Abstract: An oil well being subjected to an acid stimulation may be treated with a corrosion inhibitor including an Ammonium Iodide Ion Source, a first carbonyl containing compound having a general formula: and a second carbonyl containing compound having the general formula: wherein R1 is an alkyl or aromatic group, R2 is a hydrogen, alkyl or aromatic group, and R3 is a hydrogen or an alkyl group having from 1 to 6 carbons; and wherein the alkyl or aromatic groups of R1, R2, or R3 may further comprise a nitrogen, phosphorous, halogen or second oxygen moiety; and wherein the oil well being treated has zone being treated at a temperature of from about 90 to about 500° F.

Abstract: Methods that include a method comprising providing a hydrocarbon-acid emulsion composition that comprises an acid phase, a hydrocarbon blend phase, and an emulsifying agent; and placing the hydrocarbon-acid emulsion composition in a subterranean formation. In some embodiments, the hydrocarbon blend phase comprises at least about 65% hydrocarbons having from six carbons (C6) through eleven carbons (C11). In other embodiments, the hydrocarbon blend phase has a flash point greater than about 100° F. Additional methods are also provided.

Abstract: The productivity of hydrocarbons from hydrocarbon-bearing calcareous or siliceous formations is enhanced by contacting the formation with a well treatment composition which contains a hydrofluoric acid source, a boron containing compound and a phosphonate acid, ester or salt thereof.

Abstract: A method for treating a subterranean formation includes forming a treatment fluid including a carrier fluid, a solid acid-precursor, and a solid scale inhibitor. The solid acid-precursor includes a material that forms an acid at downhole conditions in the subterranean formation. The method further includes adding a solid acid-responsive material into the treatment fluid, where the solid acid-responsive material enhances formation of acid from the solid acid-precursor in acidic conditions. The method includes performing an acid fracture treatment and inhibiting scale formation within the subterranean formation. The solid scale inhibitor allows for long-term scale inhibition after the treatment.

Abstract: Methods and compositions that include a method comprising: providing a treatment fluid comprising at least a plurality of degradable diverting agents that comprise at least one degradable material selected from the group consisting of a fatty alcohol, a fatty acid salt, a fatty ester, a proteinous material, and a combination thereof; and introducing the treatment fluid into a subterranean formation during a subterranean operation via a well bore.

Abstract: A process is disclosed for treating an underground formation, which process comprises: (a) introducing into the underground formation a micellar dispersion comprising water, one or more organic acid precursors, one or more surfactants and, optionally, one or more salts, co-surfactants and/or organic liquids that are not organic acid precursors; and (b) allowing (i) the micellar dispersion to solubilize hydrocarbons, emulsions or water blocks present in the underground formation, and (ii) at least a portion of the organic acid precursor to hydrolyze in-situ to produce sufficient organic acid to substantively dissolve acid soluble material present in or adjacent to filter cakes or other damage in the underground formation.

Abstract: An acid-in-oil emulsion having a corrosion inhibitor as the external phase has been found to prevent downhole corrosion when acidizing carbonate formations to enhance hydrocarbon recovery.

Abstract: An acidizing formulation for use in the stimulation of hydrocarbon production is stable when packaged and stored as a single fluid for periods exceeding one year. The formulation contains a miscibility solvent which substantially prevents any phase separation between the constituents and lack of dispersion of the additives in the fluid.

Abstract: A composition and a method for treating a subterranean formation with an injection liquid containing liquid carbon dioxide, a treating liquid and optionally a foaming agent and/or methanol. The treating liquid may be an acid, a corrosion inhibitor, a solvent or a scale inhibitor.

Abstract: A well treating composition containing a polysaccharide-based water-superabsorbent material has particularly applicability as a thermal insulating, fracturing or acid stimulation fluid. The water-superabsorbent material is capable of absorbing, at a minimum, its own weight. Particularly effective are biodegradable materials containing guar gum and carrageenan. The composition may further contain a crosslinking agent, brine and/or a viscosifying polymer or a gelling agent. As an oil-based fluid, the crosslinking agent is absorbed onto the water-superabsorbent material and serves to effectively delay crosslinking.

