Working fluids, such as drilling fluids, may remove heat from other fluids, tools, equipments and environments and transfer it to other locations by using reversible phase change elements. The heat removal occurs through the absorption of heat by one or more phase transitions or a sequence of phase transitions in the elements of the working fluid. For instance, heat is absorbed when the phase change portions of the reversible phase change elements change phase including, but not necessarily limited to, a change from solid to smectic liquid crystal, from solid to nematic liquid crystal, from smectic liquid crystal to isotropic liquid, from nematic liquid crystal to isotropic liquid, from solid to isotropic liquid, and sequences and combinations thereof. Heat is released when the phase change reverses. These phase changes are first-order transitions and are associated with a latent heat or enthalpy.

Compositions and methods for coated or uncoated particulates, such as proppants, are provided that can, among other things, provide a hydrophobic surface that can enhance well productivity and other compositions and methods are disclosed.

The disclosure is directed to polyelectrolyte complex nanoparticles that can be used to deliver agents deep into hydrocarbon reservoirs. Methods of making and using said polyelectrolyte complex nanoparticles are also provided.

A wellbore fluid may include a gemini surfactant, a zwitterionic surfactant, an activator, and an aqueous base fluid. The gemini surfactant may have a structure represented by formula (I):

##STR00001##

where R.sup.1 is a C.sub.1-C.sub.10 hydrocarbon group, m and o are each, independently, an integer ranging from 1 to 4, and n is an integer ranging from 8 to 12.

Compositions and methods comprising certain microemulsions and certain clay control additives for enhancing clay swelling protection and persistency in treating swelling clay of a subterranean formation of oil and/or gas wells are generally provided. The combination of certain microemulsions and certain clay control additives exhibit synergistic effects by enhancing clay swelling protection and persistency in treating swelling clay. The well treatment composition may use up to four times less concentration of clay control additive compared to using the same clay control additive alone, while still providing the same, similar, or higher degree of clay swelling protection and enhanced persistency. The microemulsion and the clay control additive may be added to a carrier fluid to form the well treatment composition, which is injected into the subterranean formation to provide enhanced clay swelling protection and persistency of continuing to provide clay swelling protection for a longer period of time during flowback.

The present invention relates to a hydraulic fracturing fluid composition comprising a homogeneous non-aqueous organic phase mixture which mixture comprises a base fluid and one or more surfactants.

The present disclosure is directed to polyanionic surfactants, surfactant mixtures, compositions derived thereof, and uses thereof in hydrocarbon recovery. Methods of making polyanionic surfactants are also described.

A composition includes a nonionic fluorinated polymeric surfactant, a nonfluorinated surfactant, and a scale treatment. Additionally, a method for scale treatment is provided. The method includes injecting gas into the aforementioned composition to produce a foam and injecting the foam into a formation. In the formation, the foam may be exposed to a first temperature at which it has a first viscosity. The foam may be maintained inside the formation for a period of time, and then recovered from the formation, at which point it is exposed to a second temperature and has a second viscosity.

In one embodiment, the present technology provides a surfactant composition comprising an imide compound in an optional solvent for use in a hydrocarbon base fluid to improve the emulsification of an acidizing agent in the hydrocarbon base fluid. In another embodiment, the present technology provides a method of employing an acidizing well-bore stimulation fluid containing the surfactant composition to stimulate a reservoir.

Provided herein are compounds, compositions, and methods having application in the field of enhanced oil recovery (EOR). In particular, the compounds, compositions, and methods provided can be used for the recovery of a large range of crude oil compositions from challenging reservoirs.