Abstract: Chelating agents used in conjunction with stimulation operations in a subterranean formation can often be limited by the pH range over which they may effectively complex metal ions. Perfluorinated chelating agents may have a broader effective pH range for metal ion complexation than do other types of chelating agents, particularly at highly acidic pH values. Methods for treating a subterranean formation can comprise: providing a treatment fluid comprising a perfluorinated chelating agent having at least two carboxylic acid groups; introducing the treatment fluid into a subterranean formation; and complexing metal ions in the subterranean formation with the perfluorinated chelating agent.

Abstract: The invention provides a process for making compounds according to Formula I: where R1, R1a, R2, R2a, R3 and R3a are defined as set forth in the specification. Formula I compounds are useful as chelants and stabilizers of cations in aqueous media and the invention therefore provides a method for using the compounds in the treatment of subterranean formations, such as in acidizing operations.

Abstract: Carbon dioxide generation in a subterranean formation can be problematic for a number of reasons. Accordingly, it can be desirable to sequester at least a portion of the carbon dioxide that may be present in a subterranean formation, thereby decreasing a quantity of free carbon dioxide. Methods for sequestering carbon dioxide can comprise: providing a C02-sequestering polymer, the C02-sequestering polymer sequestering carbon dioxide more readily than it does nitrogen; introducing the C02-sequestering polymer into a subterranean formation that contains carbon dioxide; and interacting the C02-sequestering polymer with the carbon dioxide in the subterranean formation, so as to decrease a quantity of free carbon dioxide that is present in the subterranean formation.

Abstract: Particles that comprise calcium methylglycine diacetic acid salt (“Ca-MGDA salt”) may be useful for fluid diversion in subterranean operations. In some instances, the particles may be formed in the subterranean formation. For example, a method may involve introducing a treatment fluid into a wellbore penetrating a subterranean formation, wherein the treatment fluid comprises an aqueous base fluid, MGDA or salt thereof, and an acid in an amount of about 3% or greater by weight of the aqueous base fluid; acidizing a portion of the subterranean formation comprising calcium carbonate resulting in a concentration of calcium in the treatment fluid that exceeds about 50,000 ppm; and precipitating a plurality of particles that comprise a Ca-MGDA salt in the portion of the subterranean formation, thereby reducing fluid flow therethrough. In some instances, the particles that comprise Ca-MGDA salt may be included in a treatment fluid before introduction into the subterranean formation.

Abstract: Geothermal wells frequently form deposits of geothermal scale that can detrimentally affect subterranean operations. These deposits can be very difficult to remove from a surface. Conventional procedures for addressing geothermal scale often provide inadequate scale removal, in addition to creating a number of other issues. Methods for removing geothermal scale from a wellbore can comprise: introducing a descaling agent comprising an N-(phosphonoalkyl)iminodiacetic acid or any salt thereof into a wellbore of a geothermal well having geothermal scale present therein; contacting the geothermal scale with the descaling agent; and removing at least a portion of the geothermal scale from the geothermal well using the descaling agent.

Abstract: Treatment fluids can mitigate the occurrence or effects of precipitation in a subterranean formation through complexation of a metal ion therein. Methods for treating a subterranean formation can comprise: providing a treatment fluid comprising a hydroxypyridinecarboxylic acid, a salt thereof, or a tautomer thereof; introducing the treatment fluid into a subterranean formation; and complexing a metal ion in the subterranean formation with the hydroxypyridinecarboxylic acid.

Abstract: Complexing-acidizing treatment fluids can be used in various subterranean treatment operations. Some methods include: providing or preparing a complexing-acidizing treatment fluid having an acid concentration of about 0.6 Molar, the complexing-acidizing treatment fluid including: an aminopolycarboxylic acid chelating agent, an aqueous base fluid, and an acid, placing the complexing-acidizing treatment fluid in a subterranean formation matrix penetrated by a well bore; allowing the acid to generate metal cations by dissolution of the subterranean formation matrix; reacting the aminopolycarboxylic acid chelating agent with the metal cations so as to form at least a plurality of aggregate blocking agents; and allowing the aggregate blocking agents to divert the complexing-acidizing treatment fluid to a main channel in the subterranean formation matrix that is distinct from a wormhole in the subterranean formation matrix.

Abstract: The presence of iron in a subterranean formation, particularly ferric iron, can be problematic during an acidizing operation due to sludge formation that can occur. Methods for treating a subterranean formation in the presence of iron can comprise: providing a treatment fluid comprising an acid and an iron stabilization agent comprising a phosphinated carboxylic acid polymer, the treatment fluid having a pH of about 3 or below and the phosphinated carboxylic acid polymer being soluble in the treatment fluid; introducing the treatment fluid into a subterranean formation; and interacting the phosphinated carboxylic acid polymer with ferric iron in the subterranean formation.

Abstract: In situ generation of hydrogen fluoride or other reactive fluoride species can sometimes be beneficial during an acidizing operation, particularly when it is desired to limit the presence of a carrier fluid that may be present. Methods for acidizing a subterranean formation can comprise: providing a treatment fluid comprising a non-HF fluoride compound, the non-HF fluoride compound being a gas at standard temperature and pressure and that is free of boron; introducing the treatment fluid into a subterranean formation; transforming the non-HF fluoride compound into a reactive fluoride species; and etching a surface in the subterranean formation with the reactive fluoride species, the surface comprising a siliceous material.

Abstract: Methods, compositions and systems relating to complexing-acidizing treatment fluids. Some methods include: providing or preparing a complexing-acidizing treatment fluid having an acid concentration of about 0.6 Molar, the complexing-acidizing treatment fluid including: an aminopolycarboxylic acid chelating agent, an aqueous base fluid, and an acid, placing the complexing-acidizing treatment fluid in a subterranean formation matrix penetrated by a well bore; allowing the acid to generate metal cations by dissolution of the subterranean formation matrix; reacting the aminopolycarboxylic acid chelating agent with the metal cations so as to form at least a plurality of aggregate blocking agents; and allowing the aggregate blocking agents to divert the complexing-acidizing treatment fluid to a main channel in the subterranean formation matrix that is distinct from a wormhole in the subterranean formation matrix.

Abstract: Treatment fluids and methods include a method that includes the steps of providing or preparing a foamed chelating agent treatment fluid that includes: an aminopolycarboxylic acid chelating agent, an aqueous base fluid, a gas, and a foaming agent, and lacing the foamed chelating agent treatment fluid in a subterranean formation penetrated by a well bore. The aminopolycarboxylic acid chelating agent foamed fluids may also be used in equipment clean-out operations.

Abstract: Methods including providing a treatment fluid comprising a perfluorinated carboxylic acid; introducing the treatment fluid into a subterranean formation having a temperature of at least about 82° C. and having a siliceous material and/or carbonate material therein; and generating hydrofluoric acid from the perfluorinated carboxylic acid; and dissolving at least a portion of the siliceous material with the generated hydrofluoric acid.

Abstract: When used outside the pH range at which metal ion complexation normally occurs, aminopolycarboxylic acids can moderate the reaction rate of acids with carbonate minerals. Methods for treating a subterranean formation can comprise: providing a treatment fluid comprising an aqueous carrier fluid, an acid, and a chelating agent comprising an aminopolycarboxylic acid, the treatment fluid having a pH below that at which the carboxylic acid groups of the chelating agent are substantially protonated and the chelating agent is ineffective for complexing a metal ion; introducing the treatment fluid into a subterranean formation comprising a carbonate mineral; reacting the acid with the carbonate mineral, such that the acid at least partially spends and the pH of the treatment fluid rises; and once the pH of the treatment fluid rises above a pKa value for one or more of the carboxylic acid groups, complexing a metal ion with the chelating agent.

Abstract: Acidizing operations in subterranean formations that contain both a siliceous material and a source of calcium ions can often be problematic due to the generation of calcium-containing precipitates, particularly calcium fluoride. Methods for treating a subterranean formation can comprise: providing a treatment fluid having a pH ranging between about 1 and about 4.5 and comprising a chelating agent, hydrofluoric acid or a hydrofluoric acid-generating compound, and a compound having two or more quaternized amine groups; introducing the treatment fluid into a subterranean formation containing a siliceous material and a source of calcium ions; dissolving at least a portion of the siliceous material in the subterranean formation with the hydrofluoric acid or the hydrofluoric acid-generating compound; and complexing at least a portion of the calcium ions in the subterranean formation with the chelating agent.

Abstract: A method of servicing a wellbore in a subterranean formation comprising preparing a wellbore servicing fluid comprising an amino multicarboxylic acid chelating agent, a pH adjusting compound, and an aqueous base fluid, and contacting the wellbore servicing fluid with scale deposits on a surface in fluid communication with the wellbore and/or subterranean formation.

Abstract: A method of servicing a wellbore in a subterranean formation comprising preparing a wellbore servicing fluid comprising an amino polyether multicarboxylic acid chelating agent and/or an amino polyether multicarboxylic acid chelating agent precursor, and an aqueous base fluid, and contacting the wellbore servicing fluid with scale deposits on a surface in the wellbore and/or subterranean formation. A method of servicing a wellbore in a subterranean formation comprising preparing a wellbore servicing fluid comprising an amino polyether multicarboxylic chelating agent precursor and an aqueous base fluid, and contacting the wellbore servicing fluid with scale deposits on a surface in the wellbore and/or subterranean formation. A scale-removing wellbore servicing fluid comprising an amino polyether multicarboxylic acid chelating agent and/or an amino polyether multicarboxylic acid chelating agent precursor, and an aqueous base fluid.

Abstract: Treatment fluids may be used to retard the deposition of silica scale in subterranean formations. Methods for treating a subterranean formation can comprise providing a treatment fluid having a pH of 6 or less that comprises an acidic base fluid and a non-polymeric silica scale control additive, and introducing the treatment fluid into at least a portion of a subterranean formation. The non-polymeric silica scale control additive retards deposition of silica scale in the subterranean formation.

Abstract: The invention relates to methods and compositions for producing or recovering an aqueous-based fluid to be utilized or injected in a wellbore or surrounding subterranean formation. The method comprises the step of contacting an aqueous-based fluid with an aqueous-soluble breaker composition comprising an oxidizing agent and a catalyst for a time sufficient to reduce or eliminate one or more deleterious substances in the aqueous-based fluid to produce a treated aqueous-based fluid suitable for use or injection in a wellbore or surrounding subterranean formation.

Abstract: Treatment fluids can mitigate the occurrence or effects of precipitation in a subterranean formation through complexation of a metal ion therein. Methods for treating a subterranean formation can comprise: providing a treatment fluid comprising a hydroxypyridinecarboxylic acid, a salt thereof, or a tautomer thereof; introducing the treatment fluid into a subterranean formation; and complexing a metal ion in the subterranean formation with the hydroxypyridinecarboxylic acid.