Abstract: Of the many methods provided, in one embodiment, a method is provided that comprises: providing an acid-generating fluid that comprises an acid-generating compound, a base fluid, and a salt; placing the acid-generating fluid in a well bore penetrating a subterranean formation; allowing the salt to affect the hydrolysis of the acid-generating compound; and allowing the acid-generating compound to produce an acid that then acidizes at least a portion of the formation or damage contained therein.

Abstract: A method for stimulating thick or multilayered heterogeneous or homogeneous formations in a single trip without packers involves perforating with tubing conveyed perforation, then injecting a self-diverting acid, then moving the tubing string and perforating at a new location, and then injecting additional self-diverting acid. The sequence may be repeated. The acid is preferably a viscoelastic diverting acid. The self-diverting acid may be alternated with conventional treatment fluid. The job is designed to treat the least permeable zone(s) first and maximizes acid efficiency.

Abstract: A method of acidizing a subterranean formation with a diverting agent composed of a gelled or thickened viscoelastic foam or fluid generated from (i.) an amidoamine oxide gelling agent and (ii.) an acid or foam, water and/or brine. The gelled or thickened foam or fluid may be generated in-situ or introduced directly into the formation by mixing of the amidoamine oxide gelling agent and acid or foam, water and/or brine. As the acid spends, the acidizing fluid thickens. When the acid is further spent, the fluid viscosity declines eventually returning to a low viscosity state, allowing for easy cleanup. The process allows for selective acidizing of less permeable zones of the formation and more uniform stimulation of the hydrocarbon bearing formation.

Abstract: A method of treating a well consists of introducing into the wellbore a biodegradable fluid system containing a blend of lactic acid ester, such as ethyl lactate, and a fatty acid ester, such as methyl soyate. The fluid system may be further in the form of a microemulsion that is formed by combining a blend with one or more emulsifiers, an alcohol, and water. The fluid system may be used in displacement, well remediation and stimulation as well as additional, alternative applications such as the cleaning of surface and/or downhole equipment.

Abstract: An aqueous oilfield treatment fluid containing a chelating agent and an HF source is described. This fluid is effective at dissolving siliceous materials such as clays and keeping the dissolved materials in solution. In particular it is effective at preventing re-precipitation of initially-dissolved silicon as silica and therefore reduces damage to sandstones with which it is contacted. Methods are given for using this fluid for sandstone matrix stimulation, removal of clay-containing drilling fluid components and filter cakes from wellbores, sandstone acid fracturing, and gravel pack and proppant pack cleaning.

Abstract: Propped fractures in formations from which fluids are produced are described that have wormholes extending out into the formations from the faces of the fractures at locations distant from boreholes. Methods are given for creating such propped fractures having wormholes in which either a closed propped fracture is formed and then the wormholes are formed, or the entire fracture and channel system is formed before the closure occurs.

Abstract: An acid fracturing method is provided in which the acid is generated in the fracture by hydrolysis of a solid acid-precursor selected from one or more than one of lactide, glycolide, polylactic acid, polyglycolic acid, a copolymer of polylactic acid and polyglycolic acid, a copolymer of glycolic acid with other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid-containing moieties, and a copolymer of lactic acid with other hydroxy-, carboxylic acid or hydroxycarboxylic acid-containing moieties. The solid acid-precursor may be mixed with a solid acid-reactive material to accelerate the hydrolysis and/or coated to slow the hydrolysis. Water-soluble liquid compounds are also given that accelerate the hydrolysis. The method ensures that the acid contacts fracture faces far from the wellbore.

Abstract: The present invention relates to acidic treatment fluids that comprise an acid fluid and an ester-containing quaternary ammonium compound (“esterquat”) and methods of their use. One embodiment of the present invention provides a method of inhibiting metal corrosion during a subterranean treatment operation comprising using an acidic treatment fluid comprising an acidic fluid and an esterquat. Another embodiment of the present invention provides a method of reducing sludge formation during a subterranean treatment operation formation comprising the step of using an acidic treatment fluid comprising an acidic fluid and an esterquat. Another embodiment of the present invention provides a method of inhibiting the formation of emulsions during a subterranean treatment operation comprising using an acidic treatment fluid comprising an acidic fluid and an esterquat. Another embodiment of the present invention provides an acidic subterranean treatment fluid comprising an acidic fluid and an esterquat.

