A multicomponent nanocapsule composition comprising a core particle, an oil phase encapsulating the core particle, and an aqueous phase in which the encapsulated core particle is suspended is provided. The porous particle includes a cationic surfactant encapsulated in a porous particle. The oil phase includes an anionic surfactant and a zwitterionic surfactant. A method of making a multicomponent nanocapsule composition is also provided. A method of treating a hydrocarbon-bearing formation with the multicomponent nanocapsule composition is provided. The method may include providing a multicomponent nanocapsule composition, introducing the multicomponent nanocapsule composition into the hydrocarbon-bearing formation, displacing hydrocarbons from the hydrocarbon-bearing formation by contacting the multicomponent nanocapsule composition with the hydrocarbons, and recovering the hydrocarbons.

The present invention provides a co-surfactant which, when used in combination with a surfactant, can reduce the size of the surfactant micelle and can enhance the functions of the surfactant, such as the expression of microemulsion formation performance. This co-surfactant contains at least one compound represented by chemical formula (1). ##STR00001##
(In the formula, R.sup.1 is a hydrogen atom or a C.sub.1-C.sub.33 aliphatic hydrocarbon group, R.sup.2 is a C.sub.1-C.sub.33 aliphatic hydrocarbon group, the total number of carbons of R.sup.1 and R.sup.2 is 6-34, X is a single bond or a C.sub.1-C.sub.5 aliphatic hydrocarbon group, and one of A.sup.1 and A.sup.2 is —OH and the other is —O—CH.sub.2—CH(OH)—CH.sub.2OH or —O—CH(—CH.sub.2—OH).sub.2.)

The present invention provides a co-surfactant which, when used in combination with a surfactant, can reduce the size of the surfactant micelle and can enhance the functions of the surfactant, such as the expression of microemulsion formation performance. This co-surfactant contains at least one compound represented by chemical formula (1). ##STR00001##
(In the formula, R.sup.1 is a hydrogen atom or a C.sub.1-C.sub.33 aliphatic hydrocarbon group, R.sup.2 is a C.sub.1-C.sub.33 aliphatic hydrocarbon group, the total number of carbons of R.sup.1 and R.sup.2 is 6-34, X is a single bond or a C.sub.1-C.sub.5 aliphatic hydrocarbon group, and one of A.sup.1 and A.sup.2 is —OH and the other is —O—CH.sub.2—CH(OH)—CH.sub.2OH or —O—CH(—CH.sub.2—OH).sub.2.)

A biochemical viscosity reducer for heavy oil and a preparation method thereof. The viscosity reducer includes: Brevibacillus borstelensis-fermented mixed lipopeptide solution: 30 to 60 parts; compound biological enzyme: 15 to 30 parts; plant-based nonionic surfactant: 10 to 20 parts; antibacterial agent: 1 to 5 parts; stabilizer: 1 to 5 parts; and alcohol solvent: 10 to 20 parts; where, the above components are measured by mass. The preparation method includes: step 1: adding 30 to 60 parts of a Brevibacillus borstelensis-fermented mixed lipopeptide solution, 15 to 30 parts of a compound biological enzyme, 10 to 20 parts of a plant-based nonionic surfactant, and 1 to 5 parts of a stabilizer to a reactor; and step 2: adding 1 to 5 parts of an antibacterial agent and an alcohol solvent to the reactor, and stirring a resulting mixture for 60 min to 120 min.

A biochemical viscosity reducer for heavy oil and a preparation method thereof. The viscosity reducer includes: Brevibacillus borstelensis-fermented mixed lipopeptide solution: 30 to 60 parts; compound biological enzyme: 15 to 30 parts; plant-based nonionic surfactant: 10 to 20 parts; antibacterial agent: 1 to 5 parts; stabilizer: 1 to 5 parts; and alcohol solvent: 10 to 20 parts; where, the above components are measured by mass. The preparation method includes: step 1: adding 30 to 60 parts of a Brevibacillus borstelensis-fermented mixed lipopeptide solution, 15 to 30 parts of a compound biological enzyme, 10 to 20 parts of a plant-based nonionic surfactant, and 1 to 5 parts of a stabilizer to a reactor; and step 2: adding 1 to 5 parts of an antibacterial agent and an alcohol solvent to the reactor, and stirring a resulting mixture for 60 min to 120 min.

A method for modifying surface wettability of a surface of a solid substrate may include contacting the surface of the solid substrate with a brine solution containing carbon nanodots. The carbon nanodots may have carbon, oxygen, nitrogen, and hydrogen as constituent elements and may include one or more functional groups disposed at outer surfaces of the carbon nanodots. The brine solution has a salinity of greater than 30,000 TDS. A concentration of carbon nanodots in the brine solution is less than or equal to 500 ppmw. Contacting the solid substrate with the brine solution comprising the carbon nanodots is characterized by a contact duration, a contact volume, or both, that is sufficient to reduce the oil wettability of the surface of the solid substrate by at least 15%, as defined by a contact angle of a crude oil droplet contacted with the surface of the solid substrate.

A method for modifying surface wettability of a surface of a solid substrate may include contacting the surface of the solid substrate with a brine solution containing carbon nanodots. The carbon nanodots may have carbon, oxygen, nitrogen, and hydrogen as constituent elements and may include one or more functional groups disposed at outer surfaces of the carbon nanodots. The brine solution has a salinity of greater than 30,000 TDS. A concentration of carbon nanodots in the brine solution is less than or equal to 500 ppmw. Contacting the solid substrate with the brine solution comprising the carbon nanodots is characterized by a contact duration, a contact volume, or both, that is sufficient to reduce the oil wettability of the surface of the solid substrate by at least 15%, as defined by a contact angle of a crude oil droplet contacted with the surface of the solid substrate.

A method of enhanced oil recovery may comprise placing into a subterranean formation a production enhancement fluid comprising a short chain hydrocarbon phase and a silane based wettability modifier, wherein the short chain hydrocarbon phase comprises hydrocarbons having 5 or less carbon atoms; allowing the production enhancement fluid to remain in the subterranean formation for a shut-in period; and producing hydrocarbons from the subterranean formation.

Provided is a quaternary ammonium surfmer, that may have the following general formula (I): N.sup.+—R.sup.1R.sup.2R.sup.3R.sup.4 (X.sup.−), where: R.sup.1 and R.sup.2 may independently be H or a C.sub.1-C.sub.3 alkyl, R.sup.3 may be a C.sub.19+ amidoalkyl group, R.sup.4 may be a C.sub.3-C.sub.6 alkyl having a terminal olefin double bond group, and X may be a halogen. Further provided is a method for synthesizing the quaternary ammonium surfmer and a method for recovering hydrocarbons from a subterranean formation that may include injecting a treatment fluid comprising the quaternary ammonium surfmer into the subterranean formation.

Provided is a quaternary ammonium surfmer, that may have the following general formula (I): N.sup.+—R.sup.1R.sup.2R.sup.3R.sup.4 (X.sup.−), where: R.sup.1 and R.sup.2 may independently be H or a C.sub.1-C.sub.3 alkyl, R.sup.3 may be a C.sub.19+ amidoalkyl group, R.sup.4 may be a C.sub.3-C.sub.6 alkyl having a terminal olefin double bond group, and X may be a halogen. Further provided is a method for synthesizing the quaternary ammonium surfmer and a method for recovering hydrocarbons from a subterranean formation that may include injecting a treatment fluid comprising the quaternary ammonium surfmer into the subterranean formation.