion of a subterranean well comprising an aqueous base, the browning reaction product of a carbohydrate, and a cation. Inversion of non-reducing sugars is effected on selected carbohydrates, with the invention also catalyzing the browning reaction.

Abstract: Oil recovery method using polymer solutions in which highly permeable strata are made significantly less permeable while less permeable strata are not made significantly less permeable. This is accomplished by heating more permeable strata by injection of hot fluids, and then injection of a crosslinkable vinyl aromatic-conjugated diolefin polymer and a temperature activated crosslinking agent. A crosslinked gel is formed in the initially more permeable strata, permitting recovery of oil from the initially less permeable strata.

Abstract: An aqueous polymeric gel-forming composition which slowly crosslinks to form stable gels for plugging highly permeable zones in subterranean oil-bearing formations. The composition comprises an aqueous solution of a water-dispersible polymer present in a viscosifying amount and a crosslinking agent present in an amount effective to cause gelation of the polymeric solution which comprises a mixture of an aldehyde and a member selected from the group consisting of phenolic esters, naphtholic esters, halogenated phenolic esters and halogenated naphtholic esters.

Abstract: The invention is an aqueous shear-thickening composition comprising in one embodiment about 0.2% to about 1% by weight of hydroxypropyl cellulose having an average molecular weight between about 1,000,000 and about 1,300,000, about 0.1% to about 0.7% by weight of an alkali metal dodecyl sulfate in a ratio of about 2.5:1 to about 1.5:1 hydroxypropyl cellulose to alkali metal dodecyl sulfate, and water containing less than about 2000 ppm TDS.

Abstract: A novel process is disclosed for crosslinking water-soluble polymers with a hydroxyphenylalkanol crosslinking agent.

Abstract: A gel-forming composition capable of plugging highly permeable zones in a subterranean formation. The composition comprises water, a water-dispersible polyvinyl alcohol copolymer and a crosslinking agent which is a mixture of an aldehyde and a phenolic component in an amount effective to cause gelation of the aqueous solution of the copolymer. The resultant gel is exceptionally thermally stable and, therefore, can be used as an effective profile control agent in all enhanced oil recovery operations, including steam flooding. Also provided is a process for recovering oil from a subterranean oil-bearing formation.

Abstract: This invention involves cementing compositions for the oil industry and their use in cementing wells. More specifically, this invention involves the control of the gas migration or gas channeling phenomenon that occurs during the setting of a cement slurry. A cementing composition, capable of inhibiting gas channeling, comprised of gaseous fluid, hydraulic cement, and a gas channeling inhibiting additive comprised of a copolymer 2-acrylamido-2 methylpropane-3-sulphonic acid, N-vinylacylamide and acrylamide, is provided.

Abstract: A gellable aqueous composition particularly suitable for reducing the permeability of high-permeability zones in an oil reservoir is an aqueous solution comprising:a) a water-soluble organic polymer cross-linkable by the effect of a polyvalent metal ion cross-linking agent;b) a Cr(III) ion cross-linking agent;c) a buffer agent free or subtantially free of ligand characteristics towards the cross-linking agent, and chosen from organic bases and aromatic carboxylic or sulphonic acids;the solution pH being adjusted to a value within the range of about 2 to about 7.

Abstract: A cementing composition useful in cementing oil, gas and water wells, comprising water, hydraulic cement and an effective amount of water soluble fluid loss additive comprised of a copolymer of acrylamide/vinyl formamide and derivatives thereof in a weight percent ratio of from about 95:5 to 5:95, said copolymer having a molecular weight range of from about 100,000 to 3,000,000. The composition can also optionally include a dispersant such as sodium or potassium salts or a sulfonated naphthalene formaldehyde condensate.

Abstract: A new stable liquid suspension of water soluble polymer, and a method of preparation are provided. Such compositions comprise of at least an iso-parrafinic oil medium, one styrene/isoprene copolymer, a water soluble polymer and preferably some hydrophobic fumed silica mixed together in the appropriate quantities and conditions.

Abstract: The production of oil or gas from a subterranean formation is enhanced by injecting into the formation, such as in acidized fracturing, an aqueous fluid containing as a viscosifier a crosslinked vinylamine polymer. Acidizing fluids are provided containing HCl and a viscosifying amount of a gel of the crosslinked polymer, preferably poly(vinylamine) crosslinked with a diisocyanate, a polyepoxide or epichlorohydrin.

Abstract: A process for use with a polymer which is crosslinkable by reaction with an amino resin, which comprises the steps of determining a period of time within which full gelation of the polymer is to be achieved; preparing a gel-forming aqueous-based mixture comprising the polymer, a rapid amino resin crosslinking agent and a delayed amino resin crosslinking agent, the gel-forming aqueous-based mixture capable of complete gelation within the period of time so determined; partially gelling the aqueous-based mixture by reacting the polymer with the rapid amino resin crosslinking agent which is effective to complete the partial gelation by crosslinking the polymer within four hours; and fully gelling the aqueous-based mixture by reacting the polymer with the delayed amino resin crosslinking agent which is effective to complete the full gelation by crosslinking the polymer within the period of time so determined. A method of enhancing the recovery of oil from a subterranean oil-bearing formation is also provided.

Abstract: For selectively reducing permeability to water in an underground formation producing oil and/or gas, injecting into the formation a composition comprising water, at least one water soluble aldehyde compound at a concentration (by weight) of 180 to 20,000 ppm and at least one non-ionic polysaccharide at a concentration (by weight) of 200 to 5000 ppm, the concentration of aldehyde compound being higher than that of polysaccharide. The composition may be used in the water injection well or the hydrocarbon producing well and may assist in the recovery of hydrocarbons.

Abstract: An aqueous polymeric gel-forming composition capable of selectively plugging highly permeable zones in subterranean oil-bearing formations. The composition comprises an aqueous solution of an anionic acrylamide copolymer of high molecular weight, comprising about 5 to 95 weight percent of 2-acrylamido-2-methylpropanesulfonic acid, about 2 to 95 weight percent of N-vinyl-N-methyl acetamide and about 5 to 93 weight percent of acrylamide, and a crosslinking agent selected from the group consisting of transition metal ions, phenolic resins and amino resins. The compositions of this invention will form stable gels in brines of wide-ranging salinity and are effective at the pH levels encountered in carbon dioxide and water flooding operations. Also provided is a process for selectively plugging regions of higher permeability within an oil-bearing formation to improve sweep efficiency during a fluid flood oil recovery operation.

Abstract: A composition for closing pores in a formation following a steam-flooding enhanced oil recovery process. The composition comprises an aqueous temperature activated gellable mixture. This mixture is comprised of water, water dispersible polymers, phenolic compounds, and aldehyde producing compounds. Polymers which can be utilized herein include polyvinyl alcohol, polyacrylamide and poly(acrylamide-co-acrylamido-2-methylpropane sulfonate). Phenol is the phenolic compound of choice. At a formation temperature greater than 300.degree. F., trioxane, the preferred aldehyde producing compound decomposes to yield formaldehyde which reacts with phenol to form phenolic resin in situ. The resin gels the polymer and forms a solid gel in a heated zone of the formation.

Abstract: A process of profile modifying permeable soils with an environmentally safe composition of a non-toxic water-soluble polymer, a redox couple of a water-soluble ferrous salt and a non-toxic, oxidizing agent which are mixed in water and pumped into a subterranean formation wherein ferrous ion is oxidized to ferric ion to gel the polymer making the subterranean formation impermeable.