Abstract: 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.

Abstract: A method for enhancing recovery of hydrocarbons from a hydrocarbon-bearing subterranean formation includes withdrawing hydrocarbons from a production well and injecting a treatment fluid that includes carbon nanodots dispersed in a brine solution from an injection well that is spaced apart from the production well. The carbon nanodots include carbon, oxygen, nitrogen, and hydrogen and are surface functionalized. A concentration of carbon nanodots in the treatment fluid is less than or equal to 500 parts per million by weight. Injection of the treatment fluid having the carbon nanodots is characterized by an injection duration, an injection pressure, an injection volume, or a combination thereof, that is sufficient to increase cumulative oil recovery of hydrocarbons from the first subterranean formation, the second subterranean formation, or both by at least 10% compared to injecting the brine solution without the carbon nanodots.

Abstract: 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.

Abstract: A method for enhancing recovery of hydrocarbons from a hydrocarbon-bearing subterranean formation includes withdrawing hydrocarbons from a production well and injecting a treatment fluid that includes carbon nanodots dispersed in a brine solution from an injection well that is spaced apart from the production well. The carbon nanodots include carbon, oxygen, nitrogen, and hydrogen and are surface functionalized. A concentration of carbon nanodots in the treatment fluid is less than or equal to 500 parts per million by weight. Injection of the treatment fluid having the carbon nanodots is characterized by an injection duration, an injection pressure, an injection volume, or a combination thereof, that is sufficient to increase cumulative oil recovery of hydrocarbons from the first subterranean formation, the second subterranean formation, or both by at least 10% compared to injecting the brine solution without the carbon nanodots.

Abstract: A method of screening solvents for the solubilization of petroleum hydrocarbons is disclosed. The method includes dissolving petroleum hydrocarbons in a selected solvent to form a first solution, adding an ionic liquid to the first solution and blending to form a second solution and measuring absorbance of the second solution using spectroscopic techniques. The solubilization of petroleum hydrocarbons in the solvent is then determined based on the difference between the measured absorbance of the first and second solution. A system for screening solvents for the solubilization of petroleum hydrocarbons is also disclosed. The system can be used in removal of wax deposition in refinery process equipment, process flow lines, during piping operations, up-gradation of wax, prevention of clogging of pipelines, processing of sludge or for removing sludge from petroleum tank installations and enhancing the crude oil flow.

Abstract: A method of screening solvents for the solubilization of petroleum hydrocarbons is disclosed. The method includes dissolving petroleum hydrocarbons in a selected solvent to form a first solution, adding an ionic liquid to the first solution and blending to form a second solution and measuring absorbance of the second solution using spectroscopic techniques. The solubilization of petroleum hydrocarbons in the solvent is then determined based on the difference between the measured absorbance of the first and second solution. A system for screening solvents for the solubilization of petroleum hydrocarbons is also disclosed. The system can be used in removal of wax deposition in refinery process equipment, process flow lines, during piping operations, up-gradation of wax, prevention of clogging of pipelines, processing of sludge or for removing sludge from petroleum tank installations and enhancing the crude oil flow.

Abstract: A method of screening solvents for the solubilization of petroleum hydrocarbons is disclosed. The method includes dissolving petroleum hydrocarbons in a selected solvent to form a first solution, adding an ionic liquid to the first solution and blending to form a second solution and measuring absorbance of the second solution using spectroscopic techniques. The solubilization of petroleum hydrocarbons in the solvent is then determined based on the difference between the measured absorbance of the first and second solution. A system for screening solvents for the solubilization of petroleum hydrocarbons is also disclosed. The system can be used in removal of wax deposition in refinery process equipment, process flow lines, during piping operations, upgradation of wax, prevention of clogging of pipelines, processing of sludge or for removing sludge from petroleum tank installations and enhancing the crude oil flow.

Abstract: A method of screening solvents for the solubilization of petroleum hydrocarbons is disclosed. The method includes dissolving petroleum hydrocarbons in a selected solvent to form a first solution, adding an ionic liquid to the first solution and blending to form a second solution and measuring absorbance of the second solution using spectroscopic techniques. The solubilization of petroleum hydrocarbons in the solvent is then determined based on the difference between the measured absorbance of the first and second solution. A system for screening solvents for the solubilization of petroleum hydrocarbons is also disclosed. The system can be used in removal of wax deposition in refinery process equipment, process flow lines, during piping operations, upgradation of wax, prevention of clogging of pipelines, processing of sludge or for removing sludge from petroleum tank installations and enhancing the crude oil flow.