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: 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: 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: 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: 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.