A problem to be solved of the present invention is to provide a diverting agent which gradually dissolves in water. The present invention relates to a diverting agent containing a polyvinyl alcohol-based resin and a method of filling a fracture using the diverting agent.

Compositions and methods for treating kerogen in a subterranean formation by generating bromine and other halogens in situ in a subterranean formation. In some implementations, the generation of the bromine or halogen is delayed. This can occur, for example, by the decomposition of precursors, a chemical reaction, the encapsulation of precursors or reactants, or a combination of these approaches.

This invention relates to a diverter acid fluid composition for use in the stimulation of oil wells during exploration thereof, named Quovadis. The invention is used as a diverter acid fluid for the stimulation of oil wells during matrix acidification. The role thereof is to improve the efficiency of processes of stimulation of wells by acid treatment allowing the fluid to come into contact with regions of low permeability of the carbonate rock matrix, i.e., regions of difficult access. The invention also removes permanent formation damage around the well, allowing for greater coverage of the treatment and, consequently, better use of the treatment.

Methods and treatments fluids for treating a wellbore. One example method introduces the treatment fluid into the wellbore. The treatment fluid comprises an aqueous fluid, an aminopolycarboxylic acid, a nanoparticle dispersed, and an organic solvent. The treatment fluid has a pH in a range between about 5 to about 9. The method further includes contacting a rock surface in the subterranean formation; wherein at least a portion of the rock surface is coated with a hydrocarbon. The treatment fluid removes a portion of the hydrocarbon from the rock surface and alters the rock surface to be water-wet.

Described herein are methods for treating a subterranean formation penetrated by a wellbore with a retarded acidizing fluid containing an acid and an acid retarding agent, the concentrations of which are adjusted based on measured parameter values of the formation. Also described is a method for treating a subterranean formation by introducing an acid to the formation following the introduction of an acid retarding agent to the formation. Also described is a method for acid fracturing a subterranean formation including reducing the concentration of an acid retarding agent contained in a retarded acidizing fluid over the course of the acid fracturing operation.

A composition and method for treating a fracturing fluid comprising produced water with high levels of dissolved solids using a polymer crosslinked with a boron compound and a high pH alkylamine buffer. The composition improves the viscosity stability of the fracturing fluid at elevated bottom-hole temperatures, particularly when the fluid has high levels of calcium and magnesium. The composition is particularly useful with polysaccharides, including galactomannan gums, such as guar gum, locust bean gum, and karaya gum, and allows for the use of the preferred boron compound crosslinkers in high total dissolved solids fracturing fluids without the pH destabilization problems encountered with the prior art.

Dual-purpose additives that may be used as viscosifying agents and surface active agents in fluids, subterranean treatments and oilfield operations are provided. In one embodiment, the methods comprise: providing a treatment fluid comprising a base fluid and a polymeric dual-purpose additive comprising a base polymer comprising a plurality of monomer units, and one or more hydrophobic groups bonded to at least one of the monomer units; introducing the treatment fluid into at least a portion of a subterranean formation; and depolymerizing at least a portion of the dual-purpose additive to form one or more surface active fragments, each of the surface active fragments comprising one or more of the hydrophobic groups bonded to one or more of the monomer units.

A method for acid treating a carbonate reservoir with an attenuated acid formulation is provided. The method includes mixing an acidic compound with a hygroscopic chemical to form the attenuated acid formulation, and injecting the attenuated acid formulation into a carbonate formation.

A method of acidizing a formation penetrated by a wellbore that includes the steps of injecting into the wellbore at a pressure below formation fracturing pressure a treatment fluid that includes a gelling fluid including a gelling agent and a hydrophobically-modified associative polymer, and an aqueous acid; and allowing the treatment fluid to acidize the formation.

Various embodiments disclosed relate to treatment fluids comprising a compound of the formula (I): wherein G.sub.1, G.sub.2, L.sub.1, L.sub.2, L.sub.3, q, and r are defined herein. Various other embodiments relates to methods of treating subterranean formations with such treatment fluids. ##STR00001##