Abstract: A method is given for diverting acids in matrix acidizing and acid fracturing. The acids are diverted with a diverting agent that is an energized or foamed acidic viscoelastic surfactant system that contains a viscoelastic surfactant that gels and increases in viscosity when the acid in the foamed acidic viscoelastic surfactant system is spent. The method provides a synergistic combination of the diverting capabilities of foams and the diverting capabilities of viscoelastic gel systems. The resistance to flow of the gelled foamed viscoelastic surfactant system is greater than expected from a foam or a viscoelastic gel system alone.

Abstract: The present invention generally relates to aqueous, acidic compositions thickened with an amidoamine oxide gelling agent and/or viscoelastic surfactant of the general formula I: wherein R1 is a saturated or unsaturated, straight or branched chain aliphatic group of from about 7 to about 30 carbon atoms, R2 is a divalent alkylene group of 2–6 carbon atoms which may be linear or branched, substituted or unsubstituted, and R3 and R4 are independently C1–C4 alkyl or hydroxyalkyl groups or together they form a heterocyclic ring of up to six members, and R5 is hydrogen or a C1–C4 alkyl or hydroxyalkyl group. The aforementioned gelling agents advantageously provide gels that do not undergo phase separation over extended periods of time and exhibit high heat stability. The thickened acid gels of the invention have applications in household and industrial cleaners and degreasers, oilfield stimulation applications and the like.

Abstract: It has been discovered that solid, particulate dicarboxylic acids are useful as diverting agents in methods for acidizing subterranean formations to improve the uniformity of the acid treatments (acid displacement) by diverting acid to intervals of relatively less permeability. Particularly suitable solid, particulate dicarboxylic acids include, but are not necessarily limited to, those insoluble in both aqueous and hydrocarbon liquids, but which are soluble in mutual solvents or alcohol blends. These acids may have melting points of from about 180 to about 300° F. (about 82 to about 149° C.), formula molecular weights of from 146 to 400, and mesh sizes of from about 20 mesh to about 400 mesh (about 841 to about 38 microns). Particular dicarboxylic acids that fit this description include, but are not necessarily limited to, dodecanedioic acid, undecanedioic acid, decanedioic acid, azelaic acid, suberic acid, and mixtures thereof.

Abstract: Acid based micro-emulsions are disclosed comprising water, an acid blend, an anionic surfactant, a nonionic surfactant, a co-solvent, a solvent and an oxidizer. The micro-emulsions have particular utility in cleaning oil sludges and drilling mud residues from well cuttings, well formations and down hole and surface oil well drilling and production equipment.

Abstract: Aqueous liquid compositions for increasing the permeability of a subterranean formation are disclosed, the compositions being characterized by provision of fluoborate anion (fluoboric acid) and a specified compound or compounds, or mixture thereof, which chelate aluminum ions and aluminum fluoride species. Methods of treating a subterranean formation by injection of the composition(s) into the formation are also described.

Abstract: Disclosed is a copolymer useful for preparing acid gels comprising a copolymer having a copolymer backbone, the copolymer having a general formula: wherein: (a) A is an H or other terminating group; (b) R1 is an OH or NH2; (c) R2 is an O or NH; (d) Z is an integer having a value of from 1 to 4; (e) X and Y are present in a ratio (X:Y) of from 3:2 to 4:1; (f) structures I and II are present as blocks or randomly distributed along the copolymer backbone; and wherein the copolymer has a molecular weight of from about 1,000,000 to about 10,000,000.

Abstract: Stimulation, particularly fracturing or acidising, of hydrocarbon wells having bores leading to hydrocarbon bearing uses a fluid including a continuous phase of or including a compound of the formula (1): (R2)p—Ph—(CH2)m—COO—(AO)n—R1 where R1, AO, n, m, Ph, R2 and p having defined meanings and particularly where the esters are alkyl or alkenyl benzoate esters. These esters are beneficial by having a range of viscosities, especially extending to low viscosities, and attractive toxicological and environmental profiles for use in well stimulation.

Abstract: Aqueous liquid compositions for increasing the permeability of a subterranean formation are disclosed, the compositions being characterized by provision of fluoborate anion (fluoboric acid) and a specified compound or compounds, or mixture thereof, which chelate aluminum ions and aluminum fluoride species. Methods of treating a subterranean formation by injection of the composition(s) into the formation are also described.

Abstract: An acidizing composition and a method of acidizing a hydrocarbon bearing subterranean formation in the presence of ferric ions are provided. The acidizing composition includes a strong mineral acid solution, an electron donor agent, a primary electron transfer agent and a secondary electron transfer agent. The primary electron transfer agent is a source of rhenium ions. The secondary electron transfer agent is a source of iodide ion or iodine. The electron donor agent and primary and secondary electron transfer agents function together to reduce ferric ion present in the mineral acid solution to ferrous ion which in turn prevents ferric hydroxide and/or free sulfur from precipitating out of the solution and reduces the formation of sludge in crude oil in the formation. The particular electron transfer agents used in connection with the invention function with virtually all known electron donor agents.

Abstract: A method of treating a hydrocarbon-containing formation is disclosed.

Abstract: This Invention relates to a novel reversible thickener, i.e., a fluid whose viscosity can be carefully modulated—from very low viscosity to sufficient viscosity to act as a barrier to further flow; particularly preferred embodiments are directed to fluids and methods for stimulating hydrocarbon low viscosity to sufficient viscosity to act as a barrier to further flow; particularly preferred—bearing formations—i.e., to increase the production of oil/gas from the formation. In particular, the Present Invention is directed to a family of fluids (and methods incorporating those fluids) intended to be pumped through a wellbore and into the hydrocarbon-bearing formation.

Abstract: An acidizing composition and a method of acidizing a hydrocarbon bearing subterranean formation in the presence of ferric ions are provided. The acidizing composition includes a mineral acid solution, an electron donor agent, a primary electron transfer agent and a secondary electron transfer agent. The primary electron transfer agent is a source of vanadium ions. The secondary electron transfer agent is a source of iodide ion or iodine. The electron donor agent and primary and secondary electron transfer agents function together to reduce ferric ion present in the mineral acid solution to ferrous ion which in turn prevents ferric hydroxide and/or free sulfur from precipitating out of the solution and reduces the formation of sludge in crude oil in the formation.

Abstract: The improved recovery of hydrocarbons from subterranean formations by hydraulically fracturing a subterranean formation is accomplished. Fracturing fluids using a viscosifying surfactant fluid containing viscosifying micelles, for example, 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 and acidizing methods useful for increasing hydrocarbon production, limiting water production, resisting fracturing fluid loss into the subterranean formation, and reducing the equipment requirements in mixing and pumping fracturing fluid. The action of viscosifying micelles of surfactant in aqueous zones of the subterranean formation diverts fracturing fluid or acid from the aqueous zones to the hydrocarbon-bearing zones and also facilitates the flowback of increased amounts of hydrocarbons once a fractured well is placed back on production.

Abstract: The effect of various chemical or biological agents in well treatment fluids can be delayed by sequestering the agents in the discontinuous phase of an emulsion for a period of time, before the emulsion is destabilized by exposure to at least one of: (1) a change in temperature, (2) a change in pH, (3) a change in salinity, (4) a change in alcohol concentration, (5) a change in stabilizing surfactant concentration, (6) a change in organic ion concentration, (7) a change in destabilizing surfactant concentration, (8) a change in surfactant adsorbent material concentration, (9) an ultrasonic pulse, and (10) an electrical field. Upon exposure to the emulsion destabilizing condition, the agent sequestered in the discontinuous phase of the emulsion is released into the continuous phase of the fluid composition, where it can have its intended effect.

Abstract: Acid based micro-emulsions are disclosed comprising water, an acid blend, an anionic surfactant, a nonionic surfactant, a co-solvent, a solvent and an oxidizer. The micro-emulsions have particular utility in cleaning oil sludges and drilling mud residues from well cuttings, well formations and down hole and surface oil well drilling and production equipment.

Abstract: It has been discovered that dicarboxylic acids are useful in acidizing subterranean formations to improve their permeability, particularly at elevated temperature, e.g. between about 200° F. (92° C.) and about 400° F.(204° C.) Particularly suitable dicarboxylic acids include, but are not necessarily limited to, succinic acid, glutaric acid, adipic acid, and mixtures thereof.

Abstract: The present invention provides environmentally safe foamed acidizing fluids for acidizing subterranean zones, additives for foaming and stabilizing foamed acidizing fluids and methods of acidizing subterranean zones. The foamed acidizing fluids are basically comprised of an aqueous acid solution, sufficient gas to form a foam and an effective amount of an additive for foaming and stabilizing the aqueous acid solution comprised of hydrolyzed keratin.

Abstract: An acidizing composition and a method of acidizing a hydrocarbon bearing subterranean formation in the presence of ferric ions are provided. The acidizing composition includes an aqueous mineral acid solution, an electron donor agent and an electron transfer agent, the electron transfer agent being a source of molybdenum ions. When the aqueous mineral acid solution includes hydrochloric acid in an amount greater than approximately 17% by weight, the acidizing composition further includes a supplemental electron transfer agent, the supplemental electron transfer agent being a source of iodide ion or iodine. The electron donor agent and electron transfer agent function together to reduce ferric ion present in the mineral acid solution to ferrous ion which in turn prevents ferric hydroxide and/or free sulfur from precipitating out of the solution and reduces the formation of sludge in crude oil in the formation.

Abstract: Methods and compositions for reducing the precipitation of aluminum compounds following the contact of an aluminum containing subterranean formation with an acid solution containing hydrofluoric acid are provided. In accordance with the methods, a hydroxy carboxylic acid is combined with the hydrofluoric acid solution and the subterranean formation is contacted with the resulting acid solution.

Abstract: Methods and compositions for reducing the precipitation of fluoride compounds following the contact of an aluminum containing subterranean formation with an acid solution containing hydrofluoric acid are provided. In accordance with the methods, a hydroxy carboxylic acid is combined with the hydrofluoric acid solution and the subterranean formation is contacted with the resulting acid solution.

Abstract: A method for increasing the permeability of a subterranean formation is disclosed in which an amount of an aqueous mixture, sufficient to increase the permeability of the formation, comprising specified aminopolycarboxylic anionic species, and specified cationic species, is injected into the formation matrix.

Abstract: An acidizing composition and a method of acidizing a hydrocarbon bearing subterranean formation in the presence of ferric ions are provided. The acidizing composition includes a strong mineral acid solution, an electron donor agent, a primary electron transfer agent and a secondary electron transfer agent. The primary electron transfer agent is a source of rhenium ions. The secondary electron transfer agent is a source of iodide ion or iodine. The electron donor agent and primary and secondary electron transfer agents function together to reduce ferric ion present in the mineral acid solution to ferrous ion which in turn prevents ferric hydroxide and/or free sulfur from precipitating out of the solution and reduces the formation of sludge in crude oil in the formation. The particular electron transfer agents used in connection with the invention function with virtually all known electron donor agents.

Abstract: This Invention relates to a novel reversible thickener, i.e., a fluid whose viscosity can be carefully modulated—from very low viscosity to sufficient viscosity to act as a barrier to further flow; particularly preferred embodiments are directed to fluids and methods for stimulating hydrocarbon low viscosity to sufficient viscosity to act as a barrier to further flow; particularly preferred-bearing formations—i.e., to increase the production of oil/gas from the formation. In particular, the Present Invention is directed to a family of fluids (and methods incorporating those fluids) intended to be pumped through a wellbore and into the hydrocarbon-bearing formation.

Abstract: Liquids comprised solely of anions and cations (“ionic liquids”) are disclosed as novel components of fluids (and techniques relying upon those fluids) for stimulation of hydrocarbon wells. In particular, the fluids disclosed are useful in matrix acidizing. Formation of the ionic liquids of the present Invention is highly exothermic, hence the heat generated can be used, for instance, to melt de-watered drilling fluid in the near-wellbore region of the formation. Further, reaction of the ionic liquids with water results in acid generation; this acid can be used to, for instance, to stimulate a formation, either by conventional matrix acidizing or fracture acidizing. In addition, certain preferred species of the ionic liquids of the present Invention are highly stable solvents, hence they can be used as carrier fluids for highly reactive super acids (e.g., SbF5+HF) in connection with matrix acidizing.

Abstract: Methods and compositions for preventing precipitation of iron compounds during acid treatments of wells by catalyzing the rate of iron reduction during such treatments. Reduction of ferric ions is accelerated utilizing co-catalytic amounts of antimony ions in combination with other materials to minimize precipitation and other complications which result from iron compounds during acid treatments. Such other materials may include co-catalytic amounts of copper ions and optional iodide ions; as well as at least one of phosphinic acid, salt of phosphinic acid, or a mixture thereof.

Abstract: The improved recovery of hydrocarbons from subterranean formations by fracturing and matrix acidizing a subterranean formation is accomplished. Well treatment fluids having a viscoelastic surfactant fluid containing worm like micelles are useful to improve recovery of hydrocarbons and limit the loss of fracturing fluid into the formation fracture face. The viscolastic surfactant-based fracturing fluids of the present Invention are stable across a wide pH spectrum, allowing them to be used for fracturing treatments at low pH, as well as matrix acidizing treatments. In addition, the stability of these fluids is enhanced in the presence of organic anions. Two-stage fracturing treatments comprised of a viscoelastic surfactant-based fracturing fluid and a polymer-based system, wherein the two fluids are either blended or pumped into the formation sequentially (the polymer last) are also presented.

Abstract: A method of fracturing a subterranean formation, in which subterranean formation being in fluid communication with the surface includes creating a fracture in said subterranean formation, said fracture having more than one fracture faces; and injecting into said fracture an encapsulated formation etching agent, wherein said encapsulated formation etching agent includes a formation etching agent and an encapsulating agent and wherein said formation etching agent etches the fracture faces of the fracture so as to form a flow channel in said formation. The formation etching agent may be selected from mineral acids and mixtures thereof, organic acids and mixtures thereof, mineral acids and mixtures of mineral acids mixed with gelling agent, organic acids and mixtures of organic acids mixed with gelling agent, water soluble hydroxides and mixtures of water soluble hydroxides, and water soluble hydroxides and mixtures of water soluble hydroxides mixed with gelling agent.

Abstract: A solubilized iron reducing additive for acid solutions and method for preparing such a solubilized iron reducing additive. The additive includes an iron reducing agent reactable with ferric ions to produce therefrom ferrous ions and a spent iron reducing compound. The spent iron reducing compound is incapable of reacting with ferric ions to produce ferrous ions. So that the reducing process may continue, a regenerating agent is mixed with the iron reducing agent, the regenerating agent being reactable with the spent iron reducing compound for regenerating the spent iron reducing compound back to the iron reducing agent state. Because it has been found that the iron reducing agent and regenerating agent readily fall out of suspension as precipitates after short periods of time after mixing, a solubility facilitator is admixed thereto for facilitating establishment of the solubilized additive for acid solutions.

Abstract: A method and composition for removing deposits of heavy hydrocarbonaceous materials and finely divided inorganic particulate matter from wellbore and flowline surfaces using a composition containing an alkyl polyglycoside, an ethoxylated alcohol, an acid and an alkyl alcohol.

Abstract: The present invention provides methods of cleaning up a producing interval of a well bore drilled using a synthetic oil-water emulsion drill-in fluid. The methods basically comprise contacting filter cake and drill-in fluid on the walls of the well bore with three treatment fluids in three stages, the first and second treatment fluids being comprised of water, a filter cake dissolving acid, a mutual solvent and an emulsion penetrating agent. The third treatment fluid is comprised of water, a filter cake dissolving acid and a water wetting surfactant.

Abstract: New drilling fluids have been invented which are invert emulsion fluids comprising an oleaginous liquid, a non-oleaginous liquid, and a protonated amine. Such fluids are acidic and thus useful in drilling wells in which acidic gases such as CO.sub.2 or H.sub.2 S are likely to be encountered and break, i.e. de-emulsify, the drilling fluid.

Abstract: A corrosion inhibitor comprising a dispersant, an imidazoline, an amide, an alkyl pyridine and a heavy aromatic solvent. The resultant blend effectively inhibits corrosion of flow lines containing low pH mixtures of hydrocarbons, water, and acid gases.