The present invention relates to a composition for an enhanced oil recovery process, said composition comprising (a) one or more anionic cocogem surfactants; b) one or more surfactants based on nonionic vegetable fatty acids (or their synthetic analogues); c) optionally one or more, preferably commercially available, co-surfactants; d) optionally one or more agents with phase transfer property, preferably an alcohol; and e) polyacrylamide as a flow modifier.

The present invention relates to a composition for an enhanced oil recovery process, said composition comprising (a) one or more anionic cocogem surfactants; b) one or more surfactants based on nonionic vegetable fatty acids (or their synthetic analogues); c) optionally one or more, preferably commercially available, co-surfactants; d) optionally one or more agents with phase transfer property, preferably an alcohol; and e) polyacrylamide as a flow modifier.

The present embodiments generally relate to methods and compositions comprising one or more degraded in situ gelable polymers. Use of such compositions and methods comprising one or more degraded in situ gelable polymers during enhanced oil recovery may result in an increase in oil production relative to methods and/or compositions which do not comprise one or more degraded in situ gelable polymers.

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.

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 a method for treating oil well using an emulsion composition. More particularly, the method comprises a step of introducing an emulsion composition in an amount of 0.01% to 100% to pore volume of oil reservoir into the oil well, such that interfacial tension between the oil well and the reservoir reduces to 10.sup.−4 mM/m or below thereby enable removal of oil therefrom.

(No illustrative FIGURE.)

The present invention relates a method for treating oil well using an emulsion composition. More particularly, the method comprises a step of introducing an emulsion composition in an amount of 0.01% to 100% to pore volume of oil reservoir into the oil well, such that interfacial tension between the oil well and the reservoir reduces to 10.sup.−4 mM/m or below thereby enable removal of oil therefrom.

(No illustrative FIGURE.)

Disclosed herein is a copolymer concentrate in a bio-solvent that can be further diluted into a slurry composition. The bio-solvent facilitates the formation of a viscosified base fluid with the mixing being carried out in a short period of time and at ambient, providing a free flowing, pumpable, and dispersible slurry. The slurry is characterized as having excellent stability, maintaining suspension over a wide range of temperatures. In embodiments, the bio-solvent is selected from terpene and terpene-derivative-containing solvents, fatty acid alkyl esters, and mixtures thereof. The bio-solvent can be first mixed with a styrenic diblock copolymer to form a concentrate prior mixing with a hydrocarbon solvent, forming a viscosified base fluid for subsequent mixing with a water-soluble polymer to form the slurry. The bio-solvent can also be used to dilute the hydrocarbon solvent, prior to mixing with the styrenic diblock copolymer to form the viscosified base fluid.

Disclosed herein is a copolymer concentrate in a bio-solvent that can be further diluted into a slurry composition. The bio-solvent facilitates the formation of a viscosified base fluid with the mixing being carried out in a short period of time and at ambient, providing a free flowing, pumpable, and dispersible slurry. The slurry is characterized as having excellent stability, maintaining suspension over a wide range of temperatures. In embodiments, the bio-solvent is selected from terpene and terpene-derivative-containing solvents, fatty acid alkyl esters, and mixtures thereof. The bio-solvent can be first mixed with a styrenic diblock copolymer to form a concentrate prior mixing with a hydrocarbon solvent, forming a viscosified base fluid for subsequent mixing with a water-soluble polymer to form the slurry. The bio-solvent can also be used to dilute the hydrocarbon solvent, prior to mixing with the styrenic diblock copolymer to form the viscosified base fluid.

The present invention relates to a hydrated crystalline form of 2-acrylamido-2-methylpropane sulfonic acid having a 2-theta powder X-ray diffraction diagram comprising peaks at 10.58°, 11.2°, 12.65°, 13.66°, 16.28°, 18.45°, 20°, 20.4°, 22.5°, 25.5°, 25.88°, 26.47°, 28.52°, 30.28°, 30.8°, 34.09°, 38.19°, 40.69°, 41.82°, 43.74°, 46.04° degrees (+/− 0.1°. The present invention also relates to a production method for this form of 2-acrylamido-2-methylpropane sulfonic acid and a preparation method for an aqueous solution A of a salt of this form of 2-acrylamido-2-methylpropane sulfonic acid, and the (co)polymer of this form of -acrylamido-2-methylpropane sulfonic acid.