Abstract: The present invention provides improved lightweight well cement compositions useful for performing a variety of cementing applications in subterranean formations and particularly for cementing conductor pipe in offshore wells. A preferred cement composition basically comprises a hydraulic cement, an effective amount of an iron salt selected from the group of ferric chloride, ferrous chloride or mixtures thereof to reduce the transition time of the composition, sufficient water to form a pumpable slurry, an effective amount of a foaming additive for producing a foamed slurry, and sufficient gas to foam the slurry.

Abstract: Liquid hydrocarbons are gelled by the introduction of a phosphate ester and a crosslinking agent. Gelling times and viscosities are improved through the use of an enhancer which is, preferably, an oxyalkylated amine or a blend of an oxyalkylated amine with another amine or a non-nitrogen-containing component. Preferred phosphate esters are ether phosphate esters.

Abstract: Methods are provided for fracturing subterranean formations using fluids having substantially reduced polymer loadings that have performance equivalent to conventional fluids. Reduced polymer loadings provide significant advantages such as reduced treatment costs and less damage to the fracture sand pack and surrounding subterranean formations.

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: The invention relates to compositions and methods for gelling liquid hydrocarbons by the introduction of certain phosphate esters, a crosslinking agent, and an enhancer. The enhancer of the present invention is preferably an oxyalkylated amine or a blend of an oxyalkylated amine with another amine or a non-nitrogen-containing component. Mixed phosphate esters containing an oxyalkylene group are useful in the practice of the invention. Gel-forming compositions for addition to liquid hydrocarbons, as well as methods for forming fracturing fluids, are encompassed. The present compositions and methods are an improvement in the field of hydrocarbon gelling, e.g., in fracturing formations, by providing more rapid gellation and greater viscosities.

Abstract: The present invention provides improved cross-linked well treating fluids and methods for preparing and using the fluids in treating wells such as fracturing subterranean zones therein. The improved cross-linked treating fluids comprise water, a galactomannan gelling agent, a cross-linking agent for cross-linking the galactomannan gelling agent, and a viscosity stabilizing agent selected from the group consisting of formaldehyde, formic acid, or mixtures thereof. The viscosity stabilizing agent alters the properties of the well treating fluids and enables them to retain their viscosity over prolonged periods of time when compared to prior well treating fluids.

Abstract: A modified cellulose product comprising cellulose ether, such as carboxymethyl cellulose, hydroxyethyl cellullose, carboxymethyl hydroxyethyl cellulose, methyl cellulose, hydroxyethyl methyl cellulose or ethyl hydroxyethyl cellulose, or xanthan gum product, characterized in that it further comprises salts of aluminium-, ferro-, ferri-, zinc-, nickel-, tin(2)- or tin(4)-cations, and nitrilo-tri-acetic acid, 1,2-cyclo-hexan-di-amin-N,N,N′,N′-tetra-acetic acid, di-ethylen-tri-amine-penta-acetic acid, ethylen-di-oxy-bis(ethylen-nitrilo)-tetra-acetic acid, (N-(2-hydroxy-ethyl)-ethylen-diamin-N, N′,N′,tri-acetic acid, tri-ethylen-tetra-amine-hexa-acetic acid or N-(hydroxyethyl) ethylene-di-amine-tri-acetic acid as a ligand. The product can be used especially as a drilling mud additive.

Abstract: According to the present invention, a composition and method for hydraulically fracturing a subterranean formation is provided. The composition comprises an aqueous mixture of a hydrated polysaccharide, preferably a galactomannan gum, the hydrated polysaccharide having a plurality of bonding sites; a crosslinking agent for crosslinking the hydrated polysaccharide at the bonding sites at the conditions of the subterranean formation with a polyvalent metal ion to form a polyvalent metal crosslink, thereby increasing the viscosity of the hydrated polysaccharide; and a controlled solubility compound for releasing a chelating agent for controllably breaking the polyvalent metal crosslink and bonding with the polyvalent metal ion released by breaking the crosslink, thereby decreasing the viscosity of the hydrated polysaccharide.

Abstract: A fluid that is useful in stimulation operations, and in particular, in hydraulic fracturing treatments, comprises a carrier fluid; a solvatable, crosslinkable polymer; a cross-linking agent that does not cause substantial cross-linking of the polymer at temperatures less than about 105° F. and a pH of about 10 or greater; and an organic amine stabilizing agent that has a first pKa or a pH in water of at least about 9.5. One group of such amines has the formula H2N—(R1NH)n—H where R1 is C1-C4 alkyl and n is from 1-6. In one embodiment, the cross-linking agent is an organic zirconate, such as bis(hydroxyethyl)glycine zirconate. The organic zirconate is effective to cross-link the polymer when the composition is at a temperature of at least about 105° F., and a pH of about 10 or higher, preferably a pH in the range of about 10.5-12.

