King Fahd University of Petroleum and Minerals

Saudi Arabian Oil Company

Sivabalan Sakthivel

Mazen Kanj

Mahmoud Atef Abdulhamid

A method of recovering oil from a subterranean geological formation includes injecting a solution including salt water and a chitosan acetate salt polymer into the subterranean geological formation and concurrently recovering oil from a production well in the subterranean geological formation, where the chitosan acetate salt polymer has a structure according to the formula and where the chitosan acetate salt polymer alters the wettability of the subterranean geological formation. Further, the concentration of chitosan acetate salt polymer in the solution is in a range from 1 to 1,000 ppm and the contact angle of the solution on a formation surface is reduced by greater than or equal to 25% compared to a solution including salt water.

Chitosan acetate salt polymer for enhanced oil recovery applications

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.

Compositions and methods employing carbon-based nanodots for wettability alteration

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.

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Dhahran, Saudi Arabia

Sivabalan Sakthivel