Embodiments of the present disclosure generally relate to methods and formulations for enhanced oil recovery. In an embodiment, a method for treating oil-containing porous media for oil recovery includes introducing oil-containing porous media with a surfactant formulation described herein. Methods can be utilized for, e.g., wettability reversal or oil recovery. Surfactant formulations are also described.

A surfactant of formula (I):

A-(L.sub.1).sub.a-(CH.sub.2).sub.b-(L.sub.2).sub.c-X(I) wherein A is a perfluoropolyether; L.sub.1 is CONR, wherein R is selected from H and C.sub.1-6 alkyl; a is 0 or 1; b is 0 or an integer between 1 and 10; L.sub.2 is a linking group; c is 0 or 1; and X is a charged group.

A surfactant of formula (I):

A-(L.sub.1).sub.a-(CH.sub.2).sub.b-(L.sub.2).sub.c-X(I) wherein A is a perfluoropolyether; L.sub.1 is CONR, wherein R is selected from H and C.sub.1-6 alkyl; a is 0 or 1; b is 0 or an integer between 1 and 10; L.sub.2 is a linking group; c is 0 or 1; and X is a charged group.

A scale removal agent may effectively be introduced into a well having a formation temperature of 300 F. The scale removal agent is a component of a gelled fluid containing an amine oxide viscoelastic surfactant.

A scale removal agent may effectively be introduced into a well having a formation temperature of 300 F. The scale removal agent is a component of a gelled fluid containing an amine oxide viscoelastic surfactant.

Disclosed are a variety of amphoteric compounds having a heterocyclic quaternary nitrogen group. The heterocycle includes pyridines, piperidines, and pyrrolidines, and is linked to the hydrophobe via either an amide or an ester linkage. These heterocyclic amphoteric compounds can be advantageously prepared in high yield and purity by a two-step chemoenzymatic process, and have excellent surfactant properties.

Present invention relates to a process for manufacturing emulsion composition which comprises an oil phase dispersed in a continuous water phase which is stabilized with a surfactant as an emulsifier. The present invention is on a method for producing an emulsion comprising one or more fatty alcohol, one or more oil liquid at 20 C. and one or more surfactant wherein one or more surfactant is added to the dispersion of one or more fatty alcohol and one or more oil liquid at 20 C. in water at a temperature of 50 C. or higher, preferably 60 C. or higher with the condition that the temperature of the dispersion is at least 10 C. higher than the melting point of fatty alcohol having the highest melting point, more preferably between 60 and 85 C. wherein the emulsion thus obtained does not comprise dispersed droplets with a volume size larger than or equal to 10 m measured directly without dilution of the emulsion at 20 C. measured with a laser particle size analyzer suitable therefore.

Disclosed are a variety of amphoteric compounds containing a quaternary nitrogen group, a covalently bound counterion, and an ester or amide group. These amphoteric compounds can be advantageously prepared via a chemoenzymatic green process, and exhibit good surfactant properties.

A method of manufacturing a silicon carbide (SiC) sintered body and a SiC sintered body obtained by the method are provided. The method includes: preparing a composite powder by subjecting a SiC raw material and a sintering aid raw material to mechanical alloying; and sintering the composite powder, wherein the sintering aid is at least one selected from the group consisting of an AlC-based material, an AlBC-based material, and a BC-based material. Accordingly, a SiC sintered body that can be sintered at low temperature, can be densified, and has high strength and high electrical conductivity can be prepared.

Well treatment fluids may include solid particles comprising one or more components selected from the group consisting of urea, ammonium nitrate, ammonium chloride, barium hydroxide, and ammonium thiocyanate. These well treatment fluids may also include a carrier fluid, which may be an aqueous polymeric fluid, an oil, or combinations thereof. The aqueous polymeric fluid may include a polymer selected from the group consisting of guar gum, hydroxypropyl guar, carboxymethyl hydroxypropyl guar, cellulose, or polyacrylamide. The oil may include a material selected from the group consisting of diesel, mineral oil, and wax. Methods for reducing an acid carbonate reaction in a carbonate formation may include pumping a composition of solid particles into a formation; releasing the solid particles from the capsules or emulsion within the formation; and injecting an acid following the releasing step or during pumping, wherein the acid carbonate reaction is carried out at a reduced reaction rate.