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: Improved high temperature, low residue viscous well treating fluids and methods of using the fluids are provided by the present invention. The improved viscous well treating fluids are basically comprised of water; a hydrated galactomannan gelling agent; a retarded cross-linking composition for buffering the treating fluid and cross-linking the hydrated galactomannan gelling agent comprised of a liquid solvent, an organotitanate chelate and a borate ion producing compound; and a delayed gel breaker.

Abstract: Methods and compositions for reducing the permeabilities of subterranean zones are provided. The methods of the invention are basically comprised of introducing an aqueous composition comprised of a chelated organic gelling agent and a copolymer of an ethylenically unsaturated polar monomer and an ethylenically unsaturated ester or a terpolymer or tetrapolymer of an ethylenically unsaturated polar monomer, an ethylenically unsaturated ester and a monomer selected from AMPS® and/or N-vinylpyrrolidone into the zone and then allowing the aqueous composition to form a cross-linked gel in the zone.

Abstract: A process is provided for reducing the permeability of or fluid mobility within a carbonate-containing treatment region in or proximate to a hydrocarbon-bearing formation below an earthen surface penetrated by a well bore. The process is initiated by preparing a gelation solution at the earthen surface which includes an acrylamide polymer, a crosslinking agent, a stabilizing agent and an aqueous solvent. The stabilizing agent is an acid additive, acidic pH buffer system, or delayed acid generator. The crosslinking agent is a chromium(III) complex having one or more chromium(III) cations and one or more carboxylate anions. The gelation solution is injected into the well bore and displaced into the treatment region where it is gelled in situ to form a gel which substantially reduces the permeability of or fluid mobility within the treatment region.

Abstract: The addition of fibrous mixtures in intimate mixtures with particulates for fracturing and gravel packing decreases or eliminates the undesirable flowback of proppant or formation fines while stabilizing the sand pack and lowering the demand for high polymer loadings in the placement fluids. Fibers are useful for forming a porous pack in the subterranean formation. In some cases, channels or fingers of void spaces with reduced concentrations of proppant may be introduced into the proppant pack.

Abstract: Liquid hydrocarbons are gelled by the introduction of a phosphate ester and a crosslinking agent. Gelling times and viscosities are improved through the use of an enhancer which is, preferably, an oxyalkylated amine or a blend of an oxyalkylated amine with another amine or a non-nitrogen-containing component. Preferred phosphate esters are ether phosphate esters.

Abstract: Improved high temperature epoxy resin compositions, additives and methods are provided. A hardenable epoxy resin composition of the present invention is comprised of an epoxy resin, an aromatic diluent, a hardening agent and a hardening retarder for delaying the hardening of the epoxy composition at high temperatures comprised of a liquid which is soluble in the epoxy resin composition having a halide salt dissolved therein.

Abstract: The present Invention relates to hydrocarbon well stimulation, and more particularly to methods and compositions to remove (or more generally to transfer) fluid introduced into a subsurface fracture, in which the methods involve creating then exploiting chemical potential gradients at the fracture face to induce fluid flow from the fracture into the formation; the methods and compositions involve creating, or relying upon an intrisic or previously created, a selectively permeable membrane that is permeable to water but that does not allow solutes to pass through.

Abstract: Method and composition for gel formation in hydrocarbon recovery, in which an organic phosphate ester is gelled by a novel activator composition comprising iron sulfate, dibutylaminoethanol, and a phosphate surfactant.

Abstract: A process is provided for reducing the permeability of or fluid mobility within a high-temperature treatment region in or proximate to a hydrocarbon-bearing formation below an earthen surface penetrated by a well bore. The process is initiated by preparing a gelation solution at the earthen surface which includes a base loading of a high molecular weight acrylamide polymer, an additive loading of a low molecular weight acrylamide polymer, a crosslinking agent, and an aqueous solvent. The crosslinking agent is preferably a chromium(III) complex having one or more chromium(III) cations and one or more carboxylate anions. The resulting gelation solution is injected into the well bore and displaced into the treatment region where it is gelled in situ to form a gel which substantially reduces the permeability of or fluid mobility within the treatment region.

Abstract: Methods are provided for fracturing subterranean formations using fluids having substantially reduced polymer loadings that have performance equivalent to conventional fluids. Reduced polymer loadings provide significant advantages such as reduced treatment costs and less damage to the fracture sand pack and surrounding subterranean formations.

Abstract: Method and composition for gel formation in hydrocarbon recovery, in which an organic phosphate ester is gelled by a novel activator composition comprising iron sulfate, dibutylaminoethanol, and a phosphate surfactant.

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: 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 composition and a process for treating a subterranean formation are disclosed. The process comprises injecting into the subterranean formation a composition which comprises a polymer, a crosslinking agent, a liquid, optionally a clay, and further optionally a weighting agent wherein the polymer forms a gel in the formation, in the presence of the crosslinking agent.

Abstract: Heavy crude oil containing at least 1% by weight water is hydrotreated and upgraded while being produced downhole in a production well. During production the heavy crude oil containing water is subjected to sonic energy at a low frequency of 400 Hz to 10 kHz downhole in the presence of a metal hydrogenation catalyst that causes the water in the crude oil to react and form hydrogen which then hydrotreats and upgrades the heavy crude oil during production. In another embodiment, if the heavy crude oil does not contain water, the hydrogen may be formed in-situ by contacting the heavy crude oil downhole with a chemical compound comprising ammonia, hydrazine and formic acid that in the presence of a metal hydrogenation catalyst and sonic energy causes the chemical compound to react and form hydrogen which then hydrotreats the heavy crude oil during production. Suitable catalysts include nickel on zinc dust, platinum on carbon and palladium on carbon, preferably nickel on zinc dust.

Abstract: A method of formulating a zirconium lactate compound is accomplished by combining in solution lactic acid or a lactate salt with zirconium carbonate. The reacting solution forms zirconium lactate and carbon dioxide which is evolved as a gas from the solution. This eliminates the need to filter or wash the zirconium lactate in order to remove undesirable by-products. The zirconium lactate can be used as a crosslinking agent for crosslinking aqueous polymer gels used in such things as fracturing fluids for fracturing subterranean formations of oil and gas wells.

Abstract: A gelling composition comprises a multivalent metal compound-crosslinkable polymer such as a carboxylate-containing polymer, a multivalent metal compound such as a zirconium compound, a liquid, and a pH-lowering agent such as carbon dioxide wherein the composition is prepared by combining the polymer and multivalent metal compound to form a mixture and, thereafter, introducing carbon dioxide to the mixture. A process for treating a subterranean formation can comprise the steps of: (1) combining a polymer with a multivalent compound to form a mixture; (2) introducing the another mixture into a subterranean formation; and (3) introducing carbon dioxide into the mixture.

Abstract: A method of formulating an organo-zirconium compound is accomplished by combining in solution a dialdehyde such as glyoxal with zirconium carbonate. The reacting solution forms an organo-zirconium compound and carbon dioxide which is evolved as a gas from the solution. This eliminates the need to filter or wash the organo-zirconium compound in order to remove undesirable by-products. The organo-zirconium compound can be used as a crosslinking agent for crosslinking aqueous polymer gels used in fracturing fluids for fracturing subterranean formations of oil and gas wells.

Abstract: The invention provides brine based well drilling and servicing fluids which exhibit relatively thermally stable rheological and filtration characteristics. The fluids comprise a brine, an amorphous silica viscosifier, a biopolymer viscosifier, a fluid loss control additive, and a bridging agent. By utilizing both a silica viscosifier and a biopolymer viscosifier to provide the desired rheological characteristics, the fluids have enhanced thermal stability thus maintaining their suspension and hole cleaning properties over an extended temperature range.

Abstract: Disclosed are low solids, high density fluids useful as drilling, workover, and completion fluids and the like in oil and gas well operations. The fluids comprise one or more brines having a density greater than about 1500 kg/m.sup.3, a viscosifier which is a high surface area silica, a fluid loss control additive which is preferably a starch derivative, one or more water soluble or acid soluble bridging agents, and, optionally, an alkaline buffer and a polar additive.Also disclosed is an additive for the preparation of low solids, high density fluids which comprises a fumed silica and a bridging agent in a weight ratio of bridging agent to fumed silica from about 2 to about 20, and optionally, an alkaline buffer in a weight ratio of alkaline buffer to fumed silica from about 0.03 to about 2.5.

Abstract: A novel fracturing fluid composition comprising:(1) a carboxyalkyl derivatized polygalactomannan having a degree of substitution of between about 0.01 and about 3.0;(2) a zirconium salt crosslinking agent;(3) one or more thermal stabilizing agents;(4) one or more pH buffers; and(5) water;wherein said fluid is capable of maintaining at least 10 percent of its original cross-linked viscosity after three hours at a temperature greater to or equal to 250.degree. F. is provided.

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: 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 gelling composition and a process for wellbore treatment comprising injecting the composition into reservoirs are disclosed wherein the composition comprise a produced brine; a water-soluble polymer such as, for example, polyacrylamide; a crosslinker such as, for example, a complexed zirconium compound; and optionally a complexing ligand such as, for example, lactic acid.