Abstract: A method is described for treating a subterranean formation penetrated by a wellbore including injecting into the formation a treatment fluid including a rheological modifier; at least one viscoelastic surfactant (VES) at a concentration of between about 0.1 and about 10 percent by weight; and a formation-dissolving agent selected from the group consisting of hydrochloric acid, formic acid, acetic acid, lactic acid, glycolic acid, sulfamic acid, malic acid, citric acid, tartaric acid, maleic acid, methylsulfamic acid, chloroacetic acid, aminopolycarboxylic acids, 3-hydroxypropionic acid, polyaminopolycarboxylic acids, salts thereof and mixtures of said acids and salts.

Abstract: Treatment fluids containing salts, surfactants, mutual solvents and fibers may be used to remove wellbore filter cakes that have been deposited by drilling fluids. The drilling fluids may be water-base, oil-base, synthetic-base or emulsions. The fibers may be selected from polylactic acid, celluloses, polyesters, polyvinyl alcohols and polyethylene terephthalates. A combination of straight and crimped fibers is present in the treatment fluid.

Abstract: A method for treating a subterranean formation containing shale includes introducing to the subterranean formation a shale stabilizer, a surfactant, and a triggering agent simultaneously with or prior to introducing an alkali silicate to the subterranean formation, and allowing the alkali silicate and triggering agent to react to form a reaction product. Methods include coating the surface of at least a portion of the shale with the reaction product.

Abstract: A method for treating a subterranean formation containing shale is disclosed including introducing to the subterranean formation a shale stabilizer, a surfactant, and a triggering agent simultaneously with or prior to introducing an alkali silicate to the subterranean formation, and allowing the alkali silicate and triggering agent to react to form a reaction product. Coating the surface of at least a portion of the shale with the reaction product is also disclosed.

Abstract: Treatment fluids containing salts, surfactants, mutual solvents and fibers may be used to remove wellbore filter cakes that have been deposited by drilling fluids. The drilling fluids may be water-base, oil-base, synthetic-base or emulsions. The fibers may be selected from polylactic acid, celluloses, polyesters, polyvinyl alcohols and polyethylene terephthalates. A combination of straight and crimped fibers is present in the treatment fluid.

Abstract: A method is described for treating a subterranean formation penetrated by a wellbore including injecting into the formation a treatment fluid including a rheological modifier; at least one viscoelastic surfactant (VES) at a concentration of between about 0.1 and about 10 percent by weight; and a formation-dissolving agent selected from the group consisting of hydrochloric acid, formic acid, acetic acid, lactic acid, glycolic acid, sulfamic acid, malic acid, citric acid, tartaric acid, maleic acid, methylsulfamic acid, chloroacetic acid, aminopolycarboxylic acids, 3-hydroxypropionic acid, polyaminopolycarboxylic acids, salts thereof and mixtures of said acids and salts.

Abstract: A method includes positioning at least one fluid nozzle disposed upon a distal end of a fluid conduit in a cased borehole penetrating a subterranean formation at a target zone of the subterranean formation. An abrasive laden fluid is then continuously pumped through the fluid conduit and through the at least one fluid nozzle at a pressure adequate to form at least one slot through the cased borehole. The abrasive fluid contains an aqueous medium, an abrasive, an optional acid, and a viscoelastic surfactant. While continuously pumping the abrasive fluid through the fluid conduit, the wellbore may be cleaned by returning debris and material generated in the operation to the surface with the fluid. In some instances, a portion of the forming a slot through the cased borehole is conducted simultaneous with the cleanout of the wellbore.

Abstract: Cement compositions for well cementing operations comprise an isocyanate compound and solid particles. The solid particles are present in at least three distinct particle size groups. The compositions may further comprise a blocking agent and solvents such as polyols, hydrocarbon solvents, diesel or water. The compositions are particularly useful in the context of remedial cementing, which may be squeeze cementing or plug cementing.