Salt-tolerant friction-reducing terpolymer compositions are provided. The compositions can be used in a method of reducing friction resulting from turbulent flow in an aqueous fracturing fluid in a subterranean fracturing process.

Compositions containing a diverting material, and related methods and systems for diverting a fluid from a high permeability zone in an underground formation to a low permeability zone in the underground formation. The diverter material contains a polyurethane and a second polymer. The compositions, methods and systems may be used to achieve more homogeneous stimulation during a well stimulation treatment.

Provided is a well-treatment fluid that reduces a load on the environment.

A well-treatment fluid containing a non-ionic polyamino acid derivative including an -type or -type polyaspartic acid monomer unit represented by Formula (I) and an -type or -type polyaspartic acid monomer unit represented by Formula (II).

##STR00001##

The flow of well treatment fluids may be diverted from a high permeability zone to a low permeability zone within a fracture network within a subterranean formation by use of a divert system comprising dissolvable diverter particulates and proppant. At least a portion of the high permeability zone is propped open with the proppant of the divert system and at least a portion of the high permeability zone is blocked with the diverter particulates. A fluid is pumped into the formation and into a lower permeability zone farther from the wellbore. The diverter particulates in the high permeability zones may then be dissolved at in-situ reservoir conditions and hydrocarbons produced from the high permeability propped zones of the fracture network. The divert system has particular applicability in the enhancement of production of hydrocarbons from high permeability zones in a fracture network located far field from the wellbore.

The addition of at least one promoter selected from the group consisting of thiosulfate salts, sulfite salts, bisulfite salts, erythorbate salts, isoascorbate salts, and combinations thereof to an aqueous treatment fluid containing a viscosifying polymer and a peroxide helps to promote the activity of the peroxide as a breaker, thus facilitating a reduction in viscosity of the aqueous treatment fluid at lower temperatures than are possible in the absence of the promoter. The promoted aqueous treatment fluid is useful as a fracture fluid to fracture subterranean formations in oil and gas recovery.

Disclosed herein are compositions and methods for increasing recovery of hydrocarbon compounds from hydrocarbon-containing subterranean fractured rock formations. Novel emulsions and fracturing fluids are provided. The fracturing fluids convert oil-wet rocks to water-wet, yet exhibit a low tendency of composition components to sorb to the rock. The fracturing fluids do not cause formation of emulsions with hydrocarbon compounds within the subterranean fractured rock formations.

The present invention relates to an environmentally preferable microemulsion composition that is suitable for formation stimulation, remediation, and drilling operations, and a method to make and use the same. Specifically, the environmentally preferable microemulsion composition of the present invention can comprise glycol ether, terpene, ethoxylated alcohol, polyoxyethylene sorbitan ester, and a carrier fluid.

Polymers comprising polyacrylic acid or polyacrylamide grafted onto a polyethylene oxide/polypropylene oxide copolymer and/or charged nanoparticles may be added to an aqueous downhole fluid having polymers therein to viscosify the aqueous downhole fluid using an amount of such grafted polymers that is less than the amount of polymers that would be needed to viscosify an identical aqueous downhole fluid absent such grafted polymers. The grafted polymers may confer a reversible viscosity property to the fluid when the grafted polymers are dissolved in water or brine in a certain pH range.

Various embodiments disclosed relate to a silane-functionalized polyalkyleneimine (PAI) clay stabilizer for treatment of subterranean formations. In various embodiments, the present invention provides a method of treating a subterranean formation. The method can include placing in the subterranean formation a silane-functionalized PAI clay stabilizer.

Degradable particulates may allow for temporary redirection or occlusion of a fluid within a subterranean formation. However, many types of degradable particulates can be problematic for large-scale use, such as during subterranean treatment operations. Methods for treating a subterranean formation using degradable particulates may comprise: providing pre-coated particulates comprising a latently dissolvable core and a transient coating surrounding the latently dissolvable core, the latently dissolvable core and the transient coating comprising different materials; and introducing a treatment fluid comprising a carrier fluid and a plurality of the pre-coated particulates into a wellbore penetrating a subterranean formation in conjunction with a stimulation operation, a material comprising the latently dissolvable core being soluble in the carrier fluid or a formation fluid present within the subterranean